using System.Text.Json;

namespace Sandbox.Transposer;

/// <summary>
/// Direction constants used for collision resolution and movement.
/// </summary>
public enum Direction { Left, Right, Up, Down }

/// <summary>
/// Global constants and state shared across the Transposer game.
/// Mirrors the original Unity Globals class — depth layers for draw
/// ordering and persistent score tracking.
/// </summary>
public static class Globals
{
	// ── Debug ────────────────────────────────────────────────────────────
	public static bool DebugHitboxes { get; set; }

	// ── Depth layers (lower number = drawn on top) ──────────────────────
	public const int DEPTH_TEXT = -8;
	public const int DEPTH_PARTICLE = -7;
	public const int DEPTH_BLOOD_PARTICLE = -6;
	public const int DEPTH_PLAYER = -5;
	public const int DEPTH_ENEMY = -4;
	public const int DEPTH_SHINE = -3;
	public const int DEPTH_COIN = -2;
	public const int DEPTH_TRAIL = -1;
	public const int DEPTH_TILE = 0;

	public const int GRID_SQUARE_STARTING_SIZE = 64;

	public const string LEADERBOARD_STAT = "transposer_score_v1";

	// ── Score tracking (persisted across scene switches) ────────────────
	public static bool HasPlayedOnce { get; set; }
	public static int LastNumSwaps { get; set; }
	public static int LastScore { get; set; }

	private static int _highScore;
	public static int HighScore
	{
		get => _highScore;
		set
		{
			_highScore = value;
			SaveToDisk();
		}
	}

	// ── Persistence ─────────────────────────────────────────────────────
	private const string SAVE_FILE = "transposer_save.json";

	private class SaveData
	{
		public int HighScore { get; set; }
	}

	/// <summary>
	/// Load high score from disk. Call once at game startup.
	/// </summary>
	public static void LoadFromDisk()
	{
		try
		{
			if ( FileSystem.Data.FileExists( SAVE_FILE ) )
			{
				var json = FileSystem.Data.ReadAllText( SAVE_FILE );
				var data = JsonSerializer.Deserialize<SaveData>( json );
				if ( data is not null )
					_highScore = data.HighScore;
			}
		}
		catch ( System.Exception e )
		{
			Log.Warning( $"Failed to load Transposer save: {e.Message}" );
		}
	}

	private static void SaveToDisk()
	{
		try
		{
			var data = new SaveData { HighScore = _highScore };
			var json = JsonSerializer.Serialize( data );
			FileSystem.Data.WriteAllText( SAVE_FILE, json );
		}
		catch ( System.Exception e )
		{
			Log.Warning( $"Failed to save Transposer data: {e.Message}" );
		}
	}
}