// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
// Posimai Brain API - /save endpoint (UPDATED)
// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
// Purpose: Save articles from Reader with full-text content
// Location: Copy this to Synology NAS at /app/server.js or /brain/api/save.js
// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

/**
 * POST /brain/api/save
 *
 * Saves an article to Brain with full-text content and AI analysis
 *
 * Request body:
 * {
 *   url: string          // Article URL (required)
 *   title: string        // Article title (required)
 *   content: string      // Full article body from Reader (NEW!)
 *   source: string       // 'reader', 'feed', or 'bookmarklet'
 * }
 *
 * Response:
 * {
 *   success: boolean
 *   articleId: number
 *   fullTextSaved: boolean  // Debug info
 *   textLength: number      // Debug info
 * }
 */
router.post('/save', authMiddleware, async (req, res) => {
    const { url, title, content, source } = req.body || {};

    // ──────────────────────────────────────────────────────────────────
    // 1. Validation
    // ──────────────────────────────────────────────────────────────────
    if (!url || !title) {
        return res.status(400).json({
            error: 'Missing required fields: url and title are required'
        });
    }

    try {
        // ──────────────────────────────────────────────────────────────
        // 2. Get full text content
        // ──────────────────────────────────────────────────────────────
        let fullText = content || null;  // Content from Reader
        let meta = {};

        // If no content provided (e.g., from Feed, Web Share, Command Palette)
        // Fetch full text via Jina Reader API
        if (!fullText || fullText.trim().length === 0) {
            console.log(`[Brain API] No content provided, fetching via Jina Reader for ${url}`);

            try {
                // Jina Reader API call
                const jinaResponse = await fetch(`https://r.jina.ai/${url}`, {
                    headers: {
                        'User-Agent': 'Mozilla/5.0 Posimai Brain Bot'
                    },
                    timeout: 15000  // 15 second timeout
                });

                if (jinaResponse.ok) {
                    let markdown = await jinaResponse.text();

                    // Extract Markdown content (same logic as Reader)
                    const contentMarker = 'Markdown Content:';
                    const contentIndex = markdown.indexOf(contentMarker);
                    if (contentIndex !== -1) {
                        fullText = markdown.substring(contentIndex + contentMarker.length).trim();
                    } else {
                        fullText = markdown;
                    }

                    // Remove image references (same logic as Reader)
                    fullText = fullText.replace(/!\[Image\s+\d+[^\]]*\]\([^)]*\)/gmi, '');
                    fullText = fullText.replace(/!\[Image\s+\d+[^\]]*\]/gmi, '');
                    fullText = fullText.replace(/^\s*\*?\s*!\[?Image\s+\d+[^\n]*/gmi, '');
                    fullText = fullText.replace(/\[\]\([^)]*\)/gm, '');

                    console.log(`[Brain API] Fetched full text via Jina Reader (${fullText.length} chars)`);
                } else {
                    console.warn(`[Brain API] Jina Reader returned status ${jinaResponse.status}`);
                }
            } catch (error) {
                console.error('[Brain API] Jina Reader fetch failed:', error);
            }

            // Fallback: If Jina Reader failed, use OGP description
            if (!fullText || fullText.trim().length === 0) {
                console.log(`[Brain API] Jina Reader failed, falling back to OGP for ${url}`);
                meta = await fetchOGP(url);
                fullText = meta.desc || '';
            }
        } else {
            console.log(`[Brain API] Received full text content (${fullText.length} chars) for ${url}`);
        }

        // Fetch OGP metadata for favicon/og_image (regardless of full text source)
        if (!meta.favicon && !meta.ogImage) {
            meta = await fetchOGP(url);
        }

        // ──────────────────────────────────────────────────────────────
        // 3. AI Analysis with full text
        // ──────────────────────────────────────────────────────────────
        const ai = await analyzeWithGemini(title, fullText, url);

        // ──────────────────────────────────────────────────────────────
        // 4. Save to database with full_text
        // ──────────────────────────────────────────────────────────────
        const result = await pool.query(`
            INSERT INTO articles (
                user_id,
                url,
                title,
                full_text,
                summary,
                topics,
                source,
                favicon,
                og_image,
                status,
                created_at,
                updated_at
            ) VALUES (
                $1, $2, $3, $4, $5, $6, $7, $8, $9, $10, NOW(), NOW()
            )
            ON CONFLICT (user_id, url) DO UPDATE SET
                title = EXCLUDED.title,
                full_text = EXCLUDED.full_text,
                summary = EXCLUDED.summary,
                topics = EXCLUDED.topics,
                favicon = EXCLUDED.favicon,
                og_image = EXCLUDED.og_image,
                updated_at = NOW()
            RETURNING id
        `, [
            req.userId,              // $1: user_id from authMiddleware
            url,                     // $2: url
            title,                   // $3: title
            fullText,                // $4: full_text
            ai.summary,              // $5: AI-generated summary
            ai.topics,               // $6: AI-generated topics
            source || 'reader',      // $7: source
            meta.favicon || null,    // $8: favicon
            meta.ogImage || null,    // $9: og_image
            'inbox'                  // $10: default status
        ]);

        const articleId = result.rows[0].id;

        // ──────────────────────────────────────────────────────────────
        // 5. Success response
        // ──────────────────────────────────────────────────────────────
        console.log(`[Brain API] Article saved successfully: ID=${articleId}, URL=${url}, FullText=${!!fullText}, Length=${fullText?.length || 0}`);

        return res.json({
            success: true,
            articleId: articleId,
            fullTextSaved: !!fullText,       // Debug: Was full text saved?
            textLength: fullText?.length || 0  // Debug: How long is the text?
        });

    } catch (error) {
        console.error('[Brain API] Save failed:', error);

        return res.status(500).json({
            error: 'Failed to save article',
            message: error.message
        });
    }
});

// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
// Helper Functions
// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

/**
 * Fetch OGP metadata from URL
 *
 * @param {string} url - Article URL
 * @returns {Promise<{desc: string, favicon: string, ogImage: string}>}
 */
async function fetchOGP(url) {
    try {
        // Your existing OGP fetching logic
        // Example implementation:
        const response = await fetch(url, {
            headers: { 'User-Agent': 'Mozilla/5.0 Posimai Brain Bot' }
        });

        const html = await response.text();

        // Parse OGP tags (simplified example)
        const descMatch = html.match(/<meta property="og:description" content="([^"]+)"/);
        const imageMatch = html.match(/<meta property="og:image" content="([^"]+)"/);
        const faviconMatch = html.match(/<link rel="icon" href="([^"]+)"/);

        return {
            desc: descMatch ? descMatch[1] : '',
            ogImage: imageMatch ? imageMatch[1] : null,
            favicon: faviconMatch ? faviconMatch[1] : null
        };

    } catch (error) {
        console.error('[fetchOGP] Failed to fetch OGP metadata:', error);
        return { desc: '', ogImage: null, favicon: null };
    }
}

/**
 * Analyze article with Gemini AI
 *
 * @param {string} title - Article title
 * @param {string} fullText - Full article body
 * @param {string} url - Article URL
 * @returns {Promise<{summary: string, topics: string[], readingTime: number}>}
 */
async function analyzeWithGemini(title, fullText, url) {
    try {
        // Limit text length to prevent token overflow
        // Gemini Flash: ~30k tokens input, ~1 token = 3-4 chars
        // Safe limit: 5000 chars = ~1250 tokens
        const maxLength = 5000;
        const textForAnalysis = fullText?.substring(0, maxLength) || '';

        const prompt = `
以下の記事を分析してください:

タイトル: ${title}
本文:
${textForAnalysis}

以下のJSON形式で返してください:
{
  "summary": "3文の要約（本文の核心を捉えた要約）",
  "topics": ["トピック1", "トピック2"]
}

**重要**:
- summaryは本文全体の内容を踏まえた正確な要約にしてください
- topicsは記事の主要なテーマを2つ選んでください（技術、ビジネス、健康、エンタメなど）
`;

        // Gemini API call
        const model = genAI.getGenerativeModel({ model: 'gemini-2.0-flash-exp' });
        const response = await model.generateContent(prompt);
        const resultText = response.response.text();

        // Parse JSON response
        const result = JSON.parse(resultText);

        return {
            summary: result.summary || 'AI分析中...',
            topics: result.topics || []
        };

    } catch (error) {
        console.error('[Gemini AI] Analysis failed:', error);

        // Fallback: Return basic info if AI fails
        return {
            summary: 'AI分析中...',
            topics: []
        };
    }
}

// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
// Updated GET /articles endpoint (include full_text in response)
// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

/**
 * GET /brain/api/articles
 *
 * Fetch all articles for authenticated user
 * NOW INCLUDES full_text for Brain UI display
 */
router.get('/articles', authMiddleware, async (req, res) => {
    try {
        const { rows } = await pool.query(`
            SELECT
                id,
                url,
                title,
                full_text,
                summary,
                topics,
                source,
                favicon,
                og_image,
                status,
                created_at,
                updated_at
            FROM articles
            WHERE user_id = $1
            ORDER BY created_at DESC
        `, [req.userId]);

        return res.json({
            articles: rows.map(row => ({
                id: row.id,
                url: row.url,
                title: row.title,
                fullText: row.full_text,
                summary: row.summary,
                topics: row.topics,
                source: row.source,
                favicon: row.favicon,
                ogImage: row.og_image,
                status: row.status,
                createdAt: row.created_at,
                updatedAt: row.updated_at
            }))
        });

    } catch (error) {
        console.error('[Brain API] Failed to fetch articles:', error);

        return res.status(500).json({
            error: 'Failed to fetch articles',
            message: error.message
        });
    }
});

// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
// Testing & Debugging
// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

/**
 * GET /brain/api/test-save
 *
 * Debug endpoint to test if full_text is being saved correctly
 *
 * Usage: https://posimai-lab.tail72e846.ts.net/brain/api/test-save
 */
router.get('/test-save', authMiddleware, async (req, res) => {
    try {
        const { rows } = await pool.query(`
            SELECT
                id,
                title,
                LENGTH(full_text) as text_length,
                LEFT(full_text, 100) as text_preview,
                source,
                created_at
            FROM articles
            WHERE user_id = $1
            ORDER BY created_at DESC
            LIMIT 10
        `, [req.userId]);

        const stats = {
            total: rows.length,
            withFullText: rows.filter(r => r.text_length > 0).length,
            withoutFullText: rows.filter(r => r.text_length === 0 || r.text_length === null).length,
            articles: rows
        };

        return res.json(stats);

    } catch (error) {
        console.error('[Brain API] Test failed:', error);

        return res.status(500).json({
            error: 'Test failed',
            message: error.message
        });
    }
});

// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
// Export
// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

module.exports = router;

// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
// DEPLOYMENT CHECKLIST
// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
//
// 1. [ ] Run database migration: synology-brain-migration.sql
// 2. [ ] Update server.js with this code
// 3. [ ] Restart Brain API server: docker restart posimai-brain-api
// 4. [ ] Test save from Reader
// 5. [ ] Check logs: docker logs -f posimai-brain-api
// 6. [ ] Verify database: SELECT * FROM articles ORDER BY created_at DESC LIMIT 5;
// 7. [ ] Test GET /articles includes fullText
// 8. [ ] Update Brain UI to display full text (next task)
//
// ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━