using CommandLine;
using StackExchange.Redis;
using System;
using System.Collections.Generic;
using System.Threading;
using RedisManager.Utils;

namespace RedisManager.Commands
{
    /// <summary>
    /// Contains command line options and implementations for Redis Pub/Sub operations.
    /// Provides functionality for PUBLISH, SUBSCRIBE, and UNSUBSCRIBE commands.
    /// </summary>
    [Verb("publish", HelpText = "Publish a message to a channel.")]
    public class PublishOptions
    {
        [Option('i', "instance", Required = true, HelpText = "Instance name.")]
        public string Instance { get; set; }
        [Value(0, MetaName = "channel", Required = true, HelpText = "Channel name.")]
        public string Channel { get; set; }
        [Value(1, MetaName = "message", Required = true, HelpText = "Message to publish.")]
        public string Message { get; set; }
        [Option("table", Required = false, HelpText = "Output as table.")]
        public bool Table { get; set; }
    }

    [Verb("subscribe", HelpText = "Subscribe to one or more channels.")]
    public class SubscribeOptions
    {
        [Option('i', "instance", Required = true, HelpText = "Instance name.")]
        public string Instance { get; set; }
        [Value(0, MetaName = "channels", Min = 1, Required = true, HelpText = "Channels to subscribe to.")]
        public IEnumerable<string> Channels { get; set; }
    }

    [Verb("unsubscribe", HelpText = "Unsubscribe from one or more channels.")]
    public class UnsubscribeOptions
    {
        [Option('i', "instance", Required = true, HelpText = "Instance name.")]
        public string Instance { get; set; }
        [Value(0, MetaName = "channels", Min = 1, Required = true, HelpText = "Channels to unsubscribe from.")]
        public IEnumerable<string> Channels { get; set; }
    }

    public static class PubSubCommands
    {
        /// <summary>
        /// Executes the PUBLISH command to publish a message to a channel.
        /// </summary>
        /// <param name="opts">The PublishOptions containing instance, channel, and message.</param>
        /// <param name="config">The RedisManager configuration.</param>
        /// <returns>Exit code (0 for success, non-zero for failure).</returns>
        public static int RunPublish(PublishOptions opts, Config config)
        {
            var instance = RedisUtils.GetInstance(config, opts.Instance);
            using var redis = RedisUtils.ConnectRedis(instance);
            var sub = redis.GetSubscriber();
            var count = sub.Publish(opts.Channel, opts.Message);
            if (opts.Table)
                RedisUtils.PrintTable(new[] { "Channel", "Receivers" }, new List<string[]> { new[] { opts.Channel, count.ToString() } });
            else
                Console.WriteLine(Output.Green($"Published to {opts.Channel}, receivers: {count}"));
            return 0;
        }

        /// <summary>
        /// Executes the SUBSCRIBE command to subscribe to one or more channels.
        /// </summary>
        /// <param name="opts">The SubscribeOptions containing instance and channels.</param>
        /// <param name="config">The RedisManager configuration.</param>
        /// <returns>Exit code (0 for success, non-zero for failure).</returns>
        public static int RunSubscribe(SubscribeOptions opts, Config config)
        {
            var instance = RedisUtils.GetInstance(config, opts.Instance);
            using var redis = RedisUtils.ConnectRedis(instance);
            var sub = redis.GetSubscriber();
            var channels = opts.Channels;
            Console.WriteLine(Output.Yellow($"Subscribed to: {string.Join(", ", channels)}. Press Ctrl+C to exit."));
            using var cts = new CancellationTokenSource();
            Console.CancelKeyPress += (s, e) => { e.Cancel = true; cts.Cancel(); };
            foreach (var channel in channels)
            {
                sub.Subscribe(channel, (ch, msg) =>
                {
                    Console.WriteLine(Output.Cyan($"[{ch}] {msg}"));
                });
            }
            try
            {
                while (!cts.IsCancellationRequested)
                {
                    Thread.Sleep(100);
                }
            }
            catch (OperationCanceledException) { }
            Console.WriteLine(Output.Yellow("Unsubscribed and exiting."));
            return 0;
        }

        /// <summary>
        /// Executes the UNSUBSCRIBE command to unsubscribe from one or more channels.
        /// </summary>
        /// <param name="opts">The UnsubscribeOptions containing instance and channels.</param>
        /// <param name="config">The RedisManager configuration.</param>
        /// <returns>Exit code (0 for success, non-zero for failure).</returns>
        public static int RunUnsubscribe(UnsubscribeOptions opts, Config config)
        {
            var instance = RedisUtils.GetInstance(config, opts.Instance);
            using var redis = RedisUtils.ConnectRedis(instance);
            var sub = redis.GetSubscriber();
            foreach (var channel in opts.Channels)
            {
                sub.Unsubscribe(channel);
                Console.WriteLine(Output.Yellow($"Unsubscribed from {channel}"));
            }
            return 0;
        }
    }
}