using System.Collections.Generic;
using System.IO;
using MSCLoader;
using UnityEngine;

namespace MSCO
{
    /// <summary>
    /// Liest den Spielstand des Hosts und ersetzt beim Client den eigenen Spielstand
    /// vorübergehend. Der Spielstand des Clients wird vorher gesichert und beim
    /// nächsten Hauptmenü automatisch wiederhergestellt.
    /// </summary>
    public static class SaveSync
    {
        // Nur diese Dateien werden übertragen (options.txt etc. bleiben beim Spieler)
        public static readonly string[] Files =
        {
            "defaultES2File.txt", "items.txt", "meshsave.txt", "graveyard.txt", "notepad.txt"
        };

        static string SaveDir { get { return Application.persistentDataPath; } }
        static string BackupDir { get { return Path.Combine(SaveDir, "MSCO_Backup"); } }
        static string Marker { get { return Path.Combine(BackupDir, "backup_active"); } }

        public static bool HasBackup { get { return File.Exists(Marker); } }

        public static List<KeyValuePair<string, byte[]>> ReadLocalSave()
        {
            var result = new List<KeyValuePair<string, byte[]>>();
            foreach (string name in Files)
            {
                string path = Path.Combine(SaveDir, name);
                if (File.Exists(path))
                    result.Add(new KeyValuePair<string, byte[]>(name, File.ReadAllBytes(path)));
            }
            return result;
        }

        /// <summary>Eigenen Spielstand sichern (nur einmal) und die Spielstand-Dateien leeren.</summary>
        public static void BeginReceive()
        {
            if (!HasBackup)
            {
                Directory.CreateDirectory(BackupDir);
                foreach (string name in Files)
                {
                    string path = Path.Combine(SaveDir, name);
                    if (File.Exists(path)) File.Copy(path, Path.Combine(BackupDir, name), true);
                }
                File.WriteAllText(Marker, "MSCO backup of the client's own save. Restored automatically.");
                ModConsole.Print("[MSCO] Own save backed up to " + BackupDir);
            }
            DeleteSaveFiles();
        }

        public static void WriteFile(string name, byte[] data)
        {
            // Nur bekannte Dateinamen erlauben, damit der Host nichts anderes überschreiben kann
            if (System.Array.IndexOf(Files, name) < 0)
            {
                ModConsole.Warning("[MSCO] Ignored unexpected save file: " + name);
                return;
            }
            File.WriteAllBytes(Path.Combine(SaveDir, name), data);
        }

        public static void RestoreBackup()
        {
            if (!HasBackup) return;
            DeleteSaveFiles();
            foreach (string name in Files)
            {
                string backup = Path.Combine(BackupDir, name);
                if (File.Exists(backup)) File.Copy(backup, Path.Combine(SaveDir, name), true);
            }
            Directory.Delete(BackupDir, true);
            ModConsole.Print("[MSCO] Own save restored.");
        }

        static void DeleteSaveFiles()
        {
            foreach (string name in Files)
            {
                string path = Path.Combine(SaveDir, name);
                if (File.Exists(path)) File.Delete(path);
            }
        }
    }
}