using Android.Content;
using Tesses.VirtualFilesystem;
using Android.App;
using Android.Content.PM;
using AndroidX.DocumentFile.Provider;
using Tesses.VirtualFilesystem.Extensions;
namespace Tesses.VirtualFilesystem.Filesystems;


public class SAFFileSystem : SyncFileSystem
{
    public const int RequestCode = 1447775022;
    public const string SharedPreferencesFile = "tesess_vfs";
    public static void RequestDirectory(Activity app,bool canwrite=true,bool presistant=false,int reqCode=RequestCode)
    {
        Intent intent = new Intent(Intent.ActionOpenDocumentTree);
        intent.AddFlags(ActivityFlags.GrantReadUriPermission|(canwrite? ActivityFlags.GrantWriteUriPermission : 0)|(presistant?ActivityFlags.GrantPersistableUriPermission:0));
        app.StartActivityForResult(intent,reqCode);
    }
    
    public static SAFFileSystem? GetSAFFromResponse(Context? app,Intent? intent)
    {
        if(app == null || intent == null) return null;
        var uri=intent.Data;
        if(uri != null)
        {
            return new SAFFileSystem(uri,app);
        }
        return null;
    }
    public static SAFFileSystem? GetSAFFromResponsePresistant(Context? app,Intent? intent,string key)
    {
        if(app == null || intent == null) return null;
        var uri=intent.Data;
        if(uri != null)
        {
            var r = app?.ContentResolver;
            if(r == null) return null;
            var rw = intent.Flags & (ActivityFlags.GrantReadUriPermission | ActivityFlags.GrantWriteUriPermission);
            r.TakePersistableUriPermission(uri,rw);
            var app2=app?.CreatePackageContext(app.PackageName,0);
            var sharedPrefs=app2?.GetSharedPreferences(SharedPreferencesFile,FileCreationMode.Private);

            sharedPrefs?.Edit()?.PutString(key,uri.ToString())?.Apply();

            
            return new SAFFileSystem(uri,app);
        }
        return null;
    }
    public static void Revoke(Context? app,string key)
    {
        var app2=app?.CreatePackageContext(app.PackageName,0);
        var sharedPrefs=app2?.GetSharedPreferences(SharedPreferencesFile,FileCreationMode.Private);
        var res=sharedPrefs?.GetString(key,null);
        var r = app?.ContentResolver;
        if(r == null) return;

        if(string.IsNullOrWhiteSpace(res)) return;
        var uri = Android.Net.Uri.Parse(res);
        if(uri == null) return;
        r.ReleasePersistableUriPermission(uri,ActivityFlags.GrantReadUriPermission);
        sharedPrefs?.Edit()?.Remove(key)?.Apply();
    }

    public static SAFFileSystem? GetSAFFromSharedStorage(Context? app,string key)
    {
        if(app == null) return null;
        var app2=app?.CreatePackageContext(app.PackageName,0);
        var sharedPrefs=app2?.GetSharedPreferences(SharedPreferencesFile,FileCreationMode.Private);
        var res=sharedPrefs?.GetString(key,null);
        
        if(string.IsNullOrWhiteSpace(res)) return null;
        var uri = Android.Net.Uri.Parse(res);
        if(uri == null) return null;

        return new SAFFileSystem(uri,app);
    }
    

    public SAFFileSystem(global::Android.Net.Uri uri,Context? ctx)
    {
        Uri = uri;
        Context = ctx;
        
    }
    public global::Android.Net.Uri Uri {get;set;}
    public Context? Context {get;set;}

    
    public override void CreateDirectory(UnixPath directory)
    {
        if(Context != null && Uri != null)
        {

            var dir = DocumentFile.FromTreeUri(Context,Uri);
            if(dir == null) return;

            foreach(var item in directory.Parts)
            {
                var dir2= dir?.FindFile(item);
                if(dir2 != null)
                {
                    if(!dir2.IsDirectory && !dir2.IsFile && !dir2.IsVirtual)
                    {
                        dir = dir2.CreateDirectory(item);
                    }
                    else if(dir2.IsDirectory)
                    {   
                        dir = dir2;
                    }
                }
            }
            
        }
    }

    public override void DeleteDirectory(UnixPath path)
    {
        if(Context != null && Uri != null)
        {

            var dir = DocumentFile.FromTreeUri(Context,Uri);
            if(dir == null) return;

            for(int i = 0;i<path.Parts.Length;i++)
            {
                var item = path.Parts[i];
                var dir2= dir?.FindFile(item);
                if(dir2 != null)
                {
                    if(!dir2.IsDirectory && !dir2.IsFile && !dir2.IsVirtual)
                    {
                        return;
                    }
                    else if(dir2.IsDirectory)
                    {   
                        dir = dir2;
                        if(i==path.Parts.Length -1)
                            dir.Delete();
                    }
                }
            }
            
        }
    }

    public override void DeleteFile(UnixPath path)
    {
        
        if(Context != null && Uri != null)
        {

            var dir = DocumentFile.FromTreeUri(Context,Uri);
            if(dir == null) return;

            for(int i = 0;i<path.Parts.Length;i++)
            {
                var item = path.Parts[i];
                var dir2= dir?.FindFile(item);
                if(dir2 != null)
                {
                    if(!dir2.IsDirectory && !dir2.IsFile && !dir2.IsVirtual)
                    {
                        return;
                    }
                     else if(dir2.IsDirectory)
                    {
                        dir=dir2;
                    }
                    else if(dir2.IsFile)
                    {   
                        dir = dir2;
                        if(i==path.Parts.Length -1)
                            dir.Delete();
                    }
                }
            }
            
        }

    }

    public override bool DirectoryExists(UnixPath path)
    {
            if(path.IsRoot) return true;
          if(Context != null && Uri != null)
        {

            var dir = DocumentFile.FromTreeUri(Context,Uri);
            if(dir == null) return false;

            for(int i = 0;i<path.Parts.Length;i++)
            {
                var item = path.Parts[i];
                var dir2= dir?.FindFile(item);
                if(dir2 != null)
                {
                    if(!dir2.IsDirectory && !dir2.IsFile && !dir2.IsVirtual)
                    {
                        return false;
                    }
                    else if(dir2.IsDirectory)
                    {   
                        dir = dir2;
                        if(i==path.Parts.Length -1)
                            return true;
                    }
                }
            }
           
        }
         return false;
    }

    public override IEnumerable<UnixPath> EnumerateFileSystemEntries(UnixPath path)
    {
          if(Context != null && Uri != null)
        {

            var dir = DocumentFile.FromTreeUri(Context,Uri);
            if(dir == null) yield break;

            if(path.IsRoot)
            {
                foreach(var _item in dir.ListFiles())
                {
                    yield return path / _item.Name;
                }
                yield break;
            }

            for(int i = 0;i<path.Parts.Length;i++)
            {
                var item = path.Parts[i];
                var dir2= dir?.FindFile(item);
                if(dir2 != null)
                {
                    if(!dir2.IsDirectory && !dir2.IsFile && !dir2.IsVirtual)
                    {
                        yield break;
                    }
                    else if(dir2.IsDirectory)
                    {   
                        dir = dir2;
                        if(i==path.Parts.Length -1)
                        {
                            foreach(var _item in dir2.ListFiles())
                            {
                                yield return path / _item.Name;
                            }
                        }
                    }
                }
            }
           
        }
         
    }

    public override bool FileExists(UnixPath path)
    {
        if(Context != null && Uri != null)
        {

            var dir = DocumentFile.FromTreeUri(Context,Uri);
            if(dir == null) return false;

            for(int i = 0;i<path.Parts.Length;i++)
            {
                var item = path.Parts[i];
                var dir2= dir?.FindFile(item);
                if(dir2 != null)
                {
                    if(!dir2.IsDirectory && !dir2.IsFile && !dir2.IsVirtual)
                    {
                        return false;
                    }
                     else if(dir2.IsDirectory)
                    {
                        dir=dir2;
                    }
                    else if(dir2.IsFile)
                    {   
                        dir = dir2;
                        if(i==path.Parts.Length -1)
                            return true;
                    }
                }
            }
           
        }
         return false;
    }

    public override DateTime GetCreationTime(UnixPath path)
    {
          return DateTime.Now;
    }

    public override DateTime GetLastAccessTime(UnixPath path)
    {
        return DateTime.Now;
    }

    public override DateTime GetLastWriteTime(UnixPath path)
    {
         if(Context != null && Uri != null)
        {

            var dir = DocumentFile.FromTreeUri(Context,Uri);
            if(dir == null) return DateTime.Now;

            for(int i = 0;i<path.Parts.Length;i++)
            {
                var item = path.Parts[i];
                var dir2= dir?.FindFile(item);
                if(dir2 != null)
                {
                     if(dir2.Exists())
                     {

                     
                        dir = dir2;
                        if(i==path.Parts.Length -1)
                            return DateTimeOffset.FromUnixTimeSeconds(dir2.LastModified()).DateTime;
                     }
                     else return DateTime.Now;
                }
            }
           
        }
         return DateTime.Now;
    }

    public override void MoveDirectory(UnixPath src, UnixPath dest)
    {
        foreach(var item in this.EnumerateDirectories(src))
        {
            MoveDirectory(item,dest / item.Name);
        }
        foreach(var item in this.EnumerateFiles(src))
        {
            MoveFile(item,dest / item.Name);
        }
        DeleteDirectory(src);
    }

    public override void MoveFile(UnixPath src, UnixPath dest)
    {
        if(src.Parent == dest.Parent)
        {
            if(Context != null && Uri != null)
        {

            var dir = DocumentFile.FromTreeUri(Context,Uri);
            if(dir == null) return;

            for(int i = 0;i<src.Parts.Length;i++)
            {
                var item = src.Parts[i];
                var dir2= dir?.FindFile(item);
                if(dir2 != null)
                {
                    if(!dir2.IsDirectory && !dir2.IsFile && !dir2.IsVirtual)
                    {
                        return;
                    }
                    else if(dir2.IsDirectory)
                    {
                        dir=dir2;
                    }
                    else if(dir2.IsFile)
                    {   
                        dir = dir2;
                        if(i==src.Parts.Length -1)
                            dir.RenameTo(dest.Name);
                    }
                }
            }
           
        }
        
        }
        else
        {
            this.CopyFile(src,dest);
            DeleteFile(src);
        }
    }

    public override Stream Open(UnixPath path, FileMode mode, FileAccess access, FileShare share)
    {
        if(Context != null && Uri != null)
        {

            var dir = DocumentFile.FromTreeUri(Context,Uri);
            if(dir == null) throw new FileNotFoundException(path.ToString());
            
            for(int i = 0;i<path.Parts.Length;i++)
            {
                var item = path.Parts[i];
                var dir2= dir?.FindFile(item);
                if(dir2 != null)
                {
                    if(!dir2.IsDirectory && !dir2.IsFile && !dir2.IsVirtual)
                    {
                        throw new FileNotFoundException(path.ToString());
                    }
                    else if(dir2.IsDirectory)
                    {
                        dir = dir2;
                        
                    }

                    if(i==path.Parts.Length -1)
                    {
                        if(dir2?.IsFile ?? false)
                        {
                            if(mode == FileMode.CreateNew) throw new IOException("File already exists");
                            return _OpenFile(dir2.Uri,mode,access,share);
                            
                        }
                        else
                        {
                            var (mimeType,displayName)=GetDisplayNameAndMime(item);
                            var f=dir?.CreateFile(mimeType,displayName);
                            if(mode == FileMode.Open || mode == FileMode.Truncate || mode == FileMode.Append)
                                throw new IOException("File does not exist");
                            if(f != null)
                            return _OpenFile(f.Uri,mode,access,share);
                            throw new IOException("Could not open file");
                        }
                    }
                    
                }
                
            }
            
        }
        throw new FileNotFoundException(path.ToString());
    }

    private (string mimeType, string displayName) GetDisplayNameAndMime(string item)
    {
        var mime=HeyRed.Mime.MimeTypesMap.GetMimeType(item);
        if(mime == "application/octet-stream")
        {
            return ("unknown/unknown",item);
        }
        else
        {
            return (mime,Path.GetFileNameWithoutExtension(item));
        }
    }

    private Stream _OpenFile(global::Android.Net.Uri uri, FileMode mode, FileAccess access, FileShare share)
    {
        
        //FileMode.Append -> "a"
        //FileMode.Create -> "w"
        //FileMode.CreateNew -> "w"
        //FileMode.Open -> "r or w"
        //FileMode.OpenOrCreate -> "r or w"
        //FileMode.Truncate -> "t"
        //"r", "w", "wt", "wa", "rw" or "rwt"

        Stream? strm = null;

        if(access == FileAccess.Read)
            strm = Context?.ContentResolver?.OpenInputStream(uri) ?? null;

        if(access == FileAccess.Write)
            if(mode == FileMode.Truncate)
                strm = Context?.ContentResolver?.OpenOutputStream(uri,"wt");
            else if(mode == FileMode.Append)
                strm = Context?.ContentResolver?.OpenOutputStream(uri,"wa");
            else
                strm = Context?.ContentResolver?.OpenOutputStream(uri,"w");
        
        if(access == FileAccess.ReadWrite)
            if(mode == FileMode.Truncate)
                strm = Context?.ContentResolver?.OpenOutputStream(uri,"rwt");
            else
                strm = Context?.ContentResolver?.OpenOutputStream(uri,"rw");

        
        
        
        
        if(strm == null) throw new IOException("Failed to open stream");
        return strm;
        
    }

    public override void SetCreationTime(UnixPath path, DateTime time)
    {
        
    }

    public override void SetLastAccessTime(UnixPath path, DateTime time)
    {
        
    }

    public override void SetLastWriteTime(UnixPath path, DateTime time)
    {
       
    }
}