/**
 * diary-server.js
 * localhost:2626 で常時待機する軽量デーモン。
 * posimai-log のダイアリーパネルから diary.md を読み書きする。
 * Usage: npm run serve
 */
import http from 'http';
import fs from 'fs';
import path from 'path';
import { fileURLToPath } from 'url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const DIARY_FILE = path.join(__dirname, '../diary.md');
const PORT = 2626;

const server = http.createServer((req, res) => {
    // localhost 専用サーバーなので CORS はワイルドカードで問題なし
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
    res.setHeader('Access-Control-Allow-Headers', 'Content-Type');

    if (req.method === 'OPTIONS') {
        res.writeHead(204);
        res.end();
        return;
    }

    // GET /diary → diary.md の内容を返す
    if (req.url === '/diary' && req.method === 'GET') {
        const content = fs.existsSync(DIARY_FILE)
            ? fs.readFileSync(DIARY_FILE, 'utf8')
            : '';
        res.writeHead(200, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ content }));
        return;
    }

    // POST /diary → diary.md に上書き保存
    if (req.url === '/diary' && req.method === 'POST') {
        let body = '';
        req.on('data', chunk => { body += chunk; });
        req.on('end', () => {
            try {
                const { content } = JSON.parse(body);
                fs.writeFileSync(DIARY_FILE, content ?? '', 'utf8');
                res.writeHead(200, { 'Content-Type': 'application/json' });
                res.end(JSON.stringify({ ok: true }));
            } catch {
                res.writeHead(400);
                res.end();
            }
        });
        return;
    }

    res.writeHead(404);
    res.end();
});

server.listen(PORT, '127.0.0.1', () => {
    console.log(`[diary-server] http://localhost:${PORT} ready`);
    console.log(`[diary-server] diary -> ${DIARY_FILE}`);
});