using System;
using System.Net.Sockets;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;

namespace RedisManager
{
    /// <summary>
    /// Client for communicating with the RedisManager service.
    /// Connects to a running service instance and sends command requests over TCP.
    /// </summary>
    public class RedisManagerClient
    {
        private readonly string _host = "localhost";
        private readonly int _port = 6380; // Same port as service

        /// <summary>
        /// Executes a Redis command by sending it to the RedisManager service.
        /// Connects to the service, sends the command arguments, and displays the result.
        /// </summary>
        /// <param name="args">Command line arguments to execute on the service</param>
        /// <returns>Exit code (0 for success, 1 for failure)</returns>
        public async Task<int> ExecuteCommandAsync(string[] args)
        {
            try
            {
                using var client = new TcpClient();
                await client.ConnectAsync(_host, _port);

                var request = new ServiceRequest
                {
                    Command = "execute",
                    Arguments = args
                };

                var requestJson = JsonSerializer.Serialize(request) + "\n";

                using var stream = client.GetStream();
                using var writer = new StreamWriter(stream, new UTF8Encoding(false)) { AutoFlush = true };
                await writer.WriteAsync(requestJson);

                using var reader = new StreamReader(stream, new UTF8Encoding(false));
                var responseJson = await reader.ReadLineAsync();
                if (responseJson != null)
                {
                    var serviceResponse = JsonSerializer.Deserialize<ServiceResponse>(responseJson);
                    if (serviceResponse.Success)
                    {
                        Console.WriteLine(serviceResponse.Data);
                        return 0;
                    }
                    else
                    {
                        Console.WriteLine($"Error: {serviceResponse.Error}");
                        if (!string.IsNullOrEmpty(serviceResponse.ErrorCode))
                            Console.WriteLine($"Error Code: {serviceResponse.ErrorCode}");
                        if (serviceResponse.ErrorDetails != null)
                            Console.WriteLine($"Error Details: {JsonSerializer.Serialize(serviceResponse.ErrorDetails)}");
                        return 1;
                    }
                }

                Console.WriteLine("No response from service");
                return 1;
            }
            catch (SocketException)
            {
                // Special code to indicate the service is not running
                return 2;
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error communicating with service: {ex.Message}");
                return 1;
            }
        }
    }
}