const Pool = require('../../models/Pool');

class PoolRepository {
  constructor(uow) {
    this.uow = uow;
  }

  async create({ name, description = null, state = 'active', created_by }) {
    const conn = this.uow.connection;
    const [res] = await conn.execute(
      `INSERT INTO pools (name, description, state, created_by, updated_by)
       VALUES (?, ?, ?, ?, NULL)`,
      [name, description, state, created_by]
    );
    return new Pool({ id: res.insertId, name, description, state, created_by, updated_by: null });
  }

  async findAll() {
    const conn = this.uow.connection; // switched to connection
    try {
      console.debug('[PoolRepository.findAll] querying pools');
      const [rows] = await conn.execute(
        `SELECT id, name, description, state, created_at, updated_at
         FROM pools
         ORDER BY created_at DESC`
      );
      console.debug('[PoolRepository.findAll] rows fetched', { count: rows.length });
      return rows.map(r => new Pool(r));
    } catch (err) {
      console.error('[PoolRepository.findAll] query failed', err);
      // Surface a consistent error up the stack
      const e = new Error('Failed to fetch pools');
      e.status = 500;
      e.cause = err;
      throw e;
    }
  }

  // NEW: update state with enforced transitions (active <-> inactive -> archived also supported)
  async updateState(id, nextState, updated_by) {
    const conn = this.uow.connection;
    const [rows] = await conn.execute(`SELECT id, state FROM pools WHERE id = ?`, [id]);
    if (!rows || rows.length === 0) {
      const err = new Error('Pool not found');
      err.status = 404;
      throw err;
    }
    const current = rows[0].state;
    const allowed = ['active', 'inactive', 'archived'];
    if (!allowed.includes(current) || !allowed.includes(nextState)) {
      const err = new Error('Invalid state transition');
      err.status = 400;
      throw err;
    }
    if (current === nextState) {
      return new Pool({ id, state: current, updated_by }); // no-op
    }
    await conn.execute(
      `UPDATE pools SET state = ?, updated_by = ?, updated_at = NOW() WHERE id = ?`,
      [nextState, updated_by, id]
    );
    return new Pool({ id, state: nextState, updated_by });
  }
}

module.exports = PoolRepository;