using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace Gott.Services;

public class MemoryService
{
    private readonly string _dataDir;

    public string DataDir => _dataDir;

    public MemoryService(string dataDir)
    {
        _dataDir = dataDir;
    }

    /// <summary>
    /// Gibt den Memory-Ordner für einen Agent zurück. Erstellt ihn bei Bedarf.
    /// </summary>
    public string GetAgentMemoryDir(string agentId)
    {
        var dir = Path.Combine(_dataDir, "agents", agentId);
        Directory.CreateDirectory(dir);
        return dir;
    }

    /// <summary>
    /// Liest eine Memory-Datei. Gibt null zurück wenn nicht vorhanden.
    /// </summary>
    public string ReadMemoryFile(string agentId, string fileName)
    {
        var path = ResolvePath(agentId, fileName);
        if (path == null || !File.Exists(path)) return null;
        return File.ReadAllText(path);
    }

    /// <summary>
    /// Schreibt/überschreibt eine Memory-Datei.
    /// </summary>
    public void WriteMemoryFile(string agentId, string fileName, string content)
    {
        var path = ResolvePath(agentId, fileName);
        if (path == null) throw new Exception("Ungültiger Dateipfad");
        var dir = Path.GetDirectoryName(path);
        if (dir != null) Directory.CreateDirectory(dir);
        File.WriteAllText(path, content);
    }

    /// <summary>
    /// Hängt Inhalt an eine Memory-Datei an.
    /// </summary>
    public void AppendMemoryFile(string agentId, string fileName, string content)
    {
        var path = ResolvePath(agentId, fileName);
        if (path == null) throw new Exception("Ungültiger Dateipfad");
        var dir = Path.GetDirectoryName(path);
        if (dir != null) Directory.CreateDirectory(dir);
        File.AppendAllText(path, content);
    }

    /// <summary>
    /// Listet alle Memory-Dateien eines Agents auf.
    /// </summary>
    public List<string> ListMemoryFiles(string agentId, string subPath = null)
    {
        var baseDir = GetAgentMemoryDir(agentId);
        var targetDir = string.IsNullOrEmpty(subPath)
            ? baseDir
            : Path.GetFullPath(Path.Combine(baseDir, subPath));

        if (!targetDir.StartsWith(baseDir))
            throw new Exception("Zugriff außerhalb des Memory-Verzeichnisses nicht erlaubt");

        if (!Directory.Exists(targetDir))
            return new List<string>();

        var entries = new List<string>();
        foreach (var dir in Directory.GetDirectories(targetDir))
            entries.Add(Path.GetRelativePath(baseDir, dir) + "/");
        foreach (var file in Directory.GetFiles(targetDir))
            entries.Add(Path.GetRelativePath(baseDir, file));
        return entries;
    }

    /// <summary>
    /// Erstellt die Standard-Files (IDENTITY.md, SOUL.md) für einen neuen Agent.
    /// Überschreibt NICHT, falls bereits vorhanden.
    /// </summary>
    public void InitializeAgentFiles(string agentId, string agentName)
    {
        var dir = GetAgentMemoryDir(agentId);

        var identityPath = Path.Combine(dir, "IDENTITY.md");
        if (!File.Exists(identityPath))
        {
            File.WriteAllText(identityPath,
$@"# IDENTITY.md - Who Am I?

- **Name:** {agentName}
- **Creature:** Unbekannt
- **Vibe:** Unbekannt
- **Language:** Deutsch
");
        }

        var soulPath = Path.Combine(dir, "SOUL.md");
        if (!File.Exists(soulPath))
        {
            File.WriteAllText(soulPath,
@"# SOUL.md - Who You Are

## Core Truths

**Be genuinely helpful, not performatively helpful.** Skip filler words - just help. Actions speak louder.

**Be resourceful before asking.** Try to figure it out. Read the file. Check the context. _Then_ ask if you're stuck.

**Earn trust through competence.** Be careful with external actions. Be bold with internal ones (reading, organizing, building).

## Continuity

Each session, you wake up fresh. These files _are_ your memory. Read them. Update them. They're how you persist.

---

_This file is yours to evolve. As you learn who you are, update it._
");
        }
    }

    /// <summary>
    /// Liest MEMORY.md (das Haupt-Memory-File). Gibt leeren String zurück wenn nicht vorhanden.
    /// </summary>
    public string GetMainMemory(string agentId)
    {
        return ReadMemoryFile(agentId, "MEMORY.md") ?? "";
    }

    /// <summary>
    /// Löst einen Pfad relativ zum Agent-Memory-Dir auf und prüft Sandbox.
    /// </summary>
    private string ResolvePath(string agentId, string fileName)
    {
        var baseDir = GetAgentMemoryDir(agentId);
        var full = Path.GetFullPath(Path.Combine(baseDir, fileName));
        if (!full.StartsWith(baseDir))
            return null;
        return full;
    }
}