using FluentAssertions;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using Moq;
using SatelliteProvider.Common.Configs;
using SatelliteProvider.Common.DTO;
using SatelliteProvider.Common.Enums;
using SatelliteProvider.Common.Exceptions;
using SatelliteProvider.Common.Interfaces;
using SatelliteProvider.DataAccess.Models;
using SatelliteProvider.DataAccess.Repositories;
using SatelliteProvider.Services.RegionProcessing;

namespace SatelliteProvider.Tests;

public class RegionServiceTests : IDisposable
{
    private readonly string _readyDir;

    public RegionServiceTests()
    {
        _readyDir = Path.Combine(Path.GetTempPath(), "sp-region-tests-" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(_readyDir);
    }

    public void Dispose()
    {
        if (Directory.Exists(_readyDir))
        {
            Directory.Delete(_readyDir, recursive: true);
        }
    }

    private RegionService BuildService(
        Mock<IRegionRepository> regionRepo,
        Mock<IRegionRequestQueue> queue,
        Mock<ITileService> tileService)
    {
        var storage = Options.Create(new StorageConfig { ReadyDirectory = _readyDir, TilesDirectory = "/tiles" });
        var processing = Options.Create(new ProcessingConfig());
        return new RegionService(regionRepo.Object, queue.Object, tileService.Object, storage, processing, NullLogger<RegionService>.Instance);
    }

    [Fact]
    public async Task RequestRegionAsync_InsertsEntityAndQueues_BT03_AC1()
    {
        // Arrange
        var regionRepo = new Mock<IRegionRepository>();
        regionRepo.Setup(r => r.GetByIdAsync(It.IsAny<Guid>())).ReturnsAsync((RegionEntity?)null);
        var queue = new Mock<IRegionRequestQueue>();
        var tileService = new Mock<ITileService>();
        var service = BuildService(regionRepo, queue, tileService);

        var id = Guid.NewGuid();

        // Act
        var status = await service.RequestRegionAsync(id, 47.461747, 37.647063, 200, 18);

        // Assert
        status.Id.Should().Be(id);
        status.Status.Should().Be(RegionStatus.Queued);
        regionRepo.Verify(r => r.InsertAsync(It.Is<RegionEntity>(re =>
            re.Id == id &&
            re.Status == RegionStatus.Queued &&
            re.SizeMeters == 200 &&
            re.ZoomLevel == 18)), Times.Once);
        queue.Verify(q => q.EnqueueAsync(It.Is<RegionRequest>(rr =>
            rr.Id == id &&
            rr.SizeMeters == 200 &&
            rr.ZoomLevel == 18 &&
            rr.StitchTiles == false), It.IsAny<CancellationToken>()), Times.Once);
    }

    [Fact]
    public async Task RequestRegionAsync_DuplicateId_ReturnsExistingResource_NoReQueue_AZ362_AC1()
    {
        // Arrange
        var id = Guid.NewGuid();
        var existing = new RegionEntity
        {
            Id = id,
            Latitude = 47.461747,
            Longitude = 37.647063,
            SizeMeters = 200,
            ZoomLevel = 18,
            StitchTiles = false,
            Status = RegionStatus.Processing,
            TilesDownloaded = 5,
            TilesReused = 3,
            CreatedAt = DateTime.UtcNow.AddMinutes(-5),
            UpdatedAt = DateTime.UtcNow.AddMinutes(-1),
        };
        var regionRepo = new Mock<IRegionRepository>();
        regionRepo.Setup(r => r.GetByIdAsync(id)).ReturnsAsync(existing);
        var queue = new Mock<IRegionRequestQueue>(MockBehavior.Strict);
        var tileService = new Mock<ITileService>();
        var service = BuildService(regionRepo, queue, tileService);

        // Act
        var status = await service.RequestRegionAsync(id, 47.461747, 37.647063, 200, 18);

        // Assert
        status.Id.Should().Be(id);
        status.Status.Should().Be(RegionStatus.Processing, "AZ-362: returns the existing region's current status, not 'queued'");
        regionRepo.Verify(r => r.InsertAsync(It.IsAny<RegionEntity>()), Times.Never,
            "AZ-362: duplicate Id must not re-insert");
        queue.VerifyNoOtherCalls();
    }

    [Fact]
    public async Task ProcessRegionAsync_HappyPath_TransitionsToCompletedAndWritesArtifacts_BT03_AC2_AC3()
    {
        // Arrange
        var regionRepo = new Mock<IRegionRepository>();
        var queue = new Mock<IRegionRequestQueue>();
        var tileService = new Mock<ITileService>();

        var id = Guid.NewGuid();
        var entity = new RegionEntity
        {
            Id = id,
            Latitude = 47.461747,
            Longitude = 37.647063,
            SizeMeters = 200,
            ZoomLevel = 18,
            Status = RegionStatus.Queued,
            StitchTiles = false,
            CreatedAt = DateTime.UtcNow,
            UpdatedAt = DateTime.UtcNow,
        };

        regionRepo.Setup(r => r.GetByIdAsync(id)).ReturnsAsync(entity);

        var capturedStatuses = new List<RegionStatus>();
        regionRepo
            .Setup(r => r.UpdateAsync(It.IsAny<RegionEntity>()))
            .Callback<RegionEntity>(e => capturedStatuses.Add(e.Status))
            .ReturnsAsync(1);

        tileService
            .Setup(t => t.GetTilesByRegionAsync(entity.Latitude, entity.Longitude, entity.SizeMeters, entity.ZoomLevel))
            .ReturnsAsync(Array.Empty<TileMetadata>());
        tileService
            .Setup(t => t.DownloadAndStoreTilesAsync(
                entity.Latitude, entity.Longitude, entity.SizeMeters, entity.ZoomLevel,
                It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<TileMetadata>
            {
                new()
                {
                    Id = Guid.NewGuid(),
                    Latitude = entity.Latitude,
                    Longitude = entity.Longitude,
                    TileZoom = entity.ZoomLevel,
                    TileSizePixels = 256,
                    ImageType = "jpg",
                    FilePath = "tiles/18/0/0/x.jpg",
                },
            });

        var service = BuildService(regionRepo, queue, tileService);

        // Act
        await service.ProcessRegionAsync(id);

        // Assert
        capturedStatuses.Should().ContainInOrder(RegionStatus.Processing, RegionStatus.Completed);
        entity.Status.Should().Be(RegionStatus.Completed);
        entity.CsvFilePath.Should().NotBeNullOrEmpty();
        entity.SummaryFilePath.Should().NotBeNullOrEmpty();
        entity.TilesDownloaded.Should().Be(1);
        entity.TilesReused.Should().Be(0);
        File.Exists(entity.CsvFilePath!).Should().BeTrue("CSV file is written to ReadyDirectory");
        File.Exists(entity.SummaryFilePath!).Should().BeTrue("summary file is written to ReadyDirectory");
    }

    [Fact]
    public async Task ProcessRegionAsync_MissingRegionId_LogsAndReturns()
    {
        // Arrange
        var regionRepo = new Mock<IRegionRepository>();
        regionRepo.Setup(r => r.GetByIdAsync(It.IsAny<Guid>())).ReturnsAsync((RegionEntity?)null);
        var service = BuildService(regionRepo, new Mock<IRegionRequestQueue>(), new Mock<ITileService>());

        // Act
        await service.ProcessRegionAsync(Guid.NewGuid());

        // Assert
        regionRepo.Verify(r => r.UpdateAsync(It.IsAny<RegionEntity>()), Times.Never);
    }

    [Fact]
    public async Task ProcessRegionAsync_DownloaderFailure_TransitionsToFailedAndWritesErrorSummary()
    {
        // Arrange
        var regionRepo = new Mock<IRegionRepository>();
        var queue = new Mock<IRegionRequestQueue>();
        var tileService = new Mock<ITileService>();

        var id = Guid.NewGuid();
        var entity = new RegionEntity
        {
            Id = id,
            Latitude = 47.461747,
            Longitude = 37.647063,
            SizeMeters = 200,
            ZoomLevel = 18,
            Status = RegionStatus.Queued,
            StitchTiles = false,
            CreatedAt = DateTime.UtcNow,
            UpdatedAt = DateTime.UtcNow,
        };

        regionRepo.Setup(r => r.GetByIdAsync(id)).ReturnsAsync(entity);

        var capturedStatuses = new List<RegionStatus>();
        regionRepo
            .Setup(r => r.UpdateAsync(It.IsAny<RegionEntity>()))
            .Callback<RegionEntity>(e => capturedStatuses.Add(e.Status))
            .ReturnsAsync(1);

        tileService
            .Setup(t => t.GetTilesByRegionAsync(It.IsAny<double>(), It.IsAny<double>(), It.IsAny<double>(), It.IsAny<int>()))
            .ReturnsAsync(Array.Empty<TileMetadata>());
        tileService
            .Setup(t => t.DownloadAndStoreTilesAsync(
                It.IsAny<double>(), It.IsAny<double>(), It.IsAny<double>(), It.IsAny<int>(),
                It.IsAny<CancellationToken>()))
            .ThrowsAsync(new RateLimitException("Google Maps rate limit exceeded"));

        var service = BuildService(regionRepo, queue, tileService);

        // Act
        await service.ProcessRegionAsync(id);

        // Assert
        capturedStatuses.Should().ContainInOrder(RegionStatus.Processing, RegionStatus.Failed);
        entity.Status.Should().Be(RegionStatus.Failed);
        entity.SummaryFilePath.Should().NotBeNullOrEmpty();
        File.Exists(entity.SummaryFilePath!).Should().BeTrue();
        File.ReadAllText(entity.SummaryFilePath!).Should().Contain("Rate limit exceeded");
    }

    [Fact]
    public async Task ProcessRegionAsync_StitchEnabled_SetsStitchedImagePath_BT05_AC4()
    {
        // Arrange
        var regionRepo = new Mock<IRegionRepository>();
        var queue = new Mock<IRegionRequestQueue>();
        var tileService = new Mock<ITileService>();

        var id = Guid.NewGuid();
        var entity = new RegionEntity
        {
            Id = id,
            Latitude = 47.461747,
            Longitude = 37.647063,
            SizeMeters = 500,
            ZoomLevel = 18,
            Status = RegionStatus.Queued,
            StitchTiles = true,
            CreatedAt = DateTime.UtcNow,
            UpdatedAt = DateTime.UtcNow,
        };

        regionRepo.Setup(r => r.GetByIdAsync(id)).ReturnsAsync(entity);
        regionRepo.Setup(r => r.UpdateAsync(It.IsAny<RegionEntity>())).ReturnsAsync(1);

        tileService
            .Setup(t => t.GetTilesByRegionAsync(It.IsAny<double>(), It.IsAny<double>(), It.IsAny<double>(), It.IsAny<int>()))
            .ReturnsAsync(Array.Empty<TileMetadata>());
        tileService
            .Setup(t => t.DownloadAndStoreTilesAsync(
                It.IsAny<double>(), It.IsAny<double>(), It.IsAny<double>(), It.IsAny<int>(),
                It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<TileMetadata>
            {
                new()
                {
                    Id = Guid.NewGuid(),
                    Latitude = entity.Latitude,
                    Longitude = entity.Longitude,
                    TileZoom = entity.ZoomLevel,
                    TileSizePixels = 256,
                    ImageType = "jpg",
                    // Path doesn't exist on disk — stitcher will skip but still produce an empty image.
                    FilePath = Path.Combine(_readyDir, "missing.jpg"),
                },
            });

        var service = BuildService(regionRepo, queue, tileService);

        // Act
        await service.ProcessRegionAsync(id);

        // Assert
        entity.Status.Should().Be(RegionStatus.Completed);
        var stitchedPath = Path.Combine(_readyDir, $"region_{id}_stitched.jpg");
        File.Exists(stitchedPath).Should().BeTrue("stitched image must exist when stitchTiles=true");
    }

    [Fact]
    public async Task GetRegionStatusAsync_KnownId_ReturnsMappedStatus()
    {
        // Arrange
        var regionRepo = new Mock<IRegionRepository>();
        var id = Guid.NewGuid();
        regionRepo.Setup(r => r.GetByIdAsync(id))
            .ReturnsAsync(new RegionEntity { Id = id, Status = RegionStatus.Completed, TilesDownloaded = 5, TilesReused = 2 });
        var service = BuildService(regionRepo, new Mock<IRegionRequestQueue>(), new Mock<ITileService>());

        // Act
        var result = await service.GetRegionStatusAsync(id);

        // Assert
        result.Should().NotBeNull();
        result!.Status.Should().Be(RegionStatus.Completed);
        result.TilesDownloaded.Should().Be(5);
        result.TilesReused.Should().Be(2);
    }
}
