// Copyright (c) 2025 TerraByte Inc.
//
// A new internal class that contains the concrete implementation logic for
// all Git operations. This separates the "how" from the "what" defined
// in the public GitService API.

using System;
using System.IO;
using System.Linq;
using UnityEngine;
using System.Text;
using LibGit2Sharp;
using System.Globalization;
using System.ComponentModel;
using UnityEngine.Scripting;
using System.Threading.Tasks;
using Terra.Arbitrator.Settings;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace Terra.Arbitrator.Services
{
    /// <summary>
    /// A simple data container for branch information.
    /// </summary>
    [Preserve]
    public class BranchData
    {
        public string CurrentBranch { get; set; }
        public List<string> AllBranches { get; set; }
    }
    
    /// <summary>
    /// Contains the promise executor methods for all Git operations.
    /// This is an internal implementation detail and is not exposed publicly.
    /// </summary>
    [Preserve]
    internal static class GitExecutors
    {
        private static string _projectRoot;
        private static string ProjectRoot => _projectRoot ??= MainThreadDataCache.ProjectRoot;
        private const string StashMessage = "Better Git Stash";
        
        private static string GetAuthenticatedRemoteUrl()
        {
            var authUsername = BetterGitSettings.AuthUsername;
            var authPassword = BetterGitSettings.AuthPassword;

            if (string.IsNullOrEmpty(authUsername) || string.IsNullOrEmpty(authPassword))
            {
                return "origin";
            }
            
            using var repo = new Repository(ProjectRoot);
            var remote = repo.Network.Remotes["origin"];
            if (remote == null) throw new Exception("No remote named 'origin' found.");
            
            var originalUrl = remote.Url;

            var authenticatedUrl = Regex.Replace(originalUrl, 
                "://", 
                $"://{Uri.EscapeDataString(authUsername)}:{Uri.EscapeDataString(authPassword)}@");

            return authenticatedUrl;
        }
        
        public static void HasStashExecutor(Action<bool> resolve, Action<Exception> reject)
        {
            try
            {
                using var repo = new Repository(ProjectRoot);
                var stashExists = repo.Stashes.Any(s => s.Message.Contains(StashMessage));
                resolve(stashExists);
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }

        public static async void CreateOrOverwriteStashExecutor(Action<string> resolve, Action<Exception> reject, List<GitChange> changes)
        {
            try
            {
                var log = new StringBuilder();

                using (var repo = new Repository(ProjectRoot))
                {
                    var existingStash = repo.Stashes.FirstOrDefault(s => s.Message.Contains(StashMessage));
                    if (existingStash != null)
                    {
                        repo.Stashes.Remove(repo.Stashes.ToList().IndexOf(existingStash));
                        log.AppendLine("Dropped existing 'Better Git Stash'.");
                    }
                }

                var untrackedFiles = new List<string>();
                
                using (var repo = new Repository(ProjectRoot))
                {
                    foreach (var change in changes)
                    {
                        var statusEntry = repo.RetrieveStatus(change.FilePath);
                        if (statusEntry == FileStatus.NewInWorkdir)
                        {
                            untrackedFiles.Add(change.FilePath);
                        }
                    }
                }

                if (untrackedFiles.Any())
                {
                    foreach (var file in untrackedFiles)
                    {
                        await GitCommand.RunGitAsync(log, new[] { "add", file });
                    }
                    log.AppendLine($"Staged {untrackedFiles.Count} untracked files.");
                }

                var allFiles = changes.Select(c => c.FilePath).ToList();
                if (allFiles.Any())
                {
                    var stashArgs = new List<string> { "stash", "push", "-m", StashMessage, "--" };
                    stashArgs.AddRange(allFiles);
                    
                    await GitCommand.RunGitAsync(log, stashArgs.ToArray());
                }
                else
                {
                    throw new Exception("No files to stash.");
                }
                
                resolve("Successfully created new 'Better Git Stash'.");
            }
            catch (Exception ex)
            {
                Debug.LogException(ex);
                reject(ex);
            }
        }
        
        public static void DropStashExecutor(Action<string> resolve, Action<Exception> reject)
        {
            try
            {
                using var repo = new Repository(ProjectRoot);
                var stash = repo.Stashes.FirstOrDefault(s => s.Message.Contains(StashMessage));
                if (stash != null)
                {
                    repo.Stashes.Remove(repo.Stashes.ToList().IndexOf(stash));
                    resolve("'Better Git Stash' has been discarded.");
                }
                else
                {
                    resolve("No 'Better Git Stash' found to discard.");
                }
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }
        
        public static void GetStashedFilesExecutor(Action<List<GitChange>> resolve, Action<Exception> reject)
        {
            try
            {
                using var repo = new Repository(ProjectRoot);
                var stash = repo.Stashes.FirstOrDefault(s => s.Message.Contains(StashMessage));
                if (stash == null)
                {
                    resolve(new List<GitChange>());
                    return;
                }
        
                var changes = new List<GitChange>();
        
                var stashChanges = repo.Diff.Compare<TreeChanges>(stash.Base.Tree, stash.WorkTree.Tree);
                foreach (var change in stashChanges)
                {
                    changes.Add(new GitChange(change.Path, change.OldPath, change.Status));
                }
        
                var indexChanges = repo.Diff.Compare<TreeChanges>(stash.Base.Tree, stash.Index.Tree);
                foreach (var change in indexChanges)
                {
                    if (changes.All(c => c.FilePath != change.Path))
                    {
                        changes.Add(new GitChange(change.Path, change.OldPath, change.Status));
                    }
                }
        
                resolve(changes);
            }
            catch(Exception ex)
            {
                reject(ex);
            }
        }

        public static async void DiffStashedFileExecutor(Action<string> resolve, Action<Exception> reject, GitChange change)
        {
            string fileAPath = null;
            string fileBPath = null;
            
            try
            {
                using var repo = new Repository(ProjectRoot);
                var stash = repo.Stashes.FirstOrDefault(s => s.Message.Contains(StashMessage));
                if (stash == null) throw new Exception("'Better Git Stash' not found.");

                var stashedTree = stash.WorkTree.Tree; 
                var baseTree = stash.Base.Tree; 

                switch (change.Status)
                {
                    case ChangeKind.Added:
                        fileAPath = CreateTempFileWithContent("", "empty");
                        fileBPath = CreateTempFileFromBlob(stashedTree[change.FilePath]?.Target as Blob, change.FilePath);
                        break;
                    
                    case ChangeKind.Deleted:
                        fileAPath = CreateTempFileFromBlob(baseTree[change.FilePath]?.Target as Blob, change.FilePath);
                        fileBPath = CreateTempFileWithContent("", change.FilePath);
                        break;

                    case ChangeKind.Renamed:
                        fileAPath = CreateTempFileFromBlob(baseTree[change.OldFilePath]?.Target as Blob, change.OldFilePath);
                        fileBPath = Path.Combine(ProjectRoot, change.FilePath);
                        break;

                    default:
                        fileAPath = CreateTempFileFromBlob(stashedTree[change.FilePath]?.Target as Blob, change.FilePath);
                        fileBPath = Path.Combine(ProjectRoot, change.FilePath);
                        break;
                }

                if (!File.Exists(fileBPath))
                {
                    fileBPath = CreateTempFileWithContent("", Path.GetFileName(fileBPath));
                }

                await GitCommand.RunVsCodeAsync(new StringBuilder(), new[] { "--diff", fileAPath, fileBPath });
                resolve("Launched external diff tool.");
            }
            catch (Exception ex)
            {
                reject(ex);
            }
            finally
            {
                if (fileAPath != null && fileAPath.Contains(Path.GetTempPath())) File.Delete(fileAPath);
                if (fileBPath != null && fileBPath.Contains(Path.GetTempPath())) File.Delete(fileBPath);
            }
        }
        
        public static void AnalyzeStashConflictsExecutor(Action<PullAnalysisResult> resolve, Action<Exception> reject)
        {
            try
            {
                using var repo = new Repository(ProjectRoot);
                var stash = repo.Stashes.FirstOrDefault(s => s.Message.Contains(StashMessage));
                if (stash == null)
                {
                    resolve(new PullAnalysisResult(new List<string>()));
                    return;
                }

                var workTreeChanges = repo.Diff.Compare<TreeChanges>(stash.Base.Tree, stash.WorkTree.Tree).Select(c => c.Path);
                var indexChanges = repo.Diff.Compare<TreeChanges>(stash.Base.Tree, stash.Index.Tree).Select(c => c.Path);
                var stashedChanges = new HashSet<string>(workTreeChanges.Union(indexChanges));

                var localChanges = new HashSet<string>(repo.RetrieveStatus().Where(s => s.State != FileStatus.Ignored).Select(s => s.FilePath));

                var conflictingFiles = stashedChanges.Intersect(localChanges).ToList();
                
                resolve(new PullAnalysisResult(conflictingFiles));
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }

        public static async void ApplyStashAndOverwriteExecutor(Action<string> resolve, Action<Exception> reject, List<GitChange> resolutions)
        {
            var tempFiles = new Dictionary<string, string>();
            var log = new StringBuilder();
            try
            {
                foreach (var resolution in resolutions.Where(r => r.Resolution == GitChange.ConflictResolution.Mine))
                {
                    var fullPath = Path.Combine(ProjectRoot, resolution.FilePath);
                    if (File.Exists(fullPath))
                    {
                        var tempPath = Path.GetTempFileName();
                        File.Copy(fullPath, tempPath, true);
                        tempFiles[resolution.FilePath] = tempPath;
                    }
                }

                using (var repo = new Repository(ProjectRoot))
                {
                    var filesToReset = resolutions.Where(r => r.Resolution != GitChange.ConflictResolution.None).Select(r => r.FilePath).ToArray();
                    if (filesToReset.Any())
                    {
                        repo.CheckoutPaths(repo.Head.Tip.Sha, filesToReset, new CheckoutOptions { CheckoutModifiers = CheckoutModifiers.Force });
                    }
                }
                
                await GitCommand.RunGitAsync(log, new[] { "stash", "apply" });

                foreach (var entry in tempFiles)
                {
                    var finalPath = Path.Combine(ProjectRoot, entry.Key);
                    File.Copy(entry.Value, finalPath, true);
                    await GitCommand.RunGitAsync(log, new[] { "add", entry.Key });
                }

                await GitCommand.RunGitAsync(log, new[] { "stash", "drop" });

                resolve("Stash applied successfully and has been dropped.");
            }
            catch (Exception ex)
            {
                reject(new Exception($"Failed to apply stash. You may need to resolve conflicts manually. Details: {ex.Message}"));
            }
            finally
            {
                foreach (var tempFile in tempFiles.Values.Where(File.Exists))
                {
                    File.Delete(tempFile);
                }
            }
        }
        
        public static void GetBranchDataExecutor(Action<BranchData> resolve, Action<Exception> reject)
        {
            try
            {
                using var repo = new Repository(ProjectRoot);
                var data = new BranchData
                {
                    CurrentBranch = repo.Head.FriendlyName,
                    AllBranches = repo.Branches
                                      .Where(b => !b.FriendlyName.Contains("HEAD"))
                                      .Select(b => b.FriendlyName.Replace("origin/", ""))
                                      .Distinct()
                                      .OrderBy(name => name)
                                      .ToList()
                };
                resolve(data);
            }
            catch(Exception ex)
            {
                reject(ex);
            }
        }
        
        public static async void SwitchBranchExecutor(Action<string> resolve, Action<Exception> reject, string branchName)
        {
            try
            {
                var log = new StringBuilder();
                await GitCommand.RunGitAsync(log, new[] { "checkout", branchName });
                resolve($"Successfully switched to branch '{branchName}'.");
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }
        
        public static async void ResetAndSwitchBranchExecutor(Action<string> resolve, Action<Exception> reject, string branchName)
        {
            try
            {
                var log = new StringBuilder();
                await GitCommand.RunGitAsync(log, new[] { "reset", "--hard", "HEAD" });
                await GitCommand.RunGitAsync(log, new[] { "clean", "-fd" });
                await GitCommand.RunGitAsync(log, new[] { "checkout", branchName });
                resolve($"Discarded local changes and switched to branch '{branchName}'.");
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }
        
        /// <summary>
        /// Synchronous helper to get a GitChange object for a single file.
        /// This is public so it can be called by the GitService wrapper.
        /// </summary>
        public static GitChange GetChangeForFile(string filePath)
        {
            try
            {
                using var repo = new Repository(ProjectRoot);
                
                if (repo.Index.Conflicts.Any(c => c.Ours.Path == filePath))
                {
                    return new GitChange(filePath, null, ChangeKind.Conflicted);
                }

                var statusEntry = repo.RetrieveStatus(filePath);

                return statusEntry switch
                {
                    FileStatus.NewInWorkdir or FileStatus.NewInIndex => new GitChange(filePath, null, ChangeKind.Added),
                    FileStatus.ModifiedInWorkdir or FileStatus.ModifiedInIndex => new GitChange(filePath, null, ChangeKind.Modified),
                    FileStatus.DeletedFromWorkdir or FileStatus.DeletedFromIndex => new GitChange(filePath, null, ChangeKind.Deleted),
                    FileStatus.RenamedInWorkdir or FileStatus.RenamedInIndex =>
                        new GitChange(filePath, null, ChangeKind.Renamed),
                    _ => null
                };
            }
            catch { return null; } // Suppress errors if repo is in a unique state
        }
        
        // --- Promise Executor Implementations ---
        
        public static async void GetUpstreamAheadByExecutor(Action<int?> resolve, Action<Exception> reject, Action<float, string> onProgress)
        {
            try
            {
                string refSpec;
                
                using (var tempRepo = new Repository(ProjectRoot))
                {
                    var currentBranch = tempRepo.Head;
                    if (currentBranch.TrackedBranch == null)
                    {
                        resolve(0);
                        return;
                    }
                    var branchName = currentBranch.FriendlyName;
                    var remoteName = currentBranch.TrackedBranch.RemoteName;
                    refSpec = $"{branchName}:refs/remotes/{remoteName}/{branchName}";
                }
                
                var authenticatedUrl = GetAuthenticatedRemoteUrl();
                var progressReporter = new Progress<string>(line => ParseProgress(line, onProgress));
                await GitCommand.RunGitAsync(new StringBuilder(), new[] { "fetch", authenticatedUrl, refSpec, "--progress" }, progressReporter);

                using var repo = new Repository(ProjectRoot);
                resolve(repo.Head.TrackingDetails.BehindBy);
            }
            catch (Exception ex)
            {
                if (ex.Message.Contains("is not tracking a remote branch"))
                {
                    resolve(null);
                }
                else
                {
                    reject(ex);
                }
            }
        }

        public static void GetLocalStatusExecutor(Action<List<GitChange>> resolve, Action<Exception> reject)
        {
            try
            {
                var changes = new List<GitChange>();
                using var repo = new Repository(ProjectRoot);
                
                var conflictedPaths = new HashSet<string>(repo.Index.Conflicts.Select(c => c.Ours.Path));

                var statusOptions = new StatusOptions
                {
                    IncludeUntracked = true, 
                    RecurseUntrackedDirs = true,
                    DetectRenamesInIndex = true,
                    DetectRenamesInWorkDir = true
                };
                foreach (var entry in repo.RetrieveStatus(statusOptions))
                {
                    if (conflictedPaths.Contains(entry.FilePath))
                    {
                        if (changes.All(c => c.FilePath != entry.FilePath))
                        {
                           changes.Add(new GitChange(entry.FilePath, null, ChangeKind.Conflicted));
                        }
                        continue;
                    }
                    switch(entry.State)
                    {
                        case FileStatus.NewInWorkdir:
                        case FileStatus.NewInIndex:
                            changes.Add(new GitChange(entry.FilePath, null, ChangeKind.Added));
                            break;
                        
                        case FileStatus.ModifiedInWorkdir:
                        case FileStatus.ModifiedInIndex:
                            changes.Add(new GitChange(entry.FilePath, null, ChangeKind.Modified));
                            break;

                        case FileStatus.DeletedFromWorkdir:
                        case FileStatus.DeletedFromIndex:
                            changes.Add(new GitChange(entry.FilePath, null, ChangeKind.Deleted));
                            break;

                        case FileStatus.RenamedInWorkdir:
                        case FileStatus.RenamedInIndex:
                            var renameDetails = entry.HeadToIndexRenameDetails ?? entry.IndexToWorkDirRenameDetails;
                            changes.Add(renameDetails != null ? new GitChange(renameDetails.NewFilePath, renameDetails.OldFilePath, ChangeKind.Renamed)
                                : new GitChange(entry.FilePath, "Unknown", ChangeKind.Renamed));
                            break;
                    }
                }
                
                resolve(changes);
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }
        
        public static async void CommitAndPushExecutor(Action<string> resolve, Action<Exception> reject, List<GitChange> changesToCommit, string commitMessage, string username, string email, Action<float, string> onProgress)
        {
            try
            {
                if (string.IsNullOrWhiteSpace(email))
                {
                    throw new Exception("Author email is missing. Please set your email address in Project Settings > Better Git.");
                }
                
                var authenticatedUrl = GetAuthenticatedRemoteUrl();
                await GitCommand.RunGitAsync(new StringBuilder(), new[] { "fetch", authenticatedUrl });
                
                using (var repo = new Repository(ProjectRoot))
                {
                    var remote = repo.Network.Remotes["origin"];
                    if (remote == null) throw new Exception("No remote named 'origin' found.");

                    var trackingDetails = repo.Head.TrackingDetails;
                    if (trackingDetails.BehindBy > 0)
                    {
                        throw new Exception($"Push aborted. There are {trackingDetails.BehindBy.Value} incoming changes on the remote. Please pull first.");
                    }

                    var pathsToStage = new List<string>();
                    foreach (var change in changesToCommit)
                    {
                        switch (change.Status)
                        {
                            case ChangeKind.Deleted:
                                Commands.Remove(repo, change.FilePath);
                                break;
                            case ChangeKind.Renamed:
                                Commands.Remove(repo, change.OldFilePath);
                                pathsToStage.Add(change.FilePath);
                                break;
                            default:
                                pathsToStage.Add(change.FilePath);
                                break;
                        }
                    }
                    if (pathsToStage.Any()) Commands.Stage(repo, pathsToStage);

                    var status = repo.RetrieveStatus();
                    if (!status.IsDirty) throw new Exception("No effective changes were staged to commit.");
                    
                    var author = new Signature(username, email, DateTimeOffset.Now);
                    repo.Commit(commitMessage, author, author);
                }

                var progressReporter = new Progress<string>(line => ParseProgress(line, onProgress));
                using var tempRepo = new Repository(ProjectRoot);
                var currentBranch = tempRepo.Head.FriendlyName;
                await GitCommand.RunGitAsync(new StringBuilder(), new[] { "push", "--progress", authenticatedUrl, $"HEAD:{currentBranch}" }, progressReporter, 0, 141);

                resolve("Successfully committed and pushed changes!");
            }
            catch (Exception ex)
            {
                var errorMessage = ex.InnerException?.Message ?? ex.Message;
                reject(new Exception(errorMessage));
            }
        }
        
        private static void ParseProgress(string line, Action<float, string> onProgress)
        {
            if (onProgress == null || string.IsNullOrWhiteSpace(line)) return;

            line = line.Trim();
            var parts = line.Split(new[] { ':' }, 2);
            if (parts.Length < 2) return;

            var action = parts[0];
            var progressPart = parts[1];
            
            var percentIndex = progressPart.IndexOf('%');
            if (percentIndex == -1) return;

            var percentString = progressPart[..percentIndex].Trim();
            if (!float.TryParse(percentString, NumberStyles.Any, CultureInfo.InvariantCulture, out var percentage)) return;
            var progressValue = percentage / 100.0f;
            onProgress(progressValue, $"{action}...");
        }

        public static void ResetFileExecutor(Action<string> resolve, Action<Exception> reject, GitChange changeToReset)
        {
            try
            {
                using var repo = new Repository(ProjectRoot);

                switch (changeToReset.Status)
                {
                    case ChangeKind.Added:
                    {
                        Commands.Unstage(repo, changeToReset.FilePath);
                    
                        var fullPath = Path.Combine(ProjectRoot, changeToReset.FilePath);
                        if (File.Exists(fullPath))
                        {
                            File.Delete(fullPath);
                        }

                        break;
                    }
                    case ChangeKind.Renamed:
                    {
                        Commands.Unstage(repo, changeToReset.FilePath);
                        var newFullPath = Path.Combine(ProjectRoot, changeToReset.FilePath);
                        if (File.Exists(newFullPath)) File.Delete(newFullPath);
                    
                        repo.CheckoutPaths(repo.Head.Tip.Sha, new[] { changeToReset.OldFilePath }, new CheckoutOptions { CheckoutModifiers = CheckoutModifiers.Force });
                        break;
                    }
                    default:
                        repo.CheckoutPaths(repo.Head.Tip.Sha, new[] { changeToReset.FilePath }, new CheckoutOptions { CheckoutModifiers = CheckoutModifiers.Force });
                        break;
                }

                resolve($"Successfully reset changes for '{changeToReset.FilePath}'");
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }
        
        public static async void LaunchExternalDiffExecutor(Action<string> resolve, Action<Exception> reject, GitChange change)
        {
            string fileAPath = null; // Before
            string fileBPath = null; // After
            
            try
            {
                using var repo = new Repository(ProjectRoot);
                
                string GetFileContentFromHead(string path)
                {
                    var blob = repo.Head.Tip[path]?.Target as Blob;
                    return blob?.GetContentText() ?? "";
                }

                string CreateTempFile(string originalPath, string content)
                {
                    var tempPath = Path.Combine(Path.GetTempPath(), Guid.NewGuid() + Path.GetExtension(originalPath));
                    File.WriteAllText(tempPath, content);
                    return tempPath;
                }

                switch (change.Status)
                {
                    case ChangeKind.Added:
                        fileAPath = CreateTempFile(change.FilePath, ""); 
                        fileBPath = Path.Combine(ProjectRoot, change.FilePath);
                        break;
                    
                    case ChangeKind.Deleted:
                        fileAPath = CreateTempFile(change.FilePath, GetFileContentFromHead(change.FilePath));
                        fileBPath = CreateTempFile(change.FilePath, "");
                        break;

                    case ChangeKind.Renamed:
                         fileAPath = CreateTempFile(change.OldFilePath, GetFileContentFromHead(change.OldFilePath));
                         fileBPath = Path.Combine(ProjectRoot, change.FilePath);
                        break;
                    
                    default: // Modified
                        fileAPath = CreateTempFile(change.FilePath, GetFileContentFromHead(change.FilePath));
                        fileBPath = Path.Combine(ProjectRoot, change.FilePath);
                        break;
                }
                
                await GitCommand.RunVsCodeAsync(new StringBuilder(), new[] { "--diff", fileAPath, fileBPath });

                resolve("Launched external diff tool.");
            }
            catch(Win32Exception ex)
            {
                reject(new Exception("Could not launch VS Code. Ensure it is installed and the 'code' command is available in your system's PATH.", ex));
            }
            catch(Exception ex)
            {
                reject(ex);
            }
            finally
            {
                try
                {
                    if (fileAPath != null && fileAPath.Contains(Path.GetTempPath()) && File.Exists(fileAPath)) File.Delete(fileAPath);
                    if (fileBPath != null && fileBPath.Contains(Path.GetTempPath()) && File.Exists(fileBPath)) File.Delete(fileBPath);
                }
                catch(Exception cleanupEx)
                {
                    Debug.LogError($"Failed to clean up temporary diff files: {cleanupEx.Message}");
                }
            }
        }
        
        public static void FileLevelConflictCheckExecutor(Action<PullAnalysisResult> resolve, Action<Exception> reject)
        {
            try
            {
                using var repo = new Repository(ProjectRoot);
                var result = AnalyzePullConflictsInternal(repo).Result;
                resolve(result);
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }

        private static Task<PullAnalysisResult> AnalyzePullConflictsInternal(Repository repo)
        {
            var remote = repo.Network.Remotes["origin"];
            if (remote == null) throw new Exception("No remote named 'origin' was found.");
            
            var localBranch = repo.Head;
            var remoteBranch = repo.Head.TrackedBranch;
            if (remoteBranch == null) throw new Exception("Current branch is not tracking a remote branch.");
            
            var mergeBase = repo.ObjectDatabase.FindMergeBase(localBranch.Tip, remoteBranch.Tip);
            if (mergeBase == null) throw new Exception("Could not find a common ancestor.");
            
            var theirChanges = new HashSet<string>(repo.Diff.Compare<TreeChanges>(mergeBase.Tree, remoteBranch.Tip.Tree).Select(c => c.Path));
            var ourChanges = new HashSet<string>(repo.Diff.Compare<TreeChanges>(mergeBase.Tree, localBranch.Tip.Tree).Select(c => c.Path));
            foreach (var statusEntry in repo.RetrieveStatus()) ourChanges.Add(statusEntry.FilePath);
            
            return Task.FromResult(new PullAnalysisResult(ourChanges.Where(theirChanges.Contains).ToList()));
        }

        public static async void SafePullExecutor(Action<string> resolve, Action<Exception> reject)
        {
            try
            {
                var authenticatedUrl = GetAuthenticatedRemoteUrl();
                var log = new StringBuilder();
                
                string currentBranchName;
                using (var repo = new Repository(ProjectRoot))
                {
                    currentBranchName = repo.Head.FriendlyName;
                }

                await GitCommand.RunGitAsync(log, new[] { "pull", "--no-rebase", authenticatedUrl, currentBranchName }, 0, 141);
                
                resolve(log.ToString());
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }
        
        public static async void PullAndOverwriteExecutor(Action<string> resolve, Action<Exception> reject, List<GitChange> resolutions)
        {
            var tempFiles = new Dictionary<string, string>();
            var log = new StringBuilder();
            try
            {
                foreach (var resolution in resolutions.Where(r => r.Resolution == GitChange.ConflictResolution.Mine))
                {
                    var fullPath = Path.Combine(ProjectRoot, resolution.FilePath);
                    var tempPath = Path.GetTempFileName();
                    File.Copy(fullPath, tempPath, true);
                    tempFiles[resolution.FilePath] = tempPath;
                }

                using (var repo = new Repository(ProjectRoot))
                {
                    var filesToReset = resolutions.Where(r => r.Resolution != GitChange.ConflictResolution.None).Select(r => r.FilePath).ToArray();
                    if(filesToReset.Length > 0)
                    {
                        repo.CheckoutPaths(repo.Head.Tip.Sha, filesToReset, new CheckoutOptions { CheckoutModifiers = CheckoutModifiers.Force });
                    }
                }

                await GitCommand.RunGitAsync(log, new[] { "pull", "--no-rebase" }, 0, 1, 141);

                foreach (var entry in tempFiles)
                {
                    var finalPath = Path.Combine(ProjectRoot, entry.Key);
                    File.Copy(entry.Value, finalPath, true);
                    await GitCommand.RunGitAsync(log, new[] { "add", entry.Key });
                }

                var unresolvedFiles = resolutions.Where(r => r.Resolution == GitChange.ConflictResolution.None).ToList();
                if (unresolvedFiles.Any())
                {
                    var fileList = string.Join(", ", unresolvedFiles.Select(f => f.FilePath));
                    resolve($"Pull completed with unresolved conflicts in: {fileList}. Please resolve them manually.");
                }
                else
                {
                    resolve("Pull successful. Your chosen local changes have been preserved.");
                }
            }
            catch (Exception ex)
            {
                reject(ex);
            }
            finally
            {
                foreach (var tempFile in tempFiles.Values.Where(File.Exists))
                {
                    File.Delete(tempFile);
                }
            }
        }
        
        public static async void LaunchMergeToolExecutor(Action<string> resolve, Action<Exception> reject, GitChange change)
        {
            try
            {
                if (change.FilePath == null)
                {
                    reject(new Exception("Could not find file path."));
                    return;
                }
                var fileExtension = Path.GetExtension(change.FilePath).ToLower();
                if (fileExtension is ".prefab" or ".unity")
                {
                    reject(new Exception("Cannot auto-resolve conflicts for binary files. Please use an external merge tool."));
                    return;
                }
                
                await GitCommand.RunVsCodeAsync(new StringBuilder(), new[] { "--wait", change.FilePath }, 0, 141);
                
                var fullPath = Path.Combine(ProjectRoot, change.FilePath);
                var fileContent = await File.ReadAllTextAsync(fullPath);

                if (fileContent.Contains("<<<<<<<"))
                {
                    resolve($"Conflict in '{change.FilePath}' was not resolved. Please try again.");
                    return;
                }

                await GitCommand.RunGitAsync(new StringBuilder(), new[] { "add", change.FilePath });
                await GitCommand.RunGitAsync(new StringBuilder(), new[] { "reset", "HEAD", change.FilePath });
                    
                resolve($"Successfully resolved conflict in '{change.FilePath}'. The file is now modified and ready for review.");
            }
            catch (Win32Exception ex)
            {
                reject(new Exception("Could not launch VS Code. Ensure it is installed and the 'code' command is available in your system's PATH.", ex));
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }
        
        public static async void UnstageAllFilesIfSafeExecutor(Action<bool> resolve, Action<Exception> reject)
        {
            try
            {
                using var repo = new Repository(ProjectRoot);

                if (repo.Index.Conflicts.Any())
                {
                    resolve(false);
                    return;
                }

                var stagedFiles = repo.RetrieveStatus().Count(s => s.State is
                    FileStatus.NewInIndex or 
                    FileStatus.ModifiedInIndex or 
                    FileStatus.DeletedFromIndex or 
                    FileStatus.RenamedInIndex or 
                    FileStatus.TypeChangeInIndex);
                
                if (stagedFiles == 0)
                {
                    resolve(false);
                    return;
                }
                
                await GitCommand.RunGitAsync(new StringBuilder(), new[] { "reset" });
                resolve(true);
            }
            catch (Exception ex)
            {
                reject(ex);
            }
        }
        
        private static string CreateTempFileFromBlob(Blob blob, string fallbackFileName)
        {
            var content = blob?.GetContentText() ?? "";
            return CreateTempFileWithContent(content, fallbackFileName);
        }
        
        private static string CreateTempFileWithContent(string content, string originalFileName)
        {
            var tempFileName = $"{Path.GetFileName(originalFileName)}-{Path.GetRandomFileName()}";
            var tempPath = Path.Combine(Path.GetTempPath(), tempFileName);
            File.WriteAllText(tempPath, content);
            return tempPath;
        }
    }
}