using JdeScoping.ConfigManager.Core.Models;
using JdeScoping.ConfigManager.Core.Services;
using JdeScoping.DataSync.Configuration;

namespace JdeScoping.ConfigManager.Core.Tests.Services;

public class ConfigFileServiceTests
{
    private readonly IFileSystem _fileSystem;
    private readonly ConfigFileService _sut;

    public ConfigFileServiceTests()
    {
        _fileSystem = Substitute.For<IFileSystem>();
        _sut = new ConfigFileService(_fileSystem);
    }

    [Fact]
    public async Task LoadAppSettingsAsync_WithValidJson_ReturnsConfigModel()
    {
        // Arrange
        var json = """
        {
            "DataSync": {
                "Enabled": true,
                "MaxDegreeOfParallelism": 8
            }
        }
        """;
        _fileSystem.ReadAllTextAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
            .Returns(Task.FromResult(json));

        // Act
        var result = await _sut.LoadAppSettingsAsync("/config/appsettings.json");

        // Assert
        result.ShouldNotBeNull();
        result.DataSync.Enabled.ShouldBeTrue();
        result.DataSync.MaxDegreeOfParallelism.ShouldBe(8);
    }

    [Fact]
    public async Task LoadAppSettingsAsync_WithInvalidJson_ThrowsWithHelpfulMessage()
    {
        // Arrange
        var json = "{ invalid json }";
        _fileSystem.ReadAllTextAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
            .Returns(Task.FromResult(json));

        // Act & Assert
        var ex = await Should.ThrowAsync<ConfigLoadException>(
            () => _sut.LoadAppSettingsAsync("/config/appsettings.json"));
        ex.Message.ShouldContain("parse");
    }

    [Fact]
    public async Task LoadPipelineAsync_WithValidJson_ReturnsPipelineConfig()
    {
        // Arrange
        var json = """
        {
            "name": "TestPipeline",
            "isEnabled": true,
            "massSyncIntervalMinutes": 1440,
            "source": {
                "connectionStringName": "JDE",
                "query": "SELECT * FROM test"
            },
            "destination": {
                "connectionStringName": "LotFinder",
                "tableName": "TestTable"
            }
        }
        """;
        _fileSystem.ReadAllTextAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
            .Returns(Task.FromResult(json));

        // Act
        var result = await _sut.LoadPipelineAsync("/config/pipeline.test.json");

        // Assert
        result.ShouldNotBeNull();
        result.Name.ShouldBe("TestPipeline");
        result.IsEnabled.ShouldBeTrue();
        result.MassSyncIntervalMinutes.ShouldBe(1440);
    }

    [Fact]
    public async Task LoadPipelineAsync_WithInvalidJson_ThrowsConfigLoadException()
    {
        // Arrange
        var json = "{ invalid json }";
        _fileSystem.ReadAllTextAsync(Arg.Any<string>(), Arg.Any<CancellationToken>())
            .Returns(Task.FromResult(json));

        // Act & Assert
        var ex = await Should.ThrowAsync<ConfigLoadException>(
            () => _sut.LoadPipelineAsync("/config/pipeline.test.json"));
        ex.Message.ShouldContain("parse");
    }

    [Fact]
    public async Task SavePipelineAsync_SerializesAndWritesPipeline()
    {
        // Arrange
        var path = "/config/pipeline.test.json";
        var pipeline = new EtlPipelineConfig
        {
            Name = "TestPipeline",
            IsEnabled = true,
            MassSyncIntervalMinutes = 1440
        };
        string? writtenContent = null;
        _fileSystem.WriteAllTextAsync(Arg.Any<string>(), Arg.Do<string>(c => writtenContent = c), Arg.Any<CancellationToken>())
            .Returns(Task.CompletedTask);

        // Act
        await _sut.SavePipelineAsync(path, pipeline);

        // Assert
        await _fileSystem.Received(1).WriteAllTextAsync(path, Arg.Any<string>(), Arg.Any<CancellationToken>());
        writtenContent.ShouldNotBeNull();
        writtenContent.ShouldContain("TestPipeline");
    }

    [Fact]
    public async Task LoadAllPipelinesAsync_WithMultiplePipelines_ReturnsAll()
    {
        // Arrange
        var directory = "/config/pipelines";
        var files = new[]
        {
            "/config/pipelines/pipeline.first.json",
            "/config/pipelines/pipeline.second.json"
        };

        _fileSystem.DirectoryExists(directory).Returns(true);
        _fileSystem.GetFilesAsync(directory, "pipeline.*.json", Arg.Any<CancellationToken>())
            .Returns(Task.FromResult(files));

        _fileSystem.ReadAllTextAsync(files[0], Arg.Any<CancellationToken>())
            .Returns(Task.FromResult("""{"name": "First", "isEnabled": true}"""));
        _fileSystem.ReadAllTextAsync(files[1], Arg.Any<CancellationToken>())
            .Returns(Task.FromResult("""{"name": "Second", "isEnabled": false}"""));

        _fileSystem.GetFileNameWithoutExtension(files[0]).Returns("pipeline.first");
        _fileSystem.GetFileNameWithoutExtension(files[1]).Returns("pipeline.second");

        // Act
        var result = await _sut.LoadAllPipelinesAsync(directory);

        // Assert
        result.ShouldNotBeNull();
        result.Count.ShouldBe(2);
        result.ContainsKey("first").ShouldBeTrue();
        result.ContainsKey("second").ShouldBeTrue();
        result["first"].Name.ShouldBe("First");
        result["second"].IsEnabled.ShouldBeFalse();
    }

    [Fact]
    public async Task LoadAllPipelinesAsync_WithNonExistentDirectory_ReturnsEmpty()
    {
        // Arrange
        var directory = "/config/nonexistent";
        _fileSystem.DirectoryExists(directory).Returns(false);

        // Act
        var result = await _sut.LoadAllPipelinesAsync(directory);

        // Assert
        result.ShouldNotBeNull();
        result.ShouldBeEmpty();
    }

    [Fact]
    public async Task DeletePipelineFileAsync_CallsFileSystemDelete()
    {
        // Arrange
        var path = "/config/pipeline.test.json";

        // Act
        await _sut.DeletePipelineFileAsync(path);

        // Assert
        await _fileSystem.Received(1).DeleteFileAsync(path, Arg.Any<CancellationToken>());
    }

    [Fact]
    public async Task SaveAppSettingsAsync_SerializesAndWritesConfig()
    {
        // Arrange
        var path = "/config/appsettings.json";
        var config = new ConfigModel
        {
            DataSync = new DataSyncSection
            {
                Enabled = true,
                MaxDegreeOfParallelism = 16
            }
        };
        string? writtenContent = null;
        _fileSystem.WriteAllTextAsync(Arg.Any<string>(), Arg.Do<string>(c => writtenContent = c), Arg.Any<CancellationToken>())
            .Returns(Task.CompletedTask);

        // Act
        await _sut.SaveAppSettingsAsync(path, config);

        // Assert
        await _fileSystem.Received(1).WriteAllTextAsync(path, Arg.Any<string>(), Arg.Any<CancellationToken>());
        writtenContent.ShouldNotBeNull();
        writtenContent.ShouldContain("enabled");
        writtenContent.ShouldContain("16");
    }

    [Fact]
    public async Task LoadAllPipelinesAsync_SkipsInvalidPipelineFiles()
    {
        // Arrange
        var directory = "/config/pipelines";
        var files = new[]
        {
            "/config/pipelines/pipeline.valid.json",
            "/config/pipelines/pipeline.invalid.json"
        };

        _fileSystem.DirectoryExists(directory).Returns(true);
        _fileSystem.GetFilesAsync(directory, "pipeline.*.json", Arg.Any<CancellationToken>())
            .Returns(Task.FromResult(files));

        _fileSystem.ReadAllTextAsync(files[0], Arg.Any<CancellationToken>())
            .Returns(Task.FromResult("""{"name": "Valid", "isEnabled": true}"""));
        _fileSystem.ReadAllTextAsync(files[1], Arg.Any<CancellationToken>())
            .Returns(Task.FromResult("{ invalid json }"));

        _fileSystem.GetFileNameWithoutExtension(files[0]).Returns("pipeline.valid");
        _fileSystem.GetFileNameWithoutExtension(files[1]).Returns("pipeline.invalid");

        // Act
        var result = await _sut.LoadAllPipelinesAsync(directory);

        // Assert
        result.ShouldNotBeNull();
        result.Count.ShouldBe(1);
        result.ContainsKey("valid").ShouldBeTrue();
    }

    [Fact]
    public async Task LoadAllPipelinesAsync_AssignsPipelineNameFromFilename_WhenNameIsEmpty()
    {
        // Arrange
        var directory = "/config/pipelines";
        var files = new[] { "/config/pipelines/pipeline.unnamed.json" };

        _fileSystem.DirectoryExists(directory).Returns(true);
        _fileSystem.GetFilesAsync(directory, "pipeline.*.json", Arg.Any<CancellationToken>())
            .Returns(Task.FromResult(files));

        // Pipeline with empty name
        _fileSystem.ReadAllTextAsync(files[0], Arg.Any<CancellationToken>())
            .Returns(Task.FromResult("""{"name": "", "isEnabled": true}"""));
        _fileSystem.GetFileNameWithoutExtension(files[0]).Returns("pipeline.unnamed");

        // Act
        var result = await _sut.LoadAllPipelinesAsync(directory);

        // Assert
        result.ShouldNotBeNull();
        result.Count.ShouldBe(1);
        result["unnamed"].Name.ShouldBe("unnamed");
    }
}