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 IResourceCache _resourceCache = 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();
                }
                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.CategoryButton.Clear();

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

            for (var i = 0; i < array.Length; i++)
            {
                var category = array[i];
                _constructionView.CategoryButton.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 (!_prototypeManager.TryIndex(prototype.Graph, out ConstructionGraphPrototype? graph))
                return;

            var startNode = graph.Nodes[prototype.StartNode];
            var targetNode = graph.Nodes[prototype.TargetNode];

            if (!graph.TryPath(startNode.Name, targetNode.Name, out var path))
            {
                return;
            }

            var current = startNode;
            var stepNumber = 1;

            foreach (var node in path)
            {
                if (!current.TryGetEdge(node.Name, out var edge))
                {
                    continue;
                }

                var firstNode = current == startNode;

                if (firstNode)
                {
                    stepList.AddItem(prototype.Type == ConstructionType.Item
                        ? Loc.GetString($"construction-presenter-to-craft", ("step-number", stepNumber++))
                        : Loc.GetString($"construction-presenter-to-build", ("step-number", stepNumber++)));
                }

                foreach (var step in edge.Steps)
                {
                    var icon = GetTextureForStep(_resourceCache, step);

                    switch (step)
                    {
                        case MaterialConstructionGraphStep materialStep:
                            stepList.AddItem(
                                !firstNode
                                    ? Loc.GetString(
                                        "construction-presenter-material-step",
                                        ("step-number", stepNumber++),
                                        ("amount", materialStep.Amount),
                                        ("material", materialStep.MaterialPrototype.Name))
                                    : Loc.GetString(
                                        "construction-presenter-material-first-step",
                                        ("amount", materialStep.Amount),
                                        ("material", materialStep.MaterialPrototype.Name)),
                                    icon);

                            break;

                        case ToolConstructionGraphStep toolStep:
                            stepList.AddItem(Loc.GetString(
                                                 "construction-presenter-tool-step",
                                                 ("step-number", stepNumber++),
                                                 ("tool", Loc.GetString(_prototypeManager.Index<ToolQualityPrototype>(toolStep.Tool).ToolName))),
                                             icon);
                            break;

                        case ArbitraryInsertConstructionGraphStep arbitraryStep:
                            stepList.AddItem(Loc.GetString(
                                                 "construction-presenter-arbitrary-step",
                                                 ("step-number", stepNumber++),
                                                 ("name", arbitraryStep.Name)),
                                             icon);
                            break;
                    }
                }

                current = node;
            }
        }

        private Texture? GetTextureForStep(IResourceCache resourceCache, ConstructionGraphStep step)
        {
            switch (step)
            {
                case MaterialConstructionGraphStep materialStep:
                    return materialStep.MaterialPrototype.Icon?.Frame0();

                case ToolConstructionGraphStep toolStep:
                    return _prototypeManager.Index<ToolQualityPrototype>(toolStep.Tool).Icon?.Frame0();

                case ArbitraryInsertConstructionGraphStep arbitraryStep:
                    return arbitraryStep.Icon?.Frame0();
            }

            return null;
        }

        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;
            CraftingAvailable = system.CraftingEnabled;
        }

        private void UnbindFromSystem()
        {
            var system = _constructionSystem;

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

            system.ToggleCraftingWindow -= SystemOnToggleMenu;
            system.CraftingAvailabilityChanged -= SystemCraftingAvailabilityChanged;
            _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
            }
        }
    }
}