using System;
using System.Diagnostics;
using System.IO;
using UnityEngine;

namespace Funique
{
    /// <summary>
    /// Extensions: FFmpeg <br />
    /// ------------------------------------------------ <br />
    /// 擴充: FFmpeg
    /// </summary>
    public static class FFmpegExtensions
    {
        public static string FFmpeg_StreamingAsset(this string arg)
        {
            using (Process process = new Process())
            {
                process.StartInfo.FileName = Path.Combine(Application.streamingAssetsPath, "ffmpeg", "ffmpeg.exe");
                process.StartInfo.Arguments = arg;
                process.StartInfo.UseShellExecute = false;
                process.StartInfo.CreateNoWindow = true;
                process.StartInfo.RedirectStandardError = true;
                process.StartInfo.RedirectStandardOutput = true;
                process.Start();
                string result = process.StandardError.ReadToEnd();
                process.Close();
                process.Dispose();
                return result;
            }
        }
        public static string FFmpeg(this string arg)
        {
            using (Process process = new Process())
            {
                process.StartInfo.FileName = "ffmpeg";
                process.StartInfo.Arguments = arg;
                process.StartInfo.UseShellExecute = false;
                process.StartInfo.CreateNoWindow = true;
                process.StartInfo.RedirectStandardError = true;
                process.StartInfo.RedirectStandardOutput = true;
                process.Start();
                string result = process.StandardError.ReadToEnd();
                process.Close();
                process.Dispose();
                return result;
            }
        }
        public static void FFmpegSetVideoInfo(this VideoInfo video, FFmpegPlace place)
        {
            string text = Path.Combine(Application.streamingAssetsPath, video.Path, video.FilterName);
            string ffmpegMsg = string.Empty;
            switch (place)
            {
                case FFmpegPlace.StreamingAsset:
                    ffmpegMsg = FFmpeg_StreamingAsset($" -i \"{text}\"");
                    break;
                case FFmpegPlace.environmentVariable:
                    ffmpegMsg = FFmpeg($" -i \"{text}\"");
                    break;
            }
            try
            {
                video.Time = (float)FFmpegDurationTime(ffmpegMsg);
                video.AudioChannel = FFmpegAudioChannel(ffmpegMsg);
            }
            catch (Exception ex)
            {
                FuniqueLogger.ErrorLog($"Set ffmpeg video info failed: {text}\n{ex.Message}", "Tool");
            }
        }
        public static double FFmpegDurationTime(this string ffmpegMsg)
        {
            int num = ffmpegMsg.IndexOf("Duration: ") + 10;
            int length = ffmpegMsg.IndexOf(",", num) - num;
            string text = string.Empty;
            if (num > 0 && length > 0)
                text = ffmpegMsg.Substring(num, length);
            TimeSpan timeSpan;
            if (TimeSpan.TryParse(text, out timeSpan))
            {
                return timeSpan.TotalSeconds;
            }
            return 0;
        }
        public static string FFmpegAudioChannel(this string ffmpegMsg)
        {
            string text = string.Empty;
            int num = ffmpegMsg.LastIndexOf("Stream #0:1");
            int length = -1;
            if (num != -1)
                length = ffmpegMsg.IndexOf("fltp", num) - num;
            if (num <= 0 || length <= 0)
                return null;

            text = ffmpegMsg.Substring(num, length);
            num = text.LastIndexOf("Hz, ") + 4;
            length = text.IndexOf(",", num) - num;
            if (num == -1 || length == -1)
                return null;

            text.Substring(num, length);
            return text;
        }
        public static bool FileSearch(this string sDir, string fileName)
        {
            return FileSearch(sDir, fileName, out _);
        }
        public static bool FileSearch(this string sDir, string fileName, out string fullpath)
        {
            string[] fileSystemEntries = Directory.GetFileSystemEntries(sDir, "*", SearchOption.AllDirectories);
            foreach (var i in fileSystemEntries)
            {
                if (Path.GetFileName(i) == fileName)
                {
                    fullpath = i;
                    return true;
                }
            }
            fullpath = null;
            return false;
        }
    }
}