using System.Text.Json;
using Godot;
using Mr.BrickAdventures.scripts.State;

namespace Mr.BrickAdventures.Autoloads;

/// <summary>
/// Save system that serializes POCOs directly to JSON.
/// </summary>
public partial class SaveSystem : Node
{
    [Export] public string SavePath { get; set; } = "user://savegame.json";
    [Export] public int Version { get; set; } = 2; // Bumped version for new format

    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        WriteIndented = true,
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
    };

    public override void _Ready()
    {
        // No longer needs GameManager reference - works with GameStateStore directly
    }

    public void SaveGame()
    {
        var store = GameStateStore.Instance;
        if (store == null)
        {
            GD.PrintErr("SaveSystem: GameStateStore not available.");
            return;
        }

        var saveData = new SaveData
        {
            Version = Version,
            Player = store.Player,
            CurrentLevel = store.Session.CurrentLevel
        };

        try
        {
            var json = JsonSerializer.Serialize(saveData, JsonOptions);
            using var file = FileAccess.Open(SavePath, FileAccess.ModeFlags.Write);
            file.StoreString(json);
            GD.Print("Game saved to: ", SavePath);
            EventBus.EmitGameSaved();
        }
        catch (System.Exception e)
        {
            GD.PrintErr($"SaveSystem: Failed to save game: {e.Message}");
        }
    }

    public bool LoadGame()
    {
        if (!FileAccess.FileExists(SavePath))
        {
            GD.Print("SaveSystem: No save file found.");
            return false;
        }

        try
        {
            using var file = FileAccess.Open(SavePath, FileAccess.ModeFlags.Read);
            var json = file.GetAsText();
            var saveData = JsonSerializer.Deserialize<SaveData>(json, JsonOptions);

            if (saveData == null)
            {
                GD.PrintErr("SaveSystem: Failed to deserialize save data.");
                return false;
            }

            if (saveData.Version != Version)
            {
                GD.PrintErr($"SaveSystem: Version mismatch. Expected {Version}, found {saveData.Version}");
                return false;
            }

            var store = GameStateStore.Instance;
            if (store == null)
            {
                GD.PrintErr("SaveSystem: GameStateStore not available.");
                return false;
            }

            // Apply loaded state
            store.Player = saveData.Player ?? new PlayerState();
            store.Session.CurrentLevel = saveData.CurrentLevel;

            GD.Print("Game loaded from: ", SavePath);
            return true;
        }
        catch (System.Exception e)
        {
            GD.PrintErr($"SaveSystem: Failed to load game: {e.Message}");
            return false;
        }
    }

    public bool CheckSaveExists() => FileAccess.FileExists(SavePath);

    public void DeleteSave()
    {
        if (FileAccess.FileExists(SavePath))
        {
            DirAccess.RemoveAbsolute(ProjectSettings.GlobalizePath(SavePath));
            GD.Print("Save file deleted.");
        }
    }
}

/// <summary>
/// Container for save data.
/// </summary>
public class SaveData
{
    public int Version { get; set; }
    public PlayerState Player { get; set; }
    public int CurrentLevel { get; set; }
}