using Maki.Structures.Channels;
using Maki.Structures.Gateway;
using Maki.Structures.Guilds;
using Maki.Structures.Messages;
using Maki.Structures.Presences;
using Maki.Structures.Users;
using System;
using System.Collections.Generic;
using System.Linq;

namespace Maki.Gateway
{
    /// <summary>
    /// Gateway connection shard manager
    /// </summary>
    class GatewayShardClient : IDisposable
    {
        /// <summary>
        /// Managed (active) shards
        /// </summary>
        private readonly List<GatewayShard> Shards = new List<GatewayShard>();

        private readonly object Lock = new object();

        /// <summary>
        /// Parent DiscordClient instance
        /// </summary>
        private Discord Client;

        /// <summary>
        /// Number of active managed shards
        /// </summary>
        public int ShardCount
            => Shards.Count;

        /// <summary>
        /// Constructor
        /// </summary>
        /// <param name="client">Parent DiscordClient instance</param>
        public GatewayShardClient(Discord client)
            => Client = client;

        /// <summary>
        /// Creates a new Gateway Shard
        /// </summary>
        /// <param name="id">Id of the shard</param>
        /// <returns>New Gateway Shard</returns>
        public GatewayShard Create(int id)
        {
            GatewayShard shard = new GatewayShard(id, Client);
            ApplyEvents(shard);

            lock (Lock)
                Shards.Add(shard);

            return shard;
        }

        /// <summary>
        /// Destroys a Gateway Shard
        /// </summary>
        /// <param name="shard">Shard to destroy</param>
        public void Destroy(GatewayShard shard)
        {
            lock (Lock)
                Shards.Remove(shard);

            // Disconnect and Dispose are called separately so OnSocketClose is called properly
            shard.Disconnect();
            RemoveEvents(shard);
            shard.Dispose();
        }

        /// <summary>
        /// Destroys all shards
        /// </summary>
        public void Disconnect()
        {
            lock (Lock)
                Shards.ToList().ForEach(x => Destroy(x));
        }

        /// <summary>
        /// Links all gateway events handlers to the shard
        /// </summary>
        /// <param name="shard">Shard to link events to</param>
        private void ApplyEvents(GatewayShard shard)
        {
            shard.OnCallCreate += OnCallCreate;
            shard.OnCallDelete += OnCallDelete;
            shard.OnCallUpdate += OnCallUpdate;
            shard.OnVoiceServerUpdate += OnVoiceServerUpdate;
            shard.OnVoiceStateUpdate += OnVoiceStateUpdate;

            shard.OnChannelCreate += OnChannelCreate;
            shard.OnChannelDelete += OnChannelDelete;
            shard.OnChannelPinsAck += OnChannelPinsAck;
            shard.OnChannelPinsUpdate += OnChannelPinsUpdate;
            shard.OnChannelRecipientAdd += OnChannelRecipientAdd;
            shard.OnChannelRecipientRemove += OnChannelRecipientRemove;
            shard.OnChannelUpdate += OnChannelUpdate;

            shard.OnGuildBanAdd += OnGuildBanAdd;
            shard.OnGuildBanRemove += OnGuildBanRemove;
            shard.OnGuildCreate += OnGuildCreate;
            shard.OnGuildDelete += OnGuildDelete;
            shard.OnGuildEmojisUpdate += OnGuildEmojisUpdate;
            shard.OnGuildIntegrationsUpdate += OnGuildIntegrationsUpdate;
            shard.OnGuildMemberAdd += OnGuildMemberAdd;
            shard.OnGuildMemberUpdate += OnGuildMemberUpdate;
            shard.OnGuildMemberRemove += OnGuildMemberRemove;
            shard.OnGuildMembersChunk += OnGuildMembersChunk;
            shard.OnGuildRoleCreate += OnGuildRoleCreate;
            shard.OnGuildRoleUpdate += OnGuildRoleUpdate;
            shard.OnGuildRoleDelete += OnGuildRoleDelete;
            shard.OnGuildUpdate += OnGuildUpdate;

            shard.OnMessageAck += OnMessageAck;
            shard.OnMessageCreate += OnMessageCreate;
            shard.OnMessageDelete += OnMessageDelete;
            shard.OnMessageDeleteBulk += OnMessageDeleteBulk;
            shard.OnMessageReactionAdd += OnMessageReactionAdd;
            shard.OnMessageReactionRemove += OnMessageReactionRemove;
            shard.OnMessageReactionsRemoveAll += OnMessageReactionsRemoveAll;
            shard.OnMessageUpdate += OnMessageUpdate;

            shard.OnTypingStart += OnTypingStart;
            shard.OnPresenceUpdate += OnPresenceUpdate;
            shard.OnPresencesReplace += OnPresencesReplace;

            shard.OnFriendSuggestionDelete += OnFriendSuggestionDelete;
            shard.OnRelationshipAdd += OnRelationshipAdd;
            shard.OnRelationshipRemove += OnRelationshipRemove;

            shard.OnReady += OnReady;
            shard.OnResumed += OnResumed;

            shard.OnUserUpdate += OnUserUpdate;
            shard.OnUserNoteUpdate += OnUserNoteUpdate;
            shard.OnUserSettingsUpdate += OnUserSettingsUpdate;

            shard.OnSocketOpen += OnSocketOpen;
            shard.OnSocketClose += OnSocketClose;
            shard.OnSocketError += OnSocketError;
            shard.OnSocketMessage += OnSocketMessage;
        }

        /// <summary>
        /// Unlinks all gateway events handlers from the shard
        /// </summary>
        /// <param name="shard">Shard to unlink events from</param>
        public void RemoveEvents(GatewayShard shard)
        {
            shard.OnCallCreate -= OnCallCreate;
            shard.OnCallDelete -= OnCallDelete;
            shard.OnCallUpdate -= OnCallUpdate;
            shard.OnVoiceServerUpdate -= OnVoiceServerUpdate;
            shard.OnVoiceStateUpdate -= OnVoiceStateUpdate;

            shard.OnChannelCreate -= OnChannelCreate;
            shard.OnChannelDelete -= OnChannelDelete;
            shard.OnChannelPinsAck -= OnChannelPinsAck;
            shard.OnChannelPinsUpdate -= OnChannelPinsUpdate;
            shard.OnChannelRecipientAdd -= OnChannelRecipientAdd;
            shard.OnChannelRecipientRemove -= OnChannelRecipientRemove;
            shard.OnChannelUpdate -= OnChannelUpdate;

            shard.OnGuildBanAdd -= OnGuildBanAdd;
            shard.OnGuildBanRemove -= OnGuildBanRemove;
            shard.OnGuildCreate -= OnGuildCreate;
            shard.OnGuildDelete -= OnGuildDelete;
            shard.OnGuildEmojisUpdate -= OnGuildEmojisUpdate;
            shard.OnGuildIntegrationsUpdate -= OnGuildIntegrationsUpdate;
            shard.OnGuildMemberAdd -= OnGuildMemberAdd;
            shard.OnGuildMemberUpdate -= OnGuildMemberUpdate;
            shard.OnGuildMemberRemove -= OnGuildMemberRemove;
            shard.OnGuildMembersChunk -= OnGuildMembersChunk;
            shard.OnGuildRoleCreate -= OnGuildRoleCreate;
            shard.OnGuildRoleUpdate -= OnGuildRoleUpdate;
            shard.OnGuildRoleDelete -= OnGuildRoleDelete;
            shard.OnGuildUpdate -= OnGuildUpdate;

            shard.OnMessageAck -= OnMessageAck;
            shard.OnMessageCreate -= OnMessageCreate;
            shard.OnMessageDelete -= OnMessageDelete;
            shard.OnMessageDeleteBulk -= OnMessageDeleteBulk;
            shard.OnMessageReactionAdd -= OnMessageReactionAdd;
            shard.OnMessageReactionRemove -= OnMessageReactionRemove;
            shard.OnMessageReactionsRemoveAll -= OnMessageReactionsRemoveAll;
            shard.OnMessageUpdate -= OnMessageUpdate;

            shard.OnTypingStart -= OnTypingStart;
            shard.OnPresenceUpdate -= OnPresenceUpdate;
            shard.OnPresencesReplace -= OnPresencesReplace;

            shard.OnFriendSuggestionDelete -= OnFriendSuggestionDelete;
            shard.OnRelationshipAdd -= OnRelationshipAdd;
            shard.OnRelationshipRemove -= OnRelationshipRemove;

            shard.OnReady -= OnReady;
            shard.OnResumed -= OnResumed;

            shard.OnUserUpdate -= OnUserUpdate;
            shard.OnUserNoteUpdate -= OnUserNoteUpdate;
            shard.OnUserSettingsUpdate -= OnUserSettingsUpdate;

            shard.OnSocketOpen -= OnSocketOpen;
            shard.OnSocketClose -= OnSocketClose;
            shard.OnSocketError -= OnSocketError;
            shard.OnSocketMessage -= OnSocketMessage;
        }

        #region Events
        public event Action<GatewayShard> OnCallCreate;
        public event Action<GatewayShard> OnCallDelete;
        public event Action<GatewayShard> OnCallUpdate;
        public event Action<GatewayShard> OnVoiceServerUpdate;
        public event Action<GatewayShard> OnVoiceStateUpdate;

        public event Action<GatewayShard, Channel> OnChannelCreate;
        public event Action<GatewayShard, Channel> OnChannelDelete;
        public event Action<GatewayShard> OnChannelPinsAck;
        public event Action<GatewayShard> OnChannelPinsUpdate;
        public event Action<GatewayShard> OnChannelRecipientAdd;
        public event Action<GatewayShard> OnChannelRecipientRemove;
        public event Action<GatewayShard, Channel> OnChannelUpdate;

        public event Action<GatewayShard, User> OnGuildBanAdd;
        public event Action<GatewayShard, User> OnGuildBanRemove;
        public event Action<GatewayShard, Guild> OnGuildCreate;
        public event Action<GatewayShard, Guild> OnGuildDelete;
        public event Action<GatewayShard, Guild> OnGuildEmojisUpdate;
        public event Action<GatewayShard, GuildIntegration> OnGuildIntegrationsUpdate;
        public event Action<GatewayShard, GuildMember> OnGuildMemberAdd;
        public event Action<GatewayShard, GuildMember> OnGuildMemberUpdate;
        public event Action<GatewayShard, GuildMember> OnGuildMemberRemove;
        public event Action<GatewayShard, GuildMembersChunk> OnGuildMembersChunk;
        public event Action<GatewayShard, GuildRole> OnGuildRoleCreate;
        public event Action<GatewayShard, GuildRole> OnGuildRoleUpdate;
        public event Action<GatewayShard, GuildRole> OnGuildRoleDelete;
        public event Action<GatewayShard, Guild> OnGuildUpdate;

        public event Action<GatewayShard> OnMessageAck;
        public event Action<GatewayShard, Message> OnMessageCreate;
        public event Action<GatewayShard, Message> OnMessageDelete;
        public event Action<GatewayShard> OnMessageDeleteBulk;
        public event Action<GatewayShard> OnMessageReactionAdd;
        public event Action<GatewayShard> OnMessageReactionRemove;
        public event Action<GatewayShard> OnMessageReactionsRemoveAll;
        public event Action<GatewayShard, Message> OnMessageUpdate;

        public event Action<GatewayShard, TypingStart> OnTypingStart;
        public event Action<GatewayShard, Presence> OnPresenceUpdate;
        public event Action<GatewayShard> OnPresencesReplace;

        public event Action<GatewayShard> OnFriendSuggestionDelete;
        public event Action<GatewayShard> OnRelationshipAdd;
        public event Action<GatewayShard> OnRelationshipRemove;

        public event Action<GatewayShard, GatewayReady> OnReady;
        public event Action<GatewayShard> OnResumed;

        public event Action<GatewayShard, User> OnUserUpdate;
        public event Action<GatewayShard> OnUserNoteUpdate;
        public event Action<GatewayShard> OnUserSettingsUpdate;

        public event Action<GatewayShard> OnSocketOpen;
        public event Action<GatewayShard, bool, ushort, string> OnSocketClose;
        public event Action<GatewayShard, Exception> OnSocketError;
        public event Action<GatewayShard, string> OnSocketMessage;
        #endregion

        #region IDisposable

        private bool IsDisposed = false;

        /// <summary>
        /// Releases all unmanaged resources used by this object
        /// </summary>
        private void Dispose(bool disposing)
        {
            if (IsDisposed)
                return;
            
            IsDisposed = true;
            Disconnect();

            if (disposing)
                GC.SuppressFinalize(true);
        }

        ~GatewayShardClient()
            => Dispose(false);

        public void Dispose()
            => Dispose(true);

        #endregion
    }
}