using System;
using System.Windows.Forms;
using System.Drawing;
using System.ComponentModel;
using FastReport.Utils;

namespace FastReport.Controls
{
    internal class StyleListBox : ListBox
    {
        private bool updating;
        private StyleCollection styles;

        public event EventHandler StyleSelected;

        public string Style
        {
            get
            {
                if (SelectedIndex < 1)
                    return "";
                return (string)Items[SelectedIndex];
            }
            set
            {
                updating = true;
                int i = Items.IndexOf(value);
                SelectedIndex = i != -1 ? i : 0;
                updating = false;
            }
        }

        public StyleCollection Styles
        {
            get { return styles; }
            set
            {
                styles = value;
                if (value != null)
                    UpdateItems();
            }
        }

        protected override void OnDrawItem(DrawItemEventArgs e)
        {
            e.DrawBackground();
            Graphics g = e.Graphics;
#if AVALONIA
            g.FontScale = 1;
#endif
            if (e.Index >= 0)
            {
                string name = (string)Items[e.Index];
                float scale = this.DpiMultiplier();
                using (TextObject sample = new TextObject())
                {
                    sample.Bounds = new RectangleF((int)(e.Bounds.Left / scale) + 2, (int)(e.Bounds.Top / scale) + 2, (int)(e.Bounds.Width / scale) - 4, (int)(e.Bounds.Height / scale) - 4);
                    sample.Text = name;
                    sample.HorzAlign = HorzAlign.Center;
                    sample.VertAlign = VertAlign.Center;
                    int index = Styles.IndexOf(name);
                    if (index != -1)
                        sample.ApplyStyle(Styles[index]);
                    using (var cache = new GraphicCache())
                    {
                        sample.Draw(new FRPaintEventArgs(g, scale, scale, cache));
                    }
                }
            }
        }

        protected override void OnSelectedIndexChanged(EventArgs e)
        {
            base.OnSelectedIndexChanged(e);
            if (updating)
                return;
            if (StyleSelected != null)
                StyleSelected(this, EventArgs.Empty);
        }

        private void UpdateItems()
        {
            Items.Clear();
            Items.Add(Res.Get("Designer,Toolbar,Style,NoStyle"));
            foreach (Style s in styles)
            {
                Items.Add(s.Name);
            }
        }

        public void UpdateDpiDependencies(Control owner)
        {
#if MONO
            // WPF: fix issues with multi-monitor dpi. Dropdown will be scaled automatically
            owner = this;
#endif
            if (owner == null)
                return;

            ItemHeight = owner.LogicalToDevice(32);
            Width = owner.LogicalToDevice(150);
            Height = (Items.Count < 8 ? Items.Count : 8) * ItemHeight + 4;
        }

        public StyleListBox()
        {
            DrawMode = DrawMode.OwnerDrawFixed;
            IntegralHeight = false;
        }
    }
}