using System.IO;
using UnityEngine;

public static class LegacyPlainSaveMigrator
{
    [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
    private static void MigrateLegacyPlainFiles()
    {
        string root = Application.persistentDataPath;
        MigrateSingleFile("daily_task", "runtime", Path.Combine(root, "daily_tasks.json"));
        MigrateSingleFile("mail_state", "runtime", Path.Combine(root, "mail_state.json"));
        MigrateSingleFile("store_state", "runtime", Path.Combine(root, "storeSystem_state.json"));

        MigratePattern("song_runtime", root, "SongData_*.json", fileNameWithoutExt =>
        {
            if (fileNameWithoutExt.StartsWith("SongData_"))
            {
                return fileNameWithoutExt.Substring("SongData_".Length);
            }

            return fileNameWithoutExt;
        });

        MigratePattern("song_export", Path.Combine(root, "SongDataJson"), "*.json", fileNameWithoutExt => fileNameWithoutExt);
        MigratePattern("song_export", Path.Combine(root, "song_json_export"), "*.json", fileNameWithoutExt => fileNameWithoutExt);
    }

    private static void MigrateSingleFile(string category, string key, string legacyPath)
    {
        if (!File.Exists(legacyPath))
        {
            return;
        }

        try
        {
            string json = File.ReadAllText(legacyPath);
            if (string.IsNullOrEmpty(json))
            {
                File.Delete(legacyPath);
                return;
            }

            SecureSaveVault.SaveRawJson(category, key, json, legacyPath);
        }
        catch (System.Exception ex)
        {
            Debug.LogWarning($"[LegacyPlainSaveMigrator] Failed to migrate {legacyPath}: {ex.Message}");
        }
    }

    private static void MigratePattern(string category, string directory, string searchPattern, System.Func<string, string> keyResolver)
    {
        if (!Directory.Exists(directory))
        {
            return;
        }

        string[] files = Directory.GetFiles(directory, searchPattern, SearchOption.TopDirectoryOnly);
        for (int i = 0; i < files.Length; i++)
        {
            string legacyPath = files[i];
            try
            {
                string json = File.ReadAllText(legacyPath);
                if (string.IsNullOrEmpty(json))
                {
                    File.Delete(legacyPath);
                    continue;
                }

                string key = keyResolver != null ? keyResolver(Path.GetFileNameWithoutExtension(legacyPath)) : Path.GetFileNameWithoutExtension(legacyPath);
                SecureSaveVault.SaveRawJson(category, key, json, legacyPath);
            }
            catch (System.Exception ex)
            {
                Debug.LogWarning($"[LegacyPlainSaveMigrator] Failed to migrate {legacyPath}: {ex.Message}");
            }
        }

        TryDeleteDirectoryIfEmpty(directory);
    }

    private static void TryDeleteDirectoryIfEmpty(string directory)
    {
        try
        {
            if (!Directory.Exists(directory))
            {
                return;
            }

            if (Directory.GetFiles(directory).Length == 0 && Directory.GetDirectories(directory).Length == 0)
            {
                Directory.Delete(directory, false);
            }
        }
        catch
        {
        }
    }
}