import puppeteer from 'puppeteer';

/**
 * 極限深度查找 (Ultimate Meta Relay Lookup)
 * 專門針對 ScheduledServerJS -> __bbox -> RelayPrefetchedStreamCache 的參數結構
 */
function nestedLookup(obj, keys = ["thread_items", "replies", "child_posts", "threaded_replies", "post", "posts", "edges", "node", "reply_threads"]) {
    let results = [];
    if (typeof obj !== "object" || obj === null) return results;

    if (Array.isArray(obj)) {
        // 關鍵修正：檢查這是否為 RelayPrefetchedStreamCache 的呼叫陣列
        // 格式通常是 ["RelayPrefetchedStreamCache", "next", null, ["key", {數據物件}]]
        if (obj[0] === "RelayPrefetchedStreamCache" && Array.isArray(obj[3])) {
            const relayData = obj[3][1]; // 取得包含數據的第二個參數
            if (relayData) results = results.concat(nestedLookup(relayData, keys));
        }
        
        for (const item of obj) {
            results = results.concat(nestedLookup(item, keys));
        }
    } else {
        // 處理 __bbox 封裝結構
        if (obj.__bbox?.require) {
            results = results.concat(nestedLookup(obj.__bbox.require, keys));
        }
        if (obj.__bbox?.define) {
            results = results.concat(nestedLookup(obj.__bbox.define, keys));
        }

        for (const k in obj) {
            // 匹配目標鍵值
            if (keys.includes(k) && obj[k] !== null) {
                // 如果是列表結構，進一步遞迴
                if ((k === "edges" || k === "thread_items" || k === "reply_threads") && Array.isArray(obj[k])) {
                    results = results.concat(nestedLookup(obj[k], keys));
                } else {
                    results.push(obj[k]);
                }
            }

            // 繼續深度遍歷
            if (typeof obj[k] === "object" && obj[k] !== null) {
                results = results.concat(nestedLookup(obj[k], keys));
            }
        }
    }
    return results;
}

/**
 * 解析單一貼文資料 (支援更多 GraphQL 變體路徑)
 */
function parseThread(data) {
    if (!data) return null;
    
    // 遍歷所有可能的 Post 容器路徑
    let post = data.post || data.node?.post || data.thread_items?.[0]?.post || (data.posts && data.posts[0]) || (data.caption ? data : null);
    
    // 處理 GraphQL result.data 結構
    if (!post && data.result?.data) {
        const d = data.result.data;
        post = d.text_post_app_info || d.post || d;
    }

    if (!post || (!post.id && !post.pk)) return null;

    const mediaType = post.media_type;
    let images = [];
    let videos = [];
    let videoThumbnail = null;

    if (mediaType === 2 && post.video_versions?.length > 0) {
        const highestResVideo = post.video_versions.reduce((max, cur) => (cur.width > max.width ? cur : max), post.video_versions[0]);
        if (highestResVideo?.url) videos.push(highestResVideo.url);
        if (post.image_versions2?.candidates?.length > 0) videoThumbnail = post.image_versions2.candidates[0].url;
    } 
    else if (mediaType === 1 && post.image_versions2?.candidates?.length > 0) {
        const highestResImage = post.image_versions2.candidates.reduce((max, cur) => (cur.width > max.width ? cur : max), post.image_versions2.candidates[0]);
        if (highestResImage?.url) images.push(highestResImage.url);
    } 
    else if (mediaType === 8 && post.carousel_media?.length > 0) {
        post.carousel_media.forEach(m => {
            if (m.media_type === 1 && m.image_versions2?.candidates?.length > 0) images.push(m.image_versions2.candidates[0].url);
            if (m.media_type === 2 && m.video_versions?.length > 0) videos.push(m.video_versions[0].url);
        });
    }

    const result = {
        text: post.caption?.text || post.text_post_app_info?.share_info?.quoted_post?.caption?.text || "",
        published_on: post.taken_at,
        id: post.id || post.pk,
        code: post.code,
        username: post.user?.username,
        // user_pic: post.user?.profile_pic_url,
        like_count: post.like_count || 0,
        reply_count: post.direct_reply_count || post.reply_count || 0,
        // images,
        // videos,
        // video_thumbnail: videoThumbnail,
        // url: post.user?.username && post.code ? `https://www.threads.net/@${post.user.username}/post/${post.code}` : null
        parent_post_id: post.text_post_app_info?.reply_to_author?.id || post.reply_to_post_id || null
        
    };

    return result.id ? result : null;
}
async function scrapeThreadDataFromDOM() {
    const items = [];
    // Threads 的每一則貼文/回覆通常封裝在 data-pressable-container="true" 的 div 中
    const containers = document.querySelectorAll('div[data-pressable-container="true"]');

    containers.forEach(container => {
        try {
            // 1. 使用者名稱
            const userEl = container.querySelector('a[href*="/@"] span[translate="no"]');
            const username = userEl ? userEl.innerText.trim() : null;

            // 2. 貼文內容 (通常在 x1a6qonq 類別中)
            const textContentEls = container.querySelectorAll('.x1a6qonq span[dir="auto"]');
            const text = Array.from(textContentEls).map(el => el.innerText).join('\n').trim();

            // 3. 發布時間
            const timeEl = container.querySelector('time');
            const published_on = timeEl ? timeEl.getAttribute('datetime') : null;

            // 4. 互動數據 (讚、回覆、轉發)
            // 我們搜尋包含特定 aria-label 的 SVG
            const getCountByLabel = (label) => {
                const svg = container.querySelector(`svg[aria-label="${label}"]`);
                if (!svg) return 0;
                // 數據通常在 SVG 旁邊的 span 裡
                const countContainer = svg.closest('div').parentElement.querySelector('span');
                return countContainer ? countContainer.innerText : "0";
            };

            const like_count_str = getCountByLabel("讚");
            const reply_count_str = getCountByLabel("回覆");

            // 5. 貼文 ID / Code (從時間連結中取得)
            const linkEl = container.querySelector('a[href*="/post/"]');
            const postUrl = linkEl ? linkEl.href : null;
            const code = postUrl ? postUrl.split('/post/')[1]?.split('/')[0] : null;

            if (username && (text || code)) {
                items.push({
                    username,
                    text,
                    published_on,
                    like_count_str,
                    reply_count_str,
                    code,
                    url: postUrl
                });
            }
        } catch (err) {
            console.error("DOM Parsing error item:", err);
        }
    });
    return items;
}
export async function getThread(postUrl, cookies) {
    if (!postUrl?.includes("threads.")) throw new Error("無效的 Threads 網址");

    const postCodeFromUrl = postUrl.split("/post/")[1]?.split("/")[0];
    console.log(`[目標鎖定] 貼文代碼: ${postCodeFromUrl}`);

    const browser = await puppeteer.launch({
       headless: true, 
       args: [
            '--disable-blink-features=AutomationControlled', 
            '--no-sandbox', 
            '--disable-setuid-sandbox',
            '--window-size=1920,1080'
        ],
        slowMo: 50 
    });


    try {
        const page = await browser.newPage();
        await page.setUserAgent('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36');
        
         if (cookies && cookies.length > 0) {
            console.log(`[Auth] 正在注入 ${cookies.length} 個 Session Cookies...`);
            try {
                // 確保每個 cookie 對象至少包含 name, value 以及 domain 或 url
                await browser.setCookie(...cookies);
                console.log("[Auth] Cookies 注入成功");
                // console.log(await browser.cookies()); 

            } catch (cookieError) {
                console.error("[Auth] Cookies 格式錯誤或注入失敗:", cookieError.message);
            }
        }
      
        await page.setViewport({ width: 1280, height: 900 });

        console.log("[2/5] 頁面跳轉中...");
        await page.goto(postUrl, { 
            waitUntil: 'domcontentloaded', 
            timeout: 10000 
        });

        try {
            await page.waitForSelector('main', { timeout: 15000 });
            console.log("[3/5] 主容器已載入");
        } catch (e) {
            console.log("[警告] 等待 main 超時，繼續執行...");
        }

        console.log("[4/5] 開始執行滾動腳本...");

        console.log("[4/5] 執行模擬滑鼠滾動以加載大量留言...");
        
        // 將滑鼠移動到頁面中心以確保滾動事件被正確接收
        await page.mouse.move(960, 540);
        
        // 執行多次模擬滑鼠滾輪滾動
        const totalScrolls = 25;
        const scrollDistance = 1000;

        // 獲取初始高度
        let lastHeight = await page.evaluate(() => document.body.scrollHeight);
        console.log(`   - 初始頁面高度: ${lastHeight}px`);

        for (let i = 0; i < totalScrolls; i++) {
            await page.mouse.wheel({ deltaY: scrollDistance });
            await new Promise(r => setTimeout(r, 1500)); // 稍微增加等待時間讓 GraphQL 有反應
            
            // 每 5 次滾動做一次大幅度動作
            if (i % 5 === 0 && i !== 0) {
                await page.mouse.wheel({ deltaY: -600 });
                await new Promise(r => setTimeout(r, 500));
                await page.mouse.wheel({ deltaY: 800 });
            }

            // 檢查高度變化
            const currentHeight = await page.evaluate(() => document.body.scrollHeight);
            if (currentHeight > lastHeight) {
                console.log(`   - 第 ${i + 1} 次滾動: 偵測到內容加載！高度增加 ${currentHeight - lastHeight}px (目前: ${currentHeight}px)`);
                lastHeight = currentHeight;
            } else {
                console.log(`   - 第 ${i + 1} 次滾動: 高度未變化 (${currentHeight}px)`);
            }
        }

        console.log("[5/5] 等待數據流穩定 (10s)...");
        await new Promise(r => setTimeout(r, 10000));


         const rawItems = await page.evaluate(scrapeThreadDataFromDOM);

        // 後處理數據：轉換數字與區分主文/回覆
        const processedItems = rawItems.map(item => ({
            ...item,
            like_count: (item.like_count_str),
            reply_count: (item.reply_count_str),
            published_at: item.published_on ? new Date(item.published_on).getTime() / 1000 : null
        }));

        const mainThread = processedItems.find(t => t.code === postCodeFromUrl);
        const replies = processedItems.filter(t => t.code !== postCodeFromUrl);

        if (!mainThread) {
            console.log("[警告] DOM 中找不到主貼文，嘗試抓取第一個項目作為主文");
        }

        console.log(`[成功] 作者: ${mainThread?.username || '未知'}，回覆數: ${replies.length}`);

        // const allScripts = await page.$$eval(
        //     'script[type="application/json"]',
        //     (scripts) => scripts.map((s) => s.textContent)
        // );

        // console.log(`[解析] 成功掃描到 ${allScripts.length} 個 JSON 區塊`);

        // let allParsedItems = new Map();

        // allScripts.forEach((content) => {
        //     if (!content || !content.includes("ScheduledServerJS")) return;
        //     try {
        //         const data = JSON.parse(content);
        //         const rawItems = nestedLookup(data).flat();

        //         rawItems.forEach(item => {
        //             if (!item) return;
        //             const parsed = parseThread(item);
        //             if (parsed && parsed.id) {
        //                 allParsedItems.set(parsed.id, parsed);
        //             }
        //         });
        //     } catch (e) {}
        // });

        // const itemsArray = Array.from(allParsedItems.values());
        
        // const mainThread = itemsArray.find(t => t.code === postCodeFromUrl);

        // if (!mainThread) {
        //     throw new Error("無法定位主貼文。這通常是因為 Auth 阻擋或頁面未完全渲染。");
        // }
        
        // const authorName = mainThread.username;
        // const replies = itemsArray.filter(t => 
        //    t.code !== postCodeFromUrl
        //    && mainThread.id.includes(t.parent_post_id)
        // ).sort((a, b) => a.published_on - b.published_on);

        // console.log(`[解析成功] 找到主貼文，作者: ${authorName}，回覆數量: ${replies.length}`);

        return { thread: mainThread, replies };

    } finally {
        await browser.close();
    }
}