using System.Linq;
using ClaudeDo.Ui.ViewModels.Modals;

namespace ClaudeDo.Ui.Tests.ViewModels;

public class UnifiedDiffParserTests
{
    [Fact]
    public void Modified_file_counts_additions_and_deletions()
    {
        const string raw =
            "diff --git a/src/Foo.cs b/src/Foo.cs\n" +
            "index 111..222 100644\n" +
            "--- a/src/Foo.cs\n" +
            "+++ b/src/Foo.cs\n" +
            "@@ -1,3 +1,3 @@\n" +
            " ctx\n" +
            "-old\n" +
            "+new\n";

        var file = Assert.Single(UnifiedDiffParser.Parse(raw));
        Assert.Equal("src/Foo.cs", file.Path);
        Assert.Equal(DiffFileStatus.Modified, file.Status);
        Assert.Equal("M", file.StatusCode);
        Assert.Equal(1, file.Additions);
        Assert.Equal(1, file.Deletions);
        Assert.True(file.HasLines);
        Assert.False(file.IsBinary);
    }

    [Fact]
    public void New_file_is_marked_added()
    {
        const string raw =
            "diff --git a/New.cs b/New.cs\n" +
            "new file mode 100644\n" +
            "index 000..abc\n" +
            "--- /dev/null\n" +
            "+++ b/New.cs\n" +
            "@@ -0,0 +1,1 @@\n" +
            "+hello\n";

        var file = Assert.Single(UnifiedDiffParser.Parse(raw));
        Assert.Equal(DiffFileStatus.Added, file.Status);
        Assert.Equal("A", file.StatusCode);
    }

    [Fact]
    public void Deleted_file_is_marked_deleted()
    {
        const string raw =
            "diff --git a/Gone.cs b/Gone.cs\n" +
            "deleted file mode 100644\n" +
            "index abc..000\n" +
            "--- a/Gone.cs\n" +
            "+++ /dev/null\n" +
            "@@ -1,1 +0,0 @@\n" +
            "-bye\n";

        var file = Assert.Single(UnifiedDiffParser.Parse(raw));
        Assert.Equal(DiffFileStatus.Deleted, file.Status);
        Assert.Equal("D", file.StatusCode);
    }

    [Fact]
    public void Rename_captures_old_and_new_path()
    {
        const string raw =
            "diff --git a/Old.cs b/New.cs\n" +
            "similarity index 100%\n" +
            "rename from Old.cs\n" +
            "rename to New.cs\n";

        var file = Assert.Single(UnifiedDiffParser.Parse(raw));
        Assert.Equal(DiffFileStatus.Renamed, file.Status);
        Assert.Equal("R", file.StatusCode);
        Assert.Equal("Old.cs", file.OldPath);
        Assert.Equal("New.cs", file.Path);
    }

    [Fact]
    public void Binary_file_is_flagged_with_no_lines()
    {
        const string raw =
            "diff --git a/img.png b/img.png\n" +
            "new file mode 100644\n" +
            "index 000..abc\n" +
            "Binary files /dev/null and b/img.png differ\n";

        var file = Assert.Single(UnifiedDiffParser.Parse(raw));
        Assert.True(file.IsBinary);
        Assert.False(file.HasLines);
        Assert.False(file.IsEmptyContent);
    }

    [Fact]
    public void Empty_new_file_reports_empty_content()
    {
        const string raw =
            "diff --git a/Empty.txt b/Empty.txt\n" +
            "new file mode 100644\n" +
            "index 000..000\n";

        var file = Assert.Single(UnifiedDiffParser.Parse(raw));
        Assert.Equal(DiffFileStatus.Added, file.Status);
        Assert.False(file.HasLines);
        Assert.True(file.IsEmptyContent);
    }
}