const pool = require('../../database/database');
const Abonemment = require('../../models/Abonemment');

class AbonemmentRepository {
  // NEW: cache table columns once per process
  static _columnsCache = null;

  // NEW: load columns for coffee_abonements
  async loadColumns() {
    if (AbonemmentRepository._columnsCache) return AbonemmentRepository._columnsCache;
    const [rows] = await pool.query(
      `SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'coffee_abonements'`
    );
    const set = new Set(rows.map(r => r.COLUMN_NAME));
    AbonemmentRepository._columnsCache = set;
    return set;
  }

  // NEW: helpers to include fields conditionally
  async hasColumn(name) {
    const cols = await this.loadColumns();
    return cols.has(name);
  }

  async createAbonement(referredBy, snapshot) {
    const conn = await pool.getConnection();
    try {
      await conn.beginTransaction();

      // NEW: dynamically assemble column list
      const cols = [
        'pack_group','status','started_at','ended_at','next_billing_at','billing_interval','interval_count',
        'price','currency','is_auto_renew','notes','pack_breakdown','first_name','last_name','email','street',
        'postal_code','city','country','frequency','referred_by'
      ];
      const vals = [
        snapshot.pack_group || '',
        snapshot.status || 'active',
        snapshot.started_at,
        snapshot.ended_at || null,
        snapshot.next_billing_at || null,
        snapshot.billing_interval,
        snapshot.interval_count,
        snapshot.price,
        snapshot.currency,
        snapshot.is_auto_renew ? 1 : 0,
        snapshot.notes || null,
        snapshot.pack_breakdown ? JSON.stringify(snapshot.pack_breakdown) : null,
        snapshot.first_name || null,
        snapshot.last_name || null,
        snapshot.email || null,
        snapshot.street || null,
        snapshot.postal_code || null,
        snapshot.city || null,
        snapshot.country || null,
        snapshot.frequency || null,
        referredBy || null,
      ];

      console.log('[CREATE ABONEMENT] Incoming snapshot user linking:', {
        actor_user_id: snapshot.actor_user_id,
        user_id: snapshot.user_id,
        purchaser_user_id: snapshot.purchaser_user_id,
        referred_by: referredBy,
      });

      // NEW: optionally include user_id and purchaser_user_id
      if (await this.hasColumn('user_id')) {
        cols.push('user_id');
        vals.push(snapshot.user_id ?? null);
      }
      if (await this.hasColumn('purchaser_user_id')) {
        cols.push('purchaser_user_id');
        vals.push(snapshot.purchaser_user_id ?? null);
      }

      const placeholders = cols.map(() => '?').join(', ');
      console.log('[CREATE ABONEMENT] Final columns:', cols);
      console.log('[CREATE ABONEMENT] Final values preview:', {
        pack_group: vals[0],
        status: vals[1],
        user_id: cols.includes('user_id') ? vals[cols.indexOf('user_id')] : undefined,
        purchaser_user_id: cols.includes('purchaser_user_id') ? vals[cols.indexOf('purchaser_user_id')] : undefined,
      });

      const [res] = await conn.query(
        `INSERT INTO coffee_abonements (${cols.join(', ')}, created_at, updated_at)
         VALUES (${placeholders}, NOW(), NOW())`,
        vals
      );
      const abonementId = res.insertId;
      console.log('[CREATE ABONEMENT] Inserted abonement ID:', abonementId);

      const historyDetails = { ...(snapshot.details || {}), pack_group: snapshot.pack_group };
      await conn.query(
        `INSERT INTO coffee_abonement_history
         (abonement_id, event_type, event_at, actor_user_id, details, created_at)
         VALUES (?, ?, ?, ?, ?, NOW())`,
        [
          abonementId,
          'created',
          snapshot.started_at,
          referredBy || snapshot.actor_user_id || null,
          JSON.stringify(historyDetails),
        ],
      );

      await conn.commit();
      const created = await this.getAbonementById(abonementId);
      console.log('[CREATE ABONEMENT] Loaded abonement row after insert:', {
        id: created?.id,
        user_id: created?.user_id,
        purchaser_user_id: created?.purchaser_user_id,
        pack_group: created?.pack_group,
        status: created?.status,
      });
      return created;
    } catch (err) {
      await conn.rollback();
      throw err;
    } finally {
      conn.release();
    }
  }

  async getAbonementById(id) {
    const [rows] = await pool.query(`SELECT * FROM coffee_abonements WHERE id = ?`, [id]);
    return rows[0] ? new Abonemment(rows[0]) : null;
  }

  async listByUser(userId, { status, limit = 50, offset = 0 } = {}) {
    const params = [userId];
    let sql = `SELECT * FROM coffee_abonements WHERE user_id = ?`;
    if (status) {
      sql += ` AND status = ?`;
      params.push(status);
    }
    sql += ` ORDER BY created_at DESC LIMIT ? OFFSET ?`;
    params.push(Number(limit), Number(offset));
    const [rows] = await pool.query(sql, params);
    return rows.map((r) => new Abonemment(r));
  }

  async updateStatus(id, newStatus, { ended_at, updated_at = new Date() } = {}) {
    await pool.query(
      `UPDATE coffee_abonements SET status = ?, ended_at = ?, updated_at = ? WHERE id = ?`,
      [newStatus, ended_at || null, updated_at, id],
    );
    return this.getAbonementById(id);
  }

  async updateBilling(id, next_billing_at, updated_at = new Date()) {
    await pool.query(
      `UPDATE coffee_abonements SET next_billing_at = ?, updated_at = ? WHERE id = ?`,
      [next_billing_at, updated_at, id],
    );
    return this.getAbonementById(id);
  }

  async appendHistory(abonementId, eventType, actorUserId, details = {}, eventAt = new Date()) {
    await pool.query(
      `INSERT INTO coffee_abonement_history
       (abonement_id, event_type, event_at, actor_user_id, details, created_at)
       VALUES (?, ?, ?, ?, ?, NOW())`,
      [abonementId, eventType, eventAt, actorUserId || null, JSON.stringify(details || {})],
    );
  }

  async transitionStatus(id, newStatus, historyPayload = {}) {
    const conn = await pool.getConnection();
    try {
      await conn.beginTransaction();
      await conn.query(
        `UPDATE coffee_abonements SET status = ?, ended_at = ?, updated_at = ? WHERE id = ?`,
        [
          newStatus,
          historyPayload.ended_at || null,
          historyPayload.updated_at || new Date(),
          id,
        ],
      );
      await conn.query(
        `INSERT INTO coffee_abonement_history
         (abonement_id, event_type, event_at, actor_user_id, details, created_at)
         VALUES (?, ?, ?, ?, ?, NOW())`,
        [
          id,
          historyPayload.event_type || 'updated',
          historyPayload.event_at || new Date(),
          historyPayload.actor_user_id || null,
          JSON.stringify(historyPayload.details || {}),
        ],
      );
      await conn.commit();
    } catch (err) {
      await conn.rollback();
      throw err;
    } finally {
      conn.release();
    }
    return this.getAbonementById(id);
  }

  async transitionBilling(id, nextBillingAt, historyPayload = {}) {
    const conn = await pool.getConnection();
    try {
      await conn.beginTransaction();
      await conn.query(
        `UPDATE coffee_abonements SET next_billing_at = ?, updated_at = ? WHERE id = ?`,
        [nextBillingAt, historyPayload.updated_at || new Date(), id],
      );
      await conn.query(
        `INSERT INTO coffee_abonement_history
         (abonement_id, event_type, event_at, actor_user_id, details, created_at)
         VALUES (?, ?, ?, ?, ?, NOW())`,
        [
          id,
          historyPayload.event_type || 'renewed',
          historyPayload.event_at || new Date(),
          historyPayload.actor_user_id || null,
          JSON.stringify(historyPayload.details || {}),
        ],
      );
      await conn.commit();
    } catch (err) {
      await conn.rollback();
      throw err;
    } finally {
      conn.release();
    }
    return this.getAbonementById(id);
  }

  async listDueForBilling(now) {
    const [rows] = await pool.query(
      `SELECT * FROM coffee_abonements
       WHERE status = 'active' AND is_auto_renew = 1 AND next_billing_at IS NOT NULL AND next_billing_at <= ?
       ORDER BY next_billing_at ASC`,
      [now],
    );
    return rows.map((r) => new Abonemment(r));
  }

  async listActiveByProduct(productId) {
    const [rows] = await pool.query(
      `SELECT * FROM coffee_abonements WHERE coffee_table_id = ? AND status = 'active'`,
      [productId],
    );
    return rows.map((r) => new Abonemment(r));
  }

  async listHistory(abonementId) {
    const [rows] = await pool.query(
      `SELECT * FROM coffee_abonement_history WHERE abonement_id = ? ORDER BY event_at ASC, id ASC`,
      [abonementId],
    );
    return rows.map((r) => ({
      id: r.id,
      abonement_id: r.abonement_id,
      event_type: r.event_type,
      event_at: r.event_at,
      actor_user_id: r.actor_user_id,
      details: r.details ? JSON.parse(r.details) : {},
      created_at: r.created_at,
    }));
  }

  async findActiveOrPausedByUserAndProduct(userId, packGroup) {
    const normalizedUserId = userId ?? null;
    const normalizedPackGroup = packGroup || '';
    const [rows] = await pool.query(
      `SELECT * FROM coffee_abonements
       WHERE pack_group = ? AND user_id <=> ? AND status IN ('active','paused')
       ORDER BY created_at DESC LIMIT 1`,
      [normalizedPackGroup, normalizedUserId],
    );
    return rows[0] ? new Abonemment(rows[0]) : null;
  }

  async updateExistingAbonementForSubscribe(id, snapshot) {
    const conn = await pool.getConnection();
    try {
      await conn.beginTransaction();

      // NEW: detect optional purchaser_user_id column
      const hasPurchaser = await this.hasColumn('purchaser_user_id');

      // Build SET clause dynamically
      const sets = [
        `status = 'active'`,
        `pack_group = ?`,
        `started_at = IFNULL(started_at, ?)`,
        `next_billing_at = ?`,
        `billing_interval = ?`,
        `interval_count = ?`,
        `price = ?`,
        `currency = ?`,
        `is_auto_renew = ?`,
        `notes = ?`,
        `recipient_email = ?`,
        `pack_breakdown = ?`,
        `updated_at = NOW()`,
      ];
      const params = [
        snapshot.pack_group || '',
        snapshot.started_at,
        snapshot.next_billing_at,
        snapshot.billing_interval,
        snapshot.interval_count,
        snapshot.price,
        snapshot.currency,
        snapshot.is_auto_renew ? 1 : 0,
        snapshot.notes || null,
        snapshot.recipient_email || null,
        snapshot.pack_breakdown ? JSON.stringify(snapshot.pack_breakdown) : null,
      ];

      if (hasPurchaser) {
        sets.splice(11, 0, `purchaser_user_id = IFNULL(purchaser_user_id, ?)`); // before pack_breakdown
        params.splice(11, 0, snapshot.purchaser_user_id ?? null);
      }

      await conn.query(
        `UPDATE coffee_abonements
         SET ${sets.join(', ')}
         WHERE id = ?`,
        [...params, id],
      );

      const historyDetails = { ...(snapshot.details || {}), reused_existing: true, pack_group: snapshot.pack_group };
      if (snapshot.recipient) historyDetails.recipient = snapshot.recipient;
      await conn.query(
        `INSERT INTO coffee_abonement_history
         (abonement_id, event_type, event_at, actor_user_id, details, created_at)
         VALUES (?, ?, ?, ?, ?, NOW())`,
        [id, 'merged_subscribe', snapshot.started_at, snapshot.actor_user_id || null, JSON.stringify(historyDetails)],
      );
      await conn.commit();
      return this.getAbonementById(id);
    } catch (err) {
      await conn.rollback();
      throw err;
    } finally {
      conn.release();
    }
  }

  // Helper: attempt insert into alias table if it exists
  async tryAliasInsert(email, abonementId, createdByUserId) {
    try {
      await pool.query(
        `INSERT INTO no_user_aboo_mails (email, abonement_id, status, source, created_by_user_id, created_at, updated_at)
         VALUES (?, ?, 'pending', 'subscribe', ?, NOW(), NOW())
         ON DUPLICATE KEY UPDATE status = 'pending', source = 'subscribe', created_by_user_id = VALUES(created_by_user_id), updated_at = NOW()`,
        [email, abonementId, createdByUserId || null],
      );
    } catch (e) {
      if (!(e && e.code === 'ER_NO_SUCH_TABLE')) throw e;
    }
  }

  // Insert/update pending ownership by email (primary table), with alias fallback
  async upsertNoUserAboMail(email, abonementId, createdByUserId) {
    const normalized = typeof email === 'string' ? email.trim().toLowerCase() : null;
    console.log('[UPSERT NO USER ABO MAIL] Normalized email:', normalized); // NEW
    console.log('[UPSERT NO USER ABO MAIL] Abonement ID:', abonementId); // NEW
    console.log('[UPSERT NO USER ABO MAIL] Created by user ID:', createdByUserId); // NEW

    if (!normalized) {
      console.log('[UPSERT NO USER ABO MAIL] Skipping due to invalid email'); // NEW
      return;
    }

    try {
      await pool.query(
        `INSERT INTO no_user_abo_mails (email, abonement_id, status, source, created_by_user_id, created_at, updated_at)
         VALUES (?, ?, 'pending', 'subscribe', ?, NOW(), NOW())
         ON DUPLICATE KEY UPDATE status = 'pending', source = 'subscribe', created_by_user_id = VALUES(created_by_user_id), updated_at = NOW()`,
        [normalized, abonementId, createdByUserId || null],
      );
      console.log('[UPSERT NO USER ABO MAIL] Successfully inserted/updated record'); // NEW
    } catch (err) {
      console.error('[UPSERT NO USER ABO MAIL] Error inserting/updating record:', err); // NEW
      throw err;
    }
  }

  // Fetch pending ownership rows for an email
  async findPendingNoUserAboMailsByEmail(email) {
    const normalized = typeof email === 'string' ? email.trim().toLowerCase() : null;
    console.log('[FIND PENDING NO USER ABO MAILS] Normalized email:', normalized); // NEW

    if (!normalized) {
      console.log('[FIND PENDING NO USER ABO MAILS] Skipping due to invalid email'); // NEW
      return [];
    }

    const [rows] = await pool.query(
      `SELECT * FROM no_user_abo_mails WHERE email = ? AND status = 'pending'`,
      [normalized],
    );
    console.log('[FIND PENDING NO USER ABO MAILS] Found rows:', rows); // NEW
    return rows || [];
  }

  // Mark a pending ownership record as linked
  async markNoUserAboMailLinked(id) {
    console.log('[MARK NO USER ABO MAIL LINKED] Marking record as linked for ID:', id); // NEW
    await pool.query(`UPDATE no_user_abo_mails SET status = 'linked', updated_at = NOW() WHERE id = ?`, [id]);
    console.log('[MARK NO USER ABO MAIL LINKED] Successfully marked record as linked'); // NEW
  }

  // Link abonement to a user (on registration)
  async linkAbonementToUser(abonementId, userId) {
    await pool.query(`UPDATE coffee_abonements SET user_id = ?, updated_at = NOW() WHERE id = ?`, [userId, abonementId]);
  }

  async findByReferredByAndEmail(referredBy, email) {
    const [rows] = await pool.query(
      `SELECT * FROM coffee_abonements
       WHERE referred_by = ? AND email = ?
       ORDER BY created_at DESC`,
      [referredBy, email],
    );
    return rows.map((row) => new Abonemment(row));
  }
}

module.exports = AbonemmentRepository;