using System.IO;
using ClaudeDo.Installer.Core;

namespace ClaudeDo.Installer.Steps;

public sealed class RegisterServiceStep : IInstallStep
{
    private const string ServiceName = "ClaudeDoWorker";

    public string Name => "Register Windows Service";

    public async Task<StepResult> ExecuteAsync(InstallContext ctx, IProgress<string> progress, CancellationToken ct)
    {
        var workerExe = Path.Combine(ctx.InstallDirectory, "worker", "ClaudeDo.Worker.exe");
        if (!File.Exists(workerExe))
            return StepResult.Fail($"Worker executable not found: {workerExe}");

        // Stop existing service (ignore errors — may not exist)
        progress.Report("Stopping existing service (if any)...");
        await RunSc($"stop {ServiceName}", ctx, progress, ct, ignoreErrors: true);

        // Delete existing service (ignore errors)
        progress.Report("Removing existing service registration (if any)...");
        await RunSc($"delete {ServiceName}", ctx, progress, ct, ignoreErrors: true);

        // Create service
        var startType = ctx.AutoStart ? "auto" : "demand";
        var createArgs = $"create {ServiceName} binPath= \"{workerExe}\" start= {startType}";

        if (ctx.ServiceAccount == "CurrentUser")
        {
            var username = Environment.UserName;
            createArgs += $" obj= \".\\{username}\"";
        }

        progress.Report("Creating service...");
        var (exitCode, output) = await RunSc(createArgs, ctx, progress, ct);
        if (exitCode != 0)
            return StepResult.Fail($"sc.exe create failed (exit {exitCode}): {output}");

        // Configure restart policy
        var delay = ctx.RestartDelayMs;
        var failureArgs = $"failure {ServiceName} reset= 86400 actions= restart/{delay}/restart/{delay}/restart/{delay}";
        progress.Report("Configuring restart policy...");
        var (failExit, failOutput) = await RunSc(failureArgs, ctx, progress, ct);
        if (failExit != 0)
            progress.Report($"Warning: failed to set restart policy (exit {failExit})");

        // Start service if auto-start
        if (ctx.AutoStart)
        {
            progress.Report("Starting service...");
            var (startExit, _) = await RunSc($"start {ServiceName}", ctx, progress, ct);
            if (startExit != 0)
                progress.Report("Warning: service created but failed to start. You may need to start it manually.");
        }

        return StepResult.Ok();
    }

    private static async Task<(int ExitCode, string Output)> RunSc(
        string arguments, InstallContext ctx, IProgress<string> progress,
        CancellationToken ct, bool ignoreErrors = false)
    {
        var result = await ProcessRunner.RunAsync("sc.exe", arguments, null, progress, ct);
        return result;
    }
}