import 'dart:math';

import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:gobang/models/chess.dart';
import 'package:gobang/models/checkerboard.dart';
import 'package:gobang/models/chess_shape.dart';
import 'package:gobang/models/circle_shape.dart';
import 'package:gobang/models/game_state.dart';
import 'package:gobang/models/position.dart';
import 'package:gobang/models/rect_shape.dart';
import 'package:gobang/models/user_context.dart';
import 'package:gobang/services/ai_service.dart';
import 'package:gobang/services/chess_flyweight_factory.dart';
import 'package:gobang/themes/black_theme_factory.dart';
import 'package:gobang/themes/blue_theme_factory.dart';
import 'package:gobang/themes/theme_factory.dart';
import 'package:gobang/utils/constants.dart';
import 'package:gobang/utils/tips_dialog.dart';

/// 对局控制器：棋盘交互、AI、主题与阶段状态
class GameController extends GetxController {
  final UserContext _userContext = UserContext();
  final Checkerboard board = Checkerboard.getInstance();
  final AiService ai = AiService.getInstance();

  final themeFactory = Rx<ThemeFactory>(BlueThemeFactory());
  final useCircle = true.obs;
  final gameOver = false.obs;
  final paintVersion = 0.obs;
  final statusText = '热身阶段 · 不能悔棋 · 不能投降'.obs;

  static const lightOn = Icon(Icons.lightbulb, color: Color(0xFFFFC857));
  static const lightOff = Icon(
    Icons.lightbulb_outline_rounded,
    color: Color(0xFFFFF8F0),
  );
  static const circleIcon = Icon(
    Icons.circle_outlined,
    color: Color(0xFFFFF8F0),
  );
  static const rectIcon = Icon(Icons.crop_square, color: Color(0xFFFFF8F0));

  Icon get currentLight =>
      themeFactory.value is BlackThemeFactory ? lightOff : lightOn;

  Icon get currentShape => useCircle.value ? circleIcon : rectIcon;

  Color get themeColor => themeFactory.value.getTheme().getThemeColor();

  @override
  void onInit() {
    super.onInit();
    ai.init();
    _refreshStatus();
  }

  void toggleTheme() {
    themeFactory.value = themeFactory.value is BlackThemeFactory
        ? BlueThemeFactory()
        : BlackThemeFactory();
  }

  void toggleShape() => useCircle.toggle();

  ChessShape _shapeFor(bool circle) =>
      circle ? CircleShape() : RectShape();

  void _refreshStatus() {
    final s = _userContext.state;
    if (s is StartState) {
      statusText.value = '热身阶段 · 不能悔棋 · 不能投降';
    } else if (s is MidState) {
      statusText.value = '入神阶段 · 可悔棋 ${3 - s.reg} 次 · 可投降';
    } else if (s is EndState) {
      statusText.value = '白热化阶段 · 悔棋已用完 · 可投降';
    }
  }

  void onBoardTap(Offset local, double boardWidth) {
    if (gameOver.value) return;

    final cell = boardWidth / (kBoardSize - 1);
    final snap = _snapToGrid(local, cell);
    if (snap == null) return;

    final (gridX, gridY, px, py) = snap;
    if (!ai.isLegal(gridX, gridY)) return;

    _userContext.play();
    final chess = ChessFlyweightFactory.getInstance().getChess('white');
    board.add(Position(
      px,
      py,
      chess,
      gridX: gridX,
      gridY: gridY,
      chessShape: _shapeFor(useCircle.value),
    ));
    ai.addChessman(gridX, gridY, 1);
    paintVersion.value++;
    _refreshStatus();

    if (ai.isWin(gridX, gridY, 1)) {
      gameOver.value = true;
      TipsDialog.show(Get.context!, '恭喜', '您打败了决策树算法').then((_) {
        resetGame();
      });
      return;
    }

    _playAi(cell);
  }

  (int, int, double, double)? _snapToGrid(Offset local, double cell) {
    final gx = (local.dx / cell).round().clamp(0, kBoardSize - 1);
    final gy = (local.dy / cell).round().clamp(0, kBoardSize - 1);
    final px = gx * cell;
    final py = gy * cell;
    final dist = sqrt(pow(local.dx - px, 2) + pow(local.dy - py, 2));
    if (dist > cell / 2 - 2) return null;
    return (gx, gy, px, py);
  }

  void _playAi(double cell) {
    final raw = ai.searchPosition();
    if (raw.dx < 0 || raw.dy < 0) return;

    final gridX = raw.dx.toInt();
    final gridY = raw.dy.toInt();
    board.add(Position(
      gridX * cell,
      gridY * cell,
      raw.chess,
      gridX: gridX,
      gridY: gridY,
      chessShape: CircleShape(),
    ));
    ai.addChessman(gridX, gridY, -1);
    paintVersion.value++;

    if (ai.isWin(gridX, gridY, -1)) {
      gameOver.value = true;
      TipsDialog.show(Get.context!, '很遗憾', '决策树算法打败了您').then((_) {
        resetGame();
      });
    }
  }

  void undo() {
    if (gameOver.value) {
      TipsDialog.show(Get.context!, '提示', '对局已结束，请重新开局');
      return;
    }
    if (!_userContext.regretChess()) {
      TipsDialog.show(Get.context!, '提示', '现阶段不能悔棋');
      return;
    }
    board.undo();
    _rebuildAiFromBoard();
    paintVersion.value++;
    _refreshStatus();
  }

  void _rebuildAiFromBoard() {
    ai.init();
    for (final po in board.state) {
      ai.addChessman(
        po.gridX,
        po.gridY,
        po.chess is WhiteChess ? 1 : -1,
      );
    }
  }

  Future<void> surrender() async {
    if (!_userContext.surrender()) {
      await TipsDialog.show(Get.context!, '提示', '现阶段不能投降');
      return;
    }
    final ok = await TipsDialog.showByChoose(
      Get.context!,
      '确认投降',
      '投降后将重新开局',
      '投降',
      '否',
    );
    if (ok == true) resetGame();
  }

  Future<void> restart() async {
    final ok = await TipsDialog.showByChoose(
      Get.context!,
      '提示',
      '是否重新开局？',
      '是',
      '否',
    );
    if (ok == true) resetGame();
  }

  void resetGame() {
    board.clean();
    _userContext.reset();
    ai.init();
    gameOver.value = false;
    paintVersion.value++;
    _refreshStatus();
  }
}