using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Text;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;

namespace Gott.Services;

public class ToolService
{
    public object[] GetToolDefinitions()
    {
        return new object[]
        {
            new
            {
                name = "read_file",
                description = "Liest den Inhalt einer Datei. Gibt den Textinhalt zurück.",
                input_schema = new
                {
                    type = "object",
                    properties = new Dictionary<string, object>
                    {
                        ["path"] = new { type = "string", description = "Relativer Dateipfad" }
                    },
                    required = new[] { "path" }
                }
            },
            new
            {
                name = "write_file",
                description = "Erstellt oder überschreibt eine Datei mit dem angegebenen Inhalt.",
                input_schema = new
                {
                    type = "object",
                    properties = new Dictionary<string, object>
                    {
                        ["path"] = new { type = "string", description = "Relativer Dateipfad" },
                        ["content"] = new { type = "string", description = "Dateiinhalt" }
                    },
                    required = new[] { "path", "content" }
                }
            },
            new
            {
                name = "edit_file",
                description = "Ersetzt einen exakten Textabschnitt in einer Datei. oldText muss exakt matchen.",
                input_schema = new
                {
                    type = "object",
                    properties = new Dictionary<string, object>
                    {
                        ["path"] = new { type = "string", description = "Relativer Dateipfad" },
                        ["old_text"] = new { type = "string", description = "Exakter Text der ersetzt werden soll" },
                        ["new_text"] = new { type = "string", description = "Neuer Text" }
                    },
                    required = new[] { "path", "old_text", "new_text" }
                }
            },
            new
            {
                name = "list_files",
                description = "Listet Dateien und Ordner in einem Verzeichnis auf.",
                input_schema = new
                {
                    type = "object",
                    properties = new Dictionary<string, object>
                    {
                        ["path"] = new { type = "string", description = "Relativer Verzeichnispfad (leer = Root)" }
                    },
                    required = Array.Empty<string>()
                }
            },
            new
            {
                name = "delete_file",
                description = "Löscht eine Datei oder ein leeres Verzeichnis.",
                input_schema = new
                {
                    type = "object",
                    properties = new Dictionary<string, object>
                    {
                        ["path"] = new { type = "string", description = "Relativer Pfad zur Datei oder zum Verzeichnis" }
                    },
                    required = new[] { "path" }
                }
            },
            new
            {
                name = "execute",
                description = "Führt einen Shell-Befehl im Workspace-Verzeichnis aus. Gibt stdout und stderr zurück. Timeout: 30 Sekunden.",
                input_schema = new
                {
                    type = "object",
                    properties = new Dictionary<string, object>
                    {
                        ["command"] = new { type = "string", description = "Shell-Befehl zum Ausführen" }
                    },
                    required = new[] { "command" }
                }
            }
        };
    }

    public async Task<string> ExecuteTool(string name, JsonElement input, string workspace)
    {
        switch (name)
        {
            case "read_file":
            {
                var path = ResolvePath(input.GetProperty("path").GetString() ?? "", workspace);
                if (!File.Exists(path))
                    return $"Fehler: Datei nicht gefunden: {Path.GetRelativePath(workspace, path)}";
                return File.ReadAllText(path);
            }
            case "write_file":
            {
                var path = ResolvePath(input.GetProperty("path").GetString() ?? "", workspace);
                var dir = Path.GetDirectoryName(path);
                if (dir != null) Directory.CreateDirectory(dir);
                var content = input.GetProperty("content").GetString() ?? "";
                File.WriteAllText(path, content);
                return $"Datei geschrieben: {Path.GetRelativePath(workspace, path)} ({content.Length} Zeichen)";
            }
            case "edit_file":
            {
                var path = ResolvePath(input.GetProperty("path").GetString() ?? "", workspace);
                if (!File.Exists(path))
                    return $"Fehler: Datei nicht gefunden: {Path.GetRelativePath(workspace, path)}";
                var fileContent = File.ReadAllText(path);
                var oldText = input.GetProperty("old_text").GetString() ?? "";
                var newText = input.GetProperty("new_text").GetString() ?? "";
                if (!fileContent.Contains(oldText))
                    return "Fehler: old_text nicht in der Datei gefunden. Exakter Match nötig.";
                fileContent = fileContent.Replace(oldText, newText);
                File.WriteAllText(path, fileContent);
                return $"Datei bearbeitet: {Path.GetRelativePath(workspace, path)}";
            }
            case "list_files":
            {
                var path = ResolvePath(input.TryGetProperty("path", out var p) ? p.GetString() ?? "" : "", workspace);
                if (!Directory.Exists(path))
                    return $"Fehler: Verzeichnis nicht gefunden: {Path.GetRelativePath(workspace, path)}";
                var entries = new List<string>();
                foreach (var dir in Directory.GetDirectories(path))
                    entries.Add(Path.GetRelativePath(workspace, dir) + "/");
                foreach (var file in Directory.GetFiles(path))
                    entries.Add(Path.GetRelativePath(workspace, file));
                return entries.Count == 0 ? "(leer)" : string.Join("\n", entries);
            }
            case "delete_file":
            {
                var path = ResolvePath(input.GetProperty("path").GetString() ?? "", workspace);
                if (File.Exists(path))
                {
                    File.Delete(path);
                    return $"Datei gelöscht: {Path.GetRelativePath(workspace, path)}";
                }
                if (Directory.Exists(path))
                {
                    Directory.Delete(path, recursive: false);
                    return $"Verzeichnis gelöscht: {Path.GetRelativePath(workspace, path)}";
                }
                return $"Fehler: Nicht gefunden: {Path.GetRelativePath(workspace, path)}";
            }
            case "execute":
            {
                var command = input.GetProperty("command").GetString() ?? "";
                var psi = new ProcessStartInfo
                {
                    FileName = "/bin/bash",
                    WorkingDirectory = workspace,
                    RedirectStandardInput = true,
                    RedirectStandardOutput = true,
                    RedirectStandardError = true,
                    UseShellExecute = false,
                    CreateNoWindow = true
                };
                using var proc = Process.Start(psi);
                if (proc == null) return "Fehler: Prozess konnte nicht gestartet werden";
                await proc.StandardInput.WriteAsync(command);
                proc.StandardInput.Close();
                var cts = new CancellationTokenSource(TimeSpan.FromSeconds(30));
                try
                {
                    await proc.WaitForExitAsync(cts.Token);
                }
                catch (OperationCanceledException)
                {
                    proc.Kill(entireProcessTree: true);
                    return "Fehler: Timeout nach 30 Sekunden - Prozess abgebrochen";
                }
                var stdout = await proc.StandardOutput.ReadToEndAsync();
                var stderr = await proc.StandardError.ReadToEndAsync();
                var result = new StringBuilder();
                if (!string.IsNullOrEmpty(stdout)) result.Append(stdout);
                if (!string.IsNullOrEmpty(stderr))
                {
                    if (result.Length > 0) result.Append("\n--- stderr ---\n");
                    result.Append(stderr);
                }
                if (result.Length == 0) result.Append($"(exit code {proc.ExitCode})");
                else if (proc.ExitCode != 0) result.Append($"\n(exit code {proc.ExitCode})");
                return result.ToString();
            }
            default:
                return $"Fehler: Unbekanntes Tool: {name}";
        }
    }

    private string ResolvePath(string relativePath, string workspace)
    {
        var full = Path.GetFullPath(Path.Combine(workspace, relativePath ?? ""));
        if (!full.StartsWith(workspace))
            throw new Exception("Zugriff außerhalb des Workspace nicht erlaubt");
        return full;
    }
}