import { describe, it, expect, beforeAll, afterAll, vi } from 'vitest';

interface TraceContext {
  traceId: string;
  tenantId: string;
  shopId: string;
  taskId: string;
  businessType: 'TOC' | 'TOB';
}

interface Product {
  id: string;
  sku: string;
  name: string;
  price: number;
  cost: number;
  stock: number;
  status: 'DRAFT' | 'ACTIVE' | 'INACTIVE';
}

interface Order {
  id: string;
  orderId: string;
  customerId: string;
  items: Array<{
    sku: string;
    quantity: number;
    price: number;
  }>;
  totalAmount: number;
  status: string;
  paymentStatus: string;
}

interface Shipment {
  orderId: string;
  carrier: string;
  trackingNumber: string;
  status: string;
}

class E2ETestHarness {
  private products: Map<string, Product> = new Map();
  private orders: Map<string, Order> = new Map();
  private shipments: Map<string, Shipment> = new Map();
  private traceLogs: Array<{ context: TraceContext; action: string; timestamp: number }> = [];

  logTrace(context: TraceContext, action: string) {
    this.traceLogs.push({
      context,
      action,
      timestamp: Date.now(),
    });
  }

  getTraceLogs(): Array<{ context: TraceContext; action: string; timestamp: number }> {
    return this.traceLogs;
  }

  clearTraceLogs() {
    this.traceLogs = [];
  }

  async createProduct(data: Partial<Product> & { sku: string }, context: TraceContext): Promise<Product> {
    this.logTrace(context, 'CREATE_PRODUCT');
    const product: Product = {
      id: `prod-${Date.now()}`,
      sku: data.sku,
      name: data.name || 'Test Product',
      price: data.price || 99.99,
      cost: data.cost || 50,
      stock: data.stock || 100,
      status: data.status || 'DRAFT',
    };
    this.products.set(product.id, product);
    return product;
  }

  async publishProduct(productId: string, context: TraceContext): Promise<Product> {
    this.logTrace(context, 'PUBLISH_PRODUCT');
    const product = this.products.get(productId);
    if (!product) throw new Error('Product not found');
    product.status = 'ACTIVE';
    return product;
  }

  async createOrder(
    data: { customerId: string; items: Array<{ sku: string; quantity: number }> },
    context: TraceContext
  ): Promise<Order> {
    this.logTrace(context, 'CREATE_ORDER');
    const order: Order = {
      id: `order-${Date.now()}`,
      orderId: `ORD-${Date.now()}`,
      customerId: data.customerId,
      items: data.items.map((item) => ({
        ...item,
        price: 99.99,
      })),
      totalAmount: data.items.reduce((sum) => sum + 99.99, 0),
      status: 'PULLED',
      paymentStatus: 'PENDING',
    };
    this.orders.set(order.id, order);
    return order;
  }

  async confirmOrder(orderId: string, context: TraceContext): Promise<Order> {
    this.logTrace(context, 'CONFIRM_ORDER');
    const order = this.orders.get(orderId);
    if (!order) throw new Error('Order not found');
    order.status = 'CONFIRMED';
    order.paymentStatus = 'PAID';
    return order;
  }

  async allocateStock(orderId: string, context: TraceContext): Promise<Order> {
    this.logTrace(context, 'ALLOCATE_STOCK');
    const order = this.orders.get(orderId);
    if (!order) throw new Error('Order not found');
    order.status = 'ALLOCATED';
    return order;
  }

  async shipOrder(orderId: string, carrier: string, context: TraceContext): Promise<Shipment> {
    this.logTrace(context, 'SHIP_ORDER');
    const order = this.orders.get(orderId);
    if (!order) throw new Error('Order not found');
    order.status = 'SHIPPED';

    const shipment: Shipment = {
      orderId,
      carrier,
      trackingNumber: `TRK-${Date.now()}`,
      status: 'IN_TRANSIT',
    };
    this.shipments.set(orderId, shipment);
    return shipment;
  }

  async deliverOrder(orderId: string, context: TraceContext): Promise<Order> {
    this.logTrace(context, 'DELIVER_ORDER');
    const order = this.orders.get(orderId);
    if (!order) throw new Error('Order not found');
    order.status = 'DELIVERED';

    const shipment = this.shipments.get(orderId);
    if (shipment) shipment.status = 'DELIVERED';

    return order;
  }

  getOrder(orderId: string): Order | undefined {
    return this.orders.get(orderId);
  }

  getProduct(productId: string): Product | undefined {
    return this.products.get(productId);
  }

  getShipment(orderId: string): Shipment | undefined {
    return this.shipments.get(orderId);
  }

  clear() {
    this.products.clear();
    this.orders.clear();
    this.shipments.clear();
    this.traceLogs = [];
  }
}

describe('End-to-End Business Flow Tests', () => {
  let harness: E2ETestHarness;
  let defaultContext: TraceContext;

  beforeAll(() => {
    harness = new E2ETestHarness();
    defaultContext = {
      traceId: 'trace-e2e-default',
      tenantId: 'tenant-001',
      shopId: 'shop-001',
      taskId: 'task-e2e',
      businessType: 'TOC',
    };
  });

  afterAll(() => {
    vi.clearAllMocks();
  });

  beforeEach(() => {
    harness.clear();
  });

  describe('TOC (B2C) Order Flow', () => {
    it('should complete full order lifecycle', async () => {
      const context: TraceContext = {
        ...defaultContext,
        traceId: 'trace-toc-order',
        businessType: 'TOC',
      };

      const product = await harness.createProduct(
        { sku: 'SKU-TOC-001', name: 'B2C Product', price: 79.99, stock: 50 },
        context
      );
      expect(product.status).toBe('DRAFT');

      const publishedProduct = await harness.publishProduct(product.id, context);
      expect(publishedProduct.status).toBe('ACTIVE');

      const order = await harness.createOrder(
        { customerId: 'cust-001', items: [{ sku: 'SKU-TOC-001', quantity: 1 }] },
        context
      );
      expect(order.status).toBe('PULLED');
      expect(order.paymentStatus).toBe('PENDING');

      const confirmedOrder = await harness.confirmOrder(order.id, context);
      expect(confirmedOrder.status).toBe('CONFIRMED');
      expect(confirmedOrder.paymentStatus).toBe('PAID');

      const allocatedOrder = await harness.allocateStock(order.id, context);
      expect(allocatedOrder.status).toBe('ALLOCATED');

      const shipment = await harness.shipOrder(order.id, 'FedEx', context);
      expect(shipment.trackingNumber).toBeDefined();
      expect(shipment.status).toBe('IN_TRANSIT');

      const deliveredOrder = await harness.deliverOrder(order.id, context);
      expect(deliveredOrder.status).toBe('DELIVERED');

      const traceLogs = harness.getTraceLogs();
      expect(traceLogs.length).toBe(7);
      traceLogs.forEach((log) => {
        expect(log.context.traceId).toBe('trace-toc-order');
        expect(log.context.businessType).toBe('TOC');
      });
    });

    it('should handle order cancellation', async () => {
      const context: TraceContext = {
        ...defaultContext,
        traceId: 'trace-order-cancel',
      };

      const product = await harness.createProduct({ sku: 'SKU-CANCEL-001' }, context);
      await harness.publishProduct(product.id, context);

      const order = await harness.createOrder(
        { customerId: 'cust-002', items: [{ sku: 'SKU-CANCEL-001', quantity: 1 }] },
        context
      );

      harness.logTrace(context, 'CANCEL_ORDER');
      const cancelledOrder = harness.getOrder(order.id);
      if (cancelledOrder) {
        cancelledOrder.status = 'CANCELLED';
      }

      expect(cancelledOrder?.status).toBe('CANCELLED');
    });
  });

  describe('TOB (B2B) Order Flow', () => {
    it('should complete B2B bulk order with review', async () => {
      const context: TraceContext = {
        ...defaultContext,
        traceId: 'trace-tob-order',
        businessType: 'TOB',
      };

      const product = await harness.createProduct(
        { sku: 'SKU-TOB-001', name: 'B2B Product', price: 49.99, cost: 30 },
        context
      );
      await harness.publishProduct(product.id, context);

      const order = await harness.createOrder(
        {
          customerId: 'corp-001',
          items: [
            { sku: 'SKU-TOB-001', quantity: 100 },
          ],
        },
        context
      );
      expect(order.status).toBe('PULLED');

      harness.logTrace(context, 'SUBMIT_FOR_REVIEW');
      const pendingOrder = harness.getOrder(order.id);
      if (pendingOrder) pendingOrder.status = 'PENDING_REVIEW';
      expect(pendingOrder?.status).toBe('PENDING_REVIEW');

      harness.logTrace(context, 'APPROVE_ORDER');
      const approvedOrder = harness.getOrder(order.id);
      if (approvedOrder) approvedOrder.status = 'CONFIRMED';
      expect(approvedOrder?.status).toBe('CONFIRMED');

      await harness.allocateStock(order.id, context);
      await harness.shipOrder(order.id, 'DHL', context);
      await harness.deliverOrder(order.id, context);

      const finalOrder = harness.getOrder(order.id);
      expect(finalOrder?.status).toBe('DELIVERED');

      const traceLogs = harness.getTraceLogs();
      const tobLogs = traceLogs.filter((log) => log.context.businessType === 'TOB');
      expect(tobLogs.length).toBeGreaterThan(0);
    });

    it('should enforce profit margin rules for B2B', async () => {
      const context: TraceContext = {
        ...defaultContext,
        traceId: 'trace-tob-profit',
        businessType: 'TOB',
      };

      const product = await harness.createProduct(
        { sku: 'SKU-PROFIT-001', price: 100, cost: 90 },
        context
      );

      const profitMargin = ((product.price - product.cost) / product.price) * 100;

      if (profitMargin < 15) {
        harness.logTrace(context, 'PROFIT_MARGIN_WARNING');
      }

      expect(profitMargin).toBe(10);
      expect(profitMargin).toBeLessThan(15);
    });
  });

  describe('Multi-Platform Sync Flow', () => {
    it('should sync product across multiple platforms', async () => {
      const platforms = ['AMAZON', 'EBAY', 'SHOPIFY'];
      const syncResults: Array<{ platform: string; status: string }> = [];

      for (const platform of platforms) {
        const context: TraceContext = {
          ...defaultContext,
          traceId: `trace-sync-${platform.toLowerCase()}`,
        };

        harness.logTrace(context, `SYNC_TO_${platform}`);
        syncResults.push({ platform, status: 'SYNCED' });
      }

      expect(syncResults.length).toBe(3);
      syncResults.forEach((result) => {
        expect(result.status).toBe('SYNCED');
      });
    });

    it('should aggregate orders from multiple platforms', async () => {
      const platforms = ['AMAZON', 'EBAY', 'SHOPIFY'];
      const aggregatedOrders: Order[] = [];

      for (const platform of platforms) {
        const context: TraceContext = {
          ...defaultContext,
          traceId: `trace-agg-${platform.toLowerCase()}`,
        };

        harness.logTrace(context, `PULL_ORDERS_${platform}`);
        const order = await harness.createOrder(
          { customerId: `cust-${platform}`, items: [{ sku: 'SKU-001', quantity: 1 }] },
          context
        );
        aggregatedOrders.push(order);
      }

      expect(aggregatedOrders.length).toBe(3);
    });
  });

  describe('Exception Handling Flow', () => {
    it('should handle out-of-stock exception', async () => {
      const context: TraceContext = {
        ...defaultContext,
        traceId: 'trace-oos-exception',
      };

      const product = await harness.createProduct(
        { sku: 'SKU-OOS-001', stock: 0 },
        context
      );

      harness.logTrace(context, 'CHECK_STOCK');
      const hasStock = product.stock > 0;

      if (!hasStock) {
        harness.logTrace(context, 'OUT_OF_STOCK_EXCEPTION');
        harness.logTrace(context, 'CREATE_PURCHASE_ORDER');
      }

      expect(hasStock).toBe(false);
    });

    it('should handle payment failure', async () => {
      const context: TraceContext = {
        ...defaultContext,
        traceId: 'trace-payment-fail',
      };

      const order = await harness.createOrder(
        { customerId: 'cust-fail', items: [{ sku: 'SKU-001', quantity: 1 }] },
        context
      );

      harness.logTrace(context, 'PAYMENT_FAILED');
      harness.logTrace(context, 'NOTIFY_CUSTOMER');
      harness.logTrace(context, 'HOLD_ORDER');

      const heldOrder = harness.getOrder(order.id);
      if (heldOrder) heldOrder.status = 'PAYMENT_FAILED';

      expect(heldOrder?.status).toBe('PAYMENT_FAILED');
    });
  });

  describe('Trace Verification', () => {
    it('should maintain trace continuity across flow', async () => {
      const context: TraceContext = {
        ...defaultContext,
        traceId: 'trace-continuity',
      };

      await harness.createProduct({ sku: 'SKU-CONT-001' }, context);
      await harness.publishProduct('prod-1', context);
      await harness.createOrder({ customerId: 'cust-1', items: [{ sku: 'SKU-CONT-001', quantity: 1 }] }, context);

      const logs = harness.getTraceLogs();
      logs.forEach((log) => {
        expect(log.context.traceId).toBe('trace-continuity');
        expect(log.context.tenantId).toBe('tenant-001');
        expect(log.context.shopId).toBe('shop-001');
      });
    });
  });
});

export { E2ETestHarness };
