using System.Diagnostics;

namespace CLI;

public static class QBE
{
    public static async Task<string?> Invoke(string ssa)
    {
        using var qbeProcess = new Process();
        qbeProcess.StartInfo = new ProcessStartInfo
        {
            FileName = "qbe",
            UseShellExecute = false,
            RedirectStandardInput = true,
            RedirectStandardOutput = true,
            RedirectStandardError = true,
            CreateNoWindow = true
        };

        qbeProcess.Start();

        await qbeProcess.StandardInput.WriteAsync(ssa);
        qbeProcess.StandardInput.Close();

        await qbeProcess.WaitForExitAsync();

        var qbeErrors = await qbeProcess.StandardError.ReadToEndAsync();
        if (!string.IsNullOrWhiteSpace(qbeErrors))
        {
            await Console.Error.WriteLineAsync("qbe error:\n" + qbeErrors);
        }

        var asm = await qbeProcess.StandardOutput.ReadToEndAsync();

        return qbeProcess.ExitCode == 0 ? asm : null;
    }
}