using System;
using System.Collections.Generic;
using System.Linq;
using Content.Client.HUD;
using Content.Client.Resources;
using Content.Shared.Construction.Prototypes;
using Content.Shared.Construction.Steps;
using Content.Shared.Tools;
using Content.Shared.Tools.Components;
using Robust.Client.Graphics;
using Robust.Client.Placement;
using Robust.Client.ResourceManagement;
using Robust.Client.UserInterface.Controls;
using Robust.Client.Utility;
using Robust.Shared.Enums;
using Robust.Shared.GameObjects;
using Robust.Shared.IoC;
using Robust.Shared.Localization;
using Robust.Shared.Prototypes;

namespace Content.Client.Construction.UI
{
    /// <summary>
    /// This class presents the Construction/Crafting UI to the client, linking the <see cref="ConstructionSystem" /> with the
    /// model. This is where the bulk of UI work is done, either calling functions in the model to change state, or collecting
    /// data out of the model to *present* to the screen though the UI framework.
    /// </summary>
    internal class ConstructionMenuPresenter : IDisposable
    {
        [Dependency] private readonly IEntitySystemManager _systemManager = default!;
        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
        [Dependency] private readonly IPlacementManager _placementManager = default!;

        private readonly IGameHud _gameHud;
        private readonly IConstructionMenuView _constructionView;

        private ConstructionSystem? _constructionSystem;
        private ConstructionPrototype? _selected;

        private bool CraftingAvailable
        {
            get => _gameHud.CraftingButtonVisible;
            set
            {
                _gameHud.CraftingButtonVisible = value;
                if (!value)
                    _constructionView.Close();
            }
        }

        /// <summary>
        /// Does the window have focus? If the window is closed, this will always return false.
        /// </summary>
        private bool IsAtFront => _constructionView.IsOpen && _constructionView.IsAtFront();

        private bool WindowOpen
        {
            get => _constructionView.IsOpen;
            set
            {
                if (value && CraftingAvailable)
                {
                    if (_constructionView.IsOpen)
                        _constructionView.MoveToFront();
                    else
                        _constructionView.OpenCentered();

                    if(_selected != null)
                        PopulateInfo(_selected);
                }
                else
                    _constructionView.Close();
            }
        }

        /// <summary>
        /// Constructs a new instance of <see cref="ConstructionMenuPresenter" />.
        /// </summary>
        /// <param name="gameHud">GUI that is being presented to.</param>
        public ConstructionMenuPresenter(IGameHud gameHud)
        {
            // This is a lot easier than a factory
            IoCManager.InjectDependencies(this);

            _gameHud = gameHud;
            _constructionView = new ConstructionMenu();

            // This is required so that if we load after the system is initialized, we can bind to it immediately
            if (_systemManager.TryGetEntitySystem<ConstructionSystem>(out var constructionSystem))
                SystemBindingChanged(constructionSystem);

            _systemManager.SystemLoaded += OnSystemLoaded;
            _systemManager.SystemUnloaded += OnSystemUnloaded;

            _placementManager.PlacementChanged += OnPlacementChanged;

            _constructionView.OnClose += () => _gameHud.CraftingButtonDown = false;
            _constructionView.ClearAllGhosts += (_, _) => _constructionSystem?.ClearAllGhosts();
            _constructionView.PopulateRecipes += OnViewPopulateRecipes;
            _constructionView.RecipeSelected += OnViewRecipeSelected;
            _constructionView.BuildButtonToggled += (_, b) => BuildButtonToggled(b);
            _constructionView.EraseButtonToggled += (_, b) =>
            {
                if (_constructionSystem is null) return;
                if (b) _placementManager.Clear();
                _placementManager.ToggleEraserHijacked(new ConstructionPlacementHijack(_constructionSystem, null));
                _constructionView.EraseButtonPressed = b;
            };

            PopulateCategories();
            OnViewPopulateRecipes(_constructionView, (string.Empty, string.Empty));

            _gameHud.CraftingButtonToggled += OnHudCraftingButtonToggled;
        }

        private void OnHudCraftingButtonToggled(bool b)
        {
            WindowOpen = b;
        }

        /// <inheritdoc />
        public void Dispose()
        {
            _constructionView.Dispose();

            SystemBindingChanged(null);
            _systemManager.SystemLoaded -= OnSystemLoaded;
            _systemManager.SystemUnloaded -= OnSystemUnloaded;

            _placementManager.PlacementChanged -= OnPlacementChanged;

            _gameHud.CraftingButtonToggled -= OnHudCraftingButtonToggled;
        }

        private void OnPlacementChanged(object? sender, EventArgs e)
        {
            _constructionView.ResetPlacement();
        }

        private void OnViewRecipeSelected(object? sender, ItemList.Item? item)
        {
            if (item is null)
            {
                _selected = null;
                _constructionView.ClearRecipeInfo();
                return;
            }

            _selected = (ConstructionPrototype) item.Metadata!;
            if (_placementManager.IsActive && !_placementManager.Eraser) UpdateGhostPlacement();
            PopulateInfo(_selected);
        }

        private void OnViewPopulateRecipes(object? sender, (string search, string catagory) args)
        {
            var (search, category) = args;
            var recipesList = _constructionView.Recipes;

            recipesList.Clear();
            var recipes = new List<ConstructionPrototype>();

            foreach (var recipe in _prototypeManager.EnumeratePrototypes<ConstructionPrototype>())
            {
                if (!string.IsNullOrEmpty(search))
                {
                    if (!recipe.Name.ToLowerInvariant().Contains(search.Trim().ToLowerInvariant()))
                        continue;
                }

                if (!string.IsNullOrEmpty(category) && category != Loc.GetString("construction-presenter-category-all"))
                {
                    if (recipe.Category != category)
                        continue;
                }

                recipes.Add(recipe);
            }

            recipes.Sort((a, b) => string.Compare(a.Name, b.Name, StringComparison.InvariantCulture));

            foreach (var recipe in recipes)
            {
                recipesList.Add(GetItem(recipe, recipesList));
            }

            // There is apparently no way to set which
        }

        private void PopulateCategories()
        {
            var uniqueCategories = new HashSet<string>();

            // hard-coded to show all recipes
            uniqueCategories.Add(Loc.GetString("construction-presenter-category-all"));

            foreach (var prototype in _prototypeManager.EnumeratePrototypes<ConstructionPrototype>())
            {
                var category = Loc.GetString(prototype.Category);

                if (!string.IsNullOrEmpty(category))
                    uniqueCategories.Add(category);
            }

            _constructionView.Category.Clear();

            var array = uniqueCategories.ToArray();
            Array.Sort(array);

            for (var i = 0; i < array.Length; i++)
            {
                var category = array[i];
                _constructionView.Category.AddItem(category, i);
            }

            _constructionView.Categories = array;
        }

        private void PopulateInfo(ConstructionPrototype prototype)
        {
            _constructionView.ClearRecipeInfo();
            _constructionView.SetRecipeInfo(prototype.Name, prototype.Description, prototype.Icon.Frame0(), prototype.Type != ConstructionType.Item);

            var stepList = _constructionView.RecipeStepList;
            GenerateStepList(prototype, stepList);
        }

        private void GenerateStepList(ConstructionPrototype prototype, ItemList stepList)
        {
            if (_constructionSystem?.GetGuide(prototype) is not { } guide)
                return;

            foreach (var entry in guide.Entries)
            {
                var text = entry.Arguments != null
                    ? Loc.GetString(entry.Localization, entry.Arguments) : Loc.GetString(entry.Localization);

                if (entry.EntryNumber is {} number)
                    text = Loc.GetString("construction-presenter-step-wrapper",
                        ("step-number", number), ("text", text));

                // The padding needs to be applied regardless of text length... (See PadLeft documentation)
                text = text.PadLeft(text.Length + entry.Padding);

                stepList.AddItem(text, entry.Icon?.Frame0(), false);
            }
        }

        private static ItemList.Item GetItem(ConstructionPrototype recipe, ItemList itemList)
        {
            return new(itemList)
            {
                Metadata = recipe,
                Text = recipe.Name,
                Icon = recipe.Icon.Frame0(),
                TooltipEnabled = true,
                TooltipText = recipe.Description
            };
        }

        private void BuildButtonToggled(bool pressed)
        {
            if (pressed)
            {
                if (_selected == null) return;

                // not bound to a construction system
                if (_constructionSystem is null)
                {
                    _constructionView.BuildButtonPressed = false;
                    return;
                }

                if (_selected.Type == ConstructionType.Item)
                {
                    _constructionSystem.TryStartItemConstruction(_selected.ID);
                    _constructionView.BuildButtonPressed = false;
                    return;
                }

                _placementManager.BeginPlacing(new PlacementInformation
                {
                    IsTile = false,
                    PlacementOption = _selected.PlacementMode
                }, new ConstructionPlacementHijack(_constructionSystem, _selected));

                UpdateGhostPlacement();
            }
            else
                _placementManager.Clear();

            _constructionView.BuildButtonPressed = pressed;
        }

        private void UpdateGhostPlacement()
        {
            if (_selected == null || _selected.Type != ConstructionType.Structure) return;

            var constructSystem = EntitySystem.Get<ConstructionSystem>();

            _placementManager.BeginPlacing(new PlacementInformation()
            {
                IsTile = false,
                PlacementOption = _selected.PlacementMode,
            }, new ConstructionPlacementHijack(constructSystem, _selected));

            _constructionView.BuildButtonPressed = true;
        }

        private void OnSystemLoaded(object? sender, SystemChangedArgs args)
        {
            if (args.System is ConstructionSystem system) SystemBindingChanged(system);
        }

        private void OnSystemUnloaded(object? sender, SystemChangedArgs args)
        {
            if (args.System is ConstructionSystem) SystemBindingChanged(null);
        }

        private void SystemBindingChanged(ConstructionSystem? newSystem)
        {
            if (newSystem is null)
            {
                if (_constructionSystem is null)
                    return;

                UnbindFromSystem();
            }
            else
            {
                if (_constructionSystem is null)
                {
                    BindToSystem(newSystem);
                    return;
                }

                UnbindFromSystem();
                BindToSystem(newSystem);
            }
        }

        private void BindToSystem(ConstructionSystem system)
        {
            _constructionSystem = system;
            system.ToggleCraftingWindow += SystemOnToggleMenu;
            system.CraftingAvailabilityChanged += SystemCraftingAvailabilityChanged;
            system.ConstructionGuideAvailable += SystemGuideAvailable;
            CraftingAvailable = system.CraftingEnabled;
        }

        private void UnbindFromSystem()
        {
            var system = _constructionSystem;

            if (system is null)
                throw new InvalidOperationException();

            system.ToggleCraftingWindow -= SystemOnToggleMenu;
            system.CraftingAvailabilityChanged -= SystemCraftingAvailabilityChanged;
            system.ConstructionGuideAvailable -= SystemGuideAvailable;
            _constructionSystem = null;
        }

        private void SystemCraftingAvailabilityChanged(object? sender, CraftingAvailabilityChangedArgs e)
        {
            CraftingAvailable = e.Available;
        }

        private void SystemOnToggleMenu(object? sender, EventArgs eventArgs)
        {
            if (!CraftingAvailable)
                return;

            if (WindowOpen)
            {
                if (IsAtFront)
                {
                    WindowOpen = false;
                    _gameHud.CraftingButtonDown = false; // This does not call CraftingButtonToggled
                }
                else
                    _constructionView.MoveToFront();
            }
            else
            {
                WindowOpen = true;
                _gameHud.CraftingButtonDown = true; // This does not call CraftingButtonToggled
            }
        }

        private void SystemGuideAvailable(object? sender, string e)
        {
            if (!CraftingAvailable)
                return;

            if (!WindowOpen)
                return;

            if (_selected == null)
                return;

            PopulateInfo(_selected);
        }
    }
}