using System;
using System.Drawing;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
using System.Windows.Forms;

namespace LrcTool
{
    internal static class LrcKanjiHiraganaInjectPage
    {
        public static Control Create(Form frmMain)
        {
            var split = new SplitContainer
            {
                Dock = DockStyle.Fill,
                SplitterDistance = 70,
                Font = new Font("MS Gothic", 9),
                Orientation = Orientation.Vertical,
            };


            var rbLeft = new RichTextBox { Dock = DockStyle.Fill, AllowDrop = true };
            var rbRight = new RichTextBox { Dock = DockStyle.Fill, ReadOnly = true };

            split.Panel1.Controls.Add(rbLeft);
            split.Panel2.Controls.Add(rbRight);

            rbLeft.DragEnter += (sender, args) =>
            {
                string[] items;
                args.Effect = args.Data.GetDataPresent(DataFormats.FileDrop)
                              && 1 == (items = (string[])args.Data.GetData(DataFormats.FileDrop)).Length
                              && File.Exists(items[0])
                    ? DragDropEffects.Copy
                    : DragDropEffects.None;
            };

            rbLeft.DragDrop += (sender, args) =>
            {
                var items = (string[])args.Data.GetData(DataFormats.FileDrop);
                var bytes = File.ReadAllBytes(items[0]);

                rbLeft.Text = 0 == args.KeyState
                    ? Encoding.Default.GetString(bytes)
                    : Encoding.UTF8.GetString(bytes);
            };

            rbLeft.TextChanged += (sender, args) =>
            {
                try
                {
                    rbRight.Text = HiraganaInject(rbLeft.Lines);
                }
                catch (Exception e)
                {
                    rbRight.Text = e.ToString();
                }
            };
            frmMain.Shown += delegate
            {
                rbLeft.Text = "[00:00.00]漢字のひらがなを自動に生成する";
            };

            return split;
        }

        private static string HiraganaInject(string[] lines)
        {
            using (var helper = new HiraganaPhoneticHelper())
            {
                var sb = new StringBuilder();

                foreach (var line in lines)
                {
                    //split by pattern
                    // kanji-kana -> handle
                    // other -> copy

                    var preMatch = Regex.Match(line, @"(\[\d\d:\d\d\.\d\d])(.*)");
                    var lineProcessed = preMatch.Groups[1].Value;
                    var content = preMatch.Groups[2].Value;

                    var matches = Regex.Matches(content, "(?:\\p{IsCJKUnifiedIdeographs}+?\\p{IsHiragana}+|\\p{IsCJKUnifiedIdeographs}+)");

                    if (0 == matches.Count)
                    {
                        sb.AppendLine(line);
                        continue;
                    }

                    var caret = 0;
                    foreach (Match match in matches)
                    {
                        if (match.Index != caret) lineProcessed += content.Substring(caret, match.Index - caret);

                        var matchValue = match.Value;
                        if (false == Regex.IsMatch(matchValue, "\\p{IsCJKUnifiedIdeographs}+"))
                        {
                            lineProcessed += matchValue;
                            caret = match.Index + match.Length;
                            continue;
                        }

                        var result = helper.GetPhonetic(matchValue);

                        var postMatch = Regex.Match(matchValue, "(\\w+?)(\\p{IsHiragana}+)");
                        if (postMatch.Success)
                        {
                            var kanji = postMatch.Groups[1].Value;
                            var after = postMatch.Groups[2].Value;
                            lineProcessed += kanji + $"({result.Substring(0, result.Length - after.Length)})" + after;
                        }
                        else
                        {
                            lineProcessed += $"{matchValue}({result})";
                        }

                        caret = match.Index + match.Length;
                    }

                    if (caret != content.Length) lineProcessed += content.Substring(caret);

                    sb.AppendLine(lineProcessed);
                }
                return sb.ToString();
            }
        }

    }
}