using GeoSigmaDrawLib;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using System.Windows.Forms;

namespace StyleLibManager
{
    /// <summary>
    /// 用户应用指定样式
    /// </summary>
    /// <param name="group">样式组</param>
    /// <param name="style">样式</param>
    public delegate void ApplyStyleHandler(string group, string style);

    /// <summary>
    /// 样式管理界面类
    /// </summary>
    public partial class FrmStyleMain : Form
    {
        /// <summary>
        /// 用户点击应用或确定
        /// </summary>
        public event ApplyStyleHandler ApplyStyle;

        private Dictionary<string, Bitmap> cache = new Dictionary<string, Bitmap>();

        private readonly ImageList imageList = new ImageList()
        {
            ColorDepth = ColorDepth.Depth24Bit,
            ImageSize = new Size(50, 50)
        };

        /// <summary>
        /// 当前选中的组，如果什么都没选中，返回 null
        /// </summary>
        public string CurrentGroup
        {
            get
            {
                return StyleGroupTreeView.SelectedNode?.Text;
            }
        }

        /// <summary>
        /// 当前选中的样式，如果什么都没选中，返回 null
        /// </summary>
        public string CurrentStyle
        {
            get
            {
                if (StyleListView.SelectedItems.Count > 0)
                {
                    return StyleListView.SelectedItems[0].Text;
                }
                return null;
            }
        }

        /// <summary>
        /// 构造函数
        /// </summary>
        public FrmStyleMain()
        {
            InitializeComponent();
            InitStyleListView();
        }

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="path">库路径</param>
        /// <exception cref="ArgumentNullException">空指针异常，geo 或 path 为 null</exception>
        /// <exception cref="IOException">IO异常，初始化样式库失败，通常是找不到目录或没有访问权限</exception>
        public FrmStyleMain(string path)
        {
            InitializeComponent();
            InitStyleListView();

            StyleGroupTreeView.AfterSelect += StyleGroupTreeView_AfterSelect;

            if (string.IsNullOrWhiteSpace(path))
            {
                throw new ArgumentNullException(nameof(path));
            }

            if (!GeoSigmaXY.StyleLibraryInit(path, true))
            {
                throw new IOException("初始化样式库失败");
            }

            var nodes = GeoSigmaXY.StyleLibraryListGroup()
                .Select(it => new TreeNode(it))
                .ToArray();

            StyleGroupTreeView.Nodes.AddRange(nodes);
        }

        private void StyleGroupTreeView_AfterSelect(object sender, TreeViewEventArgs e)
        {
            if (e.Node == null)
            {
                return;
            }

            StyleListView.BeginUpdate();

            try
            {
                StyleListView.Clear();
                StyleListView.LargeImageList.Images.Clear();

                string group = e.Node.Text;

                string[] styles = GeoSigmaXY.StyleLibraryListStyle(group);
                for (int i = 0; i < styles.Length; i++)
                {
                    AddStyleItem(group, styles, i);
                }
            }
            finally
            {
                StyleListView.EndUpdate();
            }
        }

        private void AddStyleItem(string group, string[] styles, int i)
        {
            string style = styles[i];
            string key = CacheKey(group, style);

            if (!cache.ContainsKey(key))
            {
                cache[key] = CreateBitmap(group, style);
            }

            StyleListView.LargeImageList.Images.Add(cache[key]);
            StyleListView.Items.Add(new ListViewItem(style, i));
        }

        private static string CacheKey(string group, string style)
        {
            return Path.Combine(group, style).ToString();
        }

        private Bitmap CreateBitmap(string group, string style)
        {
            int width = 50;
            int height = 50;

            Bitmap bmp = new Bitmap(width, height);
            using (Graphics gBmp = Graphics.FromImage(bmp))
            {
                IntPtr pBmpDC = gBmp.GetHdc();
                try
                {
                    GeoSigmaXY.StyleLibraryRenderStyle(group, style, pBmpDC, width, height);
                }
                finally
                {
                    gBmp.ReleaseHdc();
                }
            }

            return bmp;
        }

        private void InitStyleListView()
        {
            StyleListView.LargeImageList = imageList;
            StyleListView.View = View.LargeIcon;
            StyleListView.HideSelection = false;
            //StyleListView.VirtualMode = true;
            StyleListView.MultiSelect = false;
            StyleListView.LabelEdit = true;
        }

        private void OkButton_Click(object sender, EventArgs e)
        {
            if (CurrentGroup != null && CurrentStyle != null)
            {
                ApplyStyle?.Invoke(CurrentGroup, CurrentStyle);
            }
            DialogResult = DialogResult.OK;
            Close();
        }

        private void CancelButton_Click(object sender, EventArgs e)
        {
            DialogResult = DialogResult.Cancel;
            Close();
        }

        private void ApplyButton_Click(object sender, EventArgs e)
        {
            if (CurrentGroup != null && CurrentStyle != null)
            {
                ApplyStyle?.Invoke(CurrentGroup, CurrentStyle);
            }
        }
    }
}