const request = require("supertest");
const app = require("../server");
const User = require("../models/User");
const Street = require("../models/Street");
const Task = require("../models/Task");
const Event = require("../models/Event");
const Post = require("../models/Post");
const { generateTestId } = require('./utils/idGenerator');

describe("Performance Tests", () => {
  let testUsers = [];
  let authTokens = [];

  beforeAll(async () => {
    // Create multiple test users for concurrent testing
    for (let i = 0; i < 20; i++) {
      const user = await User.create({
        name: `Test User ${i}`,
        email: `test${i}@example.com`,
        password: "password123",
        points: Math.floor(Math.random() * 1000),
      });
      testUsers.push(user);

      const jwt = require("jsonwebtoken");
      const token = jwt.sign(
        { user: { id: user._id } },
        process.env.JWT_SECRET || "test_secret"
      );
      authTokens.push(token);
    }

    // Create test data
    await createTestData();
  });

  async function createTestData() {
    // Create streets
    const streets = [];
    for (let i = 0; i < 100; i++) {
      streets.push({
        name: `Street ${i}`,
        location: {
          type: "Point",
          coordinates: [
            -74 + (Math.random() * 0.1),
            40.7 + (Math.random() * 0.1),
          ],
        },
        status: Math.random() > 0.5 ? "available" : "adopted",
      });
    }
    await Street.insertMany(streets);

    // Create tasks
    const tasks = [];
    for (let i = 0; i < 200; i++) {
      tasks.push({
        title: `Task ${i}`,
        description: `Description for task ${i}`,
        street: { streetId: streets[Math.floor(Math.random() * streets.length)]._id },
        pointsAwarded: Math.floor(Math.random() * 20) + 5,
        status: Math.random() > 0.3 ? "pending" : "completed",
      });
    }
    await Task.insertMany(tasks);

    // Create events
    const events = [];
    for (let i = 0; i < 50; i++) {
      events.push({
        title: `Event ${i}`,
        description: `Description for event ${i}`,
        date: new Date(Date.now() + Math.random() * 30 * 24 * 60 * 60 * 1000),
        location: `Location ${i}`,
        status: "upcoming",
        participants: [],
      });
    }
    await Event.insertMany(events);

    // Create posts
    const posts = [];
    for (let i = 0; i < 150; i++) {
      posts.push({
        user: {
          userId: testUsers[Math.floor(Math.random() * testUsers.length)]._id,
          name: `User ${i}`,
        },
        content: `Post content ${i}`,
        likes: [],
        commentsCount: 0,
      });
    }
    await Post.insertMany(posts);
  }

  describe("API Response Times", () => {
    test("should respond to basic requests quickly", async () => {
      const startTime = Date.now();

      await request(app)
        .get("/api/health")
        .expect(200);

      const endTime = Date.now();
      const responseTime = endTime - startTime;

      // Health check should be very fast (< 50ms)
      expect(responseTime).toBeLessThan(50);
    });

    test("should handle street listing efficiently", async () => {
      const startTime = Date.now();

      const response = await request(app)
        .get("/api/streets")
        .expect(200);

      const endTime = Date.now();
      const responseTime = endTime - startTime;

      // Should respond within 200ms even with 100 streets
      expect(responseTime).toBeLessThan(200);
      expect(response.body.length).toBeGreaterThan(0);
    });

    test("should handle paginated requests efficiently", async () => {
      const startTime = Date.now();

      const response = await request(app)
        .get("/api/streets?page=1&limit=10")
        .expect(200);

      const endTime = Date.now();
      const responseTime = endTime - startTime;

      // Pagination should be fast (< 100ms)
      expect(responseTime).toBeLessThan(100);
      expect(response.body.docs).toHaveLength(10);
    });

    test("should handle geospatial queries efficiently", async () => {
      const startTime = Date.now();

      const response = await request(app)
        .get("/api/streets/nearby")
        .query({
          lng: -73.9654,
          lat: 40.7829,
          maxDistance: 5000,
        })
        .expect(200);

      const endTime = Date.now();
      const responseTime = endTime - startTime;

      // Geospatial queries should be efficient (< 300ms)
      expect(responseTime).toBeLessThan(300);
    });

    test("should handle complex queries efficiently", async () => {
      const startTime = Date.now();

      // Test a complex query with multiple filters
      const response = await request(app)
        .get("/api/tasks")
        .query({
          status: "pending",
          limit: 20,
          sort: "createdAt",
        })
        .expect(200);

      const endTime = Date.now();
      const responseTime = endTime - startTime;

      // Complex queries should still be reasonable (< 400ms)
      expect(responseTime).toBeLessThan(400);
    });
  });

  describe("Concurrent Request Handling", () => {
    test("should handle concurrent read requests", async () => {
      const startTime = Date.now();
      const concurrentRequests = 50;

      const promises = [];
      for (let i = 0; i < concurrentRequests; i++) {
        promises.push(request(app).get("/api/streets"));
      }

      const responses = await Promise.all(promises);
      const endTime = Date.now();
      const totalTime = endTime - startTime;

      // All requests should succeed
      responses.forEach((response) => {
        expect(response.status).toBe(200);
      });

      // Should handle 50 concurrent requests within 2 seconds
      expect(totalTime).toBeLessThan(2000);

      // Average response time should be reasonable
      const avgResponseTime = totalTime / concurrentRequests;
      expect(avgResponseTime).toBeLessThan(100);
    });

    test("should handle concurrent write requests", async () => {
      const startTime = Date.now();
      const concurrentRequests = 20;

      const promises = [];
      for (let i = 0; i < concurrentRequests; i++) {
        promises.push(
          request(app)
            .post("/api/posts")
            .set("x-auth-token", authTokens[i % authTokens.length])
            .send({
              content: `Concurrent post ${i}`,
            })
        );
      }

      const responses = await Promise.all(promises);
      const endTime = Date.now();
      const totalTime = endTime - startTime;

      // Most requests should succeed (some might fail due to rate limiting)
      const successCount = responses.filter(r => r.status === 200).length;
      expect(successCount).toBeGreaterThan(15);

      // Should handle concurrent writes within 5 seconds
      expect(totalTime).toBeLessThan(5000);
    });

    test("should handle mixed read/write workload", async () => {
      const startTime = Date.now();
      const operations = [];

      // Mix of different operations
      for (let i = 0; i < 30; i++) {
        // Read operations
        operations.push(request(app).get("/api/streets"));
        operations.push(request(app).get("/api/events"));
        
        // Write operations
        operations.push(
          request(app)
            .post("/api/posts")
            .set("x-auth-token", authTokens[i % authTokens.length])
            .send({ content: `Mixed post ${i}` })
        );
      }

      const responses = await Promise.all(operations);
      const endTime = Date.now();
      const totalTime = endTime - startTime;

      // Most operations should succeed
      const successCount = responses.filter(r => r.status === 200).length;
      expect(successCount).toBeGreaterThan(50);

      // Should handle mixed workload within 3 seconds
      expect(totalTime).toBeLessThan(3000);
    });
  });

  describe("Memory Usage", () => {
    test("should not leak memory during repeated operations", async () => {
      const initialMemory = process.memoryUsage().heapUsed;

      // Perform many operations
      for (let i = 0; i < 100; i++) {
        await request(app).get("/api/streets");
        await request(app).get("/api/events");
        await request(app).get("/api/tasks");
        
        // Force garbage collection if available
        if (global.gc) {
          global.gc();
        }
      }

      const finalMemory = process.memoryUsage().heapUsed;
      const memoryIncrease = finalMemory - initialMemory;

      // Memory increase should be reasonable (< 50MB)
      expect(memoryIncrease).toBeLessThan(50 * 1024 * 1024);
    });

    test("should handle large result sets efficiently", async () => {
      const startTime = Date.now();

      // Request a large result set
      const response = await request(app)
        .get("/api/streets?limit=100")
        .expect(200);

      const endTime = Date.now();
      const responseTime = endTime - startTime;

      // Should handle large results efficiently
      expect(responseTime).toBeLessThan(500);
      expect(response.body.length).toBeGreaterThan(0);
    });
  });

  describe("Database Performance", () => {
    test("should use database indexes effectively", async () => {
      const startTime = Date.now();

      // Query that should use indexes
      await request(app)
        .get("/api/streets")
        .query({ status: "available" });

      const endTime = Date.now();
      const queryTime = endTime - startTime;

      // Indexed queries should be fast
      expect(queryTime).toBeLessThan(100);
    });

    test("should handle database connection pooling", async () => {
      const startTime = Date.now();
      const concurrentDbOperations = 30;

      const promises = [];
      for (let i = 0; i < concurrentDbOperations; i++) {
        promises.push(
          request(app)
            .get(`/api/streets/${generateTestId()}`)
            .expect(404)
        );
      }

      await Promise.all(promises);
      const endTime = Date.now();
      const totalTime = endTime - startTime;

      // Connection pooling should handle concurrent operations efficiently
      expect(totalTime).toBeLessThan(1000);
    });

    test("should handle aggregation queries efficiently", async () => {
      const startTime = Date.now();

      // Test leaderboard (aggregation) performance
      const response = await request(app)
        .get("/api/rewards/leaderboard")
        .expect(200);

      const endTime = Date.now();
      const queryTime = endTime - startTime;

      // Aggregation should be reasonably fast
      expect(queryTime).toBeLessThan(300);
      expect(response.body.length).toBeGreaterThan(0);
    });
  });

  describe("Rate Limiting Performance", () => {
    test("should handle rate limiting efficiently", async () => {
      const startTime = Date.now();

      // Make requests that approach rate limit
      const promises = [];
      for (let i = 0; i < 95; i++) { // Just under the limit
        promises.push(
          request(app)
            .get("/api/streets")
            .set("x-auth-token", authTokens[i % authTokens.length])
        );
      }

      const responses = await Promise.all(promises);
      const endTime = Date.now();
      const totalTime = endTime - startTime;

      // Should handle requests near rate limit efficiently
      expect(totalTime).toBeLessThan(2000);

      const successCount = responses.filter(r => r.status === 200).length;
      expect(successCount).toBeGreaterThan(90);
    });
  });

  describe("Stress Tests", () => {
    test("should handle sustained load", async () => {
      const duration = 5000; // 5 seconds
      const startTime = Date.now();
      let requestCount = 0;

      while (Date.now() - startTime < duration) {
        const promises = [];
        for (let i = 0; i < 10; i++) {
          promises.push(request(app).get("/api/health"));
        }
        await Promise.all(promises);
        requestCount += 10;
      }

      const actualDuration = Date.now() - startTime;
      const requestsPerSecond = (requestCount / actualDuration) * 1000;

      // Should handle at least 50 requests per second
      expect(requestsPerSecond).toBeGreaterThan(50);
    });

    test("should maintain performance under load", async () => {
      const baselineTime = await measureResponseTime("/api/streets");

      // Apply load
      const loadPromises = [];
      for (let i = 0; i < 50; i++) {
        loadPromises.push(request(app).get("/api/events"));
      }
      await Promise.all(loadPromises);

      // Measure performance after load
      const afterLoadTime = await measureResponseTime("/api/streets");

      // Performance should not degrade significantly
      const performanceDegradation = (afterLoadTime - baselineTime) / baselineTime;
      expect(performanceDegradation).toBeLessThan(0.5); // Less than 50% degradation
    });

    async function measureResponseTime(endpoint) {
      const startTime = Date.now();
      await request(app).get(endpoint);
      return Date.now() - startTime;
    }
  });

  describe("Resource Limits", () => {
    test("should handle large payloads efficiently", async () => {
      const largeContent = "x".repeat(10000); // 10KB content

      const startTime = Date.now();
      const response = await request(app)
        .post("/api/posts")
        .set("x-auth-token", authTokens[0])
        .send({ content: largeContent })
        .expect(200);

      const endTime = Date.now();
      const responseTime = endTime - startTime;

      // Should handle large payloads reasonably
      expect(responseTime).toBeLessThan(1000);
      expect(response.body.content).toBe(largeContent);
    });

    test("should reject oversized payloads quickly", async () => {
      const oversizedContent = "x".repeat(1000000); // 1MB content

      const startTime = Date.now();
      const response = await request(app)
        .post("/api/posts")
        .set("x-auth-token", authTokens[0])
        .send({ content: oversizedContent })
        .expect(413);

      const endTime = Date.now();
      const responseTime = endTime - startTime;

      // Should reject oversized payloads quickly
      expect(responseTime).toBeLessThan(100);
    });
  });

  describe("Caching Performance", () => {
    test("should cache static responses efficiently", async () => {
      // First request
      const startTime1 = Date.now();
      await request(app).get("/api/health");
      const firstRequestTime = Date.now() - startTime1;

      // Second request (potentially cached)
      const startTime2 = Date.now();
      await request(app).get("/api/health");
      const secondRequestTime = Date.now() - startTime2;

      // Second request should be faster (if cached)
      // Note: This test depends on implementation of caching
      expect(secondRequestTime).toBeLessThanOrEqual(firstRequestTime);
    });
  });

  describe("Scalability Tests", () => {
    test("should handle increasing data volumes", async () => {
      // Create additional data
      const additionalStreets = [];
      for (let i = 0; i < 100; i++) {
        additionalStreets.push({
          name: `Additional Street ${i}`,
          location: {
            type: "Point",
            coordinates: [-74 + Math.random() * 0.1, 40.7 + Math.random() * 0.1],
          },
          status: "available",
        });
      }
      await Street.insertMany(additionalStreets);

      // Measure performance with increased data
      const startTime = Date.now();
      const response = await request(app)
        .get("/api/streets")
        .query({ limit: 50 })
        .expect(200);

      const endTime = Date.now();
      const responseTime = endTime - startTime;

      // Should maintain performance with more data
      expect(responseTime).toBeLessThan(300);
      expect(response.body.length).toBe(50);
    });

    test("should handle user growth efficiently", async () => {
      // Create additional users
      const additionalUsers = [];
      for (let i = 0; i < 50; i++) {
        additionalUsers.push({
          name: `Additional User ${i}`,
          email: `additional${i}@example.com`,
          password: "password123",
          points: Math.floor(Math.random() * 1000),
        });
      }
      await User.insertMany(additionalUsers);

      // Test leaderboard performance with more users
      const startTime = Date.now();
      const response = await request(app)
        .get("/api/rewards/leaderboard")
        .expect(200);

      const endTime = Date.now();
      const responseTime = endTime - startTime;

      // Should handle more users efficiently
      expect(responseTime).toBeLessThan(400);
      expect(response.body.length).toBeGreaterThan(0);
    });
  });
});