using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Gott.Extensions;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.DependencyInjection;

namespace Gott.Endpoints;

public static class WorkspaceEndpoint
{
    private static readonly HashSet<string> TextExtensions = new(StringComparer.OrdinalIgnoreCase)
    {
        ".cs", ".csproj", ".sln", ".json", ".xml", ".yaml", ".yml", ".toml",
        ".md", ".txt", ".log", ".csv", ".tsv",
        ".html", ".htm", ".css", ".js", ".ts", ".jsx", ".tsx",
        ".sh", ".bash", ".bat", ".ps1", ".cmd",
        ".py", ".rb", ".go", ".rs", ".java", ".kt", ".swift",
        ".c", ".cpp", ".h", ".hpp",
        ".sql", ".graphql",
        ".env", ".gitignore", ".dockerignore", ".editorconfig",
        ".razor", ".cshtml", ".vue", ".svelte",
        ".ini", ".cfg", ".conf", ".properties",
        ".dockerfile", ".makefile",
        ""  // Dateien ohne Extension (Makefile, Dockerfile, etc.)
    };

    private static readonly HashSet<string> IgnoredDirs = new(StringComparer.OrdinalIgnoreCase)
    {
        "bin", "obj", "node_modules", ".git", ".vs", ".idea",
        "publish", "dist", "out", "build", "target", ".cache"
    };

    public static void MapWorkspaceEndpoint(this IEndpointRouteBuilder app)
    {
        app.MapGet("/api/workspace/tree", HandleTree);
        app.MapGet("/api/workspace/file", HandleFile);
        app.MapPut("/api/workspace/file", HandleFileSave);
        app.MapGet("/api/workspace/browse", HandleBrowse);
        app.MapGet("/api/workspace/agent/tree", HandleAgentTree);
        app.MapGet("/api/workspace/agent/file", HandleAgentFile);
        app.MapPut("/api/workspace/agent/file", HandleAgentFileSave);
        app.MapGet("/api/workspace/raw", HandleRawFile);
    }

    private static async Task HandleTree(HttpContext ctx)
    {
        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
        var subPath = ctx.Request.Query["path"].FirstOrDefault() ?? "";

        // Workspace aus Session holen
        var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
        var session = await db.GetSession(sessionId ?? "");
        if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
        {
            ctx.Response.StatusCode = 400;
            await ctx.Response.WriteAsJsonAsync(new { error = "Kein Workspace konfiguriert" });
            return;
        }

        var basePath = Path.GetFullPath(session.Workspace);
        var targetPath = Path.GetFullPath(Path.Combine(basePath, subPath));

        // Sicherheit: nicht aus dem Workspace ausbrechen
        if (!targetPath.StartsWith(basePath))
        {
            ctx.Response.StatusCode = 403;
            return;
        }

        if (!Directory.Exists(targetPath))
        {
            ctx.Response.StatusCode = 404;
            await ctx.Response.WriteAsJsonAsync(new { error = "Verzeichnis nicht gefunden" });
            return;
        }

        var entries = new List<object>();

        // Ordner
        foreach (var dir in Directory.GetDirectories(targetPath).OrderBy(d => Path.GetFileName(d), StringComparer.OrdinalIgnoreCase))
        {
            var name = Path.GetFileName(dir);
            if (IgnoredDirs.Contains(name)) continue;

            var relPath = Path.GetRelativePath(basePath, dir).Replace('\\', '/');
            entries.Add(new { name, path = relPath, type = "dir" });
        }

        // Dateien
        foreach (var file in Directory.GetFiles(targetPath).OrderBy(f => Path.GetFileName(f), StringComparer.OrdinalIgnoreCase))
        {
            var name = Path.GetFileName(file);
            var ext = Path.GetExtension(file);
            var relPath = Path.GetRelativePath(basePath, file).Replace('\\', '/');
            var size = new FileInfo(file).Length;
            var isText = TextExtensions.Contains(ext) || IsLikelyTextFile(name);

            entries.Add(new { name, path = relPath, type = "file", ext, size, isText });
        }

        await ctx.Response.WriteAsJsonAsync(entries);
    }

    private static async Task HandleFile(HttpContext ctx)
    {
        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
        var filePath = ctx.Request.Query["path"].FirstOrDefault();

        if (string.IsNullOrEmpty(filePath))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
        var session = await db.GetSession(sessionId ?? "");
        if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
        {
            ctx.Response.StatusCode = 400;
            await ctx.Response.WriteAsJsonAsync(new { error = "Kein Workspace konfiguriert" });
            return;
        }

        var basePath = Path.GetFullPath(session.Workspace);
        var targetPath = Path.GetFullPath(Path.Combine(basePath, filePath));

        if (!targetPath.StartsWith(basePath))
        {
            ctx.Response.StatusCode = 403;
            return;
        }

        if (!File.Exists(targetPath))
        {
            ctx.Response.StatusCode = 404;
            return;
        }

        var info = new FileInfo(targetPath);

        // Max 2MB für Textdateien
        if (info.Length > 2 * 1024 * 1024)
        {
            ctx.Response.StatusCode = 413;
            await ctx.Response.WriteAsJsonAsync(new { error = "Datei zu groß (max. 2MB)" });
            return;
        }

        var content = await File.ReadAllTextAsync(targetPath);
        var lineCount = content.Split('\n').Length;

        await ctx.Response.WriteAsJsonAsync(new
        {
            path = filePath,
            name = info.Name,
            size = info.Length,
            lineCount,
            content
        });
    }

    private static async Task HandleFileSave(HttpContext ctx)
    {
        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
        var filePath = ctx.Request.Query["path"].FirstOrDefault();

        if (string.IsNullOrEmpty(filePath))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
        var session = await db.GetSession(sessionId ?? "");
        if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
        {
            ctx.Response.StatusCode = 400;
            await ctx.Response.WriteAsJsonAsync(new { error = "Kein Workspace konfiguriert" });
            return;
        }

        var basePath = Path.GetFullPath(session.Workspace);
        var targetPath = Path.GetFullPath(Path.Combine(basePath, filePath));

        if (!targetPath.StartsWith(basePath))
        {
            ctx.Response.StatusCode = 403;
            return;
        }

        if (!File.Exists(targetPath))
        {
            ctx.Response.StatusCode = 404;
            return;
        }

        using var reader = new StreamReader(ctx.Request.Body);
        var content = await reader.ReadToEndAsync();

        await File.WriteAllTextAsync(targetPath, content);

        var info = new FileInfo(targetPath);
        var lineCount = content.Split('\n').Length;

        await ctx.Response.WriteAsJsonAsync(new
        {
            path = filePath,
            name = info.Name,
            size = info.Length,
            lineCount
        });
    }

    private static async Task HandleBrowse(HttpContext ctx)
    {
        var path = ctx.Request.Query["path"].FirstOrDefault() ?? "/";

        var targetPath = Path.GetFullPath(path);
        if (!Directory.Exists(targetPath))
        {
            ctx.Response.StatusCode = 404;
            await ctx.Response.WriteAsJsonAsync(new { error = "Verzeichnis nicht gefunden" });
            return;
        }

        var entries = new List<object>();

        // Parent
        var parent = Directory.GetParent(targetPath);
        if (parent != null)
        {
            entries.Add(new { name = "..", path = parent.FullName.Replace('\\', '/'), type = "dir" });
        }

        try
        {
            foreach (var dir in Directory.GetDirectories(targetPath).OrderBy(d => Path.GetFileName(d), StringComparer.OrdinalIgnoreCase))
            {
                var name = Path.GetFileName(dir);
                if (IgnoredDirs.Contains(name)) continue;
                entries.Add(new { name, path = dir.Replace('\\', '/'), type = "dir" });
            }
        }
        catch (UnauthorizedAccessException) { }

        await ctx.Response.WriteAsJsonAsync(new { current = targetPath.Replace('\\', '/'), entries });
    }

    private static bool IsLikelyTextFile(string name)
    {
        var lower = name.ToLowerInvariant();
        return lower is "makefile" or "dockerfile" or "rakefile" or "gemfile"
            or "procfile" or "vagrantfile" or "license" or "readme"
            or "changelog" or "authors" or "contributors";
    }

    private static string GetAgentBasePath(HttpContext ctx, out string error)
    {
        error = null;
        var agentId = ctx.Request.Query["agentId"].FirstOrDefault();
        if (string.IsNullOrEmpty(agentId))
        {
            error = "agentId fehlt";
            return null;
        }

        var memoryService = ctx.RequestServices.GetRequiredService<Gott.Services.MemoryService>();
        var basePath = memoryService.GetAgentMemoryDir(agentId);

        if (!Directory.Exists(basePath))
            Directory.CreateDirectory(basePath);

        return basePath;
    }

    private static async Task HandleAgentTree(HttpContext ctx)
    {
        var basePath = GetAgentBasePath(ctx, out var error);
        if (basePath == null)
        {
            ctx.Response.StatusCode = 400;
            await ctx.Response.WriteAsJsonAsync(new { error });
            return;
        }

        var subPath = ctx.Request.Query["path"].FirstOrDefault() ?? "";
        var targetPath = Path.GetFullPath(Path.Combine(basePath, subPath));

        if (!targetPath.StartsWith(basePath))
        {
            ctx.Response.StatusCode = 403;
            return;
        }

        if (!Directory.Exists(targetPath))
        {
            ctx.Response.StatusCode = 404;
            await ctx.Response.WriteAsJsonAsync(new { error = "Verzeichnis nicht gefunden" });
            return;
        }

        var entries = new List<object>();

        foreach (var dir in Directory.GetDirectories(targetPath).OrderBy(d => Path.GetFileName(d), StringComparer.OrdinalIgnoreCase))
        {
            var name = Path.GetFileName(dir);
            if (IgnoredDirs.Contains(name)) continue;
            var relPath = Path.GetRelativePath(basePath, dir).Replace('\\', '/');
            entries.Add(new { name, path = relPath, type = "dir" });
        }

        foreach (var file in Directory.GetFiles(targetPath).OrderBy(f => Path.GetFileName(f), StringComparer.OrdinalIgnoreCase))
        {
            var name = Path.GetFileName(file);
            var ext = Path.GetExtension(file);
            var relPath = Path.GetRelativePath(basePath, file).Replace('\\', '/');
            var size = new FileInfo(file).Length;
            var isText = TextExtensions.Contains(ext) || IsLikelyTextFile(name);
            entries.Add(new { name, path = relPath, type = "file", ext, size, isText });
        }

        await ctx.Response.WriteAsJsonAsync(entries);
    }

    private static async Task HandleAgentFile(HttpContext ctx)
    {
        var basePath = GetAgentBasePath(ctx, out var error);
        if (basePath == null)
        {
            ctx.Response.StatusCode = 400;
            await ctx.Response.WriteAsJsonAsync(new { error });
            return;
        }

        var filePath = ctx.Request.Query["path"].FirstOrDefault();
        if (string.IsNullOrEmpty(filePath))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var targetPath = Path.GetFullPath(Path.Combine(basePath, filePath));
        if (!targetPath.StartsWith(basePath))
        {
            ctx.Response.StatusCode = 403;
            return;
        }

        if (!File.Exists(targetPath))
        {
            ctx.Response.StatusCode = 404;
            return;
        }

        var info = new FileInfo(targetPath);
        if (info.Length > 2 * 1024 * 1024)
        {
            ctx.Response.StatusCode = 413;
            await ctx.Response.WriteAsJsonAsync(new { error = "Datei zu groß (max. 2MB)" });
            return;
        }

        var content = await File.ReadAllTextAsync(targetPath);
        var lineCount = content.Split('\n').Length;

        await ctx.Response.WriteAsJsonAsync(new
        {
            path = filePath,
            name = info.Name,
            size = info.Length,
            lineCount,
            content
        });
    }

    private static async Task HandleAgentFileSave(HttpContext ctx)
    {
        var basePath = GetAgentBasePath(ctx, out var error);
        if (basePath == null)
        {
            ctx.Response.StatusCode = 400;
            await ctx.Response.WriteAsJsonAsync(new { error });
            return;
        }

        var filePath = ctx.Request.Query["path"].FirstOrDefault();
        if (string.IsNullOrEmpty(filePath))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var targetPath = Path.GetFullPath(Path.Combine(basePath, filePath));
        if (!targetPath.StartsWith(basePath))
        {
            ctx.Response.StatusCode = 403;
            return;
        }

        // Verzeichnis erstellen falls nötig
        var dir = Path.GetDirectoryName(targetPath);
        if (!string.IsNullOrEmpty(dir) && !Directory.Exists(dir))
            Directory.CreateDirectory(dir);

        using var reader = new StreamReader(ctx.Request.Body);
        var content = await reader.ReadToEndAsync();

        await File.WriteAllTextAsync(targetPath, content);

        var info = new FileInfo(targetPath);
        var lineCount = content.Split('\n').Length;

        await ctx.Response.WriteAsJsonAsync(new
        {
            path = filePath,
            name = info.Name,
            size = info.Length,
            lineCount
        });
    }

    private static readonly Dictionary<string, string> MimeTypes = new(StringComparer.OrdinalIgnoreCase)
    {
        { ".png", "image/png" }, { ".jpg", "image/jpeg" }, { ".jpeg", "image/jpeg" },
        { ".gif", "image/gif" }, { ".webp", "image/webp" }, { ".svg", "image/svg+xml" },
        { ".bmp", "image/bmp" }, { ".ico", "image/x-icon" },
        { ".pdf", "application/pdf" },
        { ".mp4", "video/mp4" }, { ".webm", "video/webm" },
        { ".mp3", "audio/mpeg" }, { ".wav", "audio/wav" }, { ".ogg", "audio/ogg" },
    };

    private static async Task HandleRawFile(HttpContext ctx)
    {
        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
        var filePath = ctx.Request.Query["path"].FirstOrDefault();

        if (string.IsNullOrEmpty(filePath))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
        var session = await db.GetSession(sessionId ?? "");
        if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var basePath = Path.GetFullPath(session.Workspace);
        var targetPath = Path.GetFullPath(Path.Combine(basePath, filePath));

        if (!targetPath.StartsWith(basePath))
        {
            ctx.Response.StatusCode = 403;
            return;
        }

        if (!File.Exists(targetPath))
        {
            ctx.Response.StatusCode = 404;
            return;
        }

        var ext = Path.GetExtension(targetPath);
        var contentType = MimeTypes.GetValueOrDefault(ext, "application/octet-stream");

        ctx.Response.ContentType = contentType;
        ctx.Response.Headers["Cache-Control"] = "private, max-age=3600";
        await ctx.Response.SendFileAsync(targetPath);
    }
}