import { randomBytes } from 'node:crypto';
import type { PoolConnection, ResultSetHeader, RowDataPacket } from 'mysql2/promise';
import type { MySqlPool } from '../db/mysql.js';
import type { MarketingBenefitService } from '../wallets/marketing-benefit-service.js';
import type { WalletLedgerService } from '../wallets/wallet-ledger-service.js';

export type PaymentProvider = 'WECHAT' | 'BALANCE' | 'PACKAGE' | 'GROUP_BUY' | 'TEST';

interface OrderRow extends RowDataPacket {
  id: string;
  storeId: string;
  status: string;
  totalAmountCents: number;
  paidAmountCents: number;
}
interface PaymentRow extends RowDataPacket {
  id: string;
  orderId: string;
  paymentNo: string;
  provider: PaymentProvider;
  status: string;
  amountCents: number;
}
interface ConfigRow extends RowDataPacket {
  id: string;
  credentialRef: string;
  settings: string | object;
  scopeKey: string;
}

export class PaymentError extends Error {
  constructor(public readonly code: string) { super(code); }
}

export class PaymentRepository {
  constructor(
    private readonly pool: MySqlPool,
    private readonly wallet?: Pick<WalletLedgerService, 'debitInTransaction'>,
    private readonly benefits?: Pick<MarketingBenefitService, 'confirmReservedInTransaction'>
  ) {}

  async createPayment(input: {
    tenantId: string;
    platformAppId: string;
    userId: string;
    orderId: string;
    provider: PaymentProvider;
    clientRequestId: string;
    testAdapterEnabled: boolean;
  }) {
    return this.transaction(async (connection) => {
      const order = await this.loadOwnedOrder(
        connection, input.tenantId, input.userId, input.orderId, true
      );
      if (!['PENDING_PAYMENT', 'PAID', 'RESERVED', 'IN_PROGRESS'].includes(order.status)) {
        throw new PaymentError('PAYMENT_ORDER_STATUS_INVALID');
      }
      const amountCents = Number(order.totalAmountCents) - Number(order.paidAmountCents);
      if (amountCents <= 0) throw new PaymentError('PAYMENT_NOT_REQUIRED');
      if (input.provider === 'TEST' && !input.testAdapterEnabled) {
        throw new PaymentError('TEST_PAYMENT_DISABLED');
      }
      if (!['TEST', 'BALANCE'].includes(input.provider)) {
        await this.resolveConfig(
          connection, input.tenantId, input.platformAppId, order.storeId, input.provider
        );
      }
      const [existing] = await connection.execute<PaymentRow[]>(
        `SELECT id, order_id AS orderId, payment_no AS paymentNo, provider,
                status, amount_cents AS amountCents
         FROM qipai_payments
         WHERE tenant_id = ? AND client_request_id = ? LIMIT 1`,
        [input.tenantId, input.clientRequestId]
      );
      if (existing[0]) {
        if (String(existing[0].orderId) !== input.orderId
          || existing[0].provider !== input.provider
          || Number(existing[0].amountCents) !== amountCents) {
          throw new PaymentError('PAYMENT_IDEMPOTENCY_CONFLICT');
        }
        return this.paymentResponse(existing[0], true, input.testAdapterEnabled);
      }
      const paymentNo = `PAY${Date.now()}${randomBytes(5).toString('hex').toUpperCase()}`;
      const [result] = await connection.execute<ResultSetHeader>(
        `INSERT INTO qipai_payments
          (tenant_id, platform_app_id, order_id, store_id, payment_no,
           channel, provider, client_request_id, status, amount_cents)
         VALUES (?, ?, ?, ?, ?, ?, ?, ?, 'PENDING', ?)`,
        [input.tenantId, input.platformAppId, input.orderId, order.storeId,
          paymentNo, input.provider, input.provider, input.clientRequestId, amountCents]
      );
      const paymentId = String(result.insertId);
      await connection.execute(
        `INSERT INTO qipai_payment_attempts
          (tenant_id, payment_id, attempt_no, status, request_payload, response_payload,
           completed_at)
         VALUES (?, ?, 1, 'CREATED',
           JSON_OBJECT('provider', ?, 'amountCents', ?),
           JSON_OBJECT('adapter', ?, 'credentialExposed', FALSE), UTC_TIMESTAMP(3))`,
        [input.tenantId, paymentId, input.provider, amountCents,
          input.provider === 'TEST' ? 'test' : 'configured']
      );
      if (input.provider === 'BALANCE') {
        if (!this.wallet) throw new PaymentError('WALLET_SETTLEMENT_NOT_CONFIGURED');
        await this.wallet.debitInTransaction(connection, {
          tenantId: input.tenantId,
          userId: input.userId,
          scopeType: 'STORE',
          storeId: order.storeId,
          businessType: 'ORDER_PAYMENT',
          businessId: input.orderId,
          entryType: 'CONSUME',
          amountCents,
          traceId: input.clientRequestId,
          note: 'Customer balance payment',
          metadata: { paymentId, provider: input.provider }
        });
        await this.applyPaymentSuccess(connection, {
          paymentId,
          orderId: input.orderId,
          tenantId: input.tenantId,
          userId: input.userId,
          amountCents,
          providerPaymentId: `BAL-${paymentNo}`,
          traceId: input.clientRequestId,
          reason: 'Balance payment completed'
        });
        return this.paymentResponse({
          id: paymentId, orderId: input.orderId, paymentNo, provider: input.provider,
          status: 'SUCCEEDED', amountCents
        } as PaymentRow, false, input.testAdapterEnabled);
      }
      return this.paymentResponse({
        id: paymentId, orderId: input.orderId, paymentNo, provider: input.provider,
        status: 'PENDING', amountCents
      } as PaymentRow, false, input.testAdapterEnabled);
    });
  }

  async processTestCallback(input: {
    tenantId: string;
    userId: string;
    paymentId: string;
    callbackId: string;
    amountCents: number;
    testAdapterEnabled: boolean;
    traceId: string;
  }) {
    if (!input.testAdapterEnabled) throw new PaymentError('TEST_PAYMENT_DISABLED');
    return this.transaction(async (connection) => {
      const payment = await this.loadPayment(connection, input.tenantId, input.paymentId, true);
      await this.assertOrderOwner(connection, input.tenantId, payment.orderId, input.userId);
      if (payment.provider !== 'TEST') throw new PaymentError('PAYMENT_PROVIDER_INVALID');
      const [callbackResult] = await connection.execute<ResultSetHeader>(
        `INSERT IGNORE INTO qipai_payment_callbacks
          (tenant_id, payment_id, provider, callback_id, callback_type,
           verified, payload)
         VALUES (?, ?, 'TEST', ?, 'PAYMENT_SUCCEEDED', 1,
           JSON_OBJECT('amountCents', ?))`,
        [input.tenantId, input.paymentId, input.callbackId, input.amountCents]
      );
      if (callbackResult.affectedRows === 0) {
        return { paymentId: input.paymentId, status: payment.status, idempotent: true };
      }
      if (Number(payment.amountCents) !== input.amountCents) {
        await connection.execute(
          `UPDATE qipai_payment_callbacks
           SET processing_status = 'REJECTED', error_code = 'PAYMENT_AMOUNT_MISMATCH',
               processed_at = UTC_TIMESTAMP(3)
           WHERE tenant_id = ? AND provider = 'TEST' AND callback_id = ?`,
          [input.tenantId, input.callbackId]
        );
        return {
          paymentId: input.paymentId,
          status: 'REJECTED',
          code: 'PAYMENT_AMOUNT_MISMATCH',
          idempotent: false
        };
      }
      if (payment.status === 'SUCCEEDED') {
        await connection.execute(
          `UPDATE qipai_payment_callbacks
           SET processing_status = 'DUPLICATE', processed_at = UTC_TIMESTAMP(3)
           WHERE tenant_id = ? AND provider = 'TEST' AND callback_id = ?`,
          [input.tenantId, input.callbackId]
        );
        return { paymentId: input.paymentId, status: 'SUCCEEDED', idempotent: true };
      }
      await this.applyPaymentSuccess(connection, {
        paymentId: input.paymentId,
        orderId: payment.orderId,
        tenantId: input.tenantId,
        userId: input.userId,
        amountCents: Number(payment.amountCents),
        providerPaymentId: `TEST-${input.callbackId}`,
        traceId: input.traceId,
        reason: 'Verified payment callback'
      });
      await connection.execute(
        `UPDATE qipai_payment_callbacks
         SET processing_status = 'PROCESSED', processed_at = UTC_TIMESTAMP(3)
         WHERE tenant_id = ? AND provider = 'TEST' AND callback_id = ?`,
        [input.tenantId, input.callbackId]
      );
      return { paymentId: input.paymentId, status: 'SUCCEEDED', idempotent: false };
    });
  }

  async resolveConfig(
    connection: Pick<MySqlPool, 'execute'>,
    tenantId: string,
    platformAppId: string,
    storeId: string,
    provider: PaymentProvider
  ) {
    const [rows] = await connection.execute<ConfigRow[]>(
      `SELECT id, credential_ref AS credentialRef, settings, scope_key AS scopeKey
       FROM qipai_payment_configs
       WHERE provider = ? AND enabled = 1
         AND (tenant_id IS NULL OR tenant_id = ?)
         AND (platform_app_id IS NULL OR platform_app_id = ?)
         AND (store_id IS NULL OR store_id = ?)
       ORDER BY (store_id IS NOT NULL) DESC,
                (tenant_id IS NOT NULL) DESC,
                (platform_app_id IS NOT NULL) DESC, id DESC LIMIT 1`,
      [provider, tenantId, platformAppId, storeId]
    );
    if (!rows[0]) throw new PaymentError('PAYMENT_CONFIG_NOT_FOUND');
    return {
      id: String(rows[0].id),
      credentialRef: rows[0].credentialRef,
      scopeKey: rows[0].scopeKey,
      settings: typeof rows[0].settings === 'string'
        ? JSON.parse(rows[0].settings) : rows[0].settings
    };
  }

  private paymentResponse(row: PaymentRow, idempotent: boolean, testEnabled: boolean) {
    return {
      paymentId: String(row.id),
      orderId: String(row.orderId),
      paymentNo: row.paymentNo,
      provider: row.provider,
      status: row.status,
      amountCents: Number(row.amountCents),
      idempotent,
      testCompletionAvailable: row.provider === 'TEST' && testEnabled
    };
  }

  private async loadOwnedOrder(
    connection: PoolConnection, tenantId: string, userId: string,
    orderId: string, lock: boolean
  ) {
    await this.assertOrderOwner(connection, tenantId, orderId, userId);
    return this.loadOrder(connection, tenantId, orderId, lock);
  }

  private async loadOrder(
    connection: PoolConnection, tenantId: string, orderId: string, lock: boolean
  ) {
    const [rows] = await connection.execute<Array<OrderRow & { statusVersion: number }>>(
      `SELECT id, store_id AS storeId, status, status_version AS statusVersion,
              total_amount_cents AS totalAmountCents, paid_amount_cents AS paidAmountCents
       FROM qipai_orders WHERE tenant_id = ? AND id = ? AND deleted_at IS NULL
       ${lock ? 'FOR UPDATE' : ''}`,
      [tenantId, orderId]
    );
    if (!rows[0]) throw new PaymentError('ORDER_NOT_FOUND');
    return rows[0];
  }

  private async loadPayment(
    connection: PoolConnection, tenantId: string, paymentId: string, lock: boolean
  ) {
    const [rows] = await connection.execute<PaymentRow[]>(
      `SELECT id, order_id AS orderId, payment_no AS paymentNo, provider,
              status, amount_cents AS amountCents
       FROM qipai_payments WHERE tenant_id = ? AND id = ? AND deleted_at IS NULL
       ${lock ? 'FOR UPDATE' : ''}`,
      [tenantId, paymentId]
    );
    if (!rows[0]) throw new PaymentError('PAYMENT_NOT_FOUND');
    return rows[0];
  }

  private async assertOrderOwner(
    connection: PoolConnection, tenantId: string, orderId: string, userId: string
  ) {
    const [rows] = await connection.execute<RowDataPacket[]>(
      `SELECT 1 FROM qipai_order_user_access
       WHERE tenant_id = ? AND order_id = ? AND user_id = ?`,
      [tenantId, orderId, userId]
    );
    if (!rows[0]) throw new PaymentError('ORDER_ACCESS_FORBIDDEN');
  }

  async applyPaymentSuccess(
    connection: PoolConnection,
    input: {
      paymentId: string;
      orderId: string;
      tenantId: string;
      userId?: string;
      amountCents: number;
      providerPaymentId: string;
      traceId: string;
      reason: string;
    }
  ) {
    await connection.execute(
      `UPDATE qipai_payments
       SET status = 'SUCCEEDED', provider_payment_id = ?,
           paid_at = UTC_TIMESTAMP(3), raw_notify = JSON_OBJECT('verified', TRUE)
       WHERE tenant_id = ? AND id = ? AND status = 'PENDING'`,
      [input.providerPaymentId, input.tenantId, input.paymentId]
    );
    await connection.execute(
      `UPDATE qipai_orders
       SET paid_amount_cents = paid_amount_cents + ?
       WHERE tenant_id = ? AND id = ?`,
      [input.amountCents, input.tenantId, input.orderId]
    );
    const order = await this.loadOrder(connection, input.tenantId, input.orderId, true);
    if (Number(order.paidAmountCents) >= Number(order.totalAmountCents)
      && order.status === 'PENDING_PAYMENT') {
      if (this.benefits && input.userId) {
        await this.benefits.confirmReservedInTransaction(connection, {
          tenantId: input.tenantId,
          userId: input.userId,
          orderId: input.orderId,
          traceId: input.traceId
        });
      }
      const nextVersion = Number((order as OrderRow & { statusVersion?: number }).statusVersion ?? 1) + 1;
      await connection.execute(
        `UPDATE qipai_orders SET status = 'PAID', status_version = ?,
           status_updated_at = UTC_TIMESTAMP(3)
         WHERE tenant_id = ? AND id = ?`,
        [nextVersion, input.tenantId, input.orderId]
      );
      await connection.execute(
        `UPDATE qipai_room_reservations
         SET status = 'CONSUMED', expires_at = GREATEST(expires_at, ends_at)
         WHERE tenant_id = ? AND order_id = ? AND status = 'HELD'`,
        [input.tenantId, input.orderId]
      );
      await connection.execute(
        `INSERT INTO qipai_order_status_history
          (tenant_id, order_id, from_status, to_status, action, actor_type,
           actor_id, source, reason, trace_id, metadata)
         VALUES (?, ?, 'PENDING_PAYMENT', 'PAID', 'CONFIRM_PAYMENT', 'SYSTEM',
           NULL, 'PAYMENT', ?, ?, JSON_OBJECT('statusVersion', ?, 'paymentId', ?))`,
        [input.tenantId, input.orderId, input.reason, input.traceId, nextVersion, input.paymentId]
      );
    }
  }

  private async transaction<T>(work: (connection: PoolConnection) => Promise<T>) {
    const connection = await this.pool.getConnection();
    try {
      await connection.beginTransaction();
      const result = await work(connection);
      await connection.commit();
      return result;
    } catch (error) {
      await connection.rollback();
      throw error;
    } finally {
      connection.release();
    }
  }
}