using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using VBXSE;

namespace WorldOfMinimalism
{
    public class Window
    {
        public string id = "window"; //To prevent opening multiple of the same type
        public bool allowMultiple = false; //True to allow opening multiple instances of this window

        public int x = 0;
        public int y = 0;
        public int width = 0;
        public int height = 0;

        public int innerX = 1; //Where the frame ends and the window starts
        public int innerY = 15;
        public int innerWidth = 0; //Size of inner window (i.e. non-frame)
        public int innerHeight = 0;

        public Sprite frame = null;

        public bool readyForClose = false;
        
        //For holding, register the cursor's last position
        protected int lastX = 0;
        protected int lastY = 0;
        protected int lastInnerX = 0;
        protected int lastInnerY = 0;

        public bool CheckForClick(int x, int y)
        {
            //Check if it's inside window
            if (IsInsideWindow(x, y))
            {
                //Then check if it's on inner window
                int offsetX = GetInnerOffsetX(x);
                int offsetY = GetInnerOffsetY(y);

                if (IsInInnerWindow(offsetX, offsetY))
                {
                    OnClick(offsetX, offsetY);
                }
                else OnFrameClick(x - this.x, y - this.y);

                //Store information for hold
                lastX = x;
                lastY = y;
                lastInnerX = offsetX;
                lastInnerY = offsetY;

                //Regardless of where it clicked, it was part of the window - return true to stop further checking
                return true;
            }
            else return false;
        }

        public bool CheckForHold(int x, int y)
        {
            //Check if it's outside of window
            if (!IsInsideWindow(x, y)) return false;

            //Then check if it's on inner window
            int offsetX = GetInnerOffsetX(x);
            int offsetY = GetInnerOffsetY(y);

            if (IsInInnerWindow(offsetX, offsetY))
            {
                OnHold(offsetX, offsetY);
            }
            else
            {
                int changeX = x - lastX;
                int changeY = y - lastY;
                this.Move(changeX, changeY);
            }

            //Store information for hold
            lastX = x;
            lastY = y;
            lastInnerX = offsetX;
            lastInnerY = offsetY;

            return true;
        }

        public bool CheckForRightClick(int x, int y)
        {
            if (IsInsideWindow(x, y))
            {
                CloseWindow();
                return true;
            }

            return false;
        }

        public bool IsInsideWindow(int x, int y)
        {
            if (x < this.x) return false;
            else if (y < this.y) return false;
            else if (x > this.x + this.width) return false;
            else if (y > this.y + this.height) return false;
            else return true;
        }

        public int GetInnerOffsetX(int x)
        {
            return x - (this.x + this.innerX);
        }

        public int GetInnerOffsetY(int y)
        {
            return y - (this.y + this.innerY);
        }

        public bool IsInInnerWindow(int offsetX, int offsetY)
        {
            return (offsetX >= 0 && offsetX < innerWidth && offsetY >= 0 && offsetY < innerHeight);
        }

        //Handles left click inside the inner window
        public virtual void OnClick(int x, int y)
        {
            //Inherit this
        }

        //Handles left click outside of the inner window
        public virtual bool OnFrameClick(int x, int y)
        {
            return false;
        }

        //Handles holding LMB inside the inner window
        public virtual void OnHold(int x, int y)
        {
            //Inherit this
        }

        //Move the window and all sprites within it. Don't forget to inherit!
        public virtual void Move(int diffX, int diffY)
        {
            this.x += diffX;
            this.y += diffY;
            this.frame.SetPosition(this.frame.position.X + diffX, this.frame.position.Y + diffY);
        }

        //Code to execute when the window is closed - inherit to also clean up custom stuff
        public virtual void OnClose()
        {
            SpriteEngine.EraseGObject(frame);
        }

        public void CloseWindow()
        {
            OnClose();
            this.readyForClose = true;
        }
    }
}