import { describe, it, expect } from "vitest";

/**
 * Simple Integration Tests
 * 
 * These tests verify that the API logic works correctly
 * without requiring a full database connection.
 */

describe("API Integration (Simple)", () => {
  describe("Company API Logic", () => {
    it("should validate company creation data", async () => {
      const { companySchema } = await import("@/lib/schemas");
      
      const validCompany = {
        name: "Test GmbH",
        address: "Hauptstraße 1",
        zip: "12345",
        city: "Berlin",
        country: "DE",
        invoicePrefix: "RE",
        kleinunternehmer: false,
        taxId: null,
        vatId: null,
        bankIban: null,
        bankBic: "",
      };

      const result = companySchema.safeParse(validCompany);
      expect(result.success).toBe(true);
    });

    it("should reject invalid company data", async () => {
      const { companySchema } = await import("@/lib/schemas");
      
      const invalidCompany = {
        name: "", // Invalid: empty name
        address: "Test St. 1",
        zip: "12345",
        city: "Berlin",
      };

      const result = companySchema.safeParse(invalidCompany);
      expect(result.success).toBe(false);
    });
  });

  describe("Invoice API Logic", () => {
    it("should validate invoice creation data", async () => {
      const { invoiceSchema } = await import("@/lib/schemas");
      
      const validInvoice = {
        companyId: "company-123",
        customerId: "customer-456",
        issueDate: "2026-05-08",
        dueDate: "2026-06-08",
        kleinunternehmer: false,
        items: [
          {
            position: 1,
            description: "Web Development",
            quantity: 10,
            unit: "Stunden",
            unitPrice: 100,
            taxRate: 19,
            netAmount: 1000,
            taxAmount: 190,
            grossAmount: 1190,
          },
        ],
        netTotal: 1000,
        taxTotal: 190,
        grossTotal: 1190,
      };

      const result = invoiceSchema.safeParse(validInvoice);
      expect(result.success).toBe(true);
    });

    it("should reject invoice with no items", async () => {
      const { invoiceSchema } = await import("@/lib/schemas");
      
      const invalidInvoice = {
        companyId: "company-123",
        customerId: "customer-456",
        issueDate: "2026-05-08",
        dueDate: "2026-06-08",
        items: [], // Invalid: no items
        netTotal: 0,
        taxTotal: 0,
        grossTotal: 0,
      };

      const result = invoiceSchema.safeParse(invalidInvoice);
      expect(result.success).toBe(false);
    });
  });

  describe("Customer API Logic", () => {
    it("should validate customer data", async () => {
      const { customerSchema } = await import("@/lib/schemas");
      
      const validCustomer = {
        companyId: "company-123",
        name: "Max Mustermann",
        address: "Musterstraße 1",
        zip: "12345",
        city: "Berlin",
        country: "DE",
      };

      const result = customerSchema.safeParse(validCustomer);
      expect(result.success).toBe(true);
    });

    it("should require companyId", async () => {
      const { customerSchema } = await import("@/lib/schemas");
      
      const invalidCustomer = {
        name: "Max Mustermann",
        address: "Musterstraße 1",
        zip: "12345",
        city: "Berlin",
      };

      const result = customerSchema.safeParse(invalidCustomer);
      expect(result.success).toBe(false);
    });
  });

  describe("Tax Calculation Integration", () => {
    it("should calculate invoice totals from items", async () => {
      const { calcItemAmounts, calcInvoiceTotals } = await import("@/lib/tax");
      
      const items = [
        {
          quantity: 10,
          unitPrice: 100,
          taxRate: 19,
        },
        {
          quantity: 5,
          unitPrice: 200,
          taxRate: 7,
        },
      ].map((item, idx) => ({
        position: idx + 1,
        description: `Service ${idx + 1}`,
        ...item,
        ...calcItemAmounts(item.quantity, item.unitPrice, item.taxRate),
      }));

      const totals = calcInvoiceTotals(items);

      expect(totals.netTotal).toBe(2000); // 1000 + 1000
      expect(totals.taxTotal).toBe(260); // 190 + 70 (5*200*7% = 70)
      expect(totals.grossTotal).toBe(2260); // 1190 + 1070
    });

    it("should handle Kleinunternehmer calculation", async () => {
      const { calcItemAmountsKleinunternehmer, calcInvoiceTotals } = await import("@/lib/tax");
      
      const items = [
        {
          quantity: 10,
          unitPrice: 100,
        },
      ].map((item, idx) => ({
        position: idx + 1,
        description: "Service",
        ...item,
        ...calcItemAmountsKleinunternehmer(item.quantity, item.unitPrice),
        taxRate: 0,
      }));

      const totals = calcInvoiceTotals(items);

      expect(totals.netTotal).toBe(1000);
      expect(totals.taxTotal).toBe(0);
      expect(totals.grossTotal).toBe(1000);
    });
  });

  describe("Authentication Logic", () => {
    it("should identify unauthorized requests", () => {
      const user = null;
      const isAuthenticated = user !== null;
      expect(isAuthenticated).toBe(false);
    });

    it("should identify authorized requests", () => {
      const user = { id: "user-123", role: "ADMIN" };
      const isAuthenticated = user !== null;
      expect(isAuthenticated).toBe(true);
      expect(user.role).toBe("ADMIN");
    });
  });
});