import express from 'express';
import { chromium } from 'playwright';
import cors from 'cors';
import bodyParser from 'body-parser'

const app = express();
const PORT = process.env.PORT || 7860;

app.set('json spaces', 2)

app.use(bodyParser.urlencoded({ extended: true }))
app.use(bodyParser.json())
app.use(express.json({ limit: '500mb' }));
app.use(cors());

async function extractContentFromUrl(url, browser) {
    const context = await browser.newContext({
        userAgent: 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
        viewport: { width: 1920, height: 1080 },
        locale: 'en-US',
        timezoneId: 'America/New_York'
    });
    const page = await context.newPage();
    
    try {
        // Intercept dan block resource yang tidak perlu
        await page.route('**/*', (route) => {
            const resourceType = route.request().resourceType();
            if (['font', 'media'].includes(resourceType)) {
                route.abort();
            } else {
                route.continue();
            }
        });

        await page.goto(url, {
            waitUntil: 'networkidle',
            timeout: 60000
        });
        
        // Wait for content to be visible
        await page.waitForSelector('body', { state: 'visible', timeout: 30000 });
        
        // Scroll untuk trigger lazy loading
        await page.evaluate(() => {
            return new Promise((resolve) => {
                let totalHeight = 0;
                const distance = 100;
                const timer = setInterval(() => {
                    const scrollHeight = document.body.scrollHeight;
                    window.scrollBy(0, distance);
                    totalHeight += distance;
                    
                    if(totalHeight >= scrollHeight){
                        clearInterval(timer);
                        window.scrollTo(0, 0);
                        resolve();
                    }
                }, 100);
            });
        });
        
        // Wait tambahan setelah scroll
        await page.waitForTimeout(2000);
        
        const content = await page.evaluate(() => {
            const cleanText = (text) => {
                return text ? text.replace(/\s+/g, ' ').trim() : '';
            };
            
            // Helper function untuk mendapatkan text content yang lebih baik
            const getTextContent = (element) => {
                if (!element) return '';
                
                // Clone element untuk manipulasi
                const clone = element.cloneNode(true);
                
                // Remove script dan style tags
                const scripts = clone.querySelectorAll('script, style, noscript');
                scripts.forEach(el => el.remove());
                
                // Get text content
                return cleanText(clone.textContent || clone.innerText || '');
            };
            
            const title = document.title || '';
            const metaDescription = document.querySelector('meta[name="description"]')?.content || 
                                  document.querySelector('meta[property="og:description"]')?.content || '';
            
            // Improved heading extraction
            const h1Elements = Array.from(document.querySelectorAll('h1'))
                .map(h1 => getTextContent(h1))
                .filter(text => text.length > 0);
                
            const h2Elements = Array.from(document.querySelectorAll('h2'))
                .map(h2 => getTextContent(h2))
                .filter(text => text.length > 0);
            
            // Improved paragraph extraction
            const paragraphs = Array.from(document.querySelectorAll('p'))
                .map(p => getTextContent(p))
                .filter(text => text.length > 20);
            
            // Try multiple selectors for main content
            const contentSelectors = [
                'main', 
                'article', 
                '[role="main"]',
                '.content', 
                '#content', 
                '.post-content',
                '.entry-content',
                '.article-content',
                '.page-content',
                '.main-content',
                '[itemprop="articleBody"]',
                '.story-body',
                '.article-body'
            ];
            
            let mainContent = null;
            for (const selector of contentSelectors) {
                mainContent = document.querySelector(selector);
                if (mainContent) break;
            }
            
            // Fallback: jika tidak ada main content, ambil dari body
            if (!mainContent) {
                mainContent = document.body;
            }
            
            const mainText = getTextContent(mainContent);
            
            // Jika mainText masih kosong, coba ambil semua text dari div yang panjang
            let fallbackText = '';
            if (!mainText || mainText.length < 100) {
                const allDivs = Array.from(document.querySelectorAll('div'))
                    .map(div => getTextContent(div))
                    .filter(text => text.length > 200)
                    .sort((a, b) => b.length - a.length);
                    
                fallbackText = allDivs[0] || '';
            }
            
            const finalMainText = mainText || fallbackText;
            
            // Extract links dengan filter yang lebih baik
            const links = Array.from(document.querySelectorAll('a[href]'))
                .map(a => ({
                    text: getTextContent(a),
                    href: a.href
                }))
                .filter(link => link.text && link.href && !link.href.startsWith('javascript:'))
                .slice(0, 20);

            // Extract images dengan filter yang lebih baik
            const images = Array.from(document.querySelectorAll('img[src]'))
                .filter(img => img.src && !img.src.includes('data:image'))
                .map(img => ({
                    src: img.src,
                    alt: img.alt || '',
                    title: img.title || ''
                }))
                .slice(0, 10);
            
            // Calculate word count
            const allText = finalMainText || paragraphs.join(' ') || document.body.innerText || '';
            const wordCount = allText.split(/\s+/).filter(word => word.length > 0).length;

            return {
                title,
                metaDescription,
                headings: {
                    h1: h1Elements,
                    h2: h2Elements
                },
                paragraphs,
                mainText: finalMainText,
                links,
                images,
                wordCount,
                hasContent: wordCount > 50 // Flag untuk mengecek apakah ada konten
            };
        });
        
        return {
            url,
            success: true,
            content,
            extractedAt: new Date().toISOString()
        };
    } catch (error) {
        console.error(`Error extracting ${url}:`, error);
        return {
            url,
            success: false,
            error: error.message,
            extractedAt: new Date().toISOString()
        };
    } finally {
        await context.close();
    }
}

app.post('/extract-content', async (req, res) => {
    const { urls } = req.body;
    
    if (!urls || !Array.isArray(urls)) {
        return res.status(400).json({
            success: false,
            message: 'Body harus berisi array urls'
        });
    }
    
    if (urls.length === 0) {
        return res.status(400).json({
            success: false,
            message: 'Array urls tidak boleh kosong'
        });
    }
    
    if (urls.length > 10) {
        return res.status(400).json({
            success: false,
            message: 'Maksimal 10 URLs per request'
        });
    }
    
    const validUrls = [];
    const invalidUrls = [];
    
    urls.forEach(url => {
        try {
            new URL(url);
            validUrls.push(url);
        } catch (error) {
            invalidUrls.push(url);
        }
    });
    
    if (invalidUrls.length > 0) {
        return res.status(400).json({
            success: false,
            message: 'Format URL tidak valid',
            invalidUrls
        });
    }
    
    let browser;
    
    try {
        browser = await chromium.launch({
            args: [
                '--incognito', 
                '--single-process', 
                '--no-sandbox', 
                '--no-zygote', 
                '--no-cache',
                '--disable-dev-shm-usage',
                '--disable-setuid-sandbox',
                '--disable-accelerated-2d-canvas',
                '--disable-gpu'
            ],
            executablePath: process.env.CHROME_BIN,
            headless: true,
        });
        
        const concurrencyLimit = 3;
        const results = [];
        
        for (let i = 0; i < validUrls.length; i += concurrencyLimit) {
            const batch = validUrls.slice(i, i + concurrencyLimit);
            const batchPromises = batch.map(url => extractContentFromUrl(url, browser));
            const batchResults = await Promise.all(batchPromises);
            results.push(...batchResults);
        }

        const successCount = results.filter(r => r.success).length;
        const failCount = results.filter(r => !r.success).length;
        const emptyContentCount = results.filter(r => r.success && (!r.content.hasContent || r.content.wordCount < 50)).length;

        res.json({
            success: true,
            message: `Berhasil memproses ${validUrls.length} URLs`,
            statistics: {
                total: validUrls.length,
                success: successCount,
                failed: failCount,
                emptyContent: emptyContentCount
            },
            results
        });
        
    } catch (error) {
        console.error('Error:', error);
        res.status(500).json({
            success: false,
            message: 'Terjadi kesalahan saat memproses URLs',
            error: error.message
        });
    } finally {
        if (browser) {
            await browser.close();
        }
    }
});

app.get('/health', (req, res) => {
    res.json({
        success: true,
        message: 'Content Extractor API is running',
        timestamp: new Date().toISOString()
    });
});

app.get('/', (req, res) => {
    res.json({
        success: true,
        message: 'Content Extractor API',
        endpoints: {
            'POST /extract-content': 'Extract content from URLs',
            'GET /health': 'Health check',
            'GET /': 'API information'
        },
        usage: {
            method: 'POST',
            endpoint: '/extract-content',
            body: {
                urls: ['https://example.com', 'https://another-site.com']
            }
        }
    });
});

app.use((err, req, res, next) => {
    console.error('Unhandled error:', err);
    res.status(500).json({
        success: false,
        message: 'Internal server error',
        error: process.env.NODE_ENV === 'development' ? err.message : 'Something went wrong'
    });
});

app.use((req, res) => {
    res.status(404).json({
        success: false,
        message: 'Endpoint not found'
    });
});

app.listen(PORT, () => {
    console.log(`🚀 Content Extractor API running on port ${PORT}`);
    console.log(`📖 API Documentation: http://localhost:${PORT}`);
    console.log(`🏥 Health Check: http://localhost:${PORT}/health`);
});