using System.Collections;
using System.Collections.Generic;
using System.Runtime.InteropServices.WindowsRuntime;
using Content.Server.GameObjects.EntitySystems;
using Content.Shared.Research;
using Robust.Shared.GameObjects;
using Robust.Shared.Interfaces.GameObjects;
using Robust.Shared.IoC;
using Robust.Shared.Prototypes;
using Robust.Shared.Serialization;
using Robust.Shared.ViewVariables;

namespace Content.Server.GameObjects.Components.Research
{
    [RegisterComponent]
    public class ResearchServerComponent : Component
    {
        public static int ServerCount = 0;

        public override string Name => "ResearchServer";

        [ViewVariables(VVAccess.ReadWrite)]
        public string ServerName => _serverName;

        private string _serverName = "RDSERVER";
        private float _timer = 0f;
        public TechnologyDatabaseComponent Database { get; private set; }

        [ViewVariables(VVAccess.ReadWrite)]
        private int _points = 0;

        [ViewVariables(VVAccess.ReadOnly)]
        public int Id { get; private set; }

        // You could optimize research by keeping a list of unlocked recipes too.
        [ViewVariables(VVAccess.ReadOnly)]
        public IReadOnlyList<TechnologyPrototype> UnlockedTechnologies => Database.Technologies;
        [ViewVariables(VVAccess.ReadOnly)]
        public List<ResearchPointSourceComponent> PointSources { get; } = new List<ResearchPointSourceComponent>();
        [ViewVariables(VVAccess.ReadOnly)]
        public List<ResearchClientComponent> Clients { get; } = new List<ResearchClientComponent>();

        public int Point => _points;

        /// <summary>
        ///     How many points per second this R&D server gets.
        ///     The value is calculated from all point sources connected to it.
        /// </summary>
        [ViewVariables(VVAccess.ReadOnly)]
        public int PointsPerSecond
        {
            // This could be changed to PointsPerMinute quite easily for optimization.
            get
            {
                var points = 0;

                foreach (var source in PointSources)
                {
                    if (source.Active) points += source.PointsPerSecond;
                }

                return points;
            }
        }

        public override void Initialize()
        {
            base.Initialize();
            Id = ServerCount++;
            IoCManager.Resolve<IEntitySystemManager>()?.GetEntitySystem<ResearchSystem>()?.RegisterServer(this);
            Database = Owner.GetComponent<TechnologyDatabaseComponent>();
        }

        /// <inheritdoc />
        protected override void Shutdown()
        {
            base.Shutdown();
            IoCManager.Resolve<IEntitySystemManager>()?.GetEntitySystem<ResearchSystem>()?.UnregisterServer(this);
        }

        public override void ExposeData(ObjectSerializer serializer)
        {
            base.ExposeData(serializer);
            serializer.DataField(ref _serverName, "servername", "RDSERVER");
            serializer.DataField(ref _points, "points", 0);
        }

        public bool CanUnlockTechnology(TechnologyPrototype technology)
        {
            if (!Database.CanUnlockTechnology(technology) || _points < technology.RequiredPoints || Database.IsTechnologyUnlocked(technology)) return false;
            return true;
        }

        /// <summary>
        ///     Unlocks a technology, but only if there are enough research points for it.
        ///     If there are, it subtracts the amount of points from the total.
        /// </summary>
        /// <param name="technology"></param>
        /// <returns></returns>
        public bool UnlockTechnology(TechnologyPrototype technology)
        {
            if (!CanUnlockTechnology(technology)) return false;
            var result = Database.UnlockTechnology(technology);
            if(result)
                _points -= technology.RequiredPoints;
            return result;
        }

        /// <summary>
        ///     Check whether a technology is unlocked or not.
        /// </summary>
        /// <param name="technology"></param>
        /// <returns></returns>
        public bool IsTechnologyUnlocked(TechnologyPrototype technology)
        {
            return Database.IsTechnologyUnlocked(technology);
        }

        /// <summary>
        ///     Registers a remote client on this research server.
        /// </summary>
        /// <param name="client"></param>
        /// <returns></returns>
        public bool RegisterClient(ResearchClientComponent client)
        {
            if (client is ResearchPointSourceComponent source)
            {
                if (PointSources.Contains(source)) return false;
                PointSources.Add(source);
                source.Server = this;
                return true;
            }

            if (Clients.Contains(client)) return false;
            Clients.Add(client);
            client.Server = this;
            return true;
        }

        /// <summary>
        ///     Unregisters a remote client from this server.
        /// </summary>
        /// <param name="client"></param>
        public void UnregisterClient(ResearchClientComponent client)
        {
            if (client is ResearchPointSourceComponent source)
            {
                PointSources.Remove(source);
                return;
            }

            Clients.Remove(client);
        }

        public void Update(float frameTime)
        {
            _timer += frameTime;
            if (_timer < 1f) return;
            _timer = 0f;
            _points += PointsPerSecond;
        }
    }
}