using JdeScoping.ConfigManager.ViewModels.PipelineSteps;
using JdeScoping.DataSync.Configuration;
using System.Text.Json;

namespace JdeScoping.ConfigManager.Tests.ViewModels;

public class RegexTransformerViewModelTests
{
    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
    };

    private static TransformElement CreateElement(object config)
    {
        var json = JsonSerializer.Serialize(config, JsonOptions);
        using var doc = JsonDocument.Parse(json);
        return new TransformElement
        {
            TransformType = "Regex",
            Config = doc.RootElement.Clone()
        };
    }

    [Fact]
    public void Constructor_FromElement_LoadsAllProperties()
    {
        // Arrange
        var element = CreateElement(new
        {
            columnName = "BatchID",
            pattern = "^IIS_",
            replacement = "",
            ignoreCase = true,
            nonMatchBehavior = "ReturnEmpty"
        });

        // Act
        var vm = new RegexTransformerViewModel(element, () => { });

        // Assert
        Assert.Equal("BatchID", vm.ColumnName);
        Assert.Equal("^IIS_", vm.Pattern);
        Assert.Equal("", vm.Replacement);
        Assert.True(vm.IsFindReplaceMode);
        Assert.True(vm.IgnoreCase);
        Assert.Equal(NonMatchBehavior.ReturnEmpty, vm.NonMatchBehavior);
    }

    [Fact]
    public void Constructor_FromElement_MatchExtractMode_WhenReplacementNull()
    {
        // Arrange
        var element = CreateElement(new
        {
            columnName = "Code",
            pattern = @"(\d+)"
        });

        // Act
        var vm = new RegexTransformerViewModel(element, () => { });

        // Assert
        Assert.False(vm.IsFindReplaceMode);
        Assert.True(vm.IsMatchExtractMode);
    }

    [Fact]
    public void ToModel_SerializesCorrectly_FindReplaceMode()
    {
        // Arrange
        var vm = new RegexTransformerViewModel(() => { })
        {
            ColumnName = "BatchID",
            Pattern = "^IIS_",
            Replacement = "",
            IsFindReplaceMode = true,
            IgnoreCase = true,
            NonMatchBehavior = NonMatchBehavior.KeepOriginal
        };

        // Act
        var element = vm.ToModel();

        // Assert
        Assert.Equal("Regex", element.TransformType);
        Assert.True(element.Config.HasValue);

        // Parse the config to verify
        var config = element.Config!.Value;
        Assert.Equal("BatchID", config.GetProperty("columnName").GetString());
        Assert.Equal("^IIS_", config.GetProperty("pattern").GetString());
        Assert.Equal("", config.GetProperty("replacement").GetString());
        Assert.True(config.GetProperty("ignoreCase").GetBoolean());
    }

    [Fact]
    public void ToModel_SerializesCorrectly_MatchExtractMode()
    {
        // Arrange
        var vm = new RegexTransformerViewModel(() => { })
        {
            ColumnName = "Code",
            Pattern = @"(\d+)",
            IsFindReplaceMode = false
        };

        // Act
        var element = vm.ToModel();

        // Assert
        Assert.True(element.Config.HasValue);
        var config = element.Config!.Value;

        // replacement should be null in Match & Extract mode
        Assert.True(config.TryGetProperty("replacement", out var replacement));
        Assert.Equal(JsonValueKind.Null, replacement.ValueKind);
    }

    [Fact]
    public void TestPatternCommand_ValidPattern_ShowsResult()
    {
        // Arrange
        var vm = new RegexTransformerViewModel(() => { })
        {
            Pattern = "^IIS_",
            Replacement = "",
            IsFindReplaceMode = true,
            TestInput = "IIS_12345"
        };

        // Act
        vm.TestPatternCommand.Execute(null);

        // Assert
        Assert.True(vm.HasTestResult);
        Assert.False(vm.HasTestError);
        Assert.Equal("12345", vm.TestResultValue);
        Assert.Equal("Output", vm.TestResultLabel);
        Assert.Equal("✓", vm.TestResultIcon);
    }

    [Fact]
    public void TestPatternCommand_InvalidPattern_ShowsError()
    {
        // Arrange
        var vm = new RegexTransformerViewModel(() => { })
        {
            Pattern = "[invalid(regex",
            Replacement = "",
            TestInput = "test"
        };

        // Act
        vm.TestPatternCommand.Execute(null);

        // Assert
        Assert.False(vm.HasTestResult);
        Assert.True(vm.HasTestError);
        Assert.NotEmpty(vm.TestErrorMessage);
    }

    [Fact]
    public void TestPatternCommand_MatchExtract_NoMatch_ShowsNonMatchBehavior()
    {
        // Arrange
        var vm = new RegexTransformerViewModel(() => { })
        {
            Pattern = @"(\d+)",
            IsFindReplaceMode = false,
            NonMatchBehavior = NonMatchBehavior.ReturnNull,
            TestInput = "NoNumbers"
        };

        // Act
        vm.TestPatternCommand.Execute(null);

        // Assert
        Assert.True(vm.HasTestResult);
        Assert.Equal("No Match", vm.TestResultLabel);
        Assert.Equal("(null)", vm.TestResultValue);
    }

    [Fact]
    public void ModeSwitch_UpdatesPatternHelpText()
    {
        // Arrange
        var vm = new RegexTransformerViewModel(() => { })
        {
            IsFindReplaceMode = true
        };
        var findReplaceHelp = vm.PatternHelpText;

        // Act
        vm.IsFindReplaceMode = false;
        var matchExtractHelp = vm.PatternHelpText;

        // Assert
        Assert.NotEqual(findReplaceHelp, matchExtractHelp);
        Assert.Contains("capture group", matchExtractHelp, StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public void Summary_ShowsColumnAndMode()
    {
        // Arrange & Act
        var vm = new RegexTransformerViewModel(() => { })
        {
            ColumnName = "BatchID",
            IsFindReplaceMode = true
        };

        // Assert
        Assert.Contains("BatchID", vm.Summary);
        Assert.Contains("Replace", vm.Summary);
    }

    [Fact]
    public void PropertyChange_NotifiesChanged()
    {
        // Arrange
        var changedCalled = false;
        var vm = new RegexTransformerViewModel(() => changedCalled = true);

        // Act
        vm.ColumnName = "NewColumn";

        // Assert
        Assert.True(changedCalled);
    }
}