using System.Globalization;
using System.Reflection;
using Whisper;

namespace MicrophoneCS
{
	sealed record class CommandLineArgs
	{
		public int n_threads = Environment.ProcessorCount;
		public int offset_t_ms = 0;
		public int offset_n = 0;
		public int duration_ms = 0;
		public int max_context = -1;
		public int max_len = 0;

		public float word_thold = 0.01f;

		public bool speed_up = false;
		public bool translate = false;
		public bool diarize = false;
		public bool output_txt = false;
		public bool print_special = false;
		public bool print_progress = false;
		public bool print_colors = true;
		public bool no_timestamps = false;
		public int[]? prompt = null;
		public int captureDeviceIndex = 0;

		public eLanguage language = eLanguage.English;
		public string model = string.Empty;

		const bool output_wts = false;
		public bool listDevices = false;

		public void apply( ref Parameters p )
		{
			p.setFlag( eFullParamsFlags.PrintRealtime, false );
			p.setFlag( eFullParamsFlags.PrintProgress, print_progress );
			p.setFlag( eFullParamsFlags.PrintTimestamps, !no_timestamps );
			p.setFlag( eFullParamsFlags.PrintSpecial, print_special );
			p.setFlag( eFullParamsFlags.Translate, translate );
			p.language = language;
			p.cpuThreads = n_threads;
			if( max_context >= 0 )
				p.n_max_text_ctx = max_context;
			p.offset_ms = offset_t_ms;
			p.duration_ms = duration_ms;
			p.setFlag( eFullParamsFlags.TokenTimestamps, output_wts || max_len > 0 );
			p.thold_pt = word_thold;
			p.max_len = output_wts && max_len == 0 ? 60 : max_len;
			p.setFlag( eFullParamsFlags.SpeedupAudio, speed_up );
		}

		public eResultFlags resultFlags()
		{
			eResultFlags flags = eResultFlags.None;
			bool wts = output_wts || max_len > 0;
			if( !no_timestamps || wts )
				flags |= eResultFlags.Timestamps;
			if( wts || print_colors )
				flags |= eResultFlags.Tokens;
			return flags;
		}

		static eLanguage parseLanguage( string lang ) =>
			Library.languageFromCode( lang ) ?? throw new ArgumentException( $"Unknown language code \"{lang}\"" );

		public CommandLineArgs( string[] argv )
		{
			for( int i = 0; i < argv.Length; i++ )
			{
				string arg = argv[ i ];
				if( arg == "-h" || arg == "--help" )
				{
					printUsage();
					throw new OperationCanceledException();
				}
				else if( arg == "-c" || arg == "--capture" ) captureDeviceIndex = int.Parse( argv[ ++i ] );
				else if( arg == "-ld" || arg == "--list-devices" ) listDevices = true;
				else if( arg == "-t" || arg == "--threads" ) n_threads = int.Parse( argv[ ++i ] );
				else if( arg == "-ot" || arg == "--offset-t" ) offset_t_ms = int.Parse( argv[ ++i ] );
				else if( arg == "-on" || arg == "--offset-n" ) offset_n = int.Parse( argv[ ++i ] );
				else if( arg == "-d" || arg == "--duration" ) duration_ms = int.Parse( argv[ ++i ] );
				else if( arg == "-mc" || arg == "--max-context" ) max_context = int.Parse( argv[ ++i ] );
				else if( arg == "-ml" || arg == "--max-len" ) max_len = int.Parse( argv[ ++i ] );
				else if( arg == "-wt" || arg == "--word-thold" ) word_thold = float.Parse( argv[ ++i ], CultureInfo.InvariantCulture );
				else if( arg == "-su" || arg == "--speed-up" ) speed_up = true;
				else if( arg == "-tr" || arg == "--translate" ) translate = true;
				else if( arg == "-di" || arg == "--diarize" ) diarize = true;
				else if( arg == "-otxt" || arg == "--output-txt" ) output_txt = true;
				else if( arg == "-ps" || arg == "--print-special" ) print_special = true;
				else if( arg == "-nc" || arg == "--no-colors" ) print_colors = false;
				else if( arg == "-pp" || arg == "--print-progress" ) print_progress = true;
				else if( arg == "-nt" || arg == "--no-timestamps" ) no_timestamps = true;
				else if( arg == "-l" || arg == "--language" ) language = parseLanguage( argv[ ++i ] );
				else if( arg == "--prompt" ) prompt = parsePrompt( argv[ ++i ] );
				else if( arg == "-m" || arg == "--model" ) model = argv[ ++i ];
				else
					throw new ArgumentException( $"Unknown argument: \"{arg}\"" );
			}
			if( listDevices )
				return;
			if( string.IsNullOrWhiteSpace( model ) )
				throw new ArgumentException( "The model file is not provided in the arguments" );
			if( !File.Exists( model ) )
				throw new FileNotFoundException( "Model not found", model );
		}

		static string cstr( bool b ) => b.ToString();

		static int[]? parsePrompt( string str )
		{
			if( string.IsNullOrWhiteSpace( str ) )
				return null;
			// TODO: expose whisper_tokenize function, as a method of iModel COM interface
			throw new NotImplementedException();
		}

		void printUsage()
		{
			Console.WriteLine();

			Console.WriteLine( "usage: {0} [options] file0.mp3 file1.wma ...", Path.GetFileName( Assembly.GetExecutingAssembly().Location ) );
			Console.WriteLine();
			Console.WriteLine( "options:" );
			Console.WriteLine( "  -h,       --help          [default] show this help message and exit" );
			Console.WriteLine( "  -t N,     --threads N     [{0,-7:D}] number of threads to use during computation", n_threads );
			Console.WriteLine( "  -ot N,    --offset-t N    [{0,-7:D}] time offset in milliseconds", offset_t_ms );
			Console.WriteLine( "  -on N,    --offset-n N    [{0,-7:D}] segment index offset", offset_n );
			Console.WriteLine( "  -d  N,    --duration N    [{0,-7:D}] duration of audio to process in milliseconds", duration_ms );
			Console.WriteLine( "  -mc N,    --max-context N [{0,-7:D}] maximum number of text context tokens to store", max_context );
			Console.WriteLine( "  -ml N,    --max-len N     [{0,-7:D}] maximum segment length in characters", max_len );
			Console.WriteLine( "  -wt N,    --word-thold N  [{0,-7:F2}] word timestamp probability threshold", word_thold );
			Console.WriteLine( "  -su,      --speed-up      [{0,-7}] speed up audio by x2 (reduced accuracy)", cstr( speed_up ) );
			Console.WriteLine( "  -tr,      --translate     [{0,-7}] translate from source language to english", cstr( translate ) );
			Console.WriteLine( "  -di,      --diarize       [{0,-7}] stereo audio diarization", cstr( diarize ) );
			Console.WriteLine( "  -otxt,    --output-txt    [{0,-7}] output result in a text file", cstr( output_txt ) );
			Console.WriteLine( "  -ps,      --print-special [{0,-7}] print special tokens", cstr( print_special ) );
			Console.WriteLine( "  -nc,      --no-colors     [{0,-7}] do not print colors", cstr( !print_colors ) );
			Console.WriteLine( "  -nt,      --no-timestamps [{0,-7}] do not print timestamps", cstr( no_timestamps ) );
			Console.WriteLine( "  -l LANG,  --language LANG [{0,-7}] spoken language", language.getCode() );
			Console.WriteLine( "            --prompt PROMPT [       ] initial prompt" );
			Console.WriteLine( "  -m FNAME, --model FNAME   [{0,-7}] model path", model );
			Console.WriteLine( "  -f FNAME, --file FNAME    [{0,-7}] path of the input audio file", "" );
		}
	}
}