using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using MonoGameLibrary.Input;

namespace ONDClient.GUI;


public class Screen {
    
    private static Dictionary<string, Screen> screens = new();
    public static Screen CurrentScreen{ get; private set; } = Empty;
    public static Screen OverlayScreen{ get; private set; } = Empty;
        
    public static void AddScreens(Screen[] screensToAdd) {
        foreach (var screen in screensToAdd){
            Screen.screens.Add(screen.Label, screen);
        }
    }
    public static void AddScreen(string id, Screen screen, bool activate = false) {
        screens.Add(id, screen);
        if (activate) SetScreen(id);
    }
    
    public static void SetScreen(string id) {
        if (CurrentScreen.temporary){
            screens.Remove(CurrentScreen.Label);
        }
        
        CurrentScreen.Active = false;
        CurrentScreen = screens[id];
        CurrentScreen.Active = true;
    }
    
    public static void RemoveScreen(string id) {
        screens.Remove(id); 
    }

    public static void UpdateAll() {
        foreach (var screen in screens.Values){
            if (!screen.Active) continue;
            screen.Update();
        }
    }
    public static Screen Empty => new(""){temporary = true};

    public static void SetOverlayScreen(string id) {
        if (OverlayScreen.temporary){
            screens.Remove(OverlayScreen.Label);
        }

        OverlayScreen.Active = false;
        OverlayScreen = screens[id];
        OverlayScreen.Active = true;
    }

    public static void DisableOverlay() {
        OverlayScreen = Empty;
    }

    public static void DrawCurrentAndOverlay(SpriteBatch spriteBatch) {
        CurrentScreen.Draw(spriteBatch);
        OverlayScreen.Draw(spriteBatch);
    }

    public static Screen[] GetAllScreens() => screens.Values.ToArray();
    
    

    public string Label{ get; }
    private Dictionary<string, UIElement> elements = new();
    private List<UIElement> elementsInDrawOrder = new();
    
    public bool Active { get; private set; } = false;
    private InputListenerHook mouseInputHook = new(true);
    private bool temporary = false;
    
    private List<string> temporaryElements = new();
        
    public Screen(string label) {
        Label = label;
        InputManager.AddListener(InputManager.MouseButton.LEFT, () => ProcessMouseInput(InputManager.MouseState), InputTiming.PRESS, mouseInputHook);
    }

    public Screen(string label, Dictionary<string, UIElement> elements) {
        this.elements = elements;
        Label = label;
    }
    
    public UIElement this[string id] => elements[id];
    public UIElement TryGetElement(string id) => elements.TryGetValue(id, out var val) ? val : null;

    public UIElement AddElement(string id, UIElement element, bool temporary = false) {
        elements.Add(id, element);
        
        int insertIndex = elementsInDrawOrder.FindLastIndex(e => e.DrawPriority == element.DrawPriority);
        if (insertIndex == -1){
            elementsInDrawOrder.Add(element);
        }
        else{
            elementsInDrawOrder.Insert(insertIndex + 1, element);
        }

        if (temporary){
            temporaryElements.Add(id);
        }
        
        return element;
    }
    
    public void RemoveElement(string id) {
        if (!elements.ContainsKey(id)) return;
        elements.Remove(id, out var element);
        elementsInDrawOrder.RemoveAll(e => e == element);
    }

    public void RemoveTemporary() {
        temporaryElements.ForEach(RemoveElement);
        temporaryElements.Clear();
    }

    private void ProcessMouseInput(MouseState mouseState) {
        if (!Active){
            return;
        }
        foreach (var element in elements.Values){
            if (!element.Pressable) continue;
            
            if (element.IsWithinBounds(mouseState.Position)){
                element.OnMousePress();
            }
        }
    }

    private void Update() {
        foreach (var element in elements.Values){
            if (!element.Active) continue;
            element.Update();
        }
    }

    private void Draw(SpriteBatch spriteBatch) {
        foreach (var val in elementsInDrawOrder){
            val.Draw(spriteBatch);
        }
    }
}