const corsHeaders = {
  "Access-Control-Allow-Origin": "*",
  "Access-Control-Allow-Methods": "GET,PUT,POST,DELETE,OPTIONS",
  "Access-Control-Allow-Headers": "*"
};
const BILI_API = "https://api.bilibili.com";

// 通用B站请求封装
async function biliProxy(url, sessdata) {
  const headers = {
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
    "Referer": "https://www.bilibili.com/",
    "Cookie": `SESSDATA=${sessdata}`
  };
  const resp = await fetch(url, { headers });
  return await resp.json();
}

// 获取视频完整字幕文本
async function getBiliSubtitle(bvid, sessdata) {
  const viewUrl = `${BILI_API}/x/web-interface/view?bvid=${bvid}`;
  const viewData = await biliProxy(viewUrl, sessdata);
  if (viewData.code !== 0) return null;
  const cid = viewData.data.cid;
  const subUrl = `${BILI_API}/x/player/v2?cid=${cid}&bvid=${bvid}`;
  const subData = await biliProxy(subUrl, sessdata);
  if (!subData.data?.subtitle?.subtitles?.length) return null;
  const subUrlRaw = subData.data.subtitle.subtitles[0].subtitle_url;
  const subResp = await fetch(subUrlRaw);
  const subJson = await subResp.json();
  let fullText = "";
  subJson.body.forEach(item => fullText += item.content + "\n");
  return fullText;
}

// AI结构化解析字幕：食材调料 + 分步做法（强化固定格式，减少错乱）
async function parseRecipeByAI(env, text) {
  const prompt = `
你是美食菜谱提取助手，严格按照下方固定格式输出，禁止增加额外解释、禁止编造不存在的用料和步骤。
从字幕原文提取：食材、调料、用量、制作步骤。
格式模板（严格遵守）：
【食材&调料清单】
- 条目1
- 条目2

【制作步骤】
第1步：
第2步：
第3步：

字幕原文：
"""${text}"""
`;
  const res = await env.AI.run("@cf/meta/llama-3.1-8b-instruct", {
    messages: [{ role: "user", content: prompt }]
  });
  return res.response;
}

async function handle(request, env) {
  const url = new URL(request.url);
  const path = url.pathname;

  // 基础菜谱CRUD接口
  if (path === "/ping") {
    return new Response(JSON.stringify({ ok: true, msg: "pong" }), {
      headers: { ...corsHeaders, "Content-Type": "application/json" }
    });
  }
  if (path === "/list") {
    const raw = await env.RECIPE_KV.get("recipe_data");
    const list = raw ? JSON.parse(raw) : [];
    return new Response(JSON.stringify(list), {
      headers: { ...corsHeaders, "Content-Type": "application/json" }
    });
  }
  if (path === "/save" && request.method === "POST") {
    const item = await request.json();
    const raw = await env.RECIPE_KV.get("recipe_data");
    const all = raw ? JSON.parse(raw) : [];
    const idx = all.findIndex(x => x.id === item.id);
    idx >= 0 ? all[idx] = item : all.push(item);
    await env.RECIPE_KV.put("recipe_data", JSON.stringify(all));
    return new Response(JSON.stringify({ ok: true }), {
      headers: { ...corsHeaders, "Content-Type": "application/json" }
    });
  }
  if (path === "/delete" && request.method === "DELETE") {
    const id = url.searchParams.get("id");
    const raw = await env.RECIPE_KV.get("recipe_data");
    const all = raw ? JSON.parse(raw) : [];
    const filtered = all.filter(x => x.id !== id);
    await env.RECIPE_KV.put("recipe_data", JSON.stringify(filtered));
    return new Response(JSON.stringify({ ok: true }), {
      headers: { ...corsHeaders, "Content-Type": "application/json" }
    });
  }

  // B站收藏夹列表
  if (path === "/bili/folders") {
    const mid = url.searchParams.get("mid");
    const sessdata = url.searchParams.get("sessdata");
    if (!mid || !sessdata) {
      return new Response(JSON.stringify({ code: -1, msg: "缺少mid或sessdata参数" }), { status: 400, headers: { ...corsHeaders, "Content-Type": "application/json" } });
    }
    const apiUrl = `${BILI_API}/x/v3/fav/folder/created/list-all?up_mid=${mid}`;
    const resData = await biliProxy(apiUrl, sessdata);
    return new Response(JSON.stringify(resData), { headers: { ...corsHeaders, "Content-Type": "application/json" } });
  }

  // 收藏夹视频分页接口
  if (path === "/bili/resources") {
    const media_id = url.searchParams.get("media_id");
    const sessdata = url.searchParams.get("sessdata");
    const pn = url.searchParams.get("pn") || "1";
    const ps = 20;
    if (!media_id || !sessdata) {
      return new Response(JSON.stringify({ code: -1, msg: "缺少media_id或sessdata参数" }), { status: 400, headers: { ...corsHeaders, "Content-Type": "application/json" } });
    }
    const apiUrl = `${BILI_API}/x/v3/fav/resource/list?media_id=${media_id}&pn=${pn}&ps=${ps}&order=mtime`;
    const resData = await biliProxy(apiUrl, sessdata);
    return new Response(JSON.stringify(resData), { headers: { ...corsHeaders, "Content-Type": "application/json" } });
  }

  // 单视频字幕抓取 + AI菜谱解析
  if (path === "/bili/parse-recipe") {
    const bvid = url.searchParams.get("bvid");
    const sessdata = url.searchParams.get("sessdata");
    if (!bvid || !sessdata) {
      return new Response(JSON.stringify({ code: -1, msg: "缺少bvid或sessdata" }), { status: 400, headers: { ...corsHeaders, "Content-Type": "application/json" } });
    }
    try {
      const subText = await getBiliSubtitle(bvid, sessdata);
      if (!subText) {
        return new Response(JSON.stringify({ code: 0, hasSub: false, msg: "该视频无可用字幕，无法自动拆分菜谱" }), { headers: { ...corsHeaders, "Content-Type": "application/json" } });
      }
      const aiResult = await parseRecipeByAI(env, subText);
      return new Response(JSON.stringify({ code: 0, hasSub: true, content: aiResult }), { headers: { ...corsHeaders, "Content-Type": "application/json" } });
    } catch (err) {
      return new Response(JSON.stringify({ code: -2, msg: "AI解析失败：" + err.message }), { headers: { ...corsHeaders, "Content-Type": "application/json" } });
    }
  }

  return new Response("Not found", { status: 404, headers: corsHeaders });
}

export default {
  async fetch(request, env, ctx) {
    if (request.method === "OPTIONS") return new Response(null, { headers: corsHeaders });
    return await handle(request, env);
  }
};