using OECS;
using R3;

namespace TicTacToe;

public static class Program
{
    public static void Main()
    {
        var world = new World();

        // ── Setup reactivity logging ──────────────────────────────────
        //
        // Each subscription appends to a shared log buffer. The log is
        // printed after the board render so Console.Clear() doesn't wipe it.

        var reactivityLog = new List<string>();

        // 1. Log every entity-level change (creates, destroys).
        world.ObserveEntityChanges().Subscribe(change =>
        {
            if (change.ComponentType != null) return;
            reactivityLog.Add($"[react] {change}");
        });

        // 2. Log every Mark component change (placed on a cell).
        world.ObserveComponentChanges<Mark>().Subscribe(change =>
        {
            reactivityLog.Add($"[react] {change}");
        });

        // 3. Log every GameState singleton change.
        world.ObserveComponentChanges<GameState>().Subscribe(change =>
        {
            reactivityLog.Add($"[react] {change}");
        });

        // 4. Log changes matching a query: cells that have a Mark.
        var markedQuery = world.Query().With<Cell>().With<Mark>().Build();
        world.ObserveQuery(markedQuery).Subscribe(change =>
        {
            reactivityLog.Add($"[react:query] {change}");
        });

        // ── Load initial state from CSV ───────────────────────────────

        var csvPath = Path.Combine(AppContext.BaseDirectory, "Data", "board.csv");
        CsvLoader.LoadCells(world, csvPath);
        world.PostChanges(); // flush entity-created notifications

        // ── Initialize singleton ──────────────────────────────────────

        world.SetSingleton(new GameState
        {
            CurrentPlayer = Player.X,
            Status = GameStatus.Playing,
            MoveCount = 0
        });
        world.PostChanges();

        // ── Wire up systems ───────────────────────────────────────────

        var group = new SystemGroup(world);
        group.Add(new WinCheckSystem(world));
        group.Add(new RenderSystem(world));

        // ── Game loop ─────────────────────────────────────────────────

        // Initial render.
        group.RunLogical();
        PrintReactivityLog(reactivityLog);

        while (true)
        {
            ref var state = ref world.GetSingleton<GameState>();
            if (state.Status != GameStatus.Playing)
                break;

            var input = Console.ReadLine();
            if (string.IsNullOrWhiteSpace(input))
                continue;

            var parts = input.Trim().Split(' ', StringSplitOptions.RemoveEmptyEntries);
            if (parts.Length != 2 ||
                !int.TryParse(parts[0], out var row) ||
                !int.TryParse(parts[1], out var col))
            {
                Console.WriteLine("  Invalid input. Try \"1 2\".");
                continue;
            }

            if (row < 0 || row > 2 || col < 0 || col > 2)
            {
                Console.WriteLine("  Row and col must be 0–2.");
                continue;
            }

            world.Commands.Enqueue(new PlaceMarkCommand { Row = row, Col = col });
            group.RunLogical();
            PrintReactivityLog(reactivityLog);
        }

        // ── Final state ───────────────────────────────────────────────

        Console.WriteLine();
        Console.WriteLine("=== Game over ===");
        PrintReactivityLog(reactivityLog);
    }

    private static void PrintReactivityLog(List<string> log)
    {
        if (log.Count == 0) return;
        Console.WriteLine("── reactivity log ──");
        foreach (var entry in log)
            Console.WriteLine(entry);
        Console.WriteLine();
        log.Clear();
    }
}