libgit_backend.cpp

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright The KiCad Developers, see AUTHORS.TXT for contributors.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/gpl-3.0.html
 * or you may search the http://www.gnu.org website for the version 3 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
 
#include "libgit_backend.h"
 
#include "git_clone_handler.h"
#include "git_commit_handler.h"
#include "git_push_handler.h"
#include "git_add_to_index_handler.h"
#include "git_remove_from_index_handler.h"
#include "git_status_handler.h"
#include "git_config_handler.h"
#include "git_init_handler.h"
#include "git_branch_handler.h"
#include "git_pull_handler.h"
#include "git_revert_handler.h"
#include "project_git_utils.h"
#include "kicad_git_common.h"
#include "kicad_git_memory.h"
#include "trace_helpers.h"
 
#include "kicad_git_compat.h"
#include <wx/filename.h>
#include <wx/log.h>
#include <gestfich.h>
#include <algorithm>
#include <iterator>
#include <memory>
#include <time.h>
 
static std::string getFirstLineFromCommitMessage( const std::string& aMessage )
{
    if( aMessage.empty() )
        return aMessage;
 
    size_t firstLineEnd = aMessage.find_first_of( '\n' );
 
    if( firstLineEnd != std::string::npos )
        return aMessage.substr( 0, firstLineEnd );
 
    return aMessage;
}
 
 
static std::string getFormattedCommitDate( const git_time& aTime )
{
    char   dateBuffer[64];
    time_t time = static_cast<time_t>( aTime.time );
    struct tm timeInfo;
 
#ifdef _WIN32
    localtime_s( &timeInfo, &time );
#else
    gmtime_r( &time, &timeInfo );
#endif
 
    strftime( dateBuffer, sizeof( dateBuffer ), "%Y-%b-%d %H:%M:%S", &timeInfo );
    return dateBuffer;
}
 
 
void LIBGIT_BACKEND::Init()
{
    git_libgit2_init();
}
 
 
void LIBGIT_BACKEND::Shutdown()
{
    // Wait for any abandoned git cleanup threads to finish before tearing
    // down libgit2.  A worker still inside libgit2 (for example, blocked on
    // recv() under git_remote_fetch) would otherwise race teardown and
    // invoke undefined behaviour.  Five seconds is long enough to cover a
    // transport error timeout but short enough to avoid a perceptibly slow
    // exit when the remote is truly unreachable.
 
    constexpr auto kOrphanJoinTimeout = std::chrono::seconds( 5 );
    size_t         stuck = m_orphanRegistry.JoinAll( kOrphanJoinTimeout );
 
    if( stuck > 0 )
    {
        wxLogTrace( traceGit,
                    "LIBGIT_BACKEND::Shutdown(): %zu orphan git thread(s) "
                    "did not finish within %lld ms; skipping libgit2 shutdown",
                    stuck,
                    static_cast<long long>( kOrphanJoinTimeout.count() ) );
 
        // A stuck worker is still executing inside libgit2.  Calling
        // git_libgit2_shutdown() now would free state the worker is actively
        // reading.  Leave libgit2 initialised and let the OS reclaim
        // resources when the process exits.
 
        return;
    }
 
    git_libgit2_shutdown();
}
 
 
bool LIBGIT_BACKEND::IsLibraryAvailable()
{
#if ( LIBGIT2_VER_MAJOR >= 1 ) || ( LIBGIT2_VER_MINOR >= 99 )
    int major = 0, minor = 0, rev = 0;
    return git_libgit2_version( &major, &minor, &rev ) == GIT_OK;
#else
    // On older platforms, assume available when building with libgit2
    return true;
#endif
}
 
 
bool LIBGIT_BACKEND::Clone( GIT_CLONE_HANDLER* aHandler )
{
    KIGIT_COMMON* common = aHandler->GetCommon();
    std::unique_lock<std::mutex> lock( common->m_gitActionMutex, std::try_to_lock );
 
    if( !lock.owns_lock() )
    {
        wxLogTrace( traceGit, "GIT_CLONE_HANDLER::PerformClone() could not lock" );
        return false;
    }
 
    wxFileName clonePath( aHandler->GetClonePath() );
 
    if( !clonePath.DirExists() )
    {
        if( !clonePath.Mkdir( wxS_DIR_DEFAULT, wxPATH_MKDIR_FULL ) )
        {
            aHandler->AddErrorString( wxString::Format( _( "Could not create directory '%s'" ),
                                                        aHandler->GetClonePath() ) );
            return false;
        }
    }
 
    git_clone_options cloneOptions;
    git_clone_init_options( &cloneOptions, GIT_CLONE_OPTIONS_VERSION );
    cloneOptions.checkout_opts.checkout_strategy = GIT_CHECKOUT_SAFE;
    cloneOptions.checkout_opts.progress_cb = clone_progress_cb;
    cloneOptions.checkout_opts.progress_payload = aHandler;
    cloneOptions.fetch_opts.callbacks.transfer_progress = transfer_progress_cb;
    cloneOptions.fetch_opts.callbacks.credentials = credentials_cb;
    cloneOptions.fetch_opts.callbacks.payload = aHandler;
    cloneOptions.fetch_opts.proxy_opts.type = GIT_PROXY_AUTO;
 
    aHandler->TestedTypes() = 0;
    aHandler->ResetNextKey();
    git_repository* newRepo = nullptr;
    wxString        remote = common->m_remote;
 
    if( git_clone( &newRepo, remote.mbc_str(), aHandler->GetClonePath().mbc_str(),
                   &cloneOptions ) != 0 )
    {
        aHandler->AddErrorString( wxString::Format( _( "Could not clone repository '%s' : %s" ), remote, KIGIT_COMMON::GetLastGitError() ) );
        return false;
    }
 
    common->SetRepo( newRepo );
 
    return true;
}
 
 
CommitResult LIBGIT_BACKEND::Commit( GIT_COMMIT_HANDLER* aHandler,
                                     const std::vector<wxString>& aFiles,
                                     const wxString& aMessage,
                                     const wxString& aAuthorName,
                                     const wxString& aAuthorEmail )
{
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
        return CommitResult::Error;
 
    git_index* index = nullptr;
 
    if( git_repository_index( &index, repo ) != 0 )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to get repository index: %s" ),
                                                    KIGIT_COMMON::GetLastGitError() ) );
    return CommitResult::Error;
    }
 
    KIGIT::GitIndexPtr indexPtr( index );
 
    for( const wxString& file : aFiles )
    {
        if( git_index_add_bypath( index, file.mb_str() ) != 0 )
        {
            aHandler->AddErrorString( wxString::Format( _( "Failed to add file to index: %s" ),
                                                        KIGIT_COMMON::GetLastGitError() ) );
            return CommitResult::Error;
        }
    }
 
    if( git_index_write( index ) != 0 )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to write index: %s" ),
                                                    KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    git_oid tree_id;
 
    if( git_index_write_tree( &tree_id, index ) != 0 )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to write tree: %s" ),
                                                    KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    git_tree* tree = nullptr;
 
    if( git_tree_lookup( &tree, repo, &tree_id ) != 0 )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to lookup tree: %s" ),
                                                    KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    KIGIT::GitTreePtr treePtr( tree );
    git_commit* parent = nullptr;
 
    if( git_repository_head_unborn( repo ) == 0 )
    {
        git_reference* headRef = nullptr;
 
        if( git_repository_head( &headRef, repo ) != 0 )
        {
            aHandler->AddErrorString( wxString::Format( _( "Failed to get HEAD reference: %s" ),
                                                        KIGIT_COMMON::GetLastGitError() ) );
            return CommitResult::Error;
        }
 
        KIGIT::GitReferencePtr headRefPtr( headRef );
 
        if( git_reference_peel( (git_object**) &parent, headRef, GIT_OBJECT_COMMIT ) != 0 )
        {
            aHandler->AddErrorString( wxString::Format( _( "Failed to get commit: %s" ),
                                                        KIGIT_COMMON::GetLastGitError() ) );
            return CommitResult::Error;
        }
    }
 
    KIGIT::GitCommitPtr parentPtr( parent );
 
    git_signature* author = nullptr;
 
    if( git_signature_now( &author, aAuthorName.mb_str(), aAuthorEmail.mb_str() ) != 0 )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to create author signature: %s" ),
                                                    KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    KIGIT::GitSignaturePtr authorPtr( author );
    git_oid                oid;
    size_t                 parentsCount = parent ? 1 : 0;
 
#if( LIBGIT2_VER_MAJOR == 1 && LIBGIT2_VER_MINOR == 8               \
    && ( LIBGIT2_VER_REVISION < 2 || LIBGIT2_VER_REVISION == 3 ) )
    git_commit* const parents[1] = { parent };
    git_commit** const parentsPtr = parent ? parents : nullptr;
#else
    const git_commit* parents[1] = { parent };
    const git_commit** parentsPtr = parent ? parents : nullptr;
#endif
 
    if( git_commit_create( &oid, repo, "HEAD", author, author, nullptr,
                           aMessage.mb_str(), tree, parentsCount, parentsPtr ) != 0 )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to create commit: %s" ),
                                                    KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    return CommitResult::Success;
}
 
 
CommitResult LIBGIT_BACKEND::Amend( GIT_COMMIT_HANDLER* aHandler, const std::vector<wxString>& aFiles,
                                    const wxString& aMessage, const wxString& aAuthorName,
                                    const wxString& aAuthorEmail )
{
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
        return CommitResult::Error;
 
    if( git_repository_head_unborn( repo ) != 0 )
    {
        aHandler->AddErrorString( _( "Cannot amend: the branch has no commits yet." ) );
        return CommitResult::Error;
    }
 
    git_reference* headRef = nullptr;
 
    if( git_repository_head( &headRef, repo ) != 0 )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Failed to get HEAD reference: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    KIGIT::GitReferencePtr headRefPtr( headRef );
    git_commit*            headCommit = nullptr;
 
    if( git_reference_peel( (git_object**) &headCommit, headRef, GIT_OBJECT_COMMIT ) != 0 )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Failed to get HEAD commit: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    KIGIT::GitCommitPtr headCommitPtr( headCommit );
    git_index*          index = nullptr;
 
    if( git_repository_index( &index, repo ) != 0 )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Failed to get repository index: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    KIGIT::GitIndexPtr indexPtr( index );
 
    git_commit* parentCommit = nullptr;
 
    if( git_commit_parentcount( headCommit ) > 0 && git_commit_parent( &parentCommit, headCommit, 0 ) != 0 )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Failed to get parent commit: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    KIGIT::GitCommitPtr parentCommitPtr( parentCommit );
 
    if( aFiles.empty() )
    {
        git_tree* headTree = nullptr;
 
        if( git_commit_tree( &headTree, headCommit ) != 0 )
        {
            aHandler->AddErrorString(
                    wxString::Format( _( "Failed to get HEAD tree: %s" ), KIGIT_COMMON::GetLastGitError() ) );
            return CommitResult::Error;
        }
 
        KIGIT::GitTreePtr headTreePtr( headTree );
 
        if( git_index_read_tree( index, headTree ) != 0 )
        {
            aHandler->AddErrorString(
                    wxString::Format( _( "Failed to reset index: %s" ), KIGIT_COMMON::GetLastGitError() ) );
            return CommitResult::Error;
        }
    }
    else
    {
        // Rebuild from the parent's tree so files can be dropped, then re-apply the selected files.
        if( parentCommit )
        {
            git_tree* parentTree = nullptr;
 
            if( git_commit_tree( &parentTree, parentCommit ) != 0 )
            {
                aHandler->AddErrorString(
                        wxString::Format( _( "Failed to get parent tree: %s" ), KIGIT_COMMON::GetLastGitError() ) );
                return CommitResult::Error;
            }
 
            KIGIT::GitTreePtr parentTreePtr( parentTree );
 
            if( git_index_read_tree( index, parentTree ) != 0 )
            {
                aHandler->AddErrorString(
                        wxString::Format( _( "Failed to reset index: %s" ), KIGIT_COMMON::GetLastGitError() ) );
                return CommitResult::Error;
            }
        }
        else
        {
            // Amending the very first commit: start from an empty tree.
            git_index_clear( index );
        }
 
        const char* workdir = git_repository_workdir( repo );
 
        for( const wxString& file : aFiles )
        {
            bool onDisk = workdir && wxFileName::FileExists( wxString::FromUTF8( workdir ) + file );
 
            int rc = onDisk ? git_index_add_bypath( index, file.mb_str() )
                            : git_index_remove_bypath( index, file.mb_str() );
 
            if( rc != 0 )
            {
                aHandler->AddErrorString(
                        wxString::Format( _( "Failed to add file to index: %s" ), KIGIT_COMMON::GetLastGitError() ) );
                return CommitResult::Error;
            }
        }
    }
 
    if( git_index_write( index ) != 0 )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Failed to write index: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    git_oid tree_id;
 
    if( git_index_write_tree( &tree_id, index ) != 0 )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Failed to write tree: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    git_tree* tree = nullptr;
 
    if( git_tree_lookup( &tree, repo, &tree_id ) != 0 )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Failed to lookup tree: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    KIGIT::GitTreePtr treePtr( tree );
    git_signature*    author = nullptr;
 
    if( git_signature_now( &author, aAuthorName.mb_str(), aAuthorEmail.mb_str() ) != 0 )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Failed to create author signature: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    KIGIT::GitSignaturePtr authorPtr( author );
    git_oid                oid;
 
    if( git_commit_amend( &oid, headCommit, "HEAD", author, author, nullptr, aMessage.mb_str(), tree ) != 0 )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Failed to amend commit: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return CommitResult::Error;
    }
 
    return CommitResult::Success;
}
 
 
PushResult LIBGIT_BACKEND::Push( GIT_PUSH_HANDLER* aHandler, bool aForce )
{
    KIGIT_COMMON* common = aHandler->GetCommon();
    std::unique_lock<std::mutex> lock( common->m_gitActionMutex, std::try_to_lock );
 
    if( !lock.owns_lock() )
    {
        wxLogTrace( traceGit, "GIT_PUSH_HANDLER::PerformPush: Could not lock mutex" );
        return PushResult::Error;
    }
 
    PushResult result = PushResult::Success;
 
    wxString    remoteName = common->GetRemoteNameOrDefault();
    std::string remoteNameUtf8 = remoteName.utf8_string();
    git_remote* remote = nullptr;
 
    if( git_remote_lookup( &remote, aHandler->GetRepo(), remoteNameUtf8.c_str() ) != 0 )
    {
        aHandler->AddErrorString( wxString::Format( _( "Could not lookup remote '%s'" ),
                                                    remoteName ) );
        return PushResult::Error;
    }
 
    KIGIT::GitRemotePtr remotePtr(remote);
 
    git_remote_callbacks remoteCallbacks;
    git_remote_init_callbacks( &remoteCallbacks, GIT_REMOTE_CALLBACKS_VERSION );
    remoteCallbacks.sideband_progress = progress_cb;
    remoteCallbacks.transfer_progress = transfer_progress_cb;
    remoteCallbacks.update_tips = update_cb;
    remoteCallbacks.push_transfer_progress = push_transfer_progress_cb;
    remoteCallbacks.credentials = credentials_cb;
    remoteCallbacks.payload = aHandler;
 
    git_proxy_options proxyOpts;
    git_proxy_init_options( &proxyOpts, GIT_PROXY_OPTIONS_VERSION );
    proxyOpts.type = GIT_PROXY_AUTO;
    common->SetCancelled( false );
 
    aHandler->TestedTypes() = 0;
    aHandler->ResetNextKey();
 
    if( git_remote_connect( remote, GIT_DIRECTION_PUSH, &remoteCallbacks, &proxyOpts, nullptr ) )
    {
        aHandler->AddErrorString( wxString::Format( _( "Could not connect to remote: %s" ),
                                                    KIGIT_COMMON::GetLastGitError() ) );
        return PushResult::Error;
    }
 
    git_push_options pushOptions;
    git_push_init_options( &pushOptions, GIT_PUSH_OPTIONS_VERSION );
    pushOptions.callbacks = remoteCallbacks;
    pushOptions.proxy_opts.type = GIT_PROXY_AUTO;
 
    git_reference* head = nullptr;
 
    if( git_repository_head( &head, aHandler->GetRepo() ) != 0 )
    {
        git_remote_disconnect( remote );
        aHandler->AddErrorString( _( "Could not get repository head" ) );
        return PushResult::Error;
    }
 
    KIGIT::GitReferencePtr headPtr( head );
 
    // Force push prepends "+" to the refspec source, matching `git push --force`.
    wxString           refspec = ( aForce ? wxS( "+" ) : wxS( "" ) ) + wxString( git_reference_name( head ) );
    std::string        refspecUtf8 = refspec.utf8_string();
    const char*        refs[1] = { refspecUtf8.c_str() };
    const git_strarray refspecs = { (char**) refs, 1 };
 
    if( git_remote_push( remote, &refspecs, &pushOptions ) )
    {
        wxString errorMsg = KIGIT_COMMON::GetLastGitError();
        aHandler->AddErrorString( wxString::Format( _( "Could not push to remote: %s" ), errorMsg ) );
        git_remote_disconnect( remote );
 
        wxString lower = errorMsg.Lower();
 
        if( lower.Contains( wxS( "non-fast-forward" ) ) || lower.Contains( wxS( "non-fastforwardable" ) )
            || lower.Contains( wxS( "would not be" ) ) )
        {
            return PushResult::NonFastForward;
        }
 
        return PushResult::Error;
    }
 
    // First push from this branch: point it at where we just pushed (git push -u).
    if( git_reference_is_branch( head ) )
    {
        git_reference* upstreamRef = nullptr;
        int            rc = git_branch_upstream( &upstreamRef, head );
 
        if( rc == GIT_ENOTFOUND )
        {
            wxString upstreamName = wxString::Format( "%s/%s", remoteName, git_reference_shorthand( head ) );
            git_branch_set_upstream( head, upstreamName.utf8_string().c_str() );
        }
        else if( rc == GIT_OK )
        {
            KIGIT::GitReferencePtr upstreamPtr( upstreamRef );
        }
    }
 
    git_remote_disconnect( remote );
 
    return result;
}
 
 
bool LIBGIT_BACKEND::HasChangedFiles( GIT_STATUS_HANDLER* aHandler )
{
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
        return false;
 
    git_status_options opts;
    git_status_init_options( &opts, GIT_STATUS_OPTIONS_VERSION );
 
    opts.show = GIT_STATUS_SHOW_INDEX_AND_WORKDIR;
    opts.flags = GIT_STATUS_OPT_INCLUDE_UNTRACKED | GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX
                 | GIT_STATUS_OPT_SORT_CASE_SENSITIVELY;
 
    git_status_list* status_list = nullptr;
 
    if( git_status_list_new( &status_list, repo, &opts ) != GIT_OK )
    {
        wxLogTrace( traceGit, "Failed to get status list: %s", KIGIT_COMMON::GetLastGitError() );
        return false;
    }
 
    KIGIT::GitStatusListPtr status_list_ptr( status_list );
    bool hasChanges = ( git_status_list_entrycount( status_list ) > 0 );
 
    return hasChanges;
}
 
 
std::map<wxString, FileStatus> LIBGIT_BACKEND::GetFileStatus( GIT_STATUS_HANDLER* aHandler,
                                                              const wxString& aPathspec )
{
    std::map<wxString, FileStatus> fileStatusMap;
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
        return fileStatusMap;
 
    git_status_options status_options;
    git_status_init_options( &status_options, GIT_STATUS_OPTIONS_VERSION );
    status_options.show = GIT_STATUS_SHOW_INDEX_AND_WORKDIR;
    status_options.flags = GIT_STATUS_OPT_INCLUDE_UNTRACKED | GIT_STATUS_OPT_INCLUDE_UNMODIFIED
                           | GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS;
 
    std::string pathspec_str;
    std::vector<const char*> pathspec_ptrs;
 
    if( !aPathspec.IsEmpty() )
    {
        pathspec_str = aPathspec.ToStdString();
        pathspec_ptrs.push_back( pathspec_str.c_str() );
 
        status_options.pathspec.strings = const_cast<char**>( pathspec_ptrs.data() );
        status_options.pathspec.count = pathspec_ptrs.size();
    }
 
    git_status_list* status_list = nullptr;
 
    if( git_status_list_new( &status_list, repo, &status_options ) != GIT_OK )
    {
        wxLogTrace( traceGit, "Failed to get git status list: %s", KIGIT_COMMON::GetLastGitError() );
        return fileStatusMap;
    }
 
    KIGIT::GitStatusListPtr statusListPtr( status_list );
 
    size_t count = git_status_list_entrycount( status_list );
    wxString repoWorkDir = aHandler->GetProjectDir();
 
    for( size_t ii = 0; ii < count; ++ii )
    {
        const git_status_entry* entry = git_status_byindex( status_list, ii );
        std::string path( entry->head_to_index ? entry->head_to_index->old_file.path
                                               : entry->index_to_workdir->old_file.path );
 
        wxString absPath = repoWorkDir + path;
        fileStatusMap[absPath] = FileStatus{ absPath,
                                             aHandler->ConvertStatus( entry->status ),
                                             static_cast<unsigned int>( entry->status ) };
    }
 
    return fileStatusMap;
}
 
 
wxString LIBGIT_BACKEND::GetCurrentBranchName( GIT_STATUS_HANDLER* aHandler )
{
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
        return wxEmptyString;
 
    git_reference* currentBranchReference = nullptr;
    int rc = git_repository_head( &currentBranchReference, repo );
    KIGIT::GitReferencePtr currentBranchReferencePtr( currentBranchReference );
 
    if( currentBranchReference )
    {
        return git_reference_shorthand( currentBranchReference );
    }
    else if( rc == GIT_EUNBORNBRANCH )
    {
        return wxEmptyString;
    }
    else
    {
        wxLogTrace( traceGit, "Failed to lookup current branch: %s", KIGIT_COMMON::GetLastGitError() );
        return wxEmptyString;
    }
}
 
 
void LIBGIT_BACKEND::UpdateRemoteStatus( GIT_STATUS_HANDLER* aHandler,
                                         const std::set<wxString>& aLocalChanges,
                                         const std::set<wxString>& aRemoteChanges,
                                         std::map<wxString, FileStatus>& aFileStatus )
{
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
        return;
 
    wxString repoWorkDir = aHandler->GetProjectDir();
 
    for( auto& [absPath, fileStatus] : aFileStatus )
    {
        wxString relativePath = absPath;
        if( relativePath.StartsWith( repoWorkDir ) )
        {
            relativePath = relativePath.Mid( repoWorkDir.length() );
 
#ifdef _WIN32
            relativePath.Replace( wxS( "\\" ), wxS( "/" ) );
#endif
        }
 
        std::string relativePathStd = relativePath.ToStdString();
 
        if( fileStatus.status == KIGIT_COMMON::GIT_STATUS::GIT_STATUS_CURRENT )
        {
            if( aLocalChanges.count( relativePathStd ) )
            {
                fileStatus.status = KIGIT_COMMON::GIT_STATUS::GIT_STATUS_AHEAD;
            }
            else if( aRemoteChanges.count( relativePathStd ) )
            {
                fileStatus.status = KIGIT_COMMON::GIT_STATUS::GIT_STATUS_BEHIND;
            }
        }
    }
}
 
 
wxString LIBGIT_BACKEND::GetWorkingDirectory( GIT_STATUS_HANDLER* aHandler )
{
    return aHandler->GetProjectDir();
}
 
 
wxString LIBGIT_BACKEND::GetWorkingDirectory( GIT_CONFIG_HANDLER* aHandler )
{
    return aHandler->GetProjectDir();
}
 
 
bool LIBGIT_BACKEND::GetConfigString( GIT_CONFIG_HANDLER* aHandler, const wxString& aKey, wxString& aValue )
{
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
        return false;
 
    git_config* config = nullptr;
 
    if( git_repository_config( &config, repo ) != GIT_OK )
    {
        wxLogTrace( traceGit, "Failed to get repository config: %s", KIGIT_COMMON::GetLastGitError() );
        return false;
    }
 
    KIGIT::GitConfigPtr configPtr( config );
 
    git_config_entry* entry = nullptr;
    int result = git_config_get_entry( &entry, config, aKey.mb_str() );
    KIGIT::GitConfigEntryPtr entryPtr( entry );
 
    if( result != GIT_OK || entry == nullptr )
    {
        wxLogTrace( traceGit, "Config key '%s' not found", aKey );
        return false;
    }
 
    aValue = wxString( entry->value );
    return true;
}
 
 
bool LIBGIT_BACKEND::IsRepository( GIT_INIT_HANDLER* aHandler, const wxString& aPath )
{
    git_repository* repo = nullptr;
    int error = git_repository_open( &repo, aPath.mb_str() );
 
    if( error == 0 )
    {
        git_repository_free( repo );
        return true;
    }
 
    return false;
}
 
 
InitResult LIBGIT_BACKEND::InitializeRepository( GIT_INIT_HANDLER* aHandler, const wxString& aPath )
{
    if( IsRepository( aHandler, aPath ) )
    {
        return InitResult::AlreadyExists;
    }
 
    git_repository* repo = nullptr;
 
    if( git_repository_init( &repo, aPath.mb_str(), 0 ) != GIT_OK )
    {
        if( repo )
            git_repository_free( repo );
 
        aHandler->AddErrorString( wxString::Format( _( "Failed to initialize Git repository: %s" ),
                                                    KIGIT_COMMON::GetLastGitError() ) );
        return InitResult::Error;
    }
 
    aHandler->GetCommon()->SetRepo( repo );
 
    wxLogTrace( traceGit, "Successfully initialized Git repository at %s", aPath );
    return InitResult::Success;
}
 
 
bool LIBGIT_BACKEND::SetupRemote( GIT_INIT_HANDLER* aHandler, const RemoteConfig& aConfig )
{
    if( aConfig.url.IsEmpty() )
        return true;
 
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
    {
        aHandler->AddErrorString( _( "No repository available to set up remote" ) );
        return false;
    }
 
    aHandler->GetCommon()->SetUsername( aConfig.username );
    aHandler->GetCommon()->SetPassword( aConfig.password );
    aHandler->GetCommon()->SetSSHKey( aConfig.sshKey );
 
    git_remote* remote = nullptr;
    wxString fullURL;
 
    if( aConfig.connType == KIGIT_COMMON::GIT_CONN_TYPE::GIT_CONN_SSH )
    {
        wxString userPrefix;
 
        if( !aConfig.url.Contains( "@" ) && !aConfig.username.IsEmpty() )
            userPrefix = aConfig.username + "@";
 
        if( aConfig.url.StartsWith( "ssh://" ) )
            fullURL = "ssh://" + userPrefix + aConfig.url.Mid( 6 );
        else if( aConfig.url.Contains( ":" ) )
            fullURL = userPrefix + aConfig.url;
        else
            fullURL = "ssh://" + userPrefix + aConfig.url;
    }
    else if( aConfig.connType == KIGIT_COMMON::GIT_CONN_TYPE::GIT_CONN_HTTPS )
    {
        fullURL = aConfig.url.StartsWith( "https" ) ? "https://" : "http://";
 
        if( !aConfig.username.empty() )
        {
            fullURL.append( aConfig.username );
 
            if( !aConfig.password.empty() )
            {
                fullURL.append( wxS( ":" ) );
                fullURL.append( aConfig.password );
            }
 
            fullURL.append( wxS( "@" ) );
        }
 
        wxString bareURL = aConfig.url;
 
        if( bareURL.StartsWith( "https://" ) )
            bareURL = bareURL.Mid( 8 );
        else if( bareURL.StartsWith( "http://" ) )
            bareURL = bareURL.Mid( 7 );
 
        fullURL.append( bareURL );
    }
    else
    {
        fullURL = aConfig.url;
    }
 
    int error;
 
    if( git_remote_lookup( &remote, repo, "origin" ) == GIT_OK )
    {
        KIGIT::GitRemotePtr remotePtr( remote );
        error = git_remote_set_url( repo, "origin", fullURL.ToStdString().c_str() );
    }
    else
    {
        error = git_remote_create_with_fetchspec( &remote, repo, "origin", fullURL.ToStdString().c_str(),
                                                  "+refs/heads/*:refs/remotes/origin/*" );
        KIGIT::GitRemotePtr remotePtr( remote );
    }
 
    if( error != GIT_OK )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Failed to set up remote: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return false;
    }
 
    // Sync the remote URL onto common so subsequent fetch/push see the right
    // connection type; otherwise credentials_cb short-circuits as local.
    aHandler->GetCommon()->SetRemote( fullURL );
 
    wxLogTrace( traceGit, "Successfully set up remote origin" );
    return true;
}
 
 
static bool lookup_branch_reference( git_repository* repo, const wxString& aBranchName,
                                     git_reference** aReference )
{
    if( git_reference_lookup( aReference, repo, aBranchName.mb_str() ) == GIT_OK )
        return true;
 
    if( git_reference_dwim( aReference, repo, aBranchName.mb_str() ) == GIT_OK )
        return true;
 
    return false;
}
 
 
BranchResult LIBGIT_BACKEND::SwitchToBranch( GIT_BRANCH_HANDLER* aHandler, const wxString& aBranchName )
{
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
    {
        aHandler->AddErrorString( _( "No repository available" ) );
        return BranchResult::Error;
    }
 
    git_reference* branchRef = nullptr;
 
    if( !lookup_branch_reference( repo, aBranchName, &branchRef ) )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to lookup branch '%s': %s" ),
                                                    aBranchName, KIGIT_COMMON::GetLastGitError() ) );
        return BranchResult::BranchNotFound;
    }
 
    KIGIT::GitReferencePtr branchRefPtr( branchRef );
    const char* branchRefName = git_reference_name( branchRef );
    git_object* branchObj = nullptr;
 
    if( git_revparse_single( &branchObj, repo, aBranchName.mb_str() ) != GIT_OK )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to find branch head for '%s': %s" ),
                                                    aBranchName, KIGIT_COMMON::GetLastGitError() ) );
        return BranchResult::Error;
    }
 
    KIGIT::GitObjectPtr branchObjPtr( branchObj );
 
 
    git_checkout_options checkoutOpts;
    git_checkout_init_options( &checkoutOpts, GIT_CHECKOUT_OPTIONS_VERSION );
    checkoutOpts.checkout_strategy = GIT_CHECKOUT_SAFE;
 
    if( git_checkout_tree( repo, branchObj, &checkoutOpts ) != GIT_OK )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to switch to branch '%s': %s" ),
                                                    aBranchName, KIGIT_COMMON::GetLastGitError() ) );
        return BranchResult::CheckoutFailed;
    }
 
    KIGIT::GitReferencePtr localBranchPtr;
    const char*            headTarget = branchRefName;
 
    if( git_reference_is_remote( branchRef ) )
    {
        wxString localName = wxString::FromUTF8( git_reference_shorthand( branchRef ) );
        size_t   slash = localName.find( '/' );
 
        if( slash != wxString::npos )
            localName = localName.Mid( slash + 1 );
 
        std::string    localNameUtf8 = localName.utf8_string();
        git_reference* localBranch = nullptr;
 
        if( git_branch_lookup( &localBranch, repo, localNameUtf8.c_str(), GIT_BRANCH_LOCAL ) != GIT_OK )
        {
            git_commit* target = nullptr;
 
            if( git_commit_lookup( &target, repo, git_object_id( branchObj ) ) != GIT_OK )
            {
                aHandler->AddErrorString( wxString::Format( _( "Failed to switch to branch '%s': %s" ), aBranchName,
                                                            KIGIT_COMMON::GetLastGitError() ) );
                return BranchResult::Error;
            }
 
            KIGIT::GitCommitPtr targetPtr( target );
 
            if( git_branch_create( &localBranch, repo, localNameUtf8.c_str(), target, 0 ) != GIT_OK )
            {
                aHandler->AddErrorString( wxString::Format( _( "Failed to create local branch '%s': %s" ), localName,
                                                            KIGIT_COMMON::GetLastGitError() ) );
                return BranchResult::Error;
            }
 
            git_branch_set_upstream( localBranch, git_reference_shorthand( branchRef ) );
        }
 
        localBranchPtr.reset( localBranch );
        headTarget = git_reference_name( localBranch );
    }
 
    if( git_repository_set_head( repo, headTarget ) != GIT_OK )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to update HEAD reference for branch '%s': %s" ),
                                                    aBranchName, KIGIT_COMMON::GetLastGitError() ) );
        return BranchResult::Error;
    }
 
    wxLogTrace( traceGit, "Successfully switched to branch '%s'", aBranchName );
    return BranchResult::Success;
}
 
 
bool LIBGIT_BACKEND::BranchExists( GIT_BRANCH_HANDLER* aHandler, const wxString& aBranchName )
{
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
        return false;
 
    git_reference* branchRef = nullptr;
    bool exists = lookup_branch_reference( repo, aBranchName, &branchRef );
 
    if( branchRef )
        git_reference_free( branchRef );
 
    return exists;
}
 
 
// Use callbacks declared/implemented in kicad_git_common.h/.cpp
 
bool LIBGIT_BACKEND::PerformFetch( GIT_PULL_HANDLER* aHandler, bool aSkipLock )
{
    if( !aHandler->GetRepo() )
    {
        wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformFetch() - No repository found" );
        return false;
    }
 
    std::unique_lock<std::mutex> lock( aHandler->GetCommon()->m_gitActionMutex, std::try_to_lock );
 
    if( !aSkipLock && !lock.owns_lock() )
    {
        wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformFetch() - Could not lock mutex" );
        return false;
    }
 
    wxString    remoteName = aHandler->GetCommon()->GetRemoteNameOrDefault();
    std::string remoteNameUtf8 = remoteName.utf8_string();
    git_remote* remote = nullptr;
 
    if( git_remote_lookup( &remote, aHandler->GetRepo(), remoteNameUtf8.c_str() ) != 0 )
    {
        wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformFetch() - Failed to lookup remote '%s'",
                    remoteName );
        aHandler->AddErrorString( wxString::Format( _( "Could not lookup remote '%s'" ),
                                                    remoteName ) );
        return false;
    }
 
    KIGIT::GitRemotePtr remotePtr( remote );
 
    git_remote_callbacks remoteCallbacks;
    git_remote_init_callbacks( &remoteCallbacks, GIT_REMOTE_CALLBACKS_VERSION );
    remoteCallbacks.sideband_progress = progress_cb;
    remoteCallbacks.transfer_progress = transfer_progress_cb;
    remoteCallbacks.credentials = credentials_cb;
    remoteCallbacks.payload = aHandler;
 
    git_proxy_options proxyOpts;
    git_proxy_init_options( &proxyOpts, GIT_PROXY_OPTIONS_VERSION );
    proxyOpts.type = GIT_PROXY_AUTO;
    aHandler->GetCommon()->SetCancelled( false );
 
    aHandler->TestedTypes() = 0;
    aHandler->ResetNextKey();
 
    if( git_remote_connect( remote, GIT_DIRECTION_FETCH, &remoteCallbacks, &proxyOpts, nullptr ) )
    {
        wxString errorMsg = KIGIT_COMMON::GetLastGitError();
        wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformFetch() - Failed to connect to remote: %s", errorMsg );
        aHandler->AddErrorString( wxString::Format( _( "Could not connect to remote '%s': %s" ),
                                                    remoteName, errorMsg ) );
        return false;
    }
 
    git_fetch_options fetchOptions;
    git_fetch_init_options( &fetchOptions, GIT_FETCH_OPTIONS_VERSION );
    fetchOptions.callbacks = remoteCallbacks;
 
    if( git_remote_fetch( remote, nullptr, &fetchOptions, nullptr ) )
    {
        wxString errorMsg = KIGIT_COMMON::GetLastGitError();
        wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformFetch() - Failed to fetch from remote: %s", errorMsg );
        aHandler->AddErrorString( wxString::Format( _( "Could not fetch data from remote '%s': %s" ),
                                                    remoteName, errorMsg ) );
        return false;
    }
 
    wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformFetch() - Fetch completed successfully" );
    return true;
}
 
 
PullResult LIBGIT_BACKEND::PerformPull( GIT_PULL_HANDLER* aHandler )
{
    PullResult result = PullResult::Success;
    std::unique_lock<std::mutex> lock( aHandler->GetCommon()->m_gitActionMutex, std::try_to_lock );
 
    if( !lock.owns_lock() )
    {
        wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformPull() - Could not lock mutex" );
        return PullResult::Error;
    }
 
    if( !PerformFetch( aHandler, true ) )
        return PullResult::Error;
 
    git_oid pull_merge_oid = {};
 
    if( git_repository_fetchhead_foreach( aHandler->GetRepo(), fetchhead_foreach_cb, &pull_merge_oid ) )
    {
        aHandler->AddErrorString( _( "Could not read 'FETCH_HEAD'" ) );
        return PullResult::Error;
    }
 
    // Add Version Control doesn't write branch.<name>.merge, so FETCH_HEAD has no
    // merge-marked entry.  Fall back to refs/remotes/<remote>/<branch> and persist
    // the upstream so subsequent pulls take the normal path.
#if ( LIBGIT2_VER_MAJOR >= 1 ) || ( LIBGIT2_VER_MINOR >= 99 )
    if( git_oid_is_zero( &pull_merge_oid ) )
#else
    if( git_oid_iszero( &pull_merge_oid ) )
#endif
    {
        git_reference* head_ref = nullptr;
 
        if( git_repository_head( &head_ref, aHandler->GetRepo() ) == GIT_OK )
        {
            KIGIT::GitReferencePtr headRefPtr( head_ref );
 
            if( git_reference_is_branch( head_ref ) )
            {
                const char* branch_shorthand = git_reference_shorthand( head_ref );
                wxString    remoteName = aHandler->GetCommon()->GetRemoteNameOrDefault();
                wxString    remoteRefName = wxString::Format( "refs/remotes/%s/%s", remoteName, branch_shorthand );
 
                if( git_reference_name_to_id( &pull_merge_oid, aHandler->GetRepo(),
                                              remoteRefName.utf8_string().c_str() )
                    == GIT_OK )
                {
                    wxString upstream = wxString::Format( "%s/%s", remoteName, branch_shorthand );
                    git_branch_set_upstream( head_ref, upstream.utf8_string().c_str() );
                }
            }
        }
    }
 
#if ( LIBGIT2_VER_MAJOR >= 1 ) || ( LIBGIT2_VER_MINOR >= 99 )
    if( git_oid_is_zero( &pull_merge_oid ) )
#else
    if( git_oid_iszero( &pull_merge_oid ) )
#endif
    {
        aHandler->AddErrorString( _( "Nothing to pull: the remote has no branch matching "
                                     "the current local branch." ) );
        return PullResult::Error;
    }
 
    git_annotated_commit* fetchhead_commit;
 
    if( git_annotated_commit_lookup( &fetchhead_commit, aHandler->GetRepo(), &pull_merge_oid ) )
    {
        aHandler->AddErrorString( _( "Could not lookup commit" ) );
        return PullResult::Error;
    }
 
    KIGIT::GitAnnotatedCommitPtr fetchheadCommitPtr( fetchhead_commit );
    const git_annotated_commit* merge_commits[] = { fetchhead_commit };
    git_merge_analysis_t        merge_analysis;
    git_merge_preference_t      merge_preference = GIT_MERGE_PREFERENCE_NONE;
 
    if( git_merge_analysis( &merge_analysis, &merge_preference, aHandler->GetRepo(), merge_commits, 1 ) )
    {
        aHandler->AddErrorString( _( "Could not analyze merge" ) );
        return PullResult::Error;
    }
 
    if( merge_analysis & GIT_MERGE_ANALYSIS_UNBORN )
    {
        aHandler->AddErrorString( _( "Invalid HEAD.  Cannot merge." ) );
        return PullResult::MergeFailed;
    }
 
    if( merge_analysis & GIT_MERGE_ANALYSIS_UP_TO_DATE )
    {
        wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformPull() - Repository is up to date" );
        git_repository_state_cleanup( aHandler->GetRepo() );
        return PullResult::UpToDate;
    }
 
    if( merge_analysis & GIT_MERGE_ANALYSIS_FASTFORWARD )
    {
        wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformPull() - Fast-forward merge" );
        return handleFastForward( aHandler );
    }
 
    if( merge_analysis & GIT_MERGE_ANALYSIS_NORMAL )
    {
        wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformPull() - Normal merge" );
 
        git_config* config = nullptr;
 
        if( git_repository_config( &config, aHandler->GetRepo() ) != GIT_OK )
        {
            wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformPull() - Failed to get repository config" );
            aHandler->AddErrorString( _( "Could not access repository configuration" ) );
            return PullResult::Error;
        }
 
        KIGIT::GitConfigPtr configPtr( config );
 
        int rebase_value = 0;
        int ret = git_config_get_bool( &rebase_value, config, "pull.rebase" );
 
        if( ret == GIT_OK && rebase_value )
        {
            wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformPull() - Using rebase based on config" );
            return handleRebase( aHandler, merge_commits, 1 );
        }
 
        wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformPull() - Using merge based on config" );
        return handleMerge( aHandler, merge_commits, 1 );
    }
 
    wxLogTrace( traceGit, "GIT_PULL_HANDLER::PerformPull() - Merge needs resolution" );
    return result;
}
 
 
PullResult LIBGIT_BACKEND::handleFastForward( GIT_PULL_HANDLER* aHandler )
{
    git_reference* rawRef = nullptr;
 
    if( git_repository_head( &rawRef, aHandler->GetRepo() ) )
    {
        aHandler->AddErrorString( _( "Could not get repository head" ) );
        return PullResult::Error;
    }
 
    KIGIT::GitReferencePtr headRef( rawRef );
 
    git_oid     updatedRefOid;
    const char* currentBranchName = git_reference_name( rawRef );
    const char* branch_shorthand = git_reference_shorthand( rawRef );
    wxString remote_name = aHandler->GetRemotename();
    wxString remoteBranchName = wxString::Format( "refs/remotes/%s/%s", remote_name, branch_shorthand );
 
    if( git_reference_name_to_id( &updatedRefOid, aHandler->GetRepo(), remoteBranchName.c_str() ) != GIT_OK )
    {
        aHandler->AddErrorString( wxString::Format( _( "Could not get reference OID for reference '%s'" ),
                                                    remoteBranchName ) );
        return PullResult::Error;
    }
 
    git_commit* targetCommit = nullptr;
 
    if( git_commit_lookup( &targetCommit, aHandler->GetRepo(), &updatedRefOid ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Could not look up target commit" ) );
        return PullResult::Error;
    }
 
    KIGIT::GitCommitPtr targetCommitPtr( targetCommit );
 
    git_tree* targetTree = nullptr;
 
    if( git_commit_tree( &targetTree, targetCommit ) != GIT_OK )
    {
        git_commit_free( targetCommit );
        aHandler->AddErrorString( _( "Could not get tree from target commit" ) );
        return PullResult::Error;
    }
 
    KIGIT::GitTreePtr targetTreePtr( targetTree );
 
    git_checkout_options checkoutOptions;
    git_checkout_init_options( &checkoutOptions, GIT_CHECKOUT_OPTIONS_VERSION );
    auto notify_cb = []( git_checkout_notify_t why, const char* path, const git_diff_file* baseline,
                         const git_diff_file* target, const git_diff_file* workdir, void* payload ) -> int
    {
        switch( why )
        {
        case GIT_CHECKOUT_NOTIFY_CONFLICT:
            wxLogTrace( traceGit, "Checkout conflict: %s", path ? path : "unknown" );
            break;
        case GIT_CHECKOUT_NOTIFY_DIRTY:
            wxLogTrace( traceGit, "Checkout dirty: %s", path ? path : "unknown" );
            break;
        case GIT_CHECKOUT_NOTIFY_UPDATED:
            wxLogTrace( traceGit, "Checkout updated: %s", path ? path : "unknown" );
            break;
        case GIT_CHECKOUT_NOTIFY_UNTRACKED:
            wxLogTrace( traceGit, "Checkout untracked: %s", path ? path : "unknown" );
            break;
        case GIT_CHECKOUT_NOTIFY_IGNORED:
            wxLogTrace( traceGit, "Checkout ignored: %s", path ? path : "unknown" );
            break;
        default:
            break;
        }
 
        return 0;
    };
 
    checkoutOptions.checkout_strategy = GIT_CHECKOUT_SAFE | GIT_CHECKOUT_ALLOW_CONFLICTS;
    checkoutOptions.notify_flags = GIT_CHECKOUT_NOTIFY_ALL;
    checkoutOptions.notify_cb = notify_cb;
 
    if( git_checkout_tree( aHandler->GetRepo(), reinterpret_cast<git_object*>( targetTree ),
                           &checkoutOptions ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Failed to perform checkout operation." ) );
        return PullResult::Error;
    }
 
    git_reference* updatedRef = nullptr;
 
    if( git_reference_set_target( &updatedRef, rawRef, &updatedRefOid, nullptr ) != GIT_OK )
    {
        aHandler->AddErrorString( wxString::Format( _( "Failed to update reference '%s' to point to '%s'" ),
                                                    currentBranchName, git_oid_tostr_s( &updatedRefOid ) ) );
        return PullResult::Error;
    }
 
    KIGIT::GitReferencePtr updatedRefPtr( updatedRef );
 
    if( git_repository_state_cleanup( aHandler->GetRepo() ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Failed to clean up repository state after fast-forward." ) );
        return PullResult::Error;
    }
 
    git_revwalk* revWalker = nullptr;
 
    if( git_revwalk_new( &revWalker, aHandler->GetRepo() ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Failed to initialize revision walker." ) );
        return PullResult::Error;
    }
 
    KIGIT::GitRevWalkPtr revWalkerPtr( revWalker );
    git_revwalk_sorting( revWalker, GIT_SORT_TIME );
 
    if( git_revwalk_push_glob( revWalker, currentBranchName ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Failed to push reference to revision walker." ) );
        return PullResult::Error;
    }
 
    std::pair<std::string, std::vector<CommitDetails>>& branchCommits = aHandler->m_fetchResults.emplace_back();
    branchCommits.first = currentBranchName;
 
    git_oid commitOid;
 
    while( git_revwalk_next( &commitOid, revWalker ) == GIT_OK )
    {
        git_commit* commit = nullptr;
 
        if( git_commit_lookup( &commit, aHandler->GetRepo(), &commitOid ) )
        {
            aHandler->AddErrorString( wxString::Format( _( "Could not lookup commit '%s'" ),
                                                        git_oid_tostr_s( &commitOid ) ) );
            return PullResult::Error;
        }
 
        KIGIT::GitCommitPtr commitPtr( commit );
 
        CommitDetails details;
        details.m_sha = git_oid_tostr_s( &commitOid );
        details.m_firstLine = getFirstLineFromCommitMessage( git_commit_message( commit ) );
        details.m_author = git_commit_author( commit )->name;
        details.m_date = getFormattedCommitDate( git_commit_author( commit )->when );
 
        branchCommits.second.push_back( details );
    }
 
    return PullResult::FastForward;
}
 
 
bool LIBGIT_BACKEND::hasUnstagedChanges( git_repository* aRepo )
{
    if( !aRepo )
        return false;
 
    git_status_options opts;
    git_status_init_options( &opts, GIT_STATUS_OPTIONS_VERSION );
 
    // Only check workdir changes (unstaged), not index changes (staged)
    opts.show = GIT_STATUS_SHOW_WORKDIR_ONLY;
    opts.flags = GIT_STATUS_OPT_INCLUDE_UNTRACKED;
 
    git_status_list* status_list = nullptr;
 
    if( git_status_list_new( &status_list, aRepo, &opts ) != GIT_OK )
    {
        wxLogTrace( traceGit, "Failed to get status list: %s", KIGIT_COMMON::GetLastGitError() );
        return false;
    }
 
    KIGIT::GitStatusListPtr status_list_ptr( status_list );
    size_t count = git_status_list_entrycount( status_list );
 
    // Check if any of the entries are actual modifications (not just untracked files)
    for( size_t ii = 0; ii < count; ++ii )
    {
        const git_status_entry* entry = git_status_byindex( status_list, ii );
 
        // Check for actual workdir modifications, not just untracked files
        if( entry->status & ( GIT_STATUS_WT_MODIFIED | GIT_STATUS_WT_DELETED | GIT_STATUS_WT_TYPECHANGE ) )
        {
            return true;
        }
    }
 
    return false;
}
 
 
PullResult LIBGIT_BACKEND::handleMerge( GIT_PULL_HANDLER* aHandler,
                                        const git_annotated_commit** aMergeHeads,
                                        size_t aMergeHeadsCount )
{
    // Check for unstaged changes before attempting merge
    if( hasUnstagedChanges( aHandler->GetRepo() ) )
    {
        aHandler->AddErrorString(
                _( "Cannot merge: you have unstaged changes. "
                   "Please commit or stash them before pulling." ) );
        return PullResult::DirtyWorkdir;
    }
 
    git_repository* repo = aHandler->GetRepo();
 
    if( git_merge( repo, aMergeHeads, aMergeHeadsCount, nullptr, nullptr ) )
    {
        wxString errorMsg = KIGIT_COMMON::GetLastGitError();
        aHandler->AddErrorString( wxString::Format( _( "Merge failed: %s" ), errorMsg ) );
        return PullResult::MergeFailed;
    }
 
    git_index* index = nullptr;
 
    if( git_repository_index( &index, repo ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Could not read repository index after merge." ) );
        return PullResult::MergeFailed;
    }
 
    KIGIT::GitIndexPtr indexPtr( index );
 
    if( git_index_has_conflicts( index ) )
    {
        // Abort the merge and restore the pre-pull state
        git_object* head_obj = nullptr;
 
        if( git_revparse_single( &head_obj, repo, "HEAD" ) == GIT_OK )
        {
            KIGIT::GitObjectPtr headObjPtr( head_obj );
            git_reset( repo, head_obj, GIT_RESET_HARD, nullptr );
        }
 
        git_repository_state_cleanup( repo );
 
        return PullResult::Conflict;
    }
 
    git_oid        tree_oid;
    git_tree*      tree = nullptr;
    git_reference* head_ref = nullptr;
    git_oid        head_oid;
    git_commit*    head_commit = nullptr;
    git_commit*    merge_commit = nullptr;
    git_signature* signature = nullptr;
 
    if( git_index_write_tree( &tree_oid, index ) != GIT_OK || git_tree_lookup( &tree, repo, &tree_oid ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Could not write the merge result." ) );
        return PullResult::MergeFailed;
    }
 
    KIGIT::GitTreePtr treePtr( tree );
 
    if( git_repository_head( &head_ref, repo ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Could not get the repository head." ) );
        return PullResult::MergeFailed;
    }
 
    KIGIT::GitReferencePtr headRefPtr( head_ref );
 
    if( git_reference_name_to_id( &head_oid, repo, "HEAD" ) != GIT_OK
        || git_commit_lookup( &head_commit, repo, &head_oid ) != GIT_OK
        || git_commit_lookup( &merge_commit, repo, git_annotated_commit_id( aMergeHeads[0] ) ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Could not look up the commits to merge." ) );
        return PullResult::MergeFailed;
    }
 
    KIGIT::GitCommitPtr headCommitPtr( head_commit );
    KIGIT::GitCommitPtr mergeCommitPtr( merge_commit );
 
    if( git_signature_default( &signature, repo ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Could not create a commit signature.  Set user.name "
                                     "and user.email in your git configuration." ) );
        return PullResult::MergeFailed;
    }
 
    KIGIT::GitSignaturePtr signaturePtr( signature );
 
    const git_commit* parents[] = { head_commit, merge_commit };
    wxString          message =
            wxString::Format( _( "Merge remote-tracking branch into %s" ), git_reference_shorthand( head_ref ) );
    git_oid merge_commit_oid;
 
    if( git_commit_create( &merge_commit_oid, repo, "HEAD", signature, signature, nullptr,
                           message.utf8_string().c_str(), tree, 2, parents )
        != GIT_OK )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Could not create merge commit: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return PullResult::MergeFailed;
    }
 
    git_repository_state_cleanup( repo );
    return PullResult::Success;
}
 
 
PullResult LIBGIT_BACKEND::handleRebase( GIT_PULL_HANDLER* aHandler,
                                         const git_annotated_commit** aMergeHeads,
                                         size_t aMergeHeadsCount )
{
    // Check for unstaged changes before attempting rebase
    if( hasUnstagedChanges( aHandler->GetRepo() ) )
    {
        aHandler->AddErrorString(
                _( "Cannot pull with rebase: you have unstaged changes. "
                   "Please commit or stash them before pulling." ) );
        return PullResult::DirtyWorkdir;
    }
 
    git_rebase_options rebase_opts;
    git_rebase_init_options( &rebase_opts, GIT_REBASE_OPTIONS_VERSION );
 
    git_rebase* rebase = nullptr;
 
    if( git_rebase_init( &rebase, aHandler->GetRepo(), nullptr, aMergeHeads[0], nullptr, &rebase_opts ) )
    {
        wxString errorMsg = KIGIT_COMMON::GetLastGitError();
        aHandler->AddErrorString( wxString::Format( _( "Rebase failed to start: %s" ), errorMsg ) );
        return PullResult::MergeFailed;
    }
 
    KIGIT::GitRebasePtr rebasePtr( rebase );
 
    while( true )
    {
        git_rebase_operation* op = nullptr;
 
        if( git_rebase_next( &op, rebase ) != 0 )
            break;
 
        if( git_rebase_commit( nullptr, rebase, nullptr, nullptr, nullptr, nullptr ) )
        {
            wxString errorMsg = KIGIT_COMMON::GetLastGitError();
            aHandler->AddErrorString( wxString::Format( _( "Rebase commit failed: %s" ), errorMsg ) );
            return PullResult::MergeFailed;
        }
    }
 
    if( git_rebase_finish( rebase, nullptr ) )
    {
        wxString errorMsg = KIGIT_COMMON::GetLastGitError();
        aHandler->AddErrorString( wxString::Format( _( "Rebase finish failed: %s" ), errorMsg ) );
        return PullResult::MergeFailed;
    }
 
    return PullResult::Success;
}
 
 
static bool lookup_upstream_ref( GIT_PULL_HANDLER* aHandler, git_reference** aUpstreamRef )
{
    git_repository* repo = aHandler->GetRepo();
    git_reference*  head_ref = nullptr;
 
    if( git_repository_head( &head_ref, repo ) != GIT_OK )
        return false;
 
    KIGIT::GitReferencePtr headRefPtr( head_ref );
    wxString               remoteName = aHandler->GetCommon()->GetRemoteNameOrDefault();
    wxString remoteRef = wxString::Format( "refs/remotes/%s/%s", remoteName, git_reference_shorthand( head_ref ) );
 
    return git_reference_lookup( aUpstreamRef, repo, remoteRef.utf8_string().c_str() ) == GIT_OK;
}
 
 
bool LIBGIT_BACKEND::ResetToUpstream( GIT_PULL_HANDLER* aHandler )
{
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
        return false;
 
    std::unique_lock<std::mutex> lock( aHandler->GetCommon()->m_gitActionMutex, std::try_to_lock );
 
    if( !lock.owns_lock() )
    {
        aHandler->AddErrorString( _( "Another git operation is in progress." ) );
        return false;
    }
 
    git_reference* upstream_ref = nullptr;
 
    if( !lookup_upstream_ref( aHandler, &upstream_ref ) )
    {
        aHandler->AddErrorString( _( "Could not find the matching remote branch." ) );
        return false;
    }
 
    KIGIT::GitReferencePtr upstreamRefPtr( upstream_ref );
    git_object*            target = nullptr;
 
    if( git_reference_peel( &target, upstream_ref, GIT_OBJECT_COMMIT ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Could not read the remote branch." ) );
        return false;
    }
 
    KIGIT::GitObjectPtr targetPtr( target );
 
    if( git_reset( repo, target, GIT_RESET_HARD, nullptr ) != GIT_OK )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Could not reset to the remote branch: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return false;
    }
 
    git_repository_state_cleanup( repo );
    return true;
}
 
 
PullResult LIBGIT_BACKEND::RebaseOntoUpstream( GIT_PULL_HANDLER* aHandler )
{
    git_repository* repo = aHandler->GetRepo();
 
    if( !repo )
        return PullResult::Error;
 
    std::unique_lock<std::mutex> lock( aHandler->GetCommon()->m_gitActionMutex, std::try_to_lock );
 
    if( !lock.owns_lock() )
    {
        aHandler->AddErrorString( _( "Another git operation is in progress." ) );
        return PullResult::Error;
    }
 
    if( hasUnstagedChanges( repo ) )
    {
        aHandler->AddErrorString( _( "Cannot rebase: you have unstaged changes.  Please commit "
                                     "or stash them first." ) );
        return PullResult::DirtyWorkdir;
    }
 
    git_reference* upstream_ref = nullptr;
 
    if( !lookup_upstream_ref( aHandler, &upstream_ref ) )
    {
        aHandler->AddErrorString( _( "Could not find the matching remote branch." ) );
        return PullResult::Error;
    }
 
    KIGIT::GitReferencePtr upstreamRefPtr( upstream_ref );
    git_annotated_commit*  onto = nullptr;
 
    if( git_annotated_commit_from_ref( &onto, repo, upstream_ref ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Could not read the remote branch." ) );
        return PullResult::Error;
    }
 
    KIGIT::GitAnnotatedCommitPtr ontoPtr( onto );
    git_signature*               signature = nullptr;
 
    if( git_signature_default( &signature, repo ) != GIT_OK )
    {
        aHandler->AddErrorString( _( "Could not create a commit signature.  Set user.name and "
                                     "user.email in your git configuration." ) );
        return PullResult::Error;
    }
 
    KIGIT::GitSignaturePtr signaturePtr( signature );
    git_rebase_options     rebase_opts;
    git_rebase_init_options( &rebase_opts, GIT_REBASE_OPTIONS_VERSION );
    git_rebase* rebase = nullptr;
 
    if( git_rebase_init( &rebase, repo, nullptr, onto, nullptr, &rebase_opts ) != GIT_OK )
    {
        aHandler->AddErrorString(
                wxString::Format( _( "Rebase failed to start: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return PullResult::Error;
    }
 
    KIGIT::GitRebasePtr   rebasePtr( rebase );
    git_rebase_operation* op = nullptr;
 
    while( git_rebase_next( &op, rebase ) == GIT_OK )
    {
        git_index* index = nullptr;
 
        if( git_repository_index( &index, repo ) == GIT_OK )
        {
            KIGIT::GitIndexPtr indexPtr( index );
 
            if( git_index_has_conflicts( index ) )
            {
                git_rebase_abort( rebase );
                aHandler->AddErrorString( _( "The rebase ran into conflicts.  This is best "
                                             "resolved from a git command line." ) );
                return PullResult::Conflict;
            }
        }
 
        git_oid commit_oid;
 
        if( git_rebase_commit( &commit_oid, rebase, nullptr, signature, nullptr, nullptr ) != GIT_OK )
        {
            git_rebase_abort( rebase );
            aHandler->AddErrorString( _( "The rebase ran into conflicts.  This is best "
                                         "resolved from a git command line." ) );
            return PullResult::Conflict;
        }
    }
 
    if( git_rebase_finish( rebase, signature ) != GIT_OK )
    {
        git_rebase_abort( rebase );
        aHandler->AddErrorString(
                wxString::Format( _( "Rebase finish failed: %s" ), KIGIT_COMMON::GetLastGitError() ) );
        return PullResult::Error;
    }
 
    return PullResult::Success;
}
 
 
void LIBGIT_BACKEND::PerformRevert( GIT_REVERT_HANDLER* aHandler )
{
    git_object* head_commit = NULL;
    git_checkout_options opts;
    git_checkout_init_options( &opts, GIT_CHECKOUT_OPTIONS_VERSION );
 
    if( git_revparse_single( &head_commit, aHandler->m_repository, "HEAD" ) != 0 )
    {
        return;
    }
 
    opts.checkout_strategy = GIT_CHECKOUT_FORCE;
    char** paths = new char*[aHandler->m_filesToRevert.size()];
 
    for( size_t ii = 0; ii < aHandler->m_filesToRevert.size(); ii++ )
    {
        paths[ii] = wxStrdup( aHandler->m_filesToRevert[ii].ToUTF8() );
    }
 
    git_strarray arr = { paths, aHandler->m_filesToRevert.size() };
 
    opts.paths = arr;
    opts.progress_cb = nullptr;
    opts.notify_cb = nullptr;
    opts.notify_payload = static_cast<void*>( aHandler );
 
    if( git_checkout_tree( aHandler->m_repository, head_commit, &opts ) != 0 )
    {
        const git_error* e = git_error_last();
 
        if( e )
        {
            wxLogTrace( traceGit, wxS( "Checkout failed: %d: %s" ), e->klass, e->message );
        }
    }
 
    for( size_t ii = 0; ii < aHandler->m_filesToRevert.size(); ii++ )
        delete( paths[ii] );
 
    delete[] paths;
 
    git_object_free( head_commit );
}
 
 
git_repository* LIBGIT_BACKEND::GetRepositoryForFile( const char* aFilename )
{
    git_repository* repo = nullptr;
    git_buf repo_path = GIT_BUF_INIT;
 
    if( git_repository_discover( &repo_path, aFilename, 0, nullptr ) != GIT_OK )
    {
        wxLogTrace( traceGit, "Can't repo discover %s: %s", aFilename,
                    KIGIT_COMMON::GetLastGitError() );
        return nullptr;
    }
 
    KIGIT::GitBufPtr repo_path_ptr( &repo_path );
 
    if( git_repository_open( &repo, repo_path.ptr ) != GIT_OK )
    {
        wxLogTrace( traceGit, "Can't open repo for %s: %s", repo_path.ptr,
                    KIGIT_COMMON::GetLastGitError() );
        return nullptr;
    }
 
    return repo;
}
 
 
int LIBGIT_BACKEND::CreateBranch( git_repository* aRepo, const wxString& aBranchName )
{
    git_oid head_oid;
 
    if( int error = git_reference_name_to_id( &head_oid, aRepo, "HEAD" ); error != GIT_OK )
    {
        wxLogTrace( traceGit, "Failed to lookup HEAD reference: %s",
                    KIGIT_COMMON::GetLastGitError() );
        return error;
    }
 
    git_commit* commit = nullptr;
 
    if( int error = git_commit_lookup( &commit, aRepo, &head_oid ); error != GIT_OK )
    {
        wxLogTrace( traceGit, "Failed to lookup commit: %s",
                    KIGIT_COMMON::GetLastGitError() );
        return error;
    }
 
    KIGIT::GitCommitPtr commitPtr( commit );
    git_reference* branchRef = nullptr;
 
    if( int error = git_branch_create( &branchRef, aRepo, aBranchName.mb_str(), commit, 0 ); error != GIT_OK )
    {
        wxLogTrace( traceGit, "Failed to create branch: %s",
                    KIGIT_COMMON::GetLastGitError() );
        return error;
    }
 
    git_reference_free( branchRef );
    return 0;
}
 
 
bool LIBGIT_BACKEND::RemoveVCS( git_repository*& aRepo, const wxString& aProjectPath,
                                bool aRemoveGitDir, wxString* aErrors )
{
    if( aRepo )
    {
        git_repository_free( aRepo );
        aRepo = nullptr;
    }
 
    if( aRemoveGitDir )
    {
        wxFileName gitDir( aProjectPath, wxEmptyString );
        gitDir.AppendDir( ".git" );
 
        if( gitDir.DirExists() )
        {
            wxString errors;
 
            if( !RmDirRecursive( gitDir.GetPath(), &errors ) )
            {
                if( aErrors )
                    *aErrors = errors;
 
                wxLogTrace( traceGit, "Failed to remove .git directory: %s", errors );
                return false;
            }
        }
    }
 
    wxLogTrace( traceGit, "Successfully removed VCS from project" );
    return true;
}
 
 
bool LIBGIT_BACKEND::AddToIndex( GIT_ADD_TO_INDEX_HANDLER* aHandler, const wxString& aFilePath )
{
    git_repository* repo = aHandler->GetRepo();
 
    git_index* index = nullptr;
    size_t     at_pos = 0;
 
    if( git_repository_index( &index, repo ) != 0 )
    {
        wxLogError( "Failed to get repository index" );
        return false;
    }
 
    KIGIT::GitIndexPtr indexPtr( index );
 
    if( git_index_find( &at_pos, index, aFilePath.ToUTF8().data() ) == GIT_OK )
    {
        wxLogError( "%s already in index", aFilePath );
        return false;
    }
 
    aHandler->m_filesToAdd.push_back( aFilePath );
    return true;
}
 
 
bool LIBGIT_BACKEND::PerformAddToIndex( GIT_ADD_TO_INDEX_HANDLER* aHandler )
{
    git_repository* repo = aHandler->GetRepo();
    git_index* index = nullptr;
 
    aHandler->m_filesFailedToAdd.clear();
 
    if( git_repository_index( &index, repo ) != 0 )
    {
        wxLogError( "Failed to get repository index" );
        std::copy( aHandler->m_filesToAdd.begin(), aHandler->m_filesToAdd.end(),
                   std::back_inserter( aHandler->m_filesFailedToAdd ) );
        return false;
    }
 
    KIGIT::GitIndexPtr indexPtr( index );
 
    for( auto& file : aHandler->m_filesToAdd )
    {
        if( git_index_add_bypath( index, file.ToUTF8().data() ) != 0 )
        {
            wxLogError( "Failed to add %s to index", file );
            aHandler->m_filesFailedToAdd.push_back( file );
            continue;
        }
    }
 
    if( git_index_write( index ) != 0 )
    {
        wxLogError( "Failed to write index" );
        aHandler->m_filesFailedToAdd.clear();
        std::copy( aHandler->m_filesToAdd.begin(), aHandler->m_filesToAdd.end(),
                   std::back_inserter( aHandler->m_filesFailedToAdd ) );
        return false;
    }
 
    return true;
}
 
 
bool LIBGIT_BACKEND::RemoveFromIndex( GIT_REMOVE_FROM_INDEX_HANDLER* aHandler, const wxString& aFilePath )
{
    git_repository* repo = aHandler->GetRepo();
    git_index*      index = nullptr;
    size_t          at_pos = 0;
 
    if( git_repository_index( &index, repo ) != 0 )
    {
        wxLogError( "Failed to get repository index" );
        return false;
    }
 
    KIGIT::GitIndexPtr indexPtr( index );
 
    if( git_index_find( &at_pos, index, aFilePath.ToUTF8().data() ) != 0 )
    {
        wxLogError( "Failed to find index entry for %s", aFilePath );
        return false;
    }
 
    aHandler->m_filesToRemove.push_back( aFilePath );
    return true;
}
 
 
void LIBGIT_BACKEND::PerformRemoveFromIndex( GIT_REMOVE_FROM_INDEX_HANDLER* aHandler )
{
    git_repository* repo = aHandler->GetRepo();
 
    for( auto& file : aHandler->m_filesToRemove )
    {
        git_index* index = nullptr;
        git_oid    oid;
 
        if( git_repository_index( &index, repo ) != 0 )
        {
            wxLogError( "Failed to get repository index" );
            return;
        }
 
        KIGIT::GitIndexPtr indexPtr( index );
 
        if( git_index_remove_bypath( index, file.ToUTF8().data() ) != 0 )
        {
            wxLogError( "Failed to remove index entry for %s", file );
            return;
        }
 
        if( git_index_write( index ) != 0 )
        {
            wxLogError( "Failed to write index" );
            return;
        }
 
        if( git_index_write_tree( &oid, index ) != 0 )
        {
            wxLogError( "Failed to write index tree" );
            return;
        }
    }
}