using ClaudeDo.Data;
using ClaudeDo.Data.Git;
using ClaudeDo.Data.Repositories;
using ClaudeDo.Worker.Hub;
using Microsoft.EntityFrameworkCore;

namespace ClaudeDo.Worker.Lifecycle;

/// <summary>
/// Startup-only sweep: warns when a list's repo has git-registered <c>claudedo/*</c> worktrees
/// that the <c>worktrees</c> table doesn't know about (e.g. left behind by a manual cleanup
/// outside the app). Detection only — nothing is removed or pruned.
/// </summary>
public sealed class UntrackedWorktreeRecovery : IHostedService
{
    public const string Phase = "untracked-worktrees";

    private const string BranchPrefix = "claudedo/";

    private readonly IDbContextFactory<ClaudeDoDbContext> _dbFactory;
    private readonly GitService _git;
    private readonly HubBroadcaster _broadcaster;
    private readonly ILogger<UntrackedWorktreeRecovery> _logger;

    public UntrackedWorktreeRecovery(
        IDbContextFactory<ClaudeDoDbContext> dbFactory,
        GitService git,
        HubBroadcaster broadcaster,
        ILogger<UntrackedWorktreeRecovery> logger)
    {
        _dbFactory = dbFactory;
        _git = git;
        _broadcaster = broadcaster;
        _logger = logger;
    }

    public async Task StartAsync(CancellationToken cancellationToken)
    {
        await using var ctx = await _dbFactory.CreateDbContextAsync(cancellationToken);
        var lists = await new ListRepository(ctx).GetAllAsync(cancellationToken);
        var dbPaths = (await new WorktreeRepository(ctx).GetAllAsync(cancellationToken))
            .Select(w => w.Path)
            .ToList();

        var foundAny = false;
        foreach (var list in lists.Where(l => !string.IsNullOrWhiteSpace(l.WorkingDir)))
        {
            List<(string Path, string? Branch)> registered;
            try
            {
                registered = await _git.ListWorktreesAsync(list.WorkingDir!, cancellationToken);
            }
            catch (Exception ex)
            {
                _logger.LogWarning(ex, "Untracked worktree recovery: git worktree list failed for {WorkingDir}", list.WorkingDir);
                continue;
            }

            var claudedoPaths = registered
                .Where(w => w.Branch is not null && w.Branch.StartsWith(BranchPrefix, StringComparison.Ordinal))
                .Select(w => w.Path);

            var untracked = FindUntrackedPaths(claudedoPaths, dbPaths);
            if (untracked.Count == 0) continue;

            foundAny = true;
            _logger.LogWarning(
                "Untracked worktree recovery: found {Count} git worktree(s) under '{Repo}' that ClaudeDo's database doesn't know about; not touched",
                untracked.Count, list.WorkingDir);
        }

        if (!foundAny)
            _logger.LogInformation("Untracked worktree recovery: no untracked worktrees found");

        await _broadcaster.OperationProgress(OperationProgressOpKeys.StartupRecovery, Phase, lists.Count, lists.Count);
    }

    public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;

    /// <summary>Registered worktree paths not present among <paramref name="dbPaths"/>, comparing normalized full paths.</summary>
    public static List<string> FindUntrackedPaths(IEnumerable<string> registeredPaths, IEnumerable<string> dbPaths)
    {
        var known = dbPaths.Select(Normalize).ToHashSet(StringComparer.OrdinalIgnoreCase);
        return registeredPaths.Where(p => !known.Contains(Normalize(p))).ToList();
    }

    private static string Normalize(string path) =>
        Path.GetFullPath(path).TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
}