using System;
using System.Drawing;
using System.Windows.Forms;

namespace PaintDotNet.CustomControl
{
    //internal sealed class
    public partial class PicturePreviewAdjustControl : BaseUserControl// Control//
    {
        System.Drawing.Point mouseDownPoint;//存储鼠标焦点的全局变量
        bool isSelected = false;

        public bool isShown = false;

        /// <summary>
        /// 是否使用原图取色
        /// </summary>
        private bool item3Checked;
        /// <summary>
        /// 原图取色-鼠标点击事件
        /// </summary>
        public event MouseEventHandler item3MouseDown;
        private void InitializeLanguageText()
        {
            this.box_Picture.Text = PdnResources.GetString("Menu.Preview.text");
        }

        /// <summary>
        /// 图像处理的预览Control
        /// 包括放大、缩小、选择、移动
        /// </summary>
        public PicturePreviewAdjustControl()
        {
            InitializeComponent();

            if (!DesignMode)
            {
                InitializeLanguageText();

                this.ZoomInButton.Image = PdnResources.GetImageResource("Icons.MenuViewZoomInIcon.png").Reference;
                this.ZoomOutButton.Image = PdnResources.GetImageResource("Icons.MenuViewZoomOutIcon.png").Reference;
                this.MoveSelectionButton.Image = PdnResources.GetImageResource("Icons.MoveSelectionToolIcon.png").Reference;
                this.PanButton.Image = PdnResources.GetImageResource("Icons.PanToolIcon.png").Reference;
            }
        }

        //放大
        private void ZoomInButton_Click(object sender, EventArgs e)
        {
            Do.TryBool(ZoomInImpl);
        }
        //放大
        private void ZoomInImpl()
        {
            //int pictureBox1CenterX = pictureBox1.Location.X + pictureBox1.Width / 2;
            //int pictureBox1CenterY = pictureBox1.Location.Y + pictureBox1.Height / 2;
            double eDelta = pictureBox1.Height * 0.25;
            double scale = 1;
            if (pictureBox1.Height > 0)
            {
                scale = (double)pictureBox1.Width / (double)pictureBox1.Height;
            }
            pictureBox1.Width += (int)(eDelta * scale * 2);
            pictureBox1.Height += (int)(eDelta * 2);
            pictureBox1.Left -= (int)(eDelta * scale * 1);
            pictureBox1.Top -= (int)(eDelta * 1);
        }

        //缩小
        private void ZoomOutButton_Click(object sender, EventArgs e)
        {
            double eDelta = pictureBox1.Height * 0.16;// 0.25;
            double scale = 1;
            if (pictureBox1.Height > 0)
            {
                scale = (double)pictureBox1.Width / (double)pictureBox1.Height;
            }
            pictureBox1.Width -= (int)(eDelta * scale * 2);
            pictureBox1.Height -= (int)(eDelta * 2);
            pictureBox1.Left += (int)(eDelta * scale * 1);
            pictureBox1.Top += (int)(eDelta * 1);
        }

        //选择
        private void MoveSelectionButton_Click(object sender, EventArgs e)
        {
            if (this.item3Checked)
            {
                pictureBox1.Cursor = Cursors.Cross;
            }
            else
            {
                pictureBox1.Cursor = Cursors.Default;
            }
        }

        //移动
        private void PanButton_Click(object sender, EventArgs e)
        {
            pictureBox1.Cursor = new Cursor(PdnResources.GetResourceStream("Cursors.PanToolCursor.cur")); 
            //Cursors.Hand;
        }

        private void pictureBox1_Click(object sender, EventArgs e)
        {

        }

        private void pictureBox1_MouseWheel(object sender, MouseEventArgs e)
        {
            double scale = 1;
            if (pictureBox1.Height > 0)
            {
                scale = (double)pictureBox1.Width / (double)pictureBox1.Height;
            }
            if (pictureBox1.Width + (int)(e.Delta * scale) > 0 && pictureBox1.Height + e.Delta > 0)
            {
                pictureBox1.Width += (int)(e.Delta * scale);
                pictureBox1.Height += e.Delta;
                pictureBox1.Left -= (int)(e.Delta * scale * 0.5);
                pictureBox1.Top -= (int)(e.Delta * 0.5);
            }
        }

        //在MouseDown处获知鼠标是否按下，并记录下此时的鼠标坐标值；
        private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left && pictureBox1.Cursor == Cursors.Hand)
            {
                mouseDownPoint.X = Cursor.Position.X;  //注：全局变量mouseDownPoint前面已定义为Point类型  
                mouseDownPoint.Y = Cursor.Position.Y;
                isSelected = true;
            }
            else if (this.item3Checked && e.Button == MouseButtons.Left && pictureBox1.Cursor == Cursors.Cross)
            {
                //获取当前位置坐标
                Rectangle rc = this.pictureBox1.ClientRectangle;
                int width = (int)this.pictureBox1.Width;// (this.compositionSurface.Width * this.scaleFactor.Ratio);
                int height = (int)this.pictureBox1.Height;// (this.compositionSurface.Height * this.scaleFactor.Ratio);
                int x = 0;
                int y = 0;
                double radio = 1;
                //垂直方向有空白
                if ((this.pictureBox1.Image.Width / (double)this.pictureBox1.Width) > (this.pictureBox1.Image.Height / (double)this.pictureBox1.Height))
                {
                    y = (int)((height - width * this.pictureBox1.Image.Height / (double)this.pictureBox1.Image.Width) / 2.0);
                    radio = this.pictureBox1.Image.Width / (double)this.pictureBox1.Width;
                }
                else if ((this.pictureBox1.Image.Width / (double)this.pictureBox1.Width) < (this.pictureBox1.Image.Height / (double)this.pictureBox1.Height))
                {
                    x = (int)((width - height * this.pictureBox1.Image.Width / (double)this.pictureBox1.Image.Height) / 2.0);
                    radio = this.pictureBox1.Image.Height / (double)this.pictureBox1.Height;
                }
                //int x = (rc.Width < width) ? this.pictureBox1.Location.X/*this.panel.AutoScrollPosition.X + offsetHalfW*/ : (rc.Width - width) / 2;
                //int y = (rc.Height < height) ? this.pictureBox1.Location.Y/*this.panel.AutoScrollPosition.Y + offsetHalfH*/ : (rc.Height - height) / 2;
                Point point = e.Location;
                point.X -= x;
                point.Y -= y;

                Point newPoint = new Point((int)((long)point.X * radio), (int)((long)point.Y * radio));
                this.item3MouseDown?.Invoke(sender, new MouseEventArgs(e.Button, e.Clicks, newPoint.X, newPoint.Y, e.Delta));
            }
        }

        public void selectColorMode(bool selectColor)
        {
            this.item3Checked = selectColor;
            if (selectColor)
            {
                pictureBox1.Cursor = Cursors.Cross;
                this.MoveSelectionButton.Focus();
            }
            else
            {
                pictureBox1.Cursor = Cursors.Default;
            }
        }

        //在MouseUp处获知鼠标是否松开，终止拖动操作；
        private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
        {
            isSelected = false;
        }

        private bool IsMouseInPanel()
        {
            if (this.panel_Picture.Left + this.box_Picture.Left < PointToClient(Cursor.Position).X
                    && PointToClient(Cursor.Position).X < this.panel_Picture.Left + this.box_Picture.Left
                    + this.panel_Picture.Width && this.panel_Picture.Top + this.box_Picture.Top
                    < PointToClient(Cursor.Position).Y && PointToClient(Cursor.Position).Y
                    < this.panel_Picture.Top + this.box_Picture.Top + this.panel_Picture.Height)
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        //图片平移,在MouseMove处添加拖动函数操作
        private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
        {
            if (isSelected && IsMouseInPanel())//确定已经激发MouseDown事件，和鼠标在picturebox的范围内
            {
                this.pictureBox1.Left = this.pictureBox1.Left + (Cursor.Position.X - mouseDownPoint.X);
                this.pictureBox1.Top = this.pictureBox1.Top + (Cursor.Position.Y - mouseDownPoint.Y);
                mouseDownPoint.X = Cursor.Position.X;
                mouseDownPoint.Y = Cursor.Position.Y;
            }
        }

        private void picturePreviewAdjustControl_Resize(object sender, EventArgs e)
        {
            if (isShown)
            {
                this.pictureBox1.Left = 0;
                this.pictureBox1.Top = 0;
                this.pictureBox1.Width = panel_Picture.Width;
                this.pictureBox1.Height = panel_Picture.Height;
            }
        }

        private void box_Picture_Enter(object sender, EventArgs e)
        {

        }
    }
}