using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Asa.FaceControl
{
    public partial class FormBase : Form
    {
        //=====属性变量=====
        private int _borderWidth = 2;
        private Bitmap _iconBmp = null;
        private Font _titleFont = new("宋体", 12f);
        private int _titleHeight = 36;

        //=====私有变量=====
        private CursorPlace place;
        private RectangleF borderRect;
        private RectangleF iconRect;
        private RectangleF titleTextRect;
        private Rectangle windowRect;
        private Bitmap iconGrayBmp;
        private bool formActivated = true;
        private readonly SolidBrush BRUSH_TEXT;
        private readonly SolidBrush BRUSH_TEXT_DISABLED;

        //=====子类变量=====
        internal IFaceThemeColor theme;

        public FormBase()
        {
            InitializeComponent();

            theme = new DarkThemeColor();
            BRUSH_TEXT = new SolidBrush(theme.FORE);
            BRUSH_TEXT_DISABLED = new SolidBrush(theme.DISABLED);

            AutoScaleMode = AutoScaleMode.None;
            BackColor = theme.BACK;
            ForeColor = theme.FORE;
            Padding = new Padding(6 + _borderWidth);
            _iconBmp = base.Icon.ToBitmap();
            iconGrayBmp = ImageConvert.ToDisabledGray(_iconBmp, 0);

            Activated += FormBase_Activated;
            Deactivate += FormBase_Deactivate;
        }





        //=====公共方法=====
        public Bitmap ToImage()
        {
            IntPtr hSrce = API.GetWindowDC(Handle);
            IntPtr hDest = API.CreateCompatibleDC(hSrce);
            IntPtr hBmp = API.CreateCompatibleBitmap(hSrce, Width, Height);
            IntPtr hOldBmp = API.SelectObject(hDest, hBmp);
            if (API.BitBlt(hDest, 0, 0, Width, Height, hSrce, 0, 0, CopyPixelOperation.SourceCopy | CopyPixelOperation.CaptureBlt))
            {
                Bitmap bmp = Image.FromHbitmap(hBmp);
                API.SelectObject(hDest, hOldBmp);
                API.DeleteObject(hBmp);
                API.DeleteDC(hDest);
                API.ReleaseDC(Handle, hSrce);
                return bmp;
            }
            return null;
        }

        public void Maximize()
        {
            windowRect = new Rectangle(Location, Size);
            Screen screen = Screen.FromControl(this);
            Top = screen.WorkingArea.Top;
            Left = screen.WorkingArea.Left;
            Width = screen.WorkingArea.Width;
            Height = screen.WorkingArea.Height;
            IsMaximized = true;
        }

        public void Restore()
        {
            Left = windowRect.Left;
            Top = windowRect.Top;
            Width = windowRect.Width;
            Height = windowRect.Height;
            IsMaximized = false;
        }



        //=====子类方法=====
        protected virtual void CalcSize()
        {
            //边框位置
            float x = _borderWidth / 2f;
            float y = _borderWidth / 2f;
            float width = ClientSize.Width - _borderWidth - 1;
            float height = ClientSize.Height - _borderWidth - 1;
            borderRect = new RectangleF(x, y, width, height);
            //titleRect = new RectangleF(x, y, width, _titleHeight);

            //标题文本位置
            using Graphics g = CreateGraphics();
            SizeF sf = g.MeasureString(Text, _titleFont);
            x = (Width - sf.Width) / 2f;
            y = (_titleHeight - sf.Height) / 2f;
            titleTextRect = new RectangleF(x, y, sf.Width, sf.Height);

            //图标位置
            if (_iconBmp != null)
            {
                height = _titleHeight - 6;
                width = _iconBmp.Width * height / _iconBmp.Height;
                iconRect = new RectangleF(borderRect.X + 3, borderRect.Y + 3, width, height);
            }
        }

        protected virtual void DrawEnabled(Graphics g)
        {
        }

        protected virtual void DrawDisabled(Graphics g)
        {
        }



        //=====事件=====
        [Browsable(true)]
        public new event EventHandler TextChanged;
        [Browsable(true)]
        public event EventHandler BorderWidthChanged;



        //=====属性=====
        [Browsable(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public int BorderWidth
        {
            get => _borderWidth;
            set
            {
                _borderWidth = value > 0 ? value : 0;
                Padding = new Padding(6 + _borderWidth);
                CalcSize();
                Refresh();
                BorderWidthChanged?.Invoke(this, new EventArgs());
            }
        }

        [Browsable(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public override string Text
        {
            get => base.Text;
            set
            {
                base.Text = value;
                CalcSize();
                Refresh();
                TextChanged?.Invoke(this, new EventArgs());
            }
        }

        [Browsable(true), Category(""), Description("图标"), DefaultValue(null)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public new Bitmap Icon
        {
            get => _iconBmp;
            set
            {
                _iconBmp = value;
                iconGrayBmp = ImageConvert.ToDisabledGray(_iconBmp, 0);
                CalcSize();
                Refresh();
            }
        }

        [Browsable(true), Category("Title"), Description("标题字体")]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public Font TitleFont
        {
            get => _titleFont;
            set
            {
                _titleFont = value;
                CalcSize();
                Refresh();
            }
        }

        [Browsable(true), Category("Title"), Description("标题栏高度"), DefaultValue(36)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public int TitleHeight
        {
            get => _titleHeight;
            set
            {
                _titleHeight = value;
                CalcSize();
                Refresh();
            }
        }

        [Browsable(false)]
        public new Font Font { get; set; }

        internal bool IsMaximized { get; set; } = false;

        internal bool CanResize { get; set; } = true;


        public void SetLostFocus(Control ctl, IntPtr ptr)
        {
            foreach (Control list in ctl.Controls)
            {
                if (list is ControlBase control)
                {
                    if (control.Handle == ptr) continue;
                    control.LostFocused();
                }
                else if (list is PanelBase)
                {
                    SetLostFocus(list, ptr);
                }
            }
        }



        private void DrawBorder(Graphics g)
        {
            if (_borderWidth > 0)
            {
                Pen borderPen = new(formActivated ? theme.BORDER_ENTER : theme.BORDER_LEAVE, _borderWidth);
                g.DrawRectangle(borderPen, borderRect.X, borderRect.Y, borderRect.Width, borderRect.Height);
            }

        }

        private void DrawTitle(Graphics g)
        {
            if (_iconBmp != null)
                g.DrawImage(formActivated ? _iconBmp : iconGrayBmp, iconRect, new RectangleF(0, 0, _iconBmp.Width, _iconBmp.Height), GraphicsUnit.Pixel);
            if (formActivated)
                g.DrawString(Text, _titleFont, BRUSH_TEXT, titleTextRect);
            else
                g.DrawString(Text, _titleFont, BRUSH_TEXT_DISABLED, titleTextRect);
        }

        private void ChangeMouseCursor(Point pt)
        {
            int space = 6;
            Cursor cursor = Cursors.Default;

            if (CanResize)
            {
                if (pt.X <= space && pt.Y <= space)  //左上角
                {
                    cursor = Cursors.SizeNWSE;
                    place = CursorPlace.LeftTop;
                }
                else if (pt.X > space && pt.X < Width - space && pt.Y <= space)  //上边
                {
                    cursor = Cursors.SizeNS;
                    place = CursorPlace.Top;
                }
                else if (pt.X >= Width - space && pt.Y <= space)  //右上角
                {
                    cursor = Cursors.SizeNESW;
                    place = CursorPlace.RightTop;
                }
                else if (pt.X <= space && pt.Y > space && pt.Y < Height - space)  //左边
                {
                    cursor = Cursors.SizeWE;
                    place = CursorPlace.Left;
                }
                else if (pt.X >= Width - space && pt.Y > space && pt.Y < Height - space)  //右边
                {
                    cursor = Cursors.SizeWE;
                    place = CursorPlace.Right;
                }
                else if (pt.X <= space && pt.Y >= Height - space)  //左下角
                {
                    cursor = Cursors.SizeNESW;
                    place = CursorPlace.LeftBottom;
                }
                else if (pt.X > space && pt.X < Width - space && pt.Y >= Height - space)  //下边
                {
                    cursor = Cursors.SizeNS;
                    place = CursorPlace.Bottom;
                }
                else if (pt.X >= Width - space - space && pt.Y >= Height - space - space)  //右下角
                {
                    cursor = Cursors.SizeNWSE;
                    place = CursorPlace.RightBottom;
                }
                else if (pt.X > space && pt.X < Width - space && pt.Y > space && pt.Y < _titleHeight)  //标题栏
                {
                    cursor = Cursors.Default;
                    place = CursorPlace.Inside;
                }
                else if (pt.X > space && pt.X < Width - space && pt.Y > _titleHeight && pt.Y < Height - space)  //中间
                {
                    cursor = Cursors.Default;
                    place = CursorPlace.None;
                }
            }
            else
            {
                if (pt.X > space && pt.X < Width - space && pt.Y > space && pt.Y < _titleHeight)  //标题栏
                {
                    cursor = Cursors.Default;
                    place = CursorPlace.Inside;
                }
                else
                {
                    cursor = Cursors.Default;
                    place = CursorPlace.None;
                }
            }

            if (cursor != Cursor)
                Cursor = cursor;
        }

        private void ChangeFormSize()
        {
            if (place == CursorPlace.None)
                return;
            API.ReleaseCapture();
            API.SendMessage(Handle, API.WM_SYSCOMMAND, (int)place, 0);
        }



        protected override void WndProc(ref Message m)
        {
            if (m.Msg == 0x0014)  //禁掉清除背景消息
                return;
            base.WndProc(ref m);
        }

        private void FormBase_Load(object sender, EventArgs e)
        {
            CalcSize();
            Refresh();

            //居中屏幕
            if (!DesignMode)
            {
                Screen screen = Screen.FromControl(this);
                int x = (screen.WorkingArea.Width - Width) / 2;
                int y = (screen.WorkingArea.Height - Height) / 2;
                Location = new Point(x, y);
            }

            windowRect = new Rectangle(Location, Size);
            Language.SetLanguage(this);
        }

        private void FormBase_Resize(object sender, EventArgs e)
        {
            CalcSize();
            Refresh();
        }

        private void FormBase_Paint(object sender, PaintEventArgs e)
        {
            BufferedGraphicsContext current = BufferedGraphicsManager.Current;
            BufferedGraphics bg = current.Allocate(e.Graphics, e.ClipRectangle);
            Graphics g = bg.Graphics;
            g.SmoothingMode = SmoothingMode.HighQuality;
            g.CompositingQuality = CompositingQuality.HighQuality;
            g.InterpolationMode = InterpolationMode.HighQualityBicubic;
            g.Clear(BackColor);  //背景

            DrawTitle(g);
            DrawBorder(g);

            bg.Render();
            bg.Dispose();
        }

        private void FormBase_MouseDown(object sender, MouseEventArgs e)
        {
            SetLostFocus(this, Handle);

            if (e.Button == MouseButtons.Left)
            {
                if (!IsMaximized)
                    ChangeFormSize();
            }
        }

        private void FormBase_MouseUp(object sender, MouseEventArgs e)
        {

        }

        private void FormBase_MouseMove(object sender, MouseEventArgs e)
        {
            if (MouseButtons == MouseButtons.None)
            {
                if (!IsMaximized)  //不是最大化
                    ChangeMouseCursor(e.Location);
            }
        }

        private void FormBase_Deactivate(object sender, EventArgs e)
        {
            formActivated = false;
            Refresh();
        }

        private void FormBase_Activated(object sender, EventArgs e)
        {
            formActivated = true;
            Refresh();
        }


        private enum CursorPlace : int
        {
            None = 0,
            Left = 0xF001,
            Top = 0xF003,
            Right = 0xF002,
            Bottom = 0xF006,
            LeftTop = 0xF004,
            RightTop = 0xF005,
            LeftBottom = 0xF007,
            RightBottom = 0xF008,
            Inside = API.SC_MOVE + API.HTCAPTION
        }

    }
}