using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using GermanApp.Application.DTOs;
using GermanApp.Application.Services;
using GermanApp.Domain.Entities;
using GermanApp.Domain.Interfaces;
using Microsoft.Extensions.Logging;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Moq;

namespace GermanApp.Tests.Unit.Application.Services;

[TestClass]
public class StoryServiceTests
{
    private Mock<IStoryRepository> _mockStoryRepository;
    private Mock<IStoryProgressRepository> _mockProgressRepository;
    private Mock<ILogger<StoryService>> _mockLogger;
    private StoryService _service;

    [TestInitialize]
    public void Setup()
    {
        _mockStoryRepository = new Mock<IStoryRepository>();
        _mockProgressRepository = new Mock<IStoryProgressRepository>();
        _mockLogger = new Mock<ILogger<StoryService>>();
        _service = new StoryService(
            _mockStoryRepository.Object,
            _mockProgressRepository.Object,
            _mockLogger.Object);
    }

    [TestMethod]
    public async Task GetByIdAsync_WithExistingId_ReturnsSegment()
    {
        // Arrange
        var segment = StorySegment.Create(1, 1, "Test content", 1, "Test Title", "Test Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment, 1);
        
        _mockStoryRepository.Setup(s => s.GetByIdAsync(1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(segment);

        // Act
        var result = await _service.GetByIdAsync(1);

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(1, result.Id);
        Assert.AreEqual("Test content", result.Content);
        Assert.AreEqual("Test Title", result.Title);
    }

    [TestMethod]
    public async Task GetByIdAsync_WithNonExistingId_ReturnsNull()
    {
        // Arrange
        _mockStoryRepository.Setup(s => s.GetByIdAsync(999, It.IsAny<CancellationToken>()))
            .ReturnsAsync((StorySegment?)null);

        // Act
        var result = await _service.GetByIdAsync(999);

        // Assert
        Assert.IsNull(result);
    }

    [TestMethod]
    public async Task GetByLevelAsync_WithExistingLevel_ReturnsSegments()
    {
        // Arrange
        var segment1 = StorySegment.Create(1, 1, "Content 1", 1, "Title 1", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment1, 1);
        var segment2 = StorySegment.Create(1, 2, "Content 2", 2, "Title 2", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment2, 2);
        
        _mockStoryRepository.Setup(s => s.GetByLevelAsync(1, false, It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<StorySegment> { segment1, segment2 });

        // Act
        var result = await _service.GetByLevelAsync(1);

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(2, result.Count);
        Assert.AreEqual("Content 1", result[0].Content);
        Assert.AreEqual("Content 2", result[1].Content);
    }

    [TestMethod]
    public async Task GetByLevelAsync_WithNoSegments_ReturnsEmptyList()
    {
        // Arrange
        _mockStoryRepository.Setup(s => s.GetByLevelAsync(1, false, It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<StorySegment>());

        // Act
        var result = await _service.GetByLevelAsync(1);

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(0, result.Count);
    }

    [TestMethod]
    public async Task GetByLessonAsync_WithExistingLesson_ReturnsSegments()
    {
        // Arrange
        var segment = StorySegment.Create(1, 1, "Test content", 1, "Test Title", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment, 1);
        
        _mockStoryRepository.Setup(s => s.GetByLessonAsync(1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<StorySegment> { segment });

        // Act
        var result = await _service.GetByLessonAsync(1);

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(1, result.Count);
        Assert.AreEqual("Test content", result[0].Content);
    }

    [TestMethod]
    public async Task CreateAsync_WithValidData_CreatesSegment()
    {
        // Arrange
        var dto = new CreateStorySegmentDto(1, 1, "New content", 1, "New Title", "New Theme");
        var createdSegment = StorySegment.Create(1, 1, "New content", 1, "New Title", "New Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(createdSegment, 10);
        
        _mockStoryRepository.Setup(s => s.GetByOrderRangeAsync(1, 1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<StorySegment>()); // No existing segment
        _mockStoryRepository.Setup(s => s.AddAsync(It.IsAny<StorySegment>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(createdSegment);

        // Act
        var result = await _service.CreateAsync(dto);

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(10, result.Id);
        Assert.AreEqual("New content", result.Content);
        _mockStoryRepository.Verify(s => s.AddAsync(It.IsAny<StorySegment>(), It.IsAny<CancellationToken>()), Times.Once);
    }

    [TestMethod]
    public async Task CreateAsync_WithDuplicateOrder_ThrowsException()
    {
        // Arrange
        var dto = new CreateStorySegmentDto(1, 1, "New content", 1, "New Title", "New Theme");
        var existingSegment = StorySegment.Create(1, 1, "Existing", 1, "Existing", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(existingSegment, 1);
        
        _mockStoryRepository.Setup(s => s.GetByOrderRangeAsync(1, 1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<StorySegment> { existingSegment });

        // Act & Assert
        try
        {
            await _service.CreateAsync(dto);
            Assert.Fail("Expected InvalidOperationException was not thrown");
        }
        catch (InvalidOperationException ex)
        {
            Assert.IsTrue(ex.Message.Contains("already exists"));
        }
    }

    [TestMethod]
    public async Task UpdateAsync_WithExistingId_UpdatesSegment()
    {
        // Arrange
        var existingSegment = StorySegment.Create(1, 1, "Old content", 1, "Old Title", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(existingSegment, 1);
        var dto = new UpdateStorySegmentDto(Content: "New content", Title: "New Title");
        
        _mockStoryRepository.Setup(s => s.GetByIdAsync(1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(existingSegment);
        _mockStoryRepository.Setup(s => s.UpdateAsync(It.IsAny<StorySegment>(), It.IsAny<CancellationToken>()))
            .Returns(Task.CompletedTask);

        // Act
        var result = await _service.UpdateAsync(1, dto);

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual("New content", result.Content);
        Assert.AreEqual("New Title", result.Title);
        _mockStoryRepository.Verify(s => s.UpdateAsync(It.IsAny<StorySegment>(), It.IsAny<CancellationToken>()), Times.Once);
    }

    [TestMethod]
    public async Task UpdateAsync_WithNonExistingId_ReturnsNull()
    {
        // Arrange
        var dto = new UpdateStorySegmentDto(Content: "New content");
        
        _mockStoryRepository.Setup(s => s.GetByIdAsync(999, It.IsAny<CancellationToken>()))
            .ReturnsAsync((StorySegment?)null);

        // Act
        var result = await _service.UpdateAsync(999, dto);

        // Assert
        Assert.IsNull(result);
    }

    [TestMethod]
    public async Task DeleteAsync_WithExistingId_DeletesSegment()
    {
        // Arrange
        _mockStoryRepository.Setup(s => s.ExistsAsync(1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(true);
        _mockStoryRepository.Setup(s => s.DeleteAsync(1, It.IsAny<CancellationToken>()))
            .Returns(Task.CompletedTask);

        // Act
        var result = await _service.DeleteAsync(1);

        // Assert
        Assert.IsTrue(result);
        _mockStoryRepository.Verify(s => s.DeleteAsync(1, It.IsAny<CancellationToken>()), Times.Once);
    }

    [TestMethod]
    public async Task DeleteAsync_WithNonExistingId_ReturnsFalse()
    {
        // Arrange
        _mockStoryRepository.Setup(s => s.ExistsAsync(999, It.IsAny<CancellationToken>()))
            .ReturnsAsync(false);

        // Act
        var result = await _service.DeleteAsync(999);

        // Assert
        Assert.IsFalse(result);
    }

    [TestMethod]
    public async Task GetNextSegmentToUnlockAsync_WithValidLesson_ReturnsSegment()
    {
        // Arrange
        var segment = StorySegment.Create(1, 2, "Next content", 2, "Next Title", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment, 2);
        
        _mockStoryRepository.Setup(s => s.GetNextSegmentToUnlockAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(segment);

        // Act
        var result = await _service.GetNextSegmentToUnlockAsync(1, 1);

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(2, result.Id);
        Assert.AreEqual("Next content", result.Content);
    }

    [TestMethod]
    public async Task GetNextSegmentToUnlockAsync_WithNoSegment_ReturnsNull()
    {
        // Arrange
        _mockStoryRepository.Setup(s => s.GetNextSegmentToUnlockAsync(1, 10, It.IsAny<CancellationToken>()))
            .ReturnsAsync((StorySegment?)null);

        // Act
        var result = await _service.GetNextSegmentToUnlockAsync(1, 10);

        // Assert
        Assert.IsNull(result);
    }

    [TestMethod]
    public async Task UpdateAudioUrlAsync_WithExistingSegment_UpdatesUrl()
    {
        // Arrange
        var segment = StorySegment.Create(1, 1, "Content", 1, "Title", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment, 1);
        
        _mockStoryRepository.Setup(s => s.GetByIdAsync(1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(segment);
        _mockStoryRepository.Setup(s => s.UpdateAsync(It.IsAny<StorySegment>(), It.IsAny<CancellationToken>()))
            .Returns(Task.CompletedTask);

        // Act
        var result = await _service.UpdateAudioUrlAsync(1, "/audio/test.wav");

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual("/audio/test.wav", result.AudioUrl);
    }

    [TestMethod]
    public async Task UpdateAudioUrlAsync_WithNonExistingSegment_ReturnsNull()
    {
        // Arrange
        _mockStoryRepository.Setup(s => s.GetByIdAsync(999, It.IsAny<CancellationToken>()))
            .ReturnsAsync((StorySegment?)null);

        // Act
        var result = await _service.UpdateAudioUrlAsync(999, "/audio/test.wav");

        // Assert
        Assert.IsNull(result);
    }

    [TestMethod]
    public async Task MarkSegmentAsCompletedAsync_WithExistingProgress_MarksAsCompleted()
    {
        // Arrange
        var progress = StoryProgress.Create(1, 1, 1);
        typeof(StoryProgress).GetProperty("Id")?.SetValue(progress, 1);
        
        _mockProgressRepository.Setup(p => p.GetByUserAndSegmentAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(progress);
        _mockProgressRepository.Setup(p => p.UpdateAsync(It.IsAny<StoryProgress>(), It.IsAny<CancellationToken>()))
            .Returns(Task.CompletedTask);

        // Act
        var result = await _service.MarkSegmentAsCompletedAsync(1, 1);

        // Assert
        Assert.IsTrue(result);
        Assert.IsTrue(progress.IsCompleted);
        Assert.IsNotNull(progress.CompletedAt);
    }

    [TestMethod]
    public async Task MarkSegmentAsCompletedAsync_WithNonExistingProgress_ReturnsFalse()
    {
        // Arrange
        _mockProgressRepository.Setup(p => p.GetByUserAndSegmentAsync(1, 999, It.IsAny<CancellationToken>()))
            .ReturnsAsync((StoryProgress?)null);

        // Act
        var result = await _service.MarkSegmentAsCompletedAsync(1, 999);

        // Assert
        Assert.IsFalse(result);
    }

    [TestMethod]
    public async Task MarkSegmentAsCompletedAsync_WithAlreadyCompleted_ReturnsFalse()
    {
        // Arrange
        var progress = StoryProgress.Create(1, 1, 1);
        typeof(StoryProgress).GetProperty("Id")?.SetValue(progress, 1);
        progress.MarkAsCompleted();
        
        _mockProgressRepository.Setup(p => p.GetByUserAndSegmentAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(progress);

        // Act
        var result = await _service.MarkSegmentAsCompletedAsync(1, 1);

        // Assert
        Assert.IsFalse(result);
    }

    [TestMethod]
    public async Task UnlockNextSegmentAsync_WithValidLesson_UnlocksSegment()
    {
        // Arrange
        var segment = StorySegment.Create(1, 2, "Next content", 2, "Next Title", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment, 2);
        
        _mockStoryRepository.Setup(s => s.GetNextSegmentToUnlockAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(segment);
        _mockProgressRepository.Setup(p => p.IsSegmentUnlockedAsync(1, 2, It.IsAny<CancellationToken>()))
            .ReturnsAsync(false);
        _mockProgressRepository.Setup(p => p.AddAsync(It.IsAny<StoryProgress>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync((StoryProgress p, CancellationToken ct) => p);

        // Act
        var result = await _service.UnlockNextSegmentAsync(1, 1, 1);

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(2, result.Id);
        _mockProgressRepository.Verify(p => p.AddAsync(It.IsAny<StoryProgress>(), It.IsAny<CancellationToken>()), Times.Once);
    }

    [TestMethod]
    public async Task UnlockNextSegmentAsync_WithAlreadyUnlocked_ReturnsSegmentWithoutAdding()
    {
        // Arrange
        var segment = StorySegment.Create(1, 2, "Next content", 2, "Next Title", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment, 2);
        
        _mockStoryRepository.Setup(s => s.GetNextSegmentToUnlockAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(segment);
        _mockProgressRepository.Setup(p => p.IsSegmentUnlockedAsync(1, 2, It.IsAny<CancellationToken>()))
            .ReturnsAsync(true);

        // Act
        var result = await _service.UnlockNextSegmentAsync(1, 1, 1);

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(2, result.Id);
        _mockProgressRepository.Verify(p => p.AddAsync(It.IsAny<StoryProgress>(), It.IsAny<CancellationToken>()), Times.Never);
    }

    [TestMethod]
    public async Task UnlockNextSegmentAsync_WithNoSegment_ReturnsNull()
    {
        // Arrange
        _mockStoryRepository.Setup(s => s.GetNextSegmentToUnlockAsync(1, 10, It.IsAny<CancellationToken>()))
            .ReturnsAsync((StorySegment?)null);

        // Act
        var result = await _service.UnlockNextSegmentAsync(1, 1, 10);

        // Assert
        Assert.IsNull(result);
    }

    [TestMethod]
    public async Task GetUserProgressAsync_WithSegments_ReturnsProgress()
    {
        // Arrange
        var segment1 = StorySegment.Create(1, 1, "Content 1", 1, "Title 1", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment1, 1);
        var segment2 = StorySegment.Create(1, 2, "Content 2", 2, "Title 2", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment2, 2);
        
        var progress1 = StoryProgress.Create(1, 1, 1);
        typeof(StoryProgress).GetProperty("Id")?.SetValue(progress1, 1);
        progress1.MarkAsCompleted();
        
        _mockStoryRepository.Setup(s => s.GetByLevelAsync(1, false, It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<StorySegment> { segment1, segment2 });
        _mockProgressRepository.Setup(p => p.GetByUserAndLevelAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<StoryProgress> { progress1 });
        _mockProgressRepository.Setup(p => p.IsSegmentUnlockedAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(true);
        _mockProgressRepository.Setup(p => p.IsSegmentUnlockedAsync(1, 2, It.IsAny<CancellationToken>()))
            .ReturnsAsync(false);
        _mockProgressRepository.Setup(p => p.IsSegmentCompletedAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(true);
        _mockProgressRepository.Setup(p => p.IsSegmentCompletedAsync(1, 2, It.IsAny<CancellationToken>()))
            .ReturnsAsync(false);
        _mockProgressRepository.Setup(p => p.GetHighestUnlockedOrderAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(1);

        // Act
        var result = await _service.GetUserProgressAsync(1, 1);

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(1, result.LevelId);
        Assert.AreEqual(2, result.TotalSegments);
        Assert.AreEqual(1, result.UnlockedSegments);
        Assert.AreEqual(2, result.Segments.Count);
    }

    [TestMethod]
    public async Task GetSegmentsNeedingAudioAsync_WithSegmentsNeedingAudio_ReturnsSegments()
    {
        // Arrange
        var segment1 = StorySegment.Create(1, 1, "Content 1", 1, "Title 1", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment1, 1);
        var segment2 = StorySegment.Create(1, 2, "Content 2", 2, "Title 2", "Theme");
        typeof(StorySegment).GetProperty("Id")?.SetValue(segment2, 2);
        segment2.UpdateAudioUrl("/audio/existing.wav");
        
        _mockStoryRepository.Setup(s => s.GetSegmentsNeedingAudioAsync(It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<StorySegment> { segment1 });

        // Act
        var result = await _service.GetSegmentsNeedingAudioAsync();

        // Assert
        Assert.IsNotNull(result);
        Assert.AreEqual(1, result.Count);
        Assert.IsNull(result[0].AudioUrl);
    }

    [TestMethod]
    public async Task IsSegmentUnlockedAsync_WithUnlockedSegment_ReturnsTrue()
    {
        // Arrange
        _mockProgressRepository.Setup(p => p.IsSegmentUnlockedAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(true);

        // Act
        var result = await _service.IsSegmentUnlockedAsync(1, 1);

        // Assert
        Assert.IsTrue(result);
    }

    [TestMethod]
    public async Task IsSegmentUnlockedAsync_WithLockedSegment_ReturnsFalse()
    {
        // Arrange
        _mockProgressRepository.Setup(p => p.IsSegmentUnlockedAsync(1, 999, It.IsAny<CancellationToken>()))
            .ReturnsAsync(false);

        // Act
        var result = await _service.IsSegmentUnlockedAsync(1, 999);

        // Assert
        Assert.IsFalse(result);
    }

    [TestMethod]
    public async Task IsSegmentCompletedAsync_WithCompletedSegment_ReturnsTrue()
    {
        // Arrange
        _mockProgressRepository.Setup(p => p.IsSegmentCompletedAsync(1, 1, It.IsAny<CancellationToken>()))
            .ReturnsAsync(true);

        // Act
        var result = await _service.IsSegmentCompletedAsync(1, 1);

        // Assert
        Assert.IsTrue(result);
    }

    [TestMethod]
    public async Task IsSegmentCompletedAsync_WithIncompleteSegment_ReturnsFalse()
    {
        // Arrange
        _mockProgressRepository.Setup(p => p.IsSegmentCompletedAsync(1, 999, It.IsAny<CancellationToken>()))
            .ReturnsAsync(false);

        // Act
        var result = await _service.IsSegmentCompletedAsync(1, 999);

        // Assert
        Assert.IsFalse(result);
    }
}