import { NextRequest, NextResponse } from "next/server";
import fs from "node:fs";
import path from "node:path";
import { parseDocxToRecipe, fillTemplate, extractTemplateRecipe, type Recipe } from "@/lib/editor135-core";

export const runtime = "nodejs";

function loadTemplate(): string {
  // 优先取项目根目录可替换的外部模板, 其次内置模板
  const external = path.join(process.cwd(), "template135.html");
  if (fs.existsSync(external)) return fs.readFileSync(external, "utf8");
  return fs.readFileSync(path.join(process.cwd(), "public", "template135.html"), "utf8");
}

export async function POST(req: NextRequest) {
  try {
    const form = await req.formData();
    const file = form.get("file");
    if (!(file instanceof File)) {
      return NextResponse.json({ error: "请上传文件(表单字段名 file)" }, { status: 400 });
    }
    if (!/\.docx$/i.test(file.name)) {
      return NextResponse.json({ error: "仅支持 .docx 文件" }, { status: 400 });
    }
    const buf = Buffer.from(await file.arrayBuffer());
    const recipe: Recipe = await parseDocxToRecipe(buf);
    if (!recipe.days.length) {
      return NextResponse.json(
        { error: "未能从文档中识别出食谱(需要包含 星期一~星期五 与 早餐/早点/午餐/体弱儿餐/午点 等关键词)" },
        { status: 422 },
      );
    }
    const template = loadTemplate();
    const templateRecipe = extractTemplateRecipe(template);
    const { html, report } = fillTemplate(template, recipe);
    const totalItems = recipe.days.reduce((n, d) => n + d.meals.reduce((k, m) => k + m.items.length, 0), 0);
    return NextResponse.json({
      fileName: file.name,
      recipe, report, html,
      summary: {
        days: recipe.days.length,
        totalItems,
        templateDays: templateRecipe.days.length,
        templateItems: templateRecipe.days.reduce((n, d) => n + d.meals.reduce((k, m) => k + m.items.length, 0), 0),
      },
    });
  } catch (e) {
    const msg = e instanceof Error ? e.message : String(e);
    return NextResponse.json({ error: `解析失败: ${msg}` }, { status: 500 });
  }
}