using AutoMapper;
using Koogle.Application.DTOs;
using Koogle.Application.Interfaces;
using Koogle.Application.Services;
using Koogle.Domain.Entities;
using Koogle.Domain.Interfaces;
using Koogle.Tests.Common;
using KoogleApp.Data;
using Microsoft.EntityFrameworkCore;
using System.Diagnostics;

namespace Koogle.Tests.Performance;

/// <summary>
/// Performance tests for critical service operations.
/// </summary>
public class ServicePerformanceTests
{
    private const int SmallDataset = 100;
    private const int MediumDataset = 1000;
    private const int LargeDataset = 10000;

    #region ClubService Performance Tests

    [Theory]
    [InlineData(SmallDataset, 50)]      // 100 records should complete in 50ms
    [InlineData(MediumDataset, 200)]    // 1000 records should complete in 200ms
    public async Task GetAllAsync_CompletesWithinTimeLimit(int recordCount, int maxMilliseconds)
    {
        // Arrange
        var options = new DbContextOptionsBuilder<AppDbContext>()
            .UseInMemoryDatabase($"PerfTest_{Guid.NewGuid()}")
            .Options;

        await using var context = new AppDbContext(options);

        // Seed data
        var clubs = Enumerable.Range(0, recordCount)
            .Select(_ => TestDataGenerator.CreateClub())
            .ToList();
        await context.Clubs.AddRangeAsync(clubs);
        await context.SaveChangesAsync();

        var mapper = TestMockHelpers.CreateClubMapperMock().Object;

        var repositoryMock = new Mock<IClubRepository>();
        repositoryMock.Setup(r => r.GetAllAsync(It.IsAny<CancellationToken>()))
            .ReturnsAsync(() => context.Clubs.Where(c => !c.IsDeleted).ToList());

        var gifServiceMock = new Mock<IClubGifService>();
        var bookingCategoryServiceMock = new Mock<IBookingCategoryService>();
        var service = new ClubService(repositoryMock.Object, mapper, context, gifServiceMock.Object, bookingCategoryServiceMock.Object);

        // Act
        var stopwatch = Stopwatch.StartNew();
        var result = await service.GetAllAsync();
        stopwatch.Stop();

        // Assert
        result.Should().HaveCount(recordCount);
        stopwatch.ElapsedMilliseconds.Should().BeLessThan(maxMilliseconds,
            $"GetAllAsync with {recordCount} records should complete within {maxMilliseconds}ms, took {stopwatch.ElapsedMilliseconds}ms");
    }

    [Fact]
    public async Task CreateAsync_CompletesQuickly()
    {
        // Arrange
        var options = new DbContextOptionsBuilder<AppDbContext>()
            .UseInMemoryDatabase($"PerfTest_CreateAsync_{Guid.NewGuid()}")
            .Options;

        await using var context = new AppDbContext(options);

        var repositoryMock = new Mock<IClubRepository>();
        repositoryMock.Setup(r => r.AddAsync(It.IsAny<Club>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync((Club c, CancellationToken _) => c);

        var mapperMock = TestMockHelpers.CreateClubMapperMock();
        var gifServiceMock = new Mock<IClubGifService>();
        var bookingCategoryServiceMock = new Mock<IBookingCategoryService>();
        var service = new ClubService(repositoryMock.Object, mapperMock.Object, context, gifServiceMock.Object, bookingCategoryServiceMock.Object);
        var dto = TestDataGenerator.CreateCreateClubDto();

        // Act
        var stopwatch = Stopwatch.StartNew();
        for (int i = 0; i < 100; i++)
        {
            await service.CreateAsync(dto);
        }
        stopwatch.Stop();

        // Assert - 100 creates should complete in under 100ms (1ms per create)
        stopwatch.ElapsedMilliseconds.Should().BeLessThan(100,
            $"100 CreateAsync calls should complete within 100ms, took {stopwatch.ElapsedMilliseconds}ms");
    }

    #endregion

    #region AutoMapper Performance Tests

    [Theory]
    [InlineData(SmallDataset, 50)]
    [InlineData(MediumDataset, 200)]
    [InlineData(LargeDataset, 1000)]
    public void Mapper_MapsClubsToDtos_Efficiently(int count, int maxMilliseconds)
    {
        // Arrange
        var mapper = TestMockHelpers.CreateClubMapperMock().Object;
        var clubs = Enumerable.Range(0, count)
            .Select(_ => TestDataGenerator.CreateClub())
            .ToList();

        // Act
        var stopwatch = Stopwatch.StartNew();
        var result = mapper.Map<List<ClubDto>>(clubs);
        stopwatch.Stop();

        // Assert
        result.Should().HaveCount(count);
        stopwatch.ElapsedMilliseconds.Should().BeLessThan(maxMilliseconds,
            $"Mapping {count} clubs should complete within {maxMilliseconds}ms, took {stopwatch.ElapsedMilliseconds}ms");
    }

    #endregion

    #region Fluxor Reducer Performance Tests

    [Theory]
    [InlineData(SmallDataset)]
    [InlineData(MediumDataset)]
    public void Reducers_HandleLargeStateLists_Efficiently(int clubCount)
    {
        // Arrange
        var clubs = TestDataGenerator.CreateClubDtos(clubCount);
        var state = Koogle.Web.Store.ClubState.ClubState.Initial with { Clubs = clubs };
        var newClub = TestDataGenerator.CreateClubDto();

        // Act - Measure time for add operation
        var stopwatch = Stopwatch.StartNew();
        for (int i = 0; i < 100; i++)
        {
            Koogle.Web.Store.ClubState.ClubReducers.OnCreateClubSuccess(
                state,
                new Koogle.Web.Store.ClubState.CreateClubSuccessAction(newClub));
        }
        stopwatch.Stop();

        // Assert - 100 reducer calls should complete quickly
        stopwatch.ElapsedMilliseconds.Should().BeLessThan(50,
            $"100 reducer calls with {clubCount} existing items should complete within 50ms");
    }

    [Theory]
    [InlineData(SmallDataset)]
    [InlineData(MediumDataset)]
    public void Reducers_DeleteFromLargeList_Efficiently(int clubCount)
    {
        // Arrange
        var clubs = TestDataGenerator.CreateClubDtos(clubCount);
        var state = Koogle.Web.Store.ClubState.ClubState.Initial with { Clubs = clubs };
        var deleteIds = clubs.Take(100).Select(c => c.Id).ToList();

        // Act - Measure time for delete operations
        var stopwatch = Stopwatch.StartNew();
        foreach (var id in deleteIds)
        {
            Koogle.Web.Store.ClubState.ClubReducers.OnDeleteClubSuccess(
                state,
                new Koogle.Web.Store.ClubState.DeleteClubSuccessAction(id));
        }
        stopwatch.Stop();

        // Assert
        stopwatch.ElapsedMilliseconds.Should().BeLessThan(100,
            $"100 delete operations on {clubCount} items should complete within 100ms");
    }

    #endregion

    #region Memory Allocation Tests

    [Fact]
    public void LargeDatasetOperations_DoNotCauseExcessiveAllocation()
    {
        // Arrange
        var clubs = TestDataGenerator.CreateClubDtos(MediumDataset);
        var state = Koogle.Web.Store.ClubState.ClubState.Initial with { Clubs = clubs };

        // Force GC to get baseline
        GC.Collect();
        GC.WaitForPendingFinalizers();
        GC.Collect();

        var memoryBefore = GC.GetTotalMemory(true);

        // Act - Perform many operations
        for (int i = 0; i < 100; i++)
        {
            var newClub = TestDataGenerator.CreateClubDto();
            Koogle.Web.Store.ClubState.ClubReducers.OnCreateClubSuccess(
                state,
                new Koogle.Web.Store.ClubState.CreateClubSuccessAction(newClub));
        }

        GC.Collect();
        GC.WaitForPendingFinalizers();
        GC.Collect();

        var memoryAfter = GC.GetTotalMemory(true);
        var memoryIncrease = memoryAfter - memoryBefore;

        // Assert - Memory increase should be reasonable (< 50MB for 100 operations)
        memoryIncrease.Should().BeLessThan(50 * 1024 * 1024,
            $"Memory increase should be less than 50MB, was {memoryIncrease / 1024 / 1024}MB");
    }

    #endregion
}