using HanaToolbox.Services.Interfaces;

namespace HanaToolbox.Services;

/// <summary>
/// Wraps a shell command to run as &lt;sid&gt;adm using `su - &lt;sid&gt;adm -c '...'`.
/// If the current OS user is already &lt;sid&gt;adm, the command is executed directly.
/// </summary>
public sealed class SuUserSwitcher(IProcessRunner runner) : IUserSwitcher
{
    public async Task<ProcessResult> RunAsAsync(
        string sid, string shellCommand,
        CancellationToken ct = default)
    {
        var sidAdm = $"{sid.ToLowerInvariant()}adm";

        if (string.Equals(Environment.UserName, sidAdm, StringComparison.OrdinalIgnoreCase))
        {
            // Already running as the correct user — run directly via bash
            return await runner.RunAsync("/bin/bash", ["-c", shellCommand], ct);
        }

        // Use `su -` to inherit the user's environment (HOME, PATH, etc.)
        return await runner.RunAsync("/bin/su", ["-", sidAdm, "-c", shellCommand], ct);
    }
}