using ImageMagick;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace MovieBarcodeGenerator {
    public class BarcodeGenerator {
        private static log4net.ILog log = log4net.LogManager.GetLogger("Generator");

        public static string ffmpegPath {
            get {
                return SharpFF.ffmpegPath;
            }
            set {
                SharpFF.ffmpegPath = value;
            }
        }

        public static void Generate(string inputFile, string outputFile, int height, int width) {
            Generate(inputFile, outputFile, height, 1, width);
        }

        public static void Generate(string inputFile, string outputFile, int height, int barWidth, int iterations) {
            log.InfoFormat("Beginning barcode generation for {0} slices.", iterations);
            if (File.Exists(outputFile)) {
                log.InfoFormat("Output file '{0}' exists. Deleting file.", outputFile);
                File.Delete(outputFile);
            }

            decimal videoLength = SharpFF.GetDuration(inputFile);

            // run these in parallel to save time
            // TODO: do all this work in a temp folder, then move the finished file to the destination
            log.Debug("Generating image slices.");
            Parallel.For(0, iterations, i => {
                string timecodeAt = SharpFF.SecondsToTimecode(i * (videoLength / iterations));
                SharpFF.ExecuteCommand(string.Format("-hide_banner -loglevel panic -nostats -y -ss {1} -i \"{0}\" -vframes 1 -an -f rawvideo -vcodec png -vf scale={4}:{5} \"{2}\\out_{3:000}.png\"", inputFile, timecodeAt, Path.GetDirectoryName(outputFile), i, barWidth, height));
            });

            log.Debug("Appending image files.");
            // use ImageMagick to crush the generated PNGs together
            using (MagickImageCollection images = new MagickImageCollection()) {
                foreach (var file in Directory.GetFiles(Path.GetDirectoryName(outputFile), "out_???.png")) {
                    images.Add(new MagickImage(file));
                }
                // create a strip from all those images
                using (IMagickImage result = images.AppendHorizontally()) {
                    // Save the result
                    result.Write(outputFile);
                }
            }

            log.Info("Cleaning up temporary files.");
            // clean up the work files
            string[] files = Directory.GetFiles(Path.GetDirectoryName(outputFile), "out_???.png");
            foreach (string file in files) {
                File.Delete(file);
            }
        }
    }
}