using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Runtime.InteropServices;

namespace ShowTrend3.Libs
{
    public static class TempDirectory
    {
        private static readonly char sl = RuntimeInformation.IsOSPlatform(OSPlatform.Linux) ? '/' : '\\';
        private static readonly string td = Directory.GetCurrentDirectory() + sl + "temp";
        private static Dictionary<string, int> readFiles = new Dictionary<string, int>();
        private static List<string> writeFiles = new List<string>();

        private static long DirectorySize(DirectoryInfo d)
        {
            long Size = 0;
            FileInfo[] fis = d.GetFiles();
            foreach (FileInfo fi in fis)
                Size += fi.Length;
            DirectoryInfo[] dis = d.GetDirectories();
            foreach (DirectoryInfo di in dis)
                Size += DirectorySize(di);
            return (Size);
        }
        public static bool Clear(long maxSize = 1073741824)
        {
            try
            {
                if (!Directory.Exists(td)) Directory.CreateDirectory(td);
                var files = new DirectoryInfo(td).GetFiles();
                foreach (var f in files)
                {
                    var t = f.Name.Split('.');
                    var dateData = new DateTime(int.Parse(t[0]), int.Parse(t[1]), int.Parse(t[2]));
                    if (readFiles.ContainsKey(f.Name) ||
                        writeFiles.Contains(f.Name) ||
                        (f.CreationTime - dateData).TotalHours > 25 ||
                        (DateTime.Now - f.CreationTime).TotalMinutes <= 2)
                        continue;
                    f.Delete();
                }

                if (DirectorySize(new DirectoryInfo(td)) < maxSize)
                    return true;

                files = new DirectoryInfo(td).GetFiles();
                foreach(var f in files)
                {
                    if (readFiles.ContainsKey(f.Name) ||
                        writeFiles.Contains(f.Name))
                        continue;
                    f.Delete();
                }
                return true;
            }
            catch (Exception e)
            {
                Console.WriteLine(CustomConverters.ExceptionToString(e));
                return false;
            }
        }
        public static async Task<bool> Delete(string name)
        {
            bool flag = false;
            try
            {
                if ( !writeFiles.Contains(name) && !File.Exists(td + sl + name))
                    return true;
                while (writeFiles.Contains(name))
                    await Task.Delay(100);
                writeFiles.Add(name);
                flag = true;
                while (readFiles.ContainsKey(name))
                    await Task.Delay(100);
                File.Delete(td + sl + name);
                writeFiles.Remove(name);
                return true;
            }
            catch(Exception e)
            {
                Console.WriteLine(CustomConverters.ExceptionToString(e));
                if(flag) writeFiles.Remove(name);
                return false;
            }
        }
        public static bool IsFileExist(string name)
        {
            return File.Exists(td + sl + name);
        }
        public static FileStream StartWrite(string name)
        {
            writeFiles.Add(name);
            return new FileStream(td + sl + name, FileMode.CreateNew);
        }
        public static void EndWrite(string name)
        {
            writeFiles.Remove(name);
        }
        public static void LockRead(string name)
        {
            if (!readFiles.ContainsKey(name))
                readFiles.Add(name, 0);
            readFiles[name]++;
        }
        public static bool CanRead(string name)
        {
            if (!IsFileExist(name))
                return false;
            return !writeFiles.Contains(name);
        }
        public static FileStream StartRead(string name)
        {
            return new FileStream(td + sl + name, FileMode.Open);
        }
        public static void EndRead(string name)
        {
            if (!readFiles.ContainsKey(name))
                return;
            if (readFiles[name] > 0)
                readFiles[name]--;
            else
                readFiles.Remove(name);
        }

    }
}