import { NextRequest, NextResponse } from "next/server";
import mammoth from "mammoth";
import * as cheerio from "cheerio";

// 餐食类型
enum MealTypeCode {
  BREAKFAST = "breakfast",
  FRUIT = "fruit",
  LUNCH = "lunch",
  SNACK = "snack",
  SPECIAL = "special",
}

// 语言名称项
interface LangName {
  zh: string;
  en?: string;
}

// 单个菜品
interface Dish {
  id: string;
  name: LangName;
}

// 单日食谱
interface DailyMeal {
  dayCode: number;
  mealCode: MealTypeCode;
  dishList: Dish[];
}

// 一周食谱
interface WeeklyMenu {
  menuId: string;
  weekNumber: string;
  title: LangName;
  days: { code: number; name: LangName }[];
  mealCategories: { code: MealTypeCode; name: LangName; sort: number }[];
  meals: DailyMeal[];
}

// 餐食类型配置
const MEAL_TYPES = [
  { code: MealTypeCode.BREAKFAST, label: "早餐" },
  { code: MealTypeCode.FRUIT, label: "水果餐" },
  { code: MealTypeCode.LUNCH, label: "中餐" },
  { code: MealTypeCode.SPECIAL, label: "体弱儿专属" },
  { code: MealTypeCode.SNACK, label: "午点" },
];

const WEEK_DAYS = [
  { code: 1, label: "周一" },
  { code: 2, label: "周二" },
  { code: 3, label: "周三" },
  { code: 4, label: "周四" },
  { code: 5, label: "周五" },
];

/**
 * 使用 Cheerio 从 HTML 中提取表格原始数据
 */
function extractRawDataFromHtml(html: string): string[][][] {
  const tableData: string[][][] = [];
  const $ = cheerio.load(html);

  const rows = $("table tr");

  rows.each((rowIndex, row) => {
    const rowData: string[][] = [];
    const cells = $(row).find("td");

    cells.each((cellIndex, cell) => {
      // 直接获取 HTML 并处理
      const rawHtml = $(cell).html() || "";

      // 替换换行标签为真实换行符
      const processed = rawHtml
        .replace(/<\/p><p[^>]*>/g, "\n")  // </p><p> → 换行
        .replace(/<br\s*\/?>/gi, "\n")
        .replace(/&nbsp;/g, " ");

      // 移除剩余 HTML 标签
      const text = processed.replace(/<[^>]+>/g, "");

      // 按换行分割
      const lines = text.split("\n").filter((line) => line.trim() !== "");

      // 对每行应用顿号/逗号/分号分割
      const finalItems: string[] = [];
      lines.forEach((line) => {
        finalItems.push(...splitCellContent(line));
      });

      rowData.push(finalItems);
    });

    if (rowData.length > 0) {
      tableData.push(rowData);
    }
  });

  return tableData;
}

/**
 * 分割单元格内容为菜品列表
 * 支持分隔符：顿号（、）、逗号（,）、分号（；）
 */
function splitCellContent(content: string): string[] {
  if (!content || content.trim() === "") return [];

  // 统一分隔符
  const normalized = content
    .replace(/；/g, "|")
    .replace(/,/g, "|")
    .replace(/、/g, "|")
    .trim();

  const parts = normalized.split("|");

  return parts
    .map((item) => item.trim())
    .filter(Boolean);
}

/**
 * 确定餐食类型
 */
function getMealType(mealName: string): MealTypeCode | null {
  if (mealName.includes("早")) return MealTypeCode.BREAKFAST;
  if (mealName.includes("水果")) return MealTypeCode.FRUIT;
  if (mealName.includes("中") || mealName.includes("午餐")) return MealTypeCode.LUNCH;
  if (mealName.includes("午点") || mealName.includes("点心")) return MealTypeCode.SNACK;
  if (mealName.includes("体弱") || mealName.includes("晚")) return MealTypeCode.SPECIAL;
  return null;
}

/**
 * 从表格数据转换为一周食谱结构
 */
function transformTableToWeeklyMenu(tableData: string[][][]): WeeklyMenu {
  const meals: DailyMeal[] = [];

  // 校验表格数据完整性
  if (tableData.length < 2 || tableData[0].length < 2) {
    console.warn("警告：表格数据不完整");
    return createEmptyMenu();
  }

  // 提取表头数据（星期几）
  const weekdays = tableData[0].slice(1).map((cell) => cell[0] || "");

  // 提取餐型行数据（从第二行开始）
  const mealTypeRows = tableData.slice(1);

  // 遍历每一天（列）
  for (let dayIndex = 0; dayIndex < weekdays.length; dayIndex++) {
    const dayName = weekdays[dayIndex];
    if (!dayName) continue;

    const columnIndex = dayIndex + 1; // 对应星期几的列索引

    // 遍历每一行餐型
    for (const row of mealTypeRows) {
      const mealName = row[0]?.[0] || ""; // 餐型名称
      if (!mealName) continue;

      const mealType = getMealType(mealName);
      if (!mealType) continue;

      // 获取当前餐型的菜品列表
      const mealItems = row[columnIndex] || [];

      // 添加到当天餐食列表
      meals.push({
        dayCode: dayIndex + 1,
        mealCode: mealType,
        dishList: mealItems.map((item, idx) => ({
          id: `${dayIndex + 1}-${mealType}-${idx + 1}`,
          name: { zh: item },
        })),
      });
    }
  }

  // 确保每天每餐都有记录
  for (const day of WEEK_DAYS) {
    for (const meal of MEAL_TYPES) {
      const exists = meals.find(
        (m) => m.dayCode === day.code && m.mealCode === meal.code
      );
      if (!exists) {
        meals.push({ dayCode: day.code, mealCode: meal.code, dishList: [] });
      }
    }
  }

  // 构建 days 数组，使用实际解析出的星期
  const days = weekdays
    .filter(Boolean)
    .map((name, index) => ({ code: index + 1, name: { zh: name } }));

  return {
    menuId: `menu-${Date.now()}`,
    weekNumber: "",
    title: { zh: "食谱", en: "Recipe" },
    days: days,
    mealCategories: MEAL_TYPES.map((m, i) => ({
      code: m.code,
      name: { zh: m.label },
      sort: i + 1,
    })),
    meals: meals.sort((a, b) => {
      if (a.dayCode !== b.dayCode) return a.dayCode - b.dayCode;
      const orderMap: Record<MealTypeCode, number> = {
        [MealTypeCode.BREAKFAST]: 0,
        [MealTypeCode.FRUIT]: 1,
        [MealTypeCode.LUNCH]: 2,
        [MealTypeCode.SNACK]: 3,
        [MealTypeCode.SPECIAL]: 4,
      };
      return orderMap[a.mealCode] - orderMap[b.mealCode];
    }),
  };
}

function createEmptyMenu(): WeeklyMenu {
  return {
    menuId: `menu-${Date.now()}`,
    weekNumber: "",
    title: { zh: "食谱", en: "Recipe" },
    days: WEEK_DAYS.map((d) => ({ code: d.code, name: { zh: d.label } })),
    mealCategories: MEAL_TYPES.map((m, i) => ({
      code: m.code,
      name: { zh: m.label },
      sort: i + 1,
    })),
    meals: [],
  };
}

export async function POST(request: NextRequest) {
  try {
    const formData = await request.formData();
    const file = formData.get("file") as File | null;

    if (!file) {
      return NextResponse.json({ error: "未上传文件" }, { status: 400 });
    }

    if (!file.name.endsWith(".docx")) {
      return NextResponse.json({ error: "仅支持 .docx 格式" }, { status: 400 });
    }

    // 读取文件为 ArrayBuffer
    const arrayBuffer = await file.arrayBuffer();
    const buffer = Buffer.from(arrayBuffer);

    // 使用 mammoth 转换为 HTML（保留表格结构）
    const { value: htmlContent } = await mammoth.convertToHtml({ buffer });

    // 使用 cheerio 提取表格数据
    const tableData = extractRawDataFromHtml(htmlContent);

    // 转换为结构化数据
    const weeklyMenu = transformTableToWeeklyMenu(tableData);

    return NextResponse.json({
      success: true,
      data: weeklyMenu,
    });
  } catch (error) {
    console.error("Parse error:", error);
    return NextResponse.json(
      { error: "文件解析失败", details: String(error) },
      { status: 500 }
    );
  }
}