using System;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Threading;
using ADOFAIRenderer.Renderer;

internal static class Program
{
    static void Assert(bool condition, string message) { if (!condition) throw new Exception(message); }
    static int Main(string[] args)
    {
        try
        {
            if (args.Length != 2) throw new ArgumentException("Pass ffmpeg.exe and a test output directory.");
            Directory.CreateDirectory(args[1]);
            var clock = new RenderClock();
            for (int i = 0; i < 60 * 60 * 4 * 60; i++) clock.Advance();
            Assert(clock.Time == 14400, "Four-hour clock drift.");
            Assert(Math.Abs(clock.SongPosition(1001, 1.5, 0.2, 0.03) - ((14399 - 0.03) * 1.5 - 0.2)) < 1e-9, "Pitch/offset mapping failed.");
            var anchored = new RenderClock();
            anchored.AnchorDsp(12345.5);
            for (int i = 0; i < 60; i++) anchored.Advance();
            Assert(anchored.DspTime == 12346.5 && anchored.Time == 1, "Audio DSP anchoring changed virtual frame time.");
            bool anchorRejected = false;
            try { anchored.AnchorDsp(0); } catch (InvalidOperationException) { anchorRejected = true; }
            Assert(anchorRejected, "DSP clock was allowed to reanchor during rendering.");
            var fast = Path.Combine(args[1], "fast.mp4");
            var slow = Path.Combine(args[1], "slow.mp4");
            Encode(args[0], fast, false);
            Encode(args[0], slow, true);
            var fastHash = Probe(args[0], "-v error -i \"" + fast + "\" -f framemd5 -");
            var slowHash = Probe(args[0], "-v error -i \"" + slow + "\" -f framemd5 -");
            Assert(fastHash == slowHash, "Different wall-clock delays changed decoded frames.");
            Assert(fastHash.Contains("#tb 0: 1/60") && fastHash.Contains("#dimensions 0: 1920x1080"), "Wrong frame rate or resolution.");
            var decoded = fastHash.Split(new[] {'\n'}, StringSplitOptions.RemoveEmptyEntries).Where(line => !line.StartsWith("#")).ToArray();
            Assert(decoded.Length == 60, "Decoded frame count mismatch.");
            Assert(decoded.Select(line => line.Split(',').Last().Trim()).Distinct().Count() == 60, "Duplicate decoded frames.");
            for (int i = 0; i < decoded.Length; i++)
            {
                var columns = decoded[i].Split(',');
                Assert(long.Parse(columns[2]) == i && int.Parse(columns[3]) == 1, "Frame timestamp or duration mismatch.");
            }
            using (var encoder = new FFmpegEncoder(args[0], Path.Combine(args[1], "bad-order.mp4")))
            {
                var frame = encoder.Rent(); frame.Index = 1; encoder.Submit(frame);
                bool failed = false;
                try { encoder.Finish(1); } catch (IOException) { failed = true; }
                Assert(failed, "Out-of-order frames were silently accepted.");
            }
            using (var encoder = new FFmpegEncoder(args[0], Path.Combine(args[1], "cancelled.mp4")))
            {
                var frame = encoder.Rent(); frame.Index = 0; encoder.Submit(frame);
            }
            bool rejected = false;
            try { using (var encoder = new FFmpegEncoder(args[0], Path.Combine(args[1], "missing", "failure.mp4"))) {
                var frame = encoder.Rent(); frame.Index = 0; encoder.Submit(frame); encoder.Finish(1);
            }} catch (IOException) { rejected = true; }
            Assert(rejected, "FFmpeg nonzero exit was ignored.");
            var wav = Path.Combine(args[1], "tone.wav");
            var muxed = Path.Combine(args[1], "with-audio.mp4");
            Probe(args[0], "-v error -f lavfi -i sine=frequency=440:sample_rate=48000:duration=1 -ac 2 -c:a pcm_f32le \"" + wav + "\"");
            FFmpegEncoder.MuxAudio(args[0], fast, wav, muxed);
            var muxedVideoHash = Probe(args[0], "-v error -i \"" + muxed + "\" -map 0:v:0 -f framemd5 -");
            Assert(muxedVideoHash == fastHash, "Audio mux changed video frames or timestamps.");
            var metadata = Probe(Path.Combine(Path.GetDirectoryName(args[0]), "ffprobe.exe"),
                "-v error -select_streams a:0 -show_entries stream=codec_name,sample_rate,channels,duration -of default=noprint_wrappers=1 \"" + muxed + "\"");
            Assert(metadata.Contains("codec_name=aac") && metadata.Contains("sample_rate=48000") && metadata.Contains("channels=2") && metadata.Contains("duration=1.000000"), "Muxed audio format/duration mismatch.");
            Console.WriteLine("PASS: four-hour clock, DSP anchoring, pitch/offset, 1080p60/60 frames, frame order, identical fast/slow video, failure, cancellation, AAC mux and matching A/V duration.");
            return 0;
        }
        catch (Exception ex) { Console.Error.WriteLine(ex); return 1; }
    }
    private static void Encode(string ffmpeg, string output, bool slow)
    {
        using (var encoder = new FFmpegEncoder(ffmpeg, output))
        {
            for (int i = 0; i < 60; i++)
            {
                var frame = encoder.Rent(); frame.Index = i;
                for (int j = 0; j < frame.Bytes.Length; j += 4) {
                    frame.Bytes[j] = (byte)(i * 4); frame.Bytes[j+1] = (byte)((j / (1920 * 4)) % 256);
                    frame.Bytes[j+2] = (byte)(255 - i * 4); frame.Bytes[j+3] = 255;
                }
                if (slow && i % 10 == 0) Thread.Sleep(100);
                encoder.Submit(frame);
            }
            encoder.Finish(60);
        }
    }
    private static string Probe(string ffmpeg, string arguments)
    {
        using (var process = Process.Start(new ProcessStartInfo(ffmpeg, arguments) {
            UseShellExecute = false, CreateNoWindow = true, RedirectStandardOutput = true
        })) {
            string result = process.StandardOutput.ReadToEnd(); process.WaitForExit();
            Assert(process.ExitCode == 0, "Video decode failed."); return result;
        }
    }
}