using Tesses.VirtualFilesystem;
using Tesses.VirtualFilesystem.Extensions;
using Tesses.VirtualFilesystem.Filesystems;
using System.Text;

LocalFileSystem fs = new LocalFileSystem();

OverlayFilesystem overlay = new OverlayFilesystem(fs.GetSubdirFilesystem(Special.CurDir / "lower"),fs.GetSubdirFilesystem(Special.CurDir / "upper"));

UnixPath path = Special.Root;
int hasGone=0;
Func<string?> Prompt = ()=>{
    Console.Write(path.ToString());
    Console.Write(": ");
   
    return Console.ReadLine();
    
};

Func<string,string[]> ParseArgs = (argStr)=>{
    List<string> args = new List<string>();
    StringBuilder b= new StringBuilder();
    bool isString=false;
    for(int i = 0;i<argStr.Length;i++)
    {
        if(argStr[i] == '\\')
        {
            i++;
            b.Append(argStr[i]);
        }
        {
        if(isString)
        {
            if(argStr[0] == '\"')
            {
                isString=false;
            }
            else
            {
                b.Append(argStr[i]);
            }
        }
        else
        {
        if(argStr[i] == '\"')
        {
            isString=true;
        }else
        if(argStr[i] == ' ')
        {
            if(b.Length >0)
            {
                args.Add(b.ToString());
                b.Clear();
            }
        }else
        {
            b.Append(argStr[i]);
        }
        }
        }
    }
    if(b.Length >0)
            {
                args.Add(b.ToString());
                b.Clear();
            }
    return args.ToArray();
};

var read = Prompt();
while(read != null)
{
    string[] _args = ParseArgs(read);
    switch(_args[0])
    {
        case "exit":
            Environment.Exit(0);
            break;
        case "ls":

            await foreach(var files in overlay.EnumerateFileSystemEntriesAsync(_args.Length > 1 ? _args[1] : path))
            {
                Console.WriteLine(files.Name);
            }
            break;
        case "cat":
            if(_args.Length > 1)
            {
                Console.Write(await overlay.ReadAllTextAsync(_args[1]));
            }
            break;
        case "cd":
            if(_args.Length > 1)
            path = _args[1];
            break;
        case "mkdir":
            if(_args.Length > 1)
            {
                
                await overlay.CreateDirectoryAsync(path / _args[1]);
            }
            break;
        case "touch":
            if(_args.Length > 1)
            {
                UnixPath p = path / _args[1];
                
                
                if(!await overlay.FileExistsAsync(p) && !await overlay.DirectoryExistsAsync(p) && !await overlay.SymlinkExistsAsync(p))
                {
                    await overlay.WriteAllTextAsync(p,"");
                }
                await overlay.SetLastWriteTimeAsync(p,DateTime.Now);
            }
            break;
        case "append":
            {
                UnixPath p = path / _args[1];
                using(var srcF = await overlay.OpenAsync(p,FileMode.Append,FileAccess.Write,FileShare.Read))
                {
                    using(var sw = new StreamWriter(srcF))
                    {
                        sw.WriteLine(_args[2]);
                    }
                }
            }
            break;
        
    }
    
    read = Prompt();
}