import express from 'express';
import * as cheerio from 'cheerio';
import { chromium } from 'playwright';

const app = express();
const PORT = 7860;

const CACHE_TTL = 3600;
const cache = new Map();

// ===== تابع تبدیل URL برتینا به لینک واقعی =====
function decodeBertinaUrl(bertinaUrl) {
    if (!bertinaUrl || !bertinaUrl.startsWith('/api/click')) {
        return bertinaUrl;
    }

    try {
        const url = new URL(bertinaUrl, 'https://search.bertina.ir');
        const dest = url.searchParams.get('dest');
        if (dest) {
            return Buffer.from(dest, 'base64').toString('utf-8');
        }
        return bertinaUrl;
    } catch {
        return bertinaUrl;
    }
}

// ===== استخراج نتایج ارگانیک =====
async function searchBertinaOrganic(query) {
    const url = `https://search.bertina.ir/search?q=${encodeURIComponent(query)}`;
    console.log(`🔍 Fetching organic results from Bertina...`);

    try {
        const response = await fetch(url, {
            headers: {
                'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36'
            },
            signal: AbortSignal.timeout(15000)
        });

        if (!response.ok) throw new Error(`HTTP ${response.status}`);
        const html = await response.text();
        const $ = cheerio.load(html);

        const results = [];
        $('article.group.animate-fade-in').each((i, el) => {
            const isAd = $(el).attr('data-ad-id') !== undefined;
            if (isAd) return;

            const link = $(el).find('h3 a');
            const title = link.text().trim();
            const href = link.attr('href') || '';
            const domain = $(el).find('cite.not-italic').text().trim();
            const snippet = $(el).find('p.mt-1.text-sm').text().trim();

            if (title && href) {
                // تبدیل URL به لینک واقعی
                const realUrl = decodeBertinaUrl(href);
                results.push({
                    title: title.slice(0, 200),
                    url: realUrl,
                    snippet: snippet.slice(0, 300),
                    site: domain || new URL(realUrl).hostname.replace('www.', '')
                });
            }
        });

        console.log(`✅ Organic results: ${results.length}`);
        return results;
    } catch (error) {
        console.error(`❌ Organic fetch error:`, error.message);
        return [];
    }
}

// ===== استخراج پاسخ هوش مصنوعی =====
async function searchBertinaAI(query) {
    console.log(`🤖 Fetching AI answer with Playwright...`);
    let browser;
    try {
        browser = await chromium.launch({
            headless: true,
            args: ['--no-sandbox', '--disable-dev-shm-usage']
        });
        const page = await browser.newPage();

        await page.goto(`https://search.bertina.ir/search?q=${encodeURIComponent(query)}`, {
            waitUntil: 'networkidle',
            timeout: 30000
        });

        // منتظر می‌مانیم تا بخش پاسخ هوش مصنوعی بارگذاری شود
        try {
            await page.waitForSelector('aside[aria-label="پاسخ هوش مصنوعی"]', {
                timeout: 10000
            });
        } catch (e) {
            console.log('⏭️ No AI answer section found');
            return null;
        }

        // استخراج متن پاسخ با سلکتور دقیق‌تر
        // متن پاسخ داخل یک div با کلاس text-sm leading-relaxed قرار دارد
        const aiAnswer = await page.$eval(
            'aside[aria-label="پاسخ هوش مصنوعی"] .text-sm.leading-relaxed',
            el => el.textContent.trim()
        ).catch(() => null);

        // اگر با سلکتور بالا پیدا نشد، از سلکتور جایگزین استفاده کن
        let aiAnswer2 = null;
        if (!aiAnswer || aiAnswer.length < 10) {
            aiAnswer2 = await page.$eval(
                'aside[aria-label="پاسخ هوش مصنوعی"] .space-y-2',
                el => el.textContent.trim()
            ).catch(() => null);
        }

        const finalAnswer = aiAnswer || aiAnswer2;

        if (finalAnswer && finalAnswer.length > 10 && !finalAnswer.includes('در حال تفکر')) {
            console.log(`✅ AI answer extracted: ${finalAnswer.slice(0, 50)}...`);
            return finalAnswer;
        }

        console.log('⏭️ AI answer content is empty or still loading');
        return null;

    } catch (error) {
        console.error(`❌ Playwright error:`, error.message);
        return null;
    } finally {
        if (browser) await browser.close();
    }
}

// ===== جستجوی اصلی =====
async function search(query) {
    const cached = cache.get(query);
    if (cached && Date.now() - cached.timestamp < CACHE_TTL * 1000) {
        console.log(`✅ Cache hit for "${query}"`);
        return cached.results;
    }

    console.log(`🔍 Searching for: "${query}"`);

    // ۱. نتایج ارگانیک
    let results = await searchBertinaOrganic(query);

    // ۲. پاسخ هوش مصنوعی
    let aiAnswer = null;
    if (results.length > 0) {
        aiAnswer = await searchBertinaAI(query);
    }

    // ۳. اگر نتیجه‌ای نبود، DuckDuckGo
    if (results.length === 0) {
        console.log(`🔄 Falling back to DuckDuckGo...`);
        try {
            const ddg = await fetch(
                `https://api.duckduckgo.com/?q=${encodeURIComponent(query)}&format=json&no_html=1&skip_disambig=1`
            );
            const data = await ddg.json();
            results = (data.RelatedTopics || [])
                .filter(t => t.FirstURL && t.Text)
                .slice(0, 10)
                .map(t => ({
                    title: t.Text.split('-')[0]?.trim() || t.Text,
                    url: t.FirstURL,
                    snippet: t.Text,
                    site: new URL(t.FirstURL).hostname.replace('www.', '')
                }));
        } catch (e) {}
    }

    const output = {
        query,
        results,
        ai_answer: aiAnswer,
        source: results.length > 0 ? 'bertina' : 'duckduckgo'
    };

    cache.set(query, { results: output, timestamp: Date.now() });
    return output;
}

// ===== مسیر جستجو =====
app.get('/search', async (req, res) => {
    const query = req.query.q;
    if (!query) {
        return res.status(400).json({ error: 'Missing query parameter' });
    }

    try {
        const result = await search(query);
        res.json(result);
    } catch (error) {
        console.error(`❌ Error:`, error.message);
        res.status(500).json({
            error: error.message,
            query,
            results: [],
            ai_answer: null
        });
    }
});

app.get('/', (req, res) => {
    res.json({
        status: 'running',
        usage: '/search?q=YOUR_QUERY',
        note: 'Bertina search + AI answer + real URLs'
    });
});

app.listen(PORT, '0.0.0.0', () => {
    console.log(`🚀 Server running on port ${PORT}`);
    console.log(`📍 Test: http://localhost:${PORT}/search?q=هوش مصنوعی`);
});