using ExtractMethod.Tooling;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;

namespace BeforeAfter.Tests.ExtractMethod;

/// <summary>
/// Shared entry point for the ExtractMethod tests: the checked-in Demo.cs
/// fixture is DATA (excluded from this project's compilation, copied to the
/// output dir) and must ALWAYS be loaded through the tool's own
/// <see cref="CompilationLoader"/> so tests exercise the exact parse +
/// scratch-compilation path the CLI uses.
/// </summary>
internal static class DemoFixture
{
    /// <summary>Where the fixture lands after the csproj copies it (link Fixtures/).</summary>
    public static string Path =>
        System.IO.Path.Combine(AppContext.BaseDirectory, "Fixtures", "Demo.cs");

    /// <summary>Parse + scratch-compile the fixture once per caller.</summary>
    public static (SyntaxTree Tree, CSharpCompilation Compilation) Load()
    {
        if (!File.Exists(Path))
        {
            throw new FileNotFoundException($"fixture missing at {Path}");
        }

        var tree = CompilationLoader.ParseFile(Path);
        var compilation = CompilationLoader.CreateCompilation(tree, "DemoFixture");
        return (tree, compilation);
    }
}