/**
 * Contract test for GET /api/v1/hedging/sessions
 * Tests the API contract for listing hedging sessions
 */

import { describe, it, expect, beforeAll, afterAll } from '@jest/globals';
import axios, { AxiosInstance } from 'axios';
import { ListHedgingSessionsResponse } from '../../src/types/hedging';

describe('GET /api/v1/hedging/sessions', () => {
  let client: AxiosInstance;
  const baseURL = 'http://localhost:3000/api/v1/hedging';

  beforeAll(() => {
    client = axios.create({
      baseURL,
      headers: {
        'Content-Type': 'application/json',
        'Authorization': 'Bearer test-api-key'
      },
      timeout: 5000
    });
  });

  afterAll(() => {
    // Cleanup if needed
  });

  describe('Basic Functionality', () => {
    it('should return list of hedging sessions', async () => {
      try {
        const response = await client.get('/sessions');
        
        // Should return 200 OK
        expect(response.status).toBe(200);
        
        // Response should match schema
        const responseData: ListHedgingSessionsResponse = response.data;
        expect(responseData.success).toBe(true);
        expect(responseData.sessions).toBeDefined();
        expect(Array.isArray(responseData.sessions)).toBe(true);
        expect(responseData.total).toBeDefined();
        expect(typeof responseData.total).toBe('number');
        expect(responseData.limit).toBeDefined();
        expect(responseData.offset).toBeDefined();
        
        // Each session should have required fields
        responseData.sessions.forEach(session => {
          expect(session.id).toBeDefined();
          expect(session.name).toBeDefined();
          expect(session.status).toBeDefined();
          expect(['pending', 'active', 'paused', 'completed', 'failed']).toContain(session.status);
          expect(session.accounts).toBeDefined();
          expect(Array.isArray(session.accounts)).toBe(true);
          expect(session.volumeTarget).toBeDefined();
          expect(session.volumeGenerated).toBeDefined();
          expect(session.startTime).toBeDefined();
        });
      } catch (error) {
        // This test should fail initially since the endpoint doesn't exist yet
        expect(error.response?.status).toBe(404);
      }
    });

    it('should return empty list when no sessions exist', async () => {
      try {
        const response = await client.get('/sessions');
        
        const responseData: ListHedgingSessionsResponse = response.data;
        expect(responseData.success).toBe(true);
        expect(responseData.sessions).toEqual([]);
        expect(responseData.total).toBe(0);
      } catch (error) {
        // This test should fail initially since the endpoint doesn't exist yet
        expect(error.response?.status).toBe(404);
      }
    });
  });

  describe('Query Parameters', () => {
    it('should filter sessions by status', async () => {
      try {
        const response = await client.get('/sessions?status=active');
        
        expect(response.status).toBe(200);
        
        const responseData: ListHedgingSessionsResponse = response.data;
        expect(responseData.success).toBe(true);
        
        // All returned sessions should have active status
        responseData.sessions.forEach(session => {
          expect(session.status).toBe('active');
        });
      } catch (error) {
        // This test should fail initially since the endpoint doesn't exist yet
        expect(error.response?.status).toBe(404);
      }
    });

    it('should filter sessions by account ID', async () => {
      try {
        const response = await client.get('/sessions?accountId=account-1');
        
        expect(response.status).toBe(200);
        
        const responseData: ListHedgingSessionsResponse = response.data;
        expect(responseData.success).toBe(true);
        
        // All returned sessions should include the specified account
        responseData.sessions.forEach(session => {
          expect(session.accounts).toContain('account-1');
        });
      } catch (error) {
        // This test should fail initially since the endpoint doesn't exist yet
        expect(error.response?.status).toBe(404);
      }
    });

    it('should support pagination with limit and offset', async () => {
      try {
        const response = await client.get('/sessions?limit=10&offset=20');
        
        expect(response.status).toBe(200);
        
        const responseData: ListHedgingSessionsResponse = response.data;
        expect(responseData.success).toBe(true);
        expect(responseData.limit).toBe(10);
        expect(responseData.offset).toBe(20);
        expect(responseData.sessions.length).toBeLessThanOrEqual(10);
      } catch (error) {
        // This test should fail initially since the endpoint doesn't exist yet
        expect(error.response?.status).toBe(404);
      }
    });

    it('should use default pagination values', async () => {
      try {
        const response = await client.get('/sessions');
        
        expect(response.status).toBe(200);
        
        const responseData: ListHedgingSessionsResponse = response.data;
        expect(responseData.success).toBe(true);
        expect(responseData.limit).toBe(50); // Default limit
        expect(responseData.offset).toBe(0); // Default offset
      } catch (error) {
        // This test should fail initially since the endpoint doesn't exist yet
        expect(error.response?.status).toBe(404);
      }
    });

    it('should handle multiple query parameters', async () => {
      try {
        const response = await client.get('/sessions?status=active&accountId=account-1&limit=5&offset=0');
        
        expect(response.status).toBe(200);
        
        const responseData: ListHedgingSessionsResponse = response.data;
        expect(responseData.success).toBe(true);
        expect(responseData.limit).toBe(5);
        expect(responseData.offset).toBe(0);
        
        // All returned sessions should match both filters
        responseData.sessions.forEach(session => {
          expect(session.status).toBe('active');
          expect(session.accounts).toContain('account-1');
        });
      } catch (error) {
        // This test should fail initially since the endpoint doesn't exist yet
        expect(error.response?.status).toBe(404);
      }
    });
  });

  describe('Error Handling', () => {
    it('should reject request without authorization header', async () => {
      const clientWithoutAuth = axios.create({
        baseURL,
        headers: {
          'Content-Type': 'application/json'
        }
      });

      try {
        await clientWithoutAuth.get('/sessions');
        fail('Should have rejected unauthorized request');
      } catch (error) {
        expect(error.response?.status).toBe(401);
      }
    });

    it('should reject request with invalid authorization token', async () => {
      const clientWithInvalidAuth = axios.create({
        baseURL,
        headers: {
          'Content-Type': 'application/json',
          'Authorization': 'Bearer invalid-token'
        }
      });

      try {
        await clientWithInvalidAuth.get('/sessions');
        fail('Should have rejected request with invalid token');
      } catch (error) {
        expect(error.response?.status).toBe(401);
      }
    });

    it('should handle invalid query parameters gracefully', async () => {
      try {
        const response = await client.get('/sessions?status=invalid_status');
        
        expect(response.status).toBe(400);
        expect(response.data.success).toBe(false);
        expect(response.data.error.code).toBe('INVALID_QUERY_PARAMETER');
      } catch (error) {
        // This test should fail initially since the endpoint doesn't exist yet
        expect(error.response?.status).toBe(404);
      }
    });

    it('should handle invalid pagination parameters', async () => {
      try {
        const response = await client.get('/sessions?limit=-1&offset=-5');
        
        expect(response.status).toBe(400);
        expect(response.data.success).toBe(false);
        expect(response.data.error.code).toBe('INVALID_QUERY_PARAMETER');
      } catch (error) {
        // This test should fail initially since the endpoint doesn't exist yet
        expect(error.response?.status).toBe(404);
      }
    });
  });

  describe('Rate Limiting', () => {
    it('should handle rate limiting gracefully', async () => {
      // Make multiple requests quickly to test rate limiting
      const requests = Array(10).fill(null).map(() => client.get('/sessions'));
      
      try {
        const responses = await Promise.all(requests);
        
        // All requests should succeed (rate limit not exceeded)
        responses.forEach(response => {
          expect(response.status).toBe(200);
        });
      } catch (error) {
        // If rate limited, should return 429
        if (error.response?.status === 429) {
          expect(error.response.status).toBe(429);
          expect(error.response.data.error.code).toBe('RATE_LIMIT_EXCEEDED');
        } else {
          // Otherwise, endpoint doesn't exist yet
          expect(error.response?.status).toBe(404);
        }
      }
    });
  });
});