import type { TrayItem, CarColor } from "./types";
import { GameConfig } from "../GameConfig";

/**
 * 篮子匹配引擎
 * 同类聚合插入 + 3 消检测
 */
export class MatchEngine {
  /**
   * 将物品插入篮子（同类聚合：新物品插到最后一个同色物品旁边）
   */
  static insertToTray(
    item: TrayItem,
    tray: TrayItem[],
  ): { newTray: TrayItem[]; insertIndex: number } {
    const newTray = [...tray];

    // 寻找最后一个同色物品的位置
    let lastSameColorIndex = -1;
    for (let i = newTray.length - 1; i >= 0; i--) {
      if (newTray[i].color === item.color) {
        lastSameColorIndex = i;
        break;
      }
    }

    let insertIndex: number;
    if (lastSameColorIndex >= 0) {
      insertIndex = lastSameColorIndex + 1;
      newTray.splice(insertIndex, 0, item);
    } else {
      insertIndex = newTray.length;
      newTray.push(item);
    }

    return { newTray, insertIndex };
  }

  /**
   * 检测篮子中是否有 3 个同色物品
   * @returns 匹配的物品列表（空数组表示无匹配）
   */
  static checkMatch(tray: TrayItem[]): TrayItem[] {
    const colorCount = new Map<CarColor, TrayItem[]>();

    for (const item of tray) {
      const list = colorCount.get(item.color) || [];
      list.push(item);
      colorCount.set(item.color, list);
    }

    for (const [, items] of colorCount) {
      if (items.length >= GameConfig.MATCH_COUNT) {
        return items.slice(0, GameConfig.MATCH_COUNT);
      }
    }

    return [];
  }

  /**
   * 从篮子中移除匹配的物品
   */
  static removeFromTray(tray: TrayItem[], matchedIds: string[]): TrayItem[] {
    const idSet = new Set(matchedIds);
    return tray.filter(item => !idSet.has(item.id));
  }

  /**
   * 判断篮子是否已满
   */
  static isTrayFull(tray: TrayItem[], capacity: number): boolean {
    return tray.length >= capacity;
  }
}