using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Shapes;
using WPFDevelopers.Helpers;
using static System.Net.WebRequestMethods;
using File = System.IO.File;

namespace VideoConcat
{
    /// <summary>
    /// Video.xaml 的交互逻辑
    /// </summary>
    public partial class Video : Window
    {
        public string text = "", outPut = "";

        public Dictionary<int, string[]> videoFolders = [];

        public DirectoryInfo Path;

        public Dictionary<int, A> AllPublicCombinVideos = [];

        int GenerateVideoCount = 0;




        public Video()
        {
            InitializeComponent();
            string currentPath = Directory.GetCurrentDirectory();

            DirectoryInfo ExecParentPath = Directory.GetParent(currentPath) ?? new DirectoryInfo("");
            if (ExecParentPath != null)
            {
                Path = ExecParentPath;
            }

        }

        private async void Button_Click(object sender, RoutedEventArgs e)
        {



            try
            {
                GenerateVideoCount = int.Parse(videoCount.Text);
            }
            catch (Exception)
            {

                MessageBox.Show("请输入正确的数字");
                return;
            }

            WriteTxt($"生成视频的个数:{GenerateVideoCount} 个");

            Check_Folder();


            MakeOutPutDir();

            startButton.IsEnabled = false;
            GenerateAllvideos(videoFolders);
            var dateStart = DateTime.Now;  //记录用时的起始时间
            await Task.Run(async () =>
            {


                List<List<string>> lists = GenerateAllvideos(videoFolders);


                await MockIOPerformanceAsync(lists);


                startButton.Dispatcher.Invoke(() =>
                {
                    startButton.IsEnabled = true;
                });

            });
            var dateEnd = DateTime.Now;
            var timeSpan = dateEnd - dateStart;//记录开票用时

            WriteTxt($"用时：{timeSpan.TotalSeconds}秒");
        }

        private void Check_Folder()
        {

            if (Path == null)
            {
                WriteTxt("获取相关视频文件目录失败！");
                return;
            }
            WriteTxt("当前目录为:" + Path.FullName);
            videoFolders.Clear();
            AllPublicCombinVideos.Clear();

            try
            {
                int k = 1;
                for (int i = 1; i < 100; i++)
                {

                    var folder = string.Format("{0:D2}", i);
                    string currentFolderPath = $"{Path}\\{folder}";
                    if (Directory.Exists(currentFolderPath))
                    {
                        WriteTxt(folder);
                        string[] videos = GetAllVideos(currentFolderPath);
                        if (videos.Length > 0)
                        {
                            videoFolders.Add(k, videos);
                            AllPublicCombinVideos.Add(k, new A());
                            k++;
                        }
                    }
                 
                }
                return;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return;
            }
        }

        private void WriteTxt(string str)
        {

            outputTxt.Dispatcher.Invoke(() =>
            {
                text += str + "\r\n";
                outputTxt.Text = text;
                scrowText.ScrollToEnd();
            });

        }

        public static string[] GetAllVideos(string path)
        {
            return Directory.GetFiles(path, "*.mp4", SearchOption.AllDirectories);
        }


        public void CombineMp4WithoutTxt(List<string> files, string StrOutMp4Path)
        {
            Process p = new();//建立外部调用线程
            p.StartInfo.FileName = Directory.GetCurrentDirectory() + "\\ffmpeg.exe";//要调用外部程序的绝对路径


            //int i = 0;
            //string vao = "";
            List<string> ooootext = [];
            
            files.ForEach(file => {
                ooootext.Add($"file '{file}'");
            });
            string tmpConcatFile = $"{outPut}\\{Guid.NewGuid().ToString()}";
            // 也可以指定编码方式 
            File.WriteAllLines(tmpConcatFile, ooootext, Encoding.ASCII);

          

            string StrArg = $"-f concat -safe 0  -i {tmpConcatFile} -c copy -bsf:a aac_adtstoasc -movflags +faststart {StrOutMp4Path}";
            //string StrArg = $"-i {combineFile} -filter_complex \"{vao} concat=n={i}:v=1:a=1 [v][a]\" -map \"[v]\" -map \"[a]\" {StrOutMp4Path}";


            p.StartInfo.Arguments = StrArg;

            p.StartInfo.UseShellExecute = false;//不使用操作系统外壳程序启动线程(一定为FALSE,详细的请看MSDN)
            p.StartInfo.RedirectStandardError = true;//把外部程序错误输出写到StandardError流中(这个一定要注意,FFMPEG的所有输出信息,都为错误输出流,用StandardOutput是捕获不到任何消息的...这是我耗费了2个多月得出来的经验...mencoder就是用standardOutput来捕获的)
            p.StartInfo.CreateNoWindow = true;//不创建进程窗口
            p.ErrorDataReceived += new DataReceivedEventHandler(Output);//外部程序(这里是FFMPEG)输出流时候产生的事件,这里是把流的处理过程转移到下面的方法中,详细请查阅MSDN
            p.Start();//启动线程
            p.BeginErrorReadLine();//开始异步读取
            p.WaitForExit();//阻塞等待进程结束
            p.Close();//关闭进程
            p.Dispose();//释放资源
        }

        private void Output(object sendProcess, DataReceivedEventArgs output)
        {
            if (!String.IsNullOrEmpty(output.Data))
            {
                WriteTxt(output.Data);
            }
        }

        public void MakeOutPutDir()
        {
            outPut = $"{Path.FullName}\\output";

            if (!Directory.Exists(outPut))
            {
                Directory.CreateDirectory(outPut);
            }
        }

        public async Task<IEnumerable<string>> MockIOPerformanceAsync(List<List<string>> ls)
        {
            List<string> lss = [];
            List<Task> tasks = [];

            foreach (var item in ls)
            {

                Task task = new(() =>
                {
                    DateTime now = DateTime.Now;
                    Random random = new Random();
                    string randomString = random.Next(100000, 999999).ToString();
                    string result = now.ToString("yyyyMMddHHmmss") + randomString;
                    CombineMp4WithoutTxt(item, $"{outPut}\\{result}.mp4");
                });

                tasks.Add(task);
                task.Start();

                if (tasks.Count >= GenerateVideoCount)
                {
                    break;
                }
            }

            foreach (var item in tasks)
            {
                await item;
            }

            return lss;
        }

        private List<List<string>> GenerateAllvideos(Dictionary<int, string[]> dict)
        {

            List<List<string>> ls = [];
            foreach (var item in dict)
            {
                ls.Add(new List<string>(item.Value));
            }
            List<List<string>> permutations = CalculatePermutations(ls);


            return permutations;
        }

        static List<List<string>> CalculatePermutations(List<List<string>> inputList)
        {
            List<List<string>> result = new List<List<string>>();

            // 递归计算全排列的辅助函数
            void Permute(List<string> currentPermutation, int index)
            {
                if (index == inputList.Count)
                {
                    result.Add(new List<string>(currentPermutation));
                    return;
                }

                foreach (string item in inputList[index])
                {
                    currentPermutation.Add(item);
                    Permute(currentPermutation, index + 1);
                    currentPermutation.RemoveAt(currentPermutation.Count - 1);
                }
            }

            Permute(new List<string>(), 0);

            return result;
        }
    }

    public class A
    {
        public int Index { get; set; }
    };

}