using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;
using UnityEngine;
using UnityEngine.UI;

public class SubtitleBlock
{
    private static readonly Regex TimeStampRegex = new Regex(@"^(?<start>\d{2}:\d{2}:\d{2},\d{3})\s+(?<end>\d{2}:\d{2}:\d{2},\d{3})$");

    public int Index { get; private set; }
    public double Length { get; private set; }
    public double From { get; private set; }
    public double To { get; private set; }
    public string Text { get; private set; }

    public SubtitleBlock(int index, double from, double to, string text)
    {
        this.Index = index;
        this.From = from;
        this.To = to;
        this.Length = to - from;
        this.Text = text;
    }
    public override string ToString()
    {
        return "Index: " + Index + " From: " + From + " To: " + To + " Text: " + Text;
    }
    static public List<SubtitleBlock> ParseSubtitles(string content)
    {
        var subtitles = new List<SubtitleBlock>();
        //var regex = new Regex($@"(?<index>\d*\s*)\n(?<start>\d*:\d*:\d*,\d*)\s*-->\s*(?<end>\d*:\d*:\d*,\d*)\s*\n(?<content>.*)\n(?<content2>.*)\n");
        var regex = new Regex(@"(?<index>\d+)\r?\n(?<start>\d{2}:\d{2}:\d{2},\d{3}) --> (?<end>\d{2}:\d{2}:\d{2},\d{3})\r?\n(?<content>.*?)(\r?\n\r?\n|$)", RegexOptions.Singleline);
        var matches = regex.Matches(content);
        foreach (Match match in matches)
        {
            var groups = match.Groups;
            int ind = int.Parse(groups["index"].Value);
            TimeSpan fromtime, totime;
            TimeSpan.TryParse(groups["start"].Value.Replace(',', '.'), out fromtime);
            TimeSpan.TryParse(groups["end"].Value.Replace(',', '.'), out totime);
            string contenttext = groups["content"].Value;
            subtitles.Add(new SubtitleBlock(ind, fromtime.TotalSeconds, totime.TotalSeconds, contenttext));
        }
        return subtitles;
    }

    //public static List<SubtitleBlock> ParseSubtitles1(string srtFilePath) 
    //{
    //    List<SubtitleBlock> subtitles = new List<SubtitleBlock>();
    //    string[] lines = File.ReadAllLines(srtFilePath);
    //    for (int i = 0; i < lines.Length; i++)
    //    {
    //        var line = lines[i].Trim();
    //        if (int.TryParse(line, out int index))
    //        {
    //            // 当前行是新字幕的索引，开始解析新的字幕
    //            int tmpIndex = index;
    //            i++; // 跳过空行
    //            var timeStampLine = lines[i];
    //            var match = TimeStampRegex.Match(timeStampLine);
    //            if (match.Success)
    //            {
    //                Double From = TimeSpan.Parse(match.Groups["start"].Value).TotalSeconds;
    //                Double To = TimeSpan.Parse(match.Groups["end"].Value).TotalSeconds;
    //            }
    //            i++; // 跳过时间戳行
    //            while (i < lines.Length && !string.IsNullOrWhiteSpace(lines[i]))
    //            {
    //                // 添加字幕文本直到遇到下一个索引
    //                string Text += lines[i++] + Environment.NewLine;
    //            }
    //            subtitles.Add(new SubtitleBlock(index,From,To,Text));
    //        }
    //    }
    //    return subtitles;

    //}

}

public class Subtitle : MonoBehaviour
{
    public float offset;
    List<SubtitleBlock> subt;
    public Text subtitletext;
    string subcontent;
    public TextAsset subTitleSource;

    void Start()
    {
        if (subTitleSource == null) return;

        subt = SubtitleBlock.ParseSubtitles(subTitleSource.text);

        offset = (float)subt[0].From;
        Play();
    }

    private void Play()
    {
        StartCoroutine(DisplaySubtitles());
    }

    public float localtimer;

    public IEnumerator DisplaySubtitles()
    {
        for (int j = 0; j < subt.Count; j++)
        {
            subt[j].ToString();
            var i = subt[j];
            subtitletext.text = "";
            if (i.From <= localtimer && i.To >= localtimer)
            {
                subtitletext.text = i.Text;
                yield return new WaitForSeconds((float)i.Length);

            }
            else if (i.From > localtimer)
            {
                yield return new WaitForSeconds(Mathf.Min((float)i.From - localtimer, 0.1f));
                j--;
            }
        }

        yield return null;
    }

}