using System.Text;

namespace LehrerApp.Api;

internal static class Cli
{
    public static Task<int> RunCreateUserAsync(string dataPath, string[] args)
    {
        if (args.Length < 2)
        {
            Console.Error.WriteLine("Verwendung: create-user <benutzername> [--password <passwort>]");
            return Task.FromResult(1);
        }
        var username = args[1];
        var password = ParsePassword(args);
        if (password is null) return Task.FromResult(1);

        Directory.CreateDirectory(dataPath);
        using var store = new UserStore(dataPath);
        if (!store.CreateUser(username, password))
        {
            Console.Error.WriteLine($"Nutzer '{username}' existiert bereits.");
            return Task.FromResult(1);
        }

        Console.WriteLine($"Nutzer '{username}' angelegt.");
        return Task.FromResult(0);
    }

    public static Task<int> RunSetPasswordAsync(string dataPath, string[] args)
    {
        if (args.Length < 2)
        {
            Console.Error.WriteLine("Verwendung: set-password <benutzername> [--password <passwort>]");
            return Task.FromResult(1);
        }
        var username = args[1];
        var password = ParsePassword(args);
        if (password is null) return Task.FromResult(1);

        Directory.CreateDirectory(dataPath);
        using var store = new UserStore(dataPath);
        if (!store.SetPassword(username, password))
        {
            Console.Error.WriteLine($"Nutzer '{username}' existiert nicht.");
            return Task.FromResult(1);
        }

        Console.WriteLine($"Passwort für '{username}' aktualisiert.");
        return Task.FromResult(0);
    }

    private static string? ParsePassword(string[] args)
    {
        string? password = null;
        for (var i = 2; i < args.Length - 1; i++)
            if (args[i] == "--password") password = args[i + 1];

        password ??= ReadPassword("Passwort (mind. 12 Zeichen): ");

        if (string.IsNullOrWhiteSpace(password) || password.Length < 12)
        {
            Console.Error.WriteLine("Passwort muss mindestens 12 Zeichen lang sein.");
            return null;
        }
        return password;
    }

    // docker exec ohne -it liefert kein TTY -> ReadKey wäre nicht möglich, dann normal lesen.
    private static string ReadPassword(string prompt)
    {
        Console.Write(prompt);
        if (Console.IsInputRedirected) return Console.ReadLine() ?? "";

        var sb = new StringBuilder();
        ConsoleKeyInfo key;
        while ((key = Console.ReadKey(intercept: true)).Key != ConsoleKey.Enter)
        {
            if (key.Key == ConsoleKey.Backspace && sb.Length > 0) { sb.Length--; Console.Write("\b \b"); }
            else if (!char.IsControl(key.KeyChar)) { sb.Append(key.KeyChar); Console.Write('*'); }
        }
        Console.WriteLine();
        return sb.ToString();
    }
}