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

namespace MrAG {
    public partial class Gui {
        public class Key {
            public bool Shift, Alt, Ctrl;
            public string Letter;
            public int Char;
        }

        public enum MouseKey : byte {Left = 1, Right = 2, Middle = 3}
        public static MouseState CurMouseState = Mouse.GetState();
        public static System.Windows.Forms.Form MainForm;
        
        public static Action<int, int, MouseKey> OnScreenMouseClick;
        public static Action<int, int, MouseKey> OnScreenMouseUp;
        public static Action<int, int, MouseKey> OnScreenMouseDown;
        public static Action<Key> OnScreenKeyPress;

        public static bool AcceptInput = true;

        
        private static List<Gui.Base> Objects = new List<Base>();
        private static int curscrollval = 0;
        private static Base _currentfocus;
        internal static bool BroughtToFront;

        public static Base CurrentFocus{
            get {
                return _currentfocus;
            }
            set {
                if (_currentfocus != null) {
                    _currentfocus.FocusLost();

                    if (_currentfocus.OnUnFocus != null)
                        _currentfocus.OnUnFocus.Invoke();
                }

                _currentfocus = value;
                
                if (_currentfocus != null){
                    _currentfocus.FocusGained();

                    if (_currentfocus.OnFocus != null)
                        _currentfocus.OnFocus.Invoke();
                }
            }
        }

        public static void Initialize(GameWindow w) {
            MainForm = (System.Windows.Forms.Form)System.Windows.Forms.Form.FromHandle(w.Handle);

            MainForm.KeyPreview = true;
            MainForm.PreviewKeyDown += new System.Windows.Forms.PreviewKeyDownEventHandler(KeyPress);
            MainForm.MouseClick += new System.Windows.Forms.MouseEventHandler(MouseClick);
            MainForm.MouseDoubleClick += new System.Windows.Forms.MouseEventHandler(MouseDoubleClick);
            MainForm.MouseUp += new System.Windows.Forms.MouseEventHandler(MouseUp);
            MainForm.MouseDown += new System.Windows.Forms.MouseEventHandler(MouseDown);
        }

        public static void AddObject(Gui.Base obj) {
            obj.Removed = false;

            Objects.Add(obj);
        }

        public static void RemoveObject(Gui.Base obj) {
            obj.Removed = true;

            if (obj.Parent != null) {
                obj.Parent.Children.Remove(obj);
            } else {
                Objects.Remove(obj);
            }
        }

        public static void Draw() {
            for (int i = 0; i < Objects.Count; i++){
                if (Objects[i].Render){
                    Objects[i].Draw();

                    if (BroughtToFront){
                        BroughtToFront = false;
                        i--;
                    }
                }
            }
        }

        public static string ParseOemKey(string Input, bool Shift)
        {
            switch (Input)
            {
                case "Space": return " ";
                case "Tab": return "    ";
                case "OemMinus": return Shift ? "_" : "-";
                case "Oemplus": return Shift ? "+" : "=";
                case "OemPeriod": return Shift ? ">" : ".";
                case "Oemcomma": return Shift ? "<" : ",";
                case "OemQuestion": return Shift ? "?" : "/";
                case "OemOpenBrackets": return Shift ? "{" : "[";
                case "Oem1": return Shift ? ":" : ";";
                case "Oem5": return Shift ? "|" : "\\";
                case "Oem6": return Shift ? "}" : "]";
                case "Oem7": return Shift ? "\"" : "'";
                case "Return": return "\n";
                case "ShiftKey": return "";
                case "Back": return "Backspace";
            }

            return "";
        }

        public static string ParseNumberKey(string Input, bool Shift)
        {
            int Num = int.Parse(Input[Input.Length - 1].ToString());

            if (Shift)
            {
                switch (int.Parse(Input[1].ToString()))
                {
                    case 1: return "!";
                    case 2: return "@";
                    case 3: return "#";
                    case 4: return "$";
                    case 5: return "%";
                    case 6: return "^";
                    case 7: return "&";
                    case 8: return "*";
                    case 9: return "(";
                    case 0: return ")";
                }
            }
            else
                return Num.ToString();

            return "";
        }

        private static void KeyPress(object sender, System.Windows.Forms.PreviewKeyDownEventArgs args) {
            string letter = "";
            string[] Parts = args.KeyData.ToString().Split(new string[] { ", " }, StringSplitOptions.None);

            if (Parts[0].Length == 1)
            {
                if (args.Shift)
                    letter += Parts[0].ToUpper();
                else
                    letter += Parts[0].ToLower();
            }
            else if ((Parts[0].Length == 2 && Parts[0][0] == 'D') || Parts[0].StartsWith("NumPad"))
                letter += ParseNumberKey(Parts[0], args.Shift);
            else
            {
                letter += ParseOemKey(Parts[0], args.Shift);
            }


            Key keypressed = new Key {
                Alt = args.Alt,
                Ctrl = args.Control,
                Shift = args.Shift,
                Letter = letter,
                Char = (int)args.KeyCode
            };

            if (CurrentFocus != null && CurrentFocus.Render && AcceptInput) {
                if (CurrentFocus.Enabled){
                    CurrentFocus.KeyPress(keypressed);

                    if (CurrentFocus.OnKeyPress != null)
                        CurrentFocus.OnKeyPress.Invoke();
                }
            } else {
                if (OnScreenKeyPress != null)
                    OnScreenKeyPress.Invoke(keypressed);
            }
        }

        private static void MouseClick(object sender, System.Windows.Forms.MouseEventArgs args) {
            if (AcceptInput){
                byte btn = 0;
                switch (args.Button) {
                    case System.Windows.Forms.MouseButtons.Left:
                        btn = 1;
                        break;

                    case System.Windows.Forms.MouseButtons.Right:
                        btn = 2;
                        break;

                    case System.Windows.Forms.MouseButtons.Middle:
                        btn = 3;
                        break;
                }

                if (CurrentFocus != null) {
                    if (CurrentFocus.Hovering()) {
                        if (!DoMouseAction(CurrentFocus, btn, 2)) {
                            if (OnScreenMouseClick != null)
                                OnScreenMouseClick.Invoke(args.X, args.Y, (MouseKey)btn);
                        }
                    } else {
                        CurrentFocus = null;
                    }
                } else {
                    if (OnScreenMouseClick != null)
                        OnScreenMouseClick.Invoke(args.X, args.Y, (MouseKey)btn);
                }
            }
        }

        private static void MouseDoubleClick(object sender, System.Windows.Forms.MouseEventArgs args) {
            if (AcceptInput){
                byte btn = 0;
                switch (args.Button) {
                    case System.Windows.Forms.MouseButtons.Left:
                        btn = 1;
                        break;

                    case System.Windows.Forms.MouseButtons.Right:
                        btn = 2;
                        break;

                    case System.Windows.Forms.MouseButtons.Middle:
                        btn = 3;
                        break;
                }

                if (CurrentFocus != null) {
                    if (CurrentFocus.Hovering()) {
                        if (!DoMouseAction(CurrentFocus, btn, 3)) {
                            if (OnScreenMouseClick != null)
                                OnScreenMouseClick.Invoke(args.X, args.Y, (MouseKey)btn);
                        }
                    } else {
                        CurrentFocus = null;
                    }
                } else {
                    if (OnScreenMouseClick != null)
                        OnScreenMouseClick.Invoke(args.X, args.Y, (MouseKey)btn);
                }
            }
        }

        private static void MouseUp(object sender, System.Windows.Forms.MouseEventArgs args) {
            if (AcceptInput){
                byte btn = 0;
                switch (args.Button) {
                    case System.Windows.Forms.MouseButtons.Left:
                        btn = 1;
                        break;

                    case System.Windows.Forms.MouseButtons.Right:
                        btn = 2;
                        break;

                    case System.Windows.Forms.MouseButtons.Middle:
                        btn = 3;
                        break;
                }

                if (CurrentFocus != null){
                    if (CurrentFocus.Hovering()) {
                        if (!DoMouseAction(CurrentFocus, btn, 1)) {
                            if (OnScreenMouseUp != null)
                                OnScreenMouseUp.Invoke(args.X, args.Y, (MouseKey)btn);
                        }
                    } else {
                        CurrentFocus = null;
                    }
                }else{
                    if (OnScreenMouseUp != null)
                        OnScreenMouseUp.Invoke(args.X, args.Y, (MouseKey)btn);
                }
            }
        }

        private static void MouseDown(object sender, System.Windows.Forms.MouseEventArgs args) {
            byte btn = 0;
            switch (args.Button) {
                case System.Windows.Forms.MouseButtons.Left:
                    btn = 1;
                    break;

                case System.Windows.Forms.MouseButtons.Right:
                    btn = 2;
                    break;

                case System.Windows.Forms.MouseButtons.Middle:
                    btn = 3;
                    break;
            }

            if (AcceptInput){
                CurrentFocus = null;

                for(int i = Objects.Count - 1; i > -1; i--)
                    if (DoMouseAction(Objects[i], btn, 0))
                        return;
            }

            if (OnScreenMouseDown != null)
                OnScreenMouseDown.Invoke(args.X, args.Y, (MouseKey)btn);
        }

        private static bool DoMouseAction(Base obj, byte btn, byte press){
            if (!obj.Render || !obj.Enabled) return false;
            
            int x = MrAG.Gui.CurMouseState.X;
            int y = MrAG.Gui.CurMouseState.Y;

            bool yes = false;
            for(int i = obj.Children.Count - 1; i > -1; i--){
                if (DoMouseAction(obj.Children[i], btn, press)){
                    yes = true;
                    break;
                }
            }

            if (!yes)
                if (obj.Hovering()){
                    yes = true;
                    CurrentFocus = obj;
                    obj.SetFocus();
                    if (press != 1)obj.BringToFront();

                    if (obj.Enabled) {
                        switch (press){
                            case 0:
                                switch (btn) {
                                    case 1:
                                        obj.LeftMousePress(x - obj.X, y - obj.Y);
                                        if (obj.OnLeftMousePress != null) obj.OnLeftMousePress.Invoke();
                                        if (obj.OnArgumentedLeftMousePress != null) obj.OnArgumentedLeftMousePress.Invoke(obj);
                                        break;

                                    case 2:
                                        obj.RightMousePress(x - obj.X, y - obj.Y);
                                        if (obj.OnRightMousePress != null) obj.OnRightMousePress.Invoke();
                                        if (obj.OnArgumentedRightMousePress != null) obj.OnArgumentedRightMousePress.Invoke(obj);
                                        break;

                                    case 3:
                                        obj.MiddleMousePress(x - obj.X, y - obj.Y);
                                        if (obj.OnLeftMousePress != null) obj.OnLeftMousePress.Invoke();
                                        if (obj.OnArgumentedLeftMousePress != null) obj.OnArgumentedLeftMousePress.Invoke(obj);
                                        break;
                                }
                                break;

                            case 1:
                                switch (btn) {
                                    case 1:
                                        obj.LeftMouseRelease(x - obj.X, y - obj.Y);
                                        if (obj.OnLeftMouseRelease != null) obj.OnLeftMouseRelease.Invoke();
                                        if (obj.OnArgumentedLeftMouseRelease != null) obj.OnArgumentedLeftMouseRelease.Invoke(obj);
                                        break;

                                    case 2:
                                        obj.RightMouseRelease(x - obj.X, y - obj.Y);
                                        if (obj.OnRightMouseRelease != null) obj.OnRightMouseRelease.Invoke();
                                        if (obj.OnArgumentedRightMouseRelease != null) obj.OnArgumentedRightMouseRelease.Invoke(obj);
                                        break;

                                    case 3:
                                        obj.MiddleMouseRelease(x - obj.X, y - obj.Y);
                                        if (obj.OnLeftMouseRelease != null) obj.OnLeftMouseRelease.Invoke();
                                        if (obj.OnArgumentedLeftMouseRelease != null) obj.OnArgumentedLeftMouseRelease.Invoke(obj);
                                        break;
                                }
                                break;

                            case 2:
                                obj.DoClick(x - obj.X, y - obj.Y, (MouseKey)btn);
                                switch (btn) {
                                    case 1:
                                        obj.LeftMouseClick(x - obj.X, y - obj.Y);
                                        if (obj.OnLeftMouseClick != null) obj.OnLeftMouseClick.Invoke();
                                        if (obj.OnArgumentedLeftMouseClick != null) obj.OnArgumentedLeftMouseClick.Invoke(obj);
                                        break;

                                    case 2:
                                        obj.RightMouseClick(x - obj.X, y - obj.Y);
                                        if (obj.OnRightMouseClick != null) obj.OnRightMouseClick.Invoke();
                                        if (obj.OnArgumentedRightMouseClick != null) obj.OnArgumentedRightMouseClick.Invoke(obj);
                                        break;

                                    case 3:
                                        obj.MiddleMouseClick(x - obj.X, y - obj.Y);
                                        if (obj.OnLeftMouseClick != null) obj.OnLeftMouseClick.Invoke();
                                        if (obj.OnArgumentedLeftMouseClick != null) obj.OnArgumentedLeftMouseClick.Invoke(obj);
                                        break;
                                }
                                break;

                            case 3:
                                obj.DoDoubleClick(x - obj.X, y - obj.Y, (MouseKey)btn);
                                switch (btn) {
                                    case 1:
                                        obj.LeftMouseClick(x - obj.X, y - obj.Y);
                                        if (obj.OnLeftDoubleMouseClick != null) obj.OnLeftDoubleMouseClick.Invoke();
                                        if (obj.OnArgumentedLeftDoubleMouseClick != null) obj.OnArgumentedLeftDoubleMouseClick.Invoke(obj);
                                        break;

                                    case 2:
                                        obj.RightMouseClick(x - obj.X, y - obj.Y);
                                        if (obj.OnRightDoubleMouseClick != null) obj.OnRightDoubleMouseClick.Invoke();
                                        if (obj.OnArgumentedRightDoubleMouseClick != null) obj.OnArgumentedRightDoubleMouseClick.Invoke(obj);
                                        break;

                                    case 3:
                                        obj.MiddleMouseClick(x - obj.X, y - obj.Y);
                                        if (obj.OnLeftDoubleMouseClick != null) obj.OnLeftDoubleMouseClick.Invoke();
                                        if (obj.OnArgumentedLeftDoubleMouseClick != null) obj.OnArgumentedLeftDoubleMouseClick.Invoke(obj);
                                        break;
                                }
                                break;
                        }
                    }
                }
            
            return yes;
        }

        public static void Update() {
            CurMouseState = Mouse.GetState();

            int scrollrem = curscrollval - CurMouseState.ScrollWheelValue;
            if (scrollrem != 0) {
                if (CurrentFocus != null) {
                    bool up = scrollrem < 0;
                    if (scrollrem < 0)
                        scrollrem = -scrollrem;

                    while (scrollrem > 0) {
                        if (up) {
                            CurrentFocus.DoScrollUp();

                            if (CurrentFocus.OnScrollUp != null)
                                CurrentFocus.OnScrollUp.Invoke();
                        
                        } else {
                            CurrentFocus.DoScrollDown();

                            if (CurrentFocus.OnScrollDown != null)
                                CurrentFocus.OnScrollDown.Invoke();
                        }

                        scrollrem -= 120;
                    }
                }

                curscrollval = CurMouseState.ScrollWheelValue;
            }

            for (int i = 0; i < Objects.Count; i++){
                Objects[i].Update();

                if (BroughtToFront){
                    BroughtToFront = false;
                    i--;
                }
            }
        }
    }
}