/**
 * Posimai Events - Synology API エンドポイント
 *
 * Brain の server.js に追記する形で統合する。
 * または /events パス以下を別サービスとして立ち上げる。
 *
 * エンドポイント:
 *   GET  /events/api/events               イベント一覧取得（フィルター対応）
 *   POST /events/api/events               n8n からのイベントデータ受信・保存
 *   POST /events/api/events/batch         n8n から複数イベントを一括登録
 *   DELETE /events/api/events/:id         イベント削除（管理用）
 *
 * 環境変数（Brain の .env と同じファイルに追記）:
 *   EVENTS_N8N_TOKEN=<n8nからのPOSTに使うトークン>
 *   GEMINI_API_KEY=<既存のBrain用を流用>
 *   DATABASE_URL=<既存のBrain用を流用>
 */

const { Pool } = require('pg');
const { GoogleGenerativeAI } = require('@google/generative-ai');

const pool = new Pool({ connectionString: process.env.DATABASE_URL });
const genAI = new GoogleGenerativeAI(process.env.GEMINI_API_KEY);

// n8n 認証ミドルウェア
function n8nAuth(req, res, next) {
    const token = process.env.EVENTS_N8N_TOKEN;
    if (!token) return next(); // トークン未設定時はスキップ（開発環境）
    const auth = req.headers['authorization'];
    if (auth !== `Bearer ${token}`) {
        return res.status(401).json({ error: 'Unauthorized' });
    }
    next();
}

// ---- GET /events/api/events ----
// クエリパラメータ:
//   from=YYYY-MM-DD  開始日以降（デフォルト: 今日から7日前）
//   to=YYYY-MM-DD    終了日まで
//   interests=sake,food  カンマ区切り
//   audience=couple,family
//   free=true
//   limit=50 (max 100)
async function getEvents(req, res) {
    try {
        const today = new Date().toISOString().slice(0,10);
        const from  = req.query.from || today;
        const to    = req.query.to;
        const interests = req.query.interests ? req.query.interests.split(',').map(s=>s.trim()) : [];
        const audience  = req.query.audience  ? req.query.audience.split(',').map(s=>s.trim())  : [];
        const isFree   = req.query.free === 'true';
        const limit    = Math.min(parseInt(req.query.limit) || 50, 100);

        let params = [from, limit];
        let where  = ['e.end_date >= $1'];
        let idx    = 3;

        if (to) { where.push(`e.start_date <= $${idx}`); params.splice(idx-1,0,to); idx++; }
        if (interests.length) { where.push(`e.interest_tags && $${idx}::text[]`); params.splice(idx-1,0,interests); idx++; }
        if (audience.length)  { where.push(`e.audience_tags && $${idx}::text[]`); params.splice(idx-1,0,audience); idx++; }
        if (isFree) { where.push('e.is_free = TRUE'); }

        const sql = `
            SELECT
                e.event_id AS id,
                e.title, e.start_date AS "startDate", e.start_time AS "startTime",
                e.end_date AS "endDate", e.end_time AS "endTime",
                e.location, e.address, e.description, e.category, e.url, e.source,
                e.interest_tags AS "interestTags", e.audience_tags AS "audienceTags",
                e.is_free AS "isFree", e.no_rsvp AS "noRsvp", e.is_outdoor AS "isOutdoor",
                e.scraped_at AS "scrapedAt"
            FROM events e
            WHERE ${where.join(' AND ')}
            ORDER BY e.start_date ASC, e.start_time ASC
            LIMIT $2
        `;

        const result = await pool.query(sql, params);
        const events = result.rows.map(row => ({
            ...row,
            startDate: row.startDate?.toISOString?.()?.slice(0,10) || row.startDate,
            endDate:   row.endDate?.toISOString?.()?.slice(0,10)   || row.endDate,
            startTime: row.startTime?.slice?.(0,5) || row.startTime,
            endTime:   row.endTime?.slice?.(0,5)   || row.endTime,
        }));

        res.json({ events, updatedAt: new Date().toISOString(), count: events.length });
    } catch (err) {
        console.error('GET /events error:', err);
        res.status(500).json({ error: 'Internal server error' });
    }
}

// ---- POST /events/api/events ----
// n8n から1件ずつ受け取る場合
// BodyにはJinaReader + Geminiが生成したイベントJSONを渡す
async function createEvent(req, res) {
    const body = req.body;
    if (!body?.title || !body?.startDate) {
        return res.status(400).json({ error: 'title and startDate are required' });
    }

    try {
        // Gemini でタグ自動付与（まだ付いていない場合）
        let interestTags = body.interestTags || [];
        let audienceTags = body.audienceTags || [];
        if (!interestTags.length && body.description) {
            const tagged = await autoTagEvent(body);
            interestTags = tagged.interestTags;
            audienceTags = tagged.audienceTags;
        }

        const eventId = body.id || `${body.source?.replace(/\s+/g,'-')}-${body.startDate}-${Date.now()}`;

        await pool.query(`
            INSERT INTO events
                (event_id, title, start_date, start_time, end_date, end_time,
                 location, address, description, category, url, source,
                 interest_tags, audience_tags, is_free, no_rsvp, is_outdoor, scraped_at)
            VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14,$15,$16,$17,NOW())
            ON CONFLICT (event_id) DO UPDATE SET
                title        = EXCLUDED.title,
                description  = EXCLUDED.description,
                interest_tags = EXCLUDED.interest_tags,
                audience_tags = EXCLUDED.audience_tags,
                scraped_at   = NOW(),
                updated_at   = NOW()
        `, [
            eventId, body.title, body.startDate, body.startTime || null,
            body.endDate || body.startDate, body.endTime || null,
            body.location || '', body.address || '',
            body.description || '', body.category || '',
            body.url || '', body.source || '',
            interestTags, audienceTags,
            body.isFree || false, body.noRsvp || false, body.isOutdoor || false
        ]);

        res.json({ ok: true, eventId });
    } catch (err) {
        console.error('POST /events error:', err);
        res.status(500).json({ error: 'Internal server error' });
    }
}

// ---- POST /events/api/events/batch ----
// n8n から複数件を一括登録する場合
async function createEventsBatch(req, res) {
    const { events } = req.body;
    if (!Array.isArray(events) || !events.length) {
        return res.status(400).json({ error: 'events array is required' });
    }

    let saved = 0, errors = 0;
    for (const ev of events) {
        try {
            const fakeReq = { body: ev };
            const fakeRes = {
                json: () => { saved++; },
                status: (c) => ({ json: () => { errors++; } })
            };
            await createEvent(fakeReq, fakeRes);
        } catch { errors++; }
    }

    res.json({ ok: true, saved, errors });
}

// ---- Gemini タグ自動付与 ----
const INTEREST_IDS = ['sake','beer','wine','food','market','music','art','craft','outdoor','sports','culture','film','learn','volunteer','kids'];
const AUDIENCE_IDS = ['couple','family','solo','senior','pet','foreign'];

async function autoTagEvent(ev) {
    try {
        const model = genAI.getGenerativeModel({ model: 'gemini-1.5-flash' });
        const prompt = `
以下のイベント情報に、最も適切なタグを付与してください。

イベント名: ${ev.title}
説明: ${ev.description}
カテゴリ: ${ev.category || '不明'}

【興味タグ候補】（複数選択可）:
sake=日本酒, beer=クラフトビール, wine=ワイン/お酒, food=グルメ/食,
market=マルシェ/市場, music=音楽/ライブ, art=アート/展示, craft=クラフト/手工芸,
outdoor=アウトドア/自然, sports=スポーツ/体験, culture=伝統/文化,
film=映画/演劇, learn=学び/セミナー, volunteer=ボランティア, kids=子ども向け

【対象者タグ候補】（複数選択可）:
couple=カップル向け, family=ファミリー歓迎, solo=ソロ歓迎,
senior=シニア向け, pet=ペット同伴OK, foreign=英語対応

JSONのみ返答:
{"interestTags":["tag1","tag2"],"audienceTags":["tag1"]}`;

        const result = await model.generateContent(prompt);
        const text = result.response.text().trim();
        const json = JSON.parse(text.match(/\{[\s\S]*\}/)[0]);
        return {
            interestTags: (json.interestTags || []).filter(t => INTEREST_IDS.includes(t)),
            audienceTags: (json.audienceTags || []).filter(t => AUDIENCE_IDS.includes(t)),
        };
    } catch {
        return { interestTags: [], audienceTags: [] };
    }
}

// ---- ルーター統合（server.js に追記する形）----
// 既存の Brain server.js の末尾に以下を追加:
//
// const eventsRouter = require('./events-api');
// app.use('/events/api', eventsRouter);
//
// または Router として export する場合:

const express = require('express');
const router  = express.Router();

router.get('/events',          getEvents);
router.post('/events',         n8nAuth, createEvent);
router.post('/events/batch',   n8nAuth, createEventsBatch);
router.delete('/events/:id',   n8nAuth, async (req, res) => {
    await pool.query('DELETE FROM events WHERE event_id = $1', [req.params.id]);
    res.json({ ok: true });
});

module.exports = router;