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

namespace Asa.Face
{
    /// <summary>
     /// 列表框
     /// </summary>
    [DefaultProperty("Text")]
    [DefaultEvent("SelectedIndexChanged")]
    public partial class SurCombo : BaseCtl
    {
        private TextBox _txt = new TextBox();
        private SurVScrollBar vsb = new SurVScrollBar();
        private ControlButton _btnPull = new ControlButton();
        private bool _pull = false;
        private bool _pullOver = false;     //下拉按钮经过
        private bool _pullDown = false;     //下拉按钮按下
        private int _itemHeight = 30;           //属性，项的高度
        private int _index = -1;
        private List<string> _list = new List<string>();
        private Rectangle[] _listRect;
        private RectangleF[] _listStrRect;
        private float _rowStep = 0;
        private float _offsetY = 0;
        private int _itemOver = -1;
        private int _headHeight = 50;

        private const int BUTTON_W = 30;

        /// <summary>
        /// 列表框
        /// </summary>
        public SurCombo()
        {
            InitializeComponent();
            MouseWheel += SurCombo_MouseWheel;

            vsb.Left = Width - BorderWidth - vsb.Width;
            vsb.Top = BorderWidth + _headHeight + 1;
            vsb.Height = Height - BorderWidth - BorderWidth - _headHeight - 1;
            vsb.Anchor = AnchorStyles.Top | AnchorStyles.Right | AnchorStyles.Bottom;
            vsb.Minimum = 0;
            vsb.Maximum = 10;
            vsb.Visible = false;
            vsb.MouseEnter += Vsb_MouseEnter;
            vsb.MouseLeave += Vsb_MouseLeave;
            vsb.ValueChanged += Vsb_ValueChanged;
            Controls.Add(vsb);

            _txt.BorderStyle = BorderStyle.None;
            _txt.BackColor = Common.BACK_COLOR;
            _txt.ForeColor = Common.FORE_COLOR;
            _txt.ImeMode = ImeMode.Disable;
            //_txt.LostFocus += Txt_LostFocus;
            //_txt.KeyPress += Txt_KeyPress;
            Controls.Add(_txt);
        }




        //==========事件==========
        /// <summary>
        /// SelectedIndex改变时发生
        /// </summary>
        [Browsable(true), Category(""), Description("SelectedIndex改变时发生")]
        public event MyEvent.Changed SelectedIndexChanged;


        //==========属性==========
        /// <summary>
        /// 单条文本项的高度
        /// </summary>
        [Browsable(true), Category(""), Description("单条文本项的高度"), DefaultValue(30)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public int ItemHeight
        {
            set
            {
                _itemHeight = value;
                CalcSize();
                Refresh();
            }
            get
            {
                return _itemHeight;
            }
        }

        /// <summary>
        /// 选中项的索引
        /// </summary>
        [Browsable(false)]
        public int SelectedIndex
        {
            set
            {
                if (_list.Count == 0 || value < 0 || value >= _list.Count)
                {
                    _index = -1;
                    _txt.Text = "";
                }
                else
                {
                    _index = value;
                    _txt.Text = _list[_index];
                }
                Refresh();
                if (Enabled)
                    SelectedIndexChanged?.Invoke(this);
            }
            get
            {
                return _index;
            }
        }

        /// <summary>
        /// 列表的总数
        /// </summary>
        [Browsable(false)]
        public int Count { get { return _list.Count; } }

        /// <summary>
        /// 显示文本只读不可更改
        /// </summary>
        [Browsable(true), Category(""), Description("显示文本只读不可更改"), DefaultValue(false)]
        public bool ReadOnly { set => _txt.ReadOnly = value; get => _txt.ReadOnly; }

        /// <summary>
        /// 显示的文本
        /// </summary>
        [Browsable(false)]
        public override string Text
        {
            set
            {
                _txt.Text = value;
            }
            get
            {
                return _txt.Text;
            }
        }

        /// <summary>
        /// 控件中文本的字体
        /// </summary>
        [Browsable(true), Category(""), Description("控件中文本的字体")]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public override Font Font
        {
            get => base.Font;
            set
            {
                base.Font = value;
                _txt.Top = BorderWidth + (Height - BorderWidth - BorderWidth - _txt.Height) / 2;
            }
        }

        /// <summary>
        /// 显示文本的对齐方式
        /// </summary>
        [Browsable(true), Category(""), Description("显示文本的对齐方式"), DefaultValue(HorizontalAlignment.Left)]
        public HorizontalAlignment TextAlign { set => _txt.TextAlign = value; get => _txt.TextAlign; }

        [Browsable(true), DefaultValue(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public new bool Enabled
        {
            set
            {
                base.Enabled = value;
                _txt.Enabled = value;
                Refresh();
            }
            get
            {
                return base.Enabled;
            }
        }


        //==========方法==========
        /// <summary>
        /// 列表框添加文本项
        /// </summary>
        /// <param name="s"></param>
        public void ItemAdd(params string[] s)
        {
            _list.AddRange(s);
            CalcSize();
            Refresh();
        }

        /// <summary>
        /// 移除指定索引的元素
        /// </summary>
        /// <param name="n">要移除的元素从零开始的索引</param>
        public void ItemRemove(int n)
        {
            if (n < 0 || n >= _list.Count) return;
            _list.RemoveAt(n); _list.RemoveAt(n);

            if (n == _index)
            {
                _index = -1;
            }
            else if (n < _index)
            {
                _index--;
            }

            CalcSize();
            Refresh();
        }

        /// <summary>
        /// 移除当前选中的元素
        /// </summary>
        public void ItemRemove()
        {
            if (_index == -1) return;
            _list.RemoveAt(_index);
            _index = -1;
            CalcSize();
            Refresh();
        }

        /// <summary>
        /// 清空列表框
        /// </summary>
        public void ItemClear()
        {
            _list.Clear();
            CalcSize();
            Refresh();
        }

        /// <summary>
        /// 列表所有文本
        /// </summary>
        /// <returns></returns>
        public string[] Items()
        {
            return _list.ToArray();
        }

        /// <summary>
        /// 列表指定文本
        /// </summary>
        /// <returns></returns>
        public string Items(int idx)
        {
            return _list[idx];
        }

        /// <summary>
        /// 设置指定列表的文本
        /// </summary>
        /// <param name="idx"></param>
        /// <param name="s"></param>
        public void Items(int idx, string s)
        {
            _list[idx] = s;
            CalcSize();
            Refresh();
        }

        /// <summary>
        /// 选中列表的第一项
        /// </summary>
        public void SelectedFirst()
        {
            if (_list.Count == 0)
            {
                _index = -1;
            }
            else
            {
                _index = 0;
                _txt.Text = _list[_index];
            }
            Refresh();
            if (Enabled)
                SelectedIndexChanged?.Invoke(this);
        }

        /// <summary>
        /// 选中列表的最后一项
        /// </summary>
        public void SelectedLast()
        {
            if (_list.Count == 0)
            {
                _index = -1;
            }
            else
            {
                _index = _list.Count - 1;
                _txt.Text = _list[_index];
            }
            Refresh();
            if (Enabled)
                SelectedIndexChanged?.Invoke(this);
        }


        //==========私有==========
        /// <summary>
        /// 计算位置大小
        /// </summary>
        protected override void CalcSize()
        {
            base.CalcSize();
            if (!_pull)
                _headHeight = Height - BorderWidth - BorderWidth;
            
            _txt.Left = BorderWidth + 3;
            _txt.Width = Width - BUTTON_W - (BorderWidth + 3) * 2;
            _txt.Top = BorderWidth + (_headHeight - _txt.Height) / 2 + 1;
            _btnPull.Rect = new Rectangle(Width - BorderWidth - BUTTON_W, BorderWidth, BUTTON_W, _headHeight);
            if (_pull)
                _btnPull.IconShape = Shape.ControlTriangle(_btnPull.Rect, 6, Direction.Top);
            else
                _btnPull.IconShape = Shape.ControlTriangle(_btnPull.Rect, 6, Direction.Bottom);

            if (!_pull) return;
            _listRect = new Rectangle[_list.Count];
            _listStrRect = new RectangleF[_list.Count];
            if (_list.Count == 0) return;

            int w = Width - BorderWidth - BorderWidth;
            int height = _list.Count * _itemHeight + BorderWidth + BorderWidth + _headHeight;
            if (height > Height)
            {
                w -= vsb.Width;
                vsb.Visible = true;
                vsb.Top = BorderWidth + _headHeight;
                vsb.Height = Height - BorderWidth - BorderWidth - _headHeight + 1;
                int n = height - Height;
                vsb.Maximum = Convert.ToInt32(Math.Ceiling(n / 10f));
                _rowStep = (float)n / vsb.Maximum;
            }
            else
            {
                vsb.Visible = false;
            }

            for (int i = 0; i < _list.Count; i++)
            {
                _listRect[i] = new Rectangle(BorderWidth, BorderWidth + _headHeight + _itemHeight * i, w, _itemHeight);
                SizeF sf = CreateGraphics().MeasureString(_list[i], Font);
                _listStrRect[i] = new RectangleF(_listRect[i].X + 6, _listRect[i].Y + (_itemHeight - sf.Height) / 2, w - 12, sf.Height);
            }


        }

        private void SurCombo_MouseDown(object sender, MouseEventArgs e)
        {
            if (!Enabled) return;
            if (e.Button != MouseButtons.Left) return;
            if (_pullOver)
            {
                _pullDown = true;
                BringToFront();
                Refresh();
            }



            if (!_pull) return;
            if (_itemOver == _index)
            {
                _index = -1;
                Refresh();
            }
            else
            {
                _index = _itemOver;
                Refresh();
            }
        }

        private void SurCombo_MouseMove(object sender, MouseEventArgs e)
        {
            if (!Enabled) return;
            if (e.Button != MouseButtons.None) return;

            bool b1 = _btnPull.Rect.Contains(e.Location);
            if (b1 != _pullOver)
            {
                _pullOver = b1;
                Refresh();
            }


            if (!_pull) return;

            int n = -1;
            int y = Convert.ToInt32(e.Y + _offsetY);
            for (int i = 0; i < _listRect.Length; i++)
            {
                if (_listRect[i].Contains(e.X, y))
                {
                    n = i;
                    break;
                }
            }

            if (_itemOver == n) return;
            _itemOver = n;
            Refresh();

        }

        private void SurCombo_MouseUp(object sender, MouseEventArgs e)
        {
            if (!Enabled) return;
            if (e.Button != MouseButtons.Left) return;
            _pullDown = false;

            if (_pull)
            {
                _pull = false;
                Height = _headHeight + BorderWidth + BorderWidth;
                vsb.Visible = false;
                if (_itemOver > -1)
                {
                    if (_index == -1)
                        _txt.Text = "";
                    else
                        _txt.Text = _list[_index];
                    SelectedIndexChanged?.Invoke(this);
                }
            }
            else
            {
                _pull = true;
                Height = _headHeight * 4;
            }

        }

        private void SurCombo_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(Common.BACK_COLOR);  //背景


            if (!DesignMode && _pull && Enabled)  //非设计模式
            {
                if (vsb.Visible)
                    _offsetY = _rowStep * vsb.Value;  //偏移

                for (int i = 0; i < _list.Count; i++)
                {
                    if (_listRect[i].Bottom - _offsetY < _headHeight) continue;
                    if (_listRect[i].Y - _offsetY > Height) break;

                    if (_index == i)
                        g.FillRectangle(Common.BLUE_BRUSH, _listRect[i].X, _listRect[i].Y - _offsetY, _listRect[i].Width, _listRect[i].Height);
                    else if (_itemOver == i)
                        g.FillRectangle(Common.OVER_BRUSH, _listRect[i].X, _listRect[i].Y - _offsetY, _listRect[i].Width, _listRect[i].Height);
                    else
                        g.FillRectangle((i % 2 == 0 ? Common.ITEM_ROW1_BRUSH : Common.ITEM_ROW2_BRUSH), _listRect[i].X, _listRect[i].Y - _offsetY, _listRect[i].Width, _listRect[i].Height);
                    RectangleF rectf = _listStrRect[i];
                    rectf.Y += _offsetY;
                    g.DrawString(_list[i], Font, Common.FORE_BRUSH, _listStrRect[i].X, _listStrRect[i].Y - _offsetY);
                }
            }

            g.FillRectangle(Common.BACK_BRUSH, BorderWidth, BorderWidth, Width - BorderWidth - BorderWidth, _headHeight);

            if (Inside && Enabled)
            {
                if (_pullDown)
                    g.FillRectangle(Common.BLUE_BRUSH, _btnPull.Rect);
                else if (_pullOver)
                    g.FillRectangle(Common.OVER_BRUSH, _btnPull.Rect);
                g.FillPath(Common.FORE_BRUSH, _btnPull.IconShape);
                if (BorderWidth > 0)
                    g.DrawRectangle(BorderInsidePen, BorderRect);
            }
            else
            {
                _pullDown = _pullOver = false;
                if (Enabled)
                    g.FillPath(Common.FORE_BRUSH, _btnPull.IconShape);
                else
                    g.FillPath(Common.BORDER_BRUSH, _btnPull.IconShape);
                if (BorderWidth > 0)
                    g.DrawRectangle(BorderOutsidePen, BorderRect);
            }


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

        private void SurCombo_MouseWheel(object sender, MouseEventArgs e)
        {
            if (!Enabled) return;
            if (!_pull) return;
            if (e.Delta > 0)
                vsb.Value--;
            else
                vsb.Value++;
        }

        private void SurCombo_MouseLeave(object sender, EventArgs e)
        {
            _itemOver = -1;
            Refresh();
        }

        private void Vsb_MouseLeave(object sender, EventArgs e)
        {
            vsb.Inside = false;
        }

        private void Vsb_MouseEnter(object sender, EventArgs e)
        {
            _itemOver = -1;
            vsb.Inside = true;
        }

        private void Vsb_ValueChanged(object sender)
        {
            Refresh();
        }


    }
}