// Promise wrappers around sqlite3's callback API. Routes use these instead of raw callbacks.
const { getDatabase } = require('./database');

function all(sql, params = []) {
    return new Promise((resolve, reject) => {
        getDatabase().all(sql, params, (err, rows) => {
            if (err) reject(err);
            else resolve(rows);
        });
    });
}

function get(sql, params = []) {
    return new Promise((resolve, reject) => {
        getDatabase().get(sql, params, (err, row) => {
            if (err) reject(err);
            else resolve(row);
        });
    });
}

function run(sql, params = []) {
    return new Promise((resolve, reject) => {
        getDatabase().run(sql, params, function (err) {
            if (err) reject(err);
            else resolve({ lastID: this.lastID, changes: this.changes });
        });
    });
}

// Executes work() inside BEGIN/COMMIT. Rolls back if work() throws.
async function transaction(work) {
    await run('BEGIN');
    try {
        const result = await work();
        await run('COMMIT');
        return result;
    } catch (err) {
        try { await run('ROLLBACK'); } catch (_) { /* swallow */ }
        throw err;
    }
}

module.exports = { all, get, run, transaction };