/* Copyright (c) 2017 Rick (rick 'at' gibbed 'dot' us)
 * 
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * 
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would
 *    be appreciated but is not required.
 * 
 * 2. Altered source versions must be plainly marked as such, and must not
 *    be misrepresented as being the original software.
 * 
 * 3. This notice may not be removed or altered from any source
 *    distribution.
 */

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;

namespace SAM.API
{
    public class Client
    {
        public Wrappers.SteamClient009 SteamClient;
        public Wrappers.SteamUser012 SteamUser;
        public Wrappers.SteamUserStats007 SteamUserStats;
        public Wrappers.SteamUtils005 SteamUtils;
        public Wrappers.SteamApps001 SteamApps001;
        public Wrappers.SteamApps003 SteamApps003;

        private int _Pipe;
        private int _User;

        private readonly List<ICallback> _Callbacks = new List<ICallback>();

        public bool Initialize(long appId)
        {
            if (appId != 0)
            {
                Environment.SetEnvironmentVariable("SteamAppId", appId.ToString(CultureInfo.InvariantCulture));
            }

            if (Steam.GetInstallPath() == null)
            {
                return false;
            }

            if (Steam.Load() == false)
            {
                return false;
            }

            this.SteamClient = Steam.CreateInterface<Wrappers.SteamClient009>("SteamClient009");
            if (this.SteamClient == null)
            {
                return false;
            }

            this._Pipe = this.SteamClient.CreateSteamPipe();
            if (this._Pipe == 0)
            {
                return false;
            }

            this._User = this.SteamClient.ConnectToGlobalUser(this._Pipe);
            if (this._User == 0)
            {
                return false;
            }

            this.SteamUtils = this.SteamClient.GetSteamUtils004(this._Pipe);
            if (appId > 0 && this.SteamUtils.GetAppId() != (uint)appId)
            {
                return false;
            }

            this.SteamUser = this.SteamClient.GetSteamUser012(this._User, this._Pipe);
            this.SteamUserStats = this.SteamClient.GetSteamUserStats006(this._User, this._Pipe);
            this.SteamApps001 = this.SteamClient.GetSteamApps001(this._User, this._Pipe);
            this.SteamApps003 = this.SteamClient.GetSteamApps003(this._User, this._Pipe);
            return true;
        }

        ~Client()
        {
            if (this.SteamClient != null)
            {
                this.SteamClient.ReleaseUser(this._Pipe, this._User);
                this._User = 0;
                this.SteamClient.ReleaseSteamPipe(this._Pipe);
                this._Pipe = 0;
            }
        }

        public TCallback CreateAndRegisterCallback<TCallback>()
            where TCallback : ICallback, new()
        {
            var callback = new TCallback();
            this._Callbacks.Add(callback);
            return callback;
        }

        private bool _RunningCallbacks;

        public void RunCallbacks(bool server)
        {
            if (this._RunningCallbacks == true)
            {
                return;
            }

            this._RunningCallbacks = true;

            Types.CallbackMessage message;
            int call;
            while (Steam.GetCallback(this._Pipe, out message, out call) == true)
            {
                var callbackId = message.Id;
                foreach (ICallback callback in this._Callbacks.Where(
                    candidate => candidate.Id == callbackId &&
                                 candidate.IsServer == server))
                {
                    callback.Run(message.ParamPointer);
                }

                Steam.FreeLastCallback(this._Pipe);
            }

            this._RunningCallbacks = false;
        }
    }
}