using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using Content.Server.Chemistry.Components.SolutionManager;
using Content.Shared.Chemistry;
using Content.Shared.Chemistry.Components;
using Content.Shared.Chemistry.Reaction;
using Content.Shared.Chemistry.Reagent;
using Content.Shared.Examine;
using Content.Shared.FixedPoint;
using JetBrains.Annotations;
using Robust.Shared.GameObjects;
using Robust.Shared.IoC;
using Robust.Shared.Localization;
using Robust.Shared.Log;
using Robust.Shared.Prototypes;
using Robust.Shared.Utility;

namespace Content.Server.Chemistry.EntitySystems
{
    /// <summary>
    /// This event alerts system that the solution was changed
    /// </summary>
    public class SolutionChangedEvent : EntityEventArgs
    {
    }

    /// <summary>
    /// Part of Chemistry system deal with SolutionContainers
    /// </summary>
    [UsedImplicitly]
    public partial class SolutionContainerSystem : EntitySystem
    {
        [Dependency]
        private readonly SharedChemicalReactionSystem _chemistrySystem = default!;

        [Dependency]
        private readonly IPrototypeManager _prototypeManager = default!;

        public override void Initialize()
        {
            base.Initialize();

            SubscribeLocalEvent<SolutionContainerManagerComponent, ComponentInit>(InitSolution);
            SubscribeLocalEvent<ExaminableSolutionComponent, ExaminedEvent>(OnExamineSolution);
        }

        private void InitSolution(EntityUid uid, SolutionContainerManagerComponent component, ComponentInit args)
        {
            foreach (var keyValue in component.Solutions)
            {
                var solutionHolder = keyValue.Value;
                if (solutionHolder.MaxVolume == FixedPoint2.Zero)
                {
                    solutionHolder.MaxVolume = solutionHolder.TotalVolume > solutionHolder.InitialMaxVolume
                        ? solutionHolder.TotalVolume
                        : solutionHolder.InitialMaxVolume;
                }

                UpdateAppearance(uid, solutionHolder);
            }
        }

        private void OnExamineSolution(EntityUid uid, ExaminableSolutionComponent examinableComponent,
            ExaminedEvent args)
        {
            SolutionContainerManagerComponent? solutionsManager = null;
            if (!Resolve(args.Examined, ref solutionsManager)
                || !solutionsManager.Solutions.TryGetValue(examinableComponent.Solution, out var solutionHolder))
                return;

            if (solutionHolder.Contents.Count == 0)
            {
                args.PushText(Loc.GetString("shared-solution-container-component-on-examine-empty-container"));
                return;
            }

            var primaryReagent = solutionHolder.GetPrimaryReagentId();

            if (!_prototypeManager.TryIndex(primaryReagent, out ReagentPrototype? proto))
            {
                Logger.Error(
                    $"{nameof(Solution)} could not find the prototype associated with {primaryReagent}.");
                return;
            }

            var colorHex = solutionHolder.Color
                .ToHexNoAlpha(); //TODO: If the chem has a dark color, the examine text becomes black on a black background, which is unreadable.
            var messageString = "shared-solution-container-component-on-examine-main-text";

            args.PushMarkup(Loc.GetString(messageString,
                ("color", colorHex),
                ("wordedAmount", Loc.GetString(solutionHolder.Contents.Count == 1
                    ? "shared-solution-container-component-on-examine-worded-amount-one-reagent"
                    : "shared-solution-container-component-on-examine-worded-amount-multiple-reagents")),
                ("desc", Loc.GetString(proto.PhysicalDescription))));
        }

        private void UpdateAppearance(EntityUid uid, Solution solution,
            AppearanceComponent? appearanceComponent = null)
        {
            if (!EntityManager.EntityExists(uid)
                || !Resolve(uid, ref appearanceComponent, false))
                return;

            var filledVolumeFraction = solution.CurrentVolume.Float() / solution.MaxVolume.Float();
            appearanceComponent.SetData(SolutionContainerVisuals.VisualState, new SolutionContainerVisualState(solution.Color, filledVolumeFraction));
        }

        /// <summary>
        ///     Removes part of the solution in the container.
        /// </summary>
        /// <param name="targetUid"></param>
        /// <param name="solutionHolder"></param>
        /// <param name="quantity">the volume of solution to remove.</param>
        /// <returns>The solution that was removed.</returns>
        public Solution SplitSolution(EntityUid targetUid, Solution solutionHolder, FixedPoint2 quantity)
        {
            var splitSol = solutionHolder.SplitSolution(quantity);
            UpdateChemicals(targetUid, solutionHolder);
            return splitSol;
        }

        private void UpdateChemicals(EntityUid uid, Solution solutionHolder, bool needsReactionsProcessing = false)
        {
            // Process reactions
            if (needsReactionsProcessing && solutionHolder.CanReact)
            {
                _chemistrySystem.FullyReactSolution(solutionHolder, uid, solutionHolder.MaxVolume);
            }

            UpdateAppearance(uid, solutionHolder);
            RaiseLocalEvent(uid, new SolutionChangedEvent());
        }

        public void RemoveAllSolution(EntityUid uid, Solution solutionHolder)
        {
            if (solutionHolder.CurrentVolume == 0)
                return;

            solutionHolder.RemoveAllSolution();
            UpdateChemicals(uid, solutionHolder);
        }

        public void RemoveAllSolution(EntityUid uid, SolutionContainerManagerComponent? solutionContainerManager = null)
        {
            if (!Resolve(uid, ref solutionContainerManager))
                return;

            foreach (var solution in solutionContainerManager.Solutions.Values)
            {
                RemoveAllSolution(uid, solution);
            }
        }

        /// <summary>
        ///     Adds reagent of an Id to the container.
        /// </summary>
        /// <param name="targetUid"></param>
        /// <param name="targetSolution">Container to which we are adding reagent</param>
        /// <param name="reagentId">The Id of the reagent to add.</param>
        /// <param name="quantity">The amount of reagent to add.</param>
        /// <param name="acceptedQuantity">The amount of reagent successfully added.</param>
        /// <returns>If all the reagent could be added.</returns>
        public bool TryAddReagent(EntityUid targetUid, Solution targetSolution, string reagentId, FixedPoint2 quantity,
            out FixedPoint2 acceptedQuantity)
        {
            acceptedQuantity = targetSolution.AvailableVolume > quantity ? quantity : targetSolution.AvailableVolume;
            targetSolution.AddReagent(reagentId, acceptedQuantity);

            if (acceptedQuantity > 0)
                UpdateChemicals(targetUid, targetSolution, true);

            return acceptedQuantity == quantity;
        }

        /// <summary>
        ///     Removes reagent of an Id to the container.
        /// </summary>
        /// <param name="targetUid"></param>
        /// <param name="container">Solution container from which we are removing reagent</param>
        /// <param name="reagentId">The Id of the reagent to remove.</param>
        /// <param name="quantity">The amount of reagent to remove.</param>
        /// <returns>If the reagent to remove was found in the container.</returns>
        public bool TryRemoveReagent(EntityUid targetUid, Solution? container, string reagentId, FixedPoint2 quantity)
        {
            if (container == null || !container.ContainsReagent(reagentId))
                return false;

            container.RemoveReagent(reagentId, quantity);
            UpdateChemicals(targetUid, container);
            return true;
        }

        /// <summary>
        ///     Adds a solution to the container, if it can fully fit.
        /// </summary>
        /// <param name="targetUid"></param>
        /// <param name="targetSolution">The container to which we try to add.</param>
        /// <param name="solution">The solution to try to add.</param>
        /// <returns>If the solution could be added.</returns>
        public bool TryAddSolution(EntityUid targetUid, Solution? targetSolution, Solution solution)
        {
            if (targetSolution == null || !targetSolution.CanAddSolution(solution) || solution.TotalVolume == 0)
                return false;

            targetSolution.AddSolution(solution);
            UpdateChemicals(targetUid, targetSolution, true);
            return true;
        }

        public bool TryGetSolution(EntityUid uid, string name,
            [NotNullWhen(true)] out Solution? solution,
            SolutionContainerManagerComponent? solutionsMgr = null)
        {
            if (!Resolve(uid, ref solutionsMgr, false))
            {
                solution = null;
                return false;
            }

            return solutionsMgr.Solutions.TryGetValue(name, out solution);
        }

        /// <summary>
        /// Will ensure a solution is added to given entity even if it's missing solutionContainerManager
        /// </summary>
        /// <param name="uid">EntityUid to which to add solution</param>
        /// <param name="name">name for the solution</param>
        /// <param name="solutionsMgr">solution components used in resolves</param>
        /// <returns>solution</returns>
        public Solution EnsureSolution(EntityUid uid, string name,
            SolutionContainerManagerComponent? solutionsMgr = null)
        {
            if (!Resolve(uid, ref solutionsMgr, false))
            {
                solutionsMgr = EntityManager.EnsureComponent<SolutionContainerManagerComponent>(uid);
            }

            if (!solutionsMgr.Solutions.ContainsKey(name))
            {
                var newSolution = new Solution();
                solutionsMgr.Solutions.Add(name, newSolution);
            }

            return solutionsMgr.Solutions[name];
        }

        public string[] RemoveEachReagent(EntityUid uid, Solution solution, FixedPoint2 quantity)
        {
            var removedReagent = new string[solution.Contents.Count];
            if (quantity <= 0)
                return Array.Empty<string>();

            var pos = 0;
            for (var i = 0; i < solution.Contents.Count; i++)
            {
                var (reagentId, curQuantity) = solution.Contents[i];
                removedReagent[pos++] = reagentId;

                var newQuantity = curQuantity - quantity;
                if (newQuantity <= 0)
                {
                    solution.Contents.RemoveSwap(i);
                    solution.TotalVolume -= curQuantity;
                }
                else
                {
                    solution.Contents[i] = new Solution.ReagentQuantity(reagentId, newQuantity);
                    solution.TotalVolume -= quantity;
                }
            }

            UpdateChemicals(uid, solution);
            return removedReagent;
        }

        public void TryRemoveAllReagents(EntityUid uid, Solution solution, List<Solution.ReagentQuantity> removeReagents)
        {
            if (removeReagents.Count == 0)
                return;

            foreach (var reagent in removeReagents)
            {
                solution.RemoveReagent(reagent.ReagentId, reagent.Quantity);
            }

            UpdateChemicals(uid, solution);
        }

        public FixedPoint2 GetReagentQuantity(EntityUid owner, string reagentId)
        {
            var reagentQuantity = FixedPoint2.New(0);
            if (EntityManager.EntityExists(owner)
                && EntityManager.TryGetComponent(owner, out SolutionContainerManagerComponent? managerComponent))
            {
                foreach (var solution in managerComponent.Solutions.Values)
                {
                    reagentQuantity += solution.GetReagentQuantity(reagentId);
                }
            }

            return reagentQuantity;
        }
    }
}