/**
 * Contract test for POST /api/v1/hedging/sessions
 * Tests the API contract for creating hedging sessions
 */

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

describe('POST /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('Request Schema Validation', () => {
    it('should accept valid hedging session creation request', async () => {
      const validRequest: CreateHedgingSessionRequest = {
        name: 'Test Hedging Session',
        accountIds: ['account-1', 'account-2'],
        volumeTarget: 10000,
        strategy: {
          symbol: 'ETH/USD',
          volumeDistribution: 'equal',
          priceRange: {
            min: 0.001,
            max: 0.01
          },
          timing: {
            minInterval: 30,
            maxInterval: 120,
            orderSize: {
              min: 100,
              max: 500
            }
          },
          riskLimits: {
            maxPositionSize: 0.1,
            stopLossThreshold: 0.05,
            maxSlippage: 0.02
          },
          orderTypes: {
            primary: 'limit',
            fallback: 'market'
          }
        }
      };

      try {
        const response = await client.post('/sessions', validRequest);
        
        // Should return 201 Created
        expect(response.status).toBe(201);
        
        // Response should match schema
        const responseData: CreateHedgingSessionResponse = response.data;
        expect(responseData.success).toBe(true);
        expect(responseData.session).toBeDefined();
        expect(responseData.session.id).toBeDefined();
        expect(responseData.session.name).toBe(validRequest.name);
        expect(responseData.session.status).toBe('pending');
        expect(responseData.session.accounts).toEqual(validRequest.accountIds);
        expect(responseData.session.strategy).toEqual(validRequest.strategy);
        expect(responseData.session.volumeTarget).toBe(validRequest.volumeTarget);
        expect(responseData.session.volumeGenerated).toBe(0);
        expect(responseData.session.startTime).toBeDefined();
        expect(responseData.session.riskBreaches).toEqual([]);
        expect(responseData.session.orders).toEqual([]);
      } catch (error) {
        // This test should fail initially since the endpoint doesn't exist yet
        expect(error.response?.status).toBe(404);
      }
    });

    it('should reject request with invalid session name', async () => {
      const invalidRequest = {
        name: 'ab', // Too short (less than 3 characters)
        accountIds: ['account-1', 'account-2'],
        volumeTarget: 10000,
        strategy: {
          symbol: 'ETH/USD',
          volumeDistribution: 'equal',
          priceRange: { min: 0.001, max: 0.01 },
          timing: { minInterval: 30, maxInterval: 120, orderSize: { min: 100, max: 500 } },
          riskLimits: { maxPositionSize: 0.1, stopLossThreshold: 0.05, maxSlippage: 0.02 },
          orderTypes: { primary: 'limit', fallback: 'market' }
        }
      };

      try {
        await client.post('/sessions', invalidRequest);
        fail('Should have rejected invalid request');
      } catch (error) {
        expect(error.response?.status).toBe(400);
        expect(error.response?.data.success).toBe(false);
        expect(error.response?.data.error.code).toBe('INVALID_STRATEGY');
      }
    });

    it('should reject request with insufficient accounts', async () => {
      const invalidRequest = {
        name: 'Test Session',
        accountIds: ['account-1'], // Only one account (need at least 2)
        volumeTarget: 10000,
        strategy: {
          symbol: 'ETH/USD',
          volumeDistribution: 'equal',
          priceRange: { min: 0.001, max: 0.01 },
          timing: { minInterval: 30, maxInterval: 120, orderSize: { min: 100, max: 500 } },
          riskLimits: { maxPositionSize: 0.1, stopLossThreshold: 0.05, maxSlippage: 0.02 },
          orderTypes: { primary: 'limit', fallback: 'market' }
        }
      };

      try {
        await client.post('/sessions', invalidRequest);
        fail('Should have rejected invalid request');
      } catch (error) {
        expect(error.response?.status).toBe(400);
        expect(error.response?.data.success).toBe(false);
        expect(error.response?.data.error.code).toBe('INSUFFICIENT_ACCOUNTS');
      }
    });

    it('should reject request with negative volume target', async () => {
      const invalidRequest = {
        name: 'Test Session',
        accountIds: ['account-1', 'account-2'],
        volumeTarget: -1000, // Negative volume target
        strategy: {
          symbol: 'ETH/USD',
          volumeDistribution: 'equal',
          priceRange: { min: 0.001, max: 0.01 },
          timing: { minInterval: 30, maxInterval: 120, orderSize: { min: 100, max: 500 } },
          riskLimits: { maxPositionSize: 0.1, stopLossThreshold: 0.05, maxSlippage: 0.02 },
          orderTypes: { primary: 'limit', fallback: 'market' }
        }
      };

      try {
        await client.post('/sessions', invalidRequest);
        fail('Should have rejected invalid request');
      } catch (error) {
        expect(error.response?.status).toBe(400);
        expect(error.response?.data.success).toBe(false);
        expect(error.response?.data.error.code).toBe('INVALID_STRATEGY');
      }
    });

    it('should reject request with invalid strategy parameters', async () => {
      const invalidRequest = {
        name: 'Test Session',
        accountIds: ['account-1', 'account-2'],
        volumeTarget: 10000,
        strategy: {
          symbol: 'ETH/USD',
          volumeDistribution: 'equal',
          priceRange: {
            min: 0.01,
            max: 0.001 // min > max (invalid)
          },
          timing: { minInterval: 30, maxInterval: 120, orderSize: { min: 100, max: 500 } },
          riskLimits: { maxPositionSize: 0.1, stopLossThreshold: 0.05, maxSlippage: 0.02 },
          orderTypes: { primary: 'limit', fallback: 'market' }
        }
      };

      try {
        await client.post('/sessions', invalidRequest);
        fail('Should have rejected invalid request');
      } catch (error) {
        expect(error.response?.status).toBe(400);
        expect(error.response?.data.success).toBe(false);
        expect(error.response?.data.error.code).toBe('INVALID_STRATEGY');
      }
    });
  });

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

      const validRequest = {
        name: 'Test Session',
        accountIds: ['account-1', 'account-2'],
        volumeTarget: 10000,
        strategy: {
          symbol: 'ETH/USD',
          volumeDistribution: 'equal',
          priceRange: { min: 0.001, max: 0.01 },
          timing: { minInterval: 30, maxInterval: 120, orderSize: { min: 100, max: 500 } },
          riskLimits: { maxPositionSize: 0.1, stopLossThreshold: 0.05, maxSlippage: 0.02 },
          orderTypes: { primary: 'limit', fallback: 'market' }
        }
      };

      try {
        await clientWithoutAuth.post('/sessions', validRequest);
        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'
        }
      });

      const validRequest = {
        name: 'Test Session',
        accountIds: ['account-1', 'account-2'],
        volumeTarget: 10000,
        strategy: {
          symbol: 'ETH/USD',
          volumeDistribution: 'equal',
          priceRange: { min: 0.001, max: 0.01 },
          timing: { minInterval: 30, maxInterval: 120, orderSize: { min: 100, max: 500 } },
          riskLimits: { maxPositionSize: 0.1, stopLossThreshold: 0.05, maxSlippage: 0.02 },
          orderTypes: { primary: 'limit', fallback: 'market' }
        }
      };

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

  describe('Business Logic Validation', () => {
    it('should reject request with inactive accounts', async () => {
      const requestWithInactiveAccount = {
        name: 'Test Session',
        accountIds: ['account-1', 'inactive-account'], // inactive-account is not active
        volumeTarget: 10000,
        strategy: {
          symbol: 'ETH/USD',
          volumeDistribution: 'equal',
          priceRange: { min: 0.001, max: 0.01 },
          timing: { minInterval: 30, maxInterval: 120, orderSize: { min: 100, max: 500 } },
          riskLimits: { maxPositionSize: 0.1, stopLossThreshold: 0.05, maxSlippage: 0.02 },
          orderTypes: { primary: 'limit', fallback: 'market' }
        }
      };

      try {
        await client.post('/sessions', requestWithInactiveAccount);
        fail('Should have rejected request with inactive account');
      } catch (error) {
        expect(error.response?.status).toBe(400);
        expect(error.response?.data.success).toBe(false);
        expect(error.response?.data.error.code).toBe('ACCOUNT_NOT_ACTIVE');
      }
    });

    it('should reject request with insufficient account balance', async () => {
      const requestWithInsufficientBalance = {
        name: 'Test Session',
        accountIds: ['account-1', 'poor-account'], // poor-account has insufficient balance
        volumeTarget: 1000000, // Very high volume target
        strategy: {
          symbol: 'ETH/USD',
          volumeDistribution: 'equal',
          priceRange: { min: 0.001, max: 0.01 },
          timing: { minInterval: 30, maxInterval: 120, orderSize: { min: 100, max: 500 } },
          riskLimits: { maxPositionSize: 0.1, stopLossThreshold: 0.05, maxSlippage: 0.02 },
          orderTypes: { primary: 'limit', fallback: 'market' }
        }
      };

      try {
        await client.post('/sessions', requestWithInsufficientBalance);
        fail('Should have rejected request with insufficient balance');
      } catch (error) {
        expect(error.response?.status).toBe(400);
        expect(error.response?.data.success).toBe(false);
        expect(error.response?.data.error.code).toBe('INSUFFICIENT_BALANCE');
      }
    });
  });
});