using System;
using System.Diagnostics;
using System.IO;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;

namespace Gott.Endpoints;

public static class BackupEndpoint
{
    public static void MapBackupEndpoint(this IEndpointRouteBuilder app)
    {
        app.MapPost("/api/backup", HandleBackup);
    }

    private static async System.Threading.Tasks.Task<IResult> HandleBackup()
    {
        var dataDir = Path.Combine(AppContext.BaseDirectory, "data");
        var dbPath = Path.Combine(dataDir, "gott.db");

        if (!File.Exists(dbPath))
            return Results.NotFound(new { error = "Datenbank nicht gefunden" });

        var backupDir = Path.Combine(dataDir, "backup");
        Directory.CreateDirectory(backupDir);

        var timestamp = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
        var archiveName = $"gott-{timestamp}.tar.gz";
        var archivePath = Path.Combine(backupDir, archiveName);

        var psi = new ProcessStartInfo
        {
            FileName = "tar",
            ArgumentList = { "-czf", archivePath, "-C", dataDir, "gott.db" },
            RedirectStandardError = true,
            UseShellExecute = false
        };

        using (var process = Process.Start(psi))
        {
            if (process == null)
                return Results.StatusCode(500);

            var stderr = await process.StandardError.ReadToEndAsync();
            await process.WaitForExitAsync();

            if (process.ExitCode != 0)
                return Results.Problem($"tar fehlgeschlagen: {stderr}");
        }

        var bytes = await File.ReadAllBytesAsync(archivePath);
        return Results.File(bytes, "application/gzip", archiveName);
    }
}