import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.ArrayList;


public class java_video_audio_werbecutter {

    /**
     * @param args
     */
    public static void main(String[] args) {

        if (args.length <3){
            System.out.println("Zu wenig argumente");
            System.out.println("Benötige Inputfilename, encode file und Outputfilename");
        }
        else{
        String[] candidates = write_ffmpeg_info(args[0]);
        Double[] positions = get_positions(candidates,args[0]);
        write_encode_file(positions,args[1],args[0],args[2]);

        }

    }

    private static void write_encode_file(Double[] positions, String outputfilename, String inputfilename, String outputvideo) {

        try {
            BufferedWriter out = new BufferedWriter (new FileWriter(outputfilename));
            out.write("#"+inputfilename+"\n");
            for (int i=0;i<positions.length;i++){
                out.write("#"+positions[i]+"\n");
            }

            int endpos=0;
            if ( positions.length / 2 == 0){
                endpos=positions.length;
            }
            else{
                endpos=positions.length-1;
            }
            for (int i=0;i<endpos;i=i+2){

                //double startpos = get_realstartpos(positions[i-0.5]);
                String out_string="ffmpeg -ss "+Double.toString(positions[i]-10)+" -i \""+inputfilename+"\" -ss 10 -t "+Double.toString(positions[i+1]-positions[i])+"  -acodec flac -vcodec libx264 -coder 1 -flags +loop -partitions +parti8x8+parti4x4+partp8x8+partp4x4+partb8x8 -me_method umh -subq 10 -me_range 24 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -b_strategy 2 -qcomp 0.6 -qmin 0 -qmax 69 -qdiff 4 -bf 8 -refs 4 -trellis 2 -level 41 -crf 24 -threads 0 -async 1000 ";
                out_string=out_string+"/tmp/"+i+".mkv\n";
                out.write(out_string);
            }
            out.write("mkvmerge -o /tmp/dummy.mkv /tmp/0.mkv");
            for (int i=2;i<endpos;i=i+2){
                out.write(" + /tmp/"+i+".mkv");
            }
            out.write("\n");
            out.write("ffmpeg -i /tmp/dummy.mkv -vcodec copy -acodec libfaac -ab 160k \""+outputvideo+"\"\n");
            out.flush();
            out.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


    }



    private static Double[] get_positions(String[] candidates, String videofilename) {
        ArrayList<Double> output = new ArrayList<Double>();
        for(int i=0;i<candidates.length;i++){
            String[] data = candidates[i].split(":");
            double a = Double.parseDouble(data[0])*3600;
            double b = Double.parseDouble(data[1])*60;
            double c = Double.parseDouble(data[2]);
            double summe=a+b+c;
            double outi = check_candidate(summe,0,videofilename);
            output.add(outi);
        }
        Double[] arr = output.toArray(new Double[output.size()]);
        return arr;
    }

    private static double check_candidate(double start, double i, String videofilename) {
        System.out.println("Check start: "+ Double.toString(start)+" offset "+ Double.toString(i));
        double start1= start -10;
        double start2= 10 + i ;
        String start1_string = Double.toString(start1);
        String start2_string = Double.toString(start2);
        String[] befehl = new String[] {"ffmpeg","-ss",start1_string,"-i",videofilename,"-t",start2_string,"-f","wav","/dev/null"};
        try {
        ProcessBuilder builder = new ProcessBuilder(befehl);
        builder.redirectErrorStream(true);
        Process process = builder.start();

        OutputStream os = process.getOutputStream();
        OutputStreamWriter osr = new OutputStreamWriter(os);

        BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));
        boolean found=false;
        osr.write("y\n");
        osr.flush();
        String line;
        while ((line = br.readLine()) != null) {
            if (line.contains("frame changed")){
                found=true;
             }
        }
        if (found){
            return 0;
        }
        else{
            double a = check_candidate(start,(i+(double)0.1),videofilename);
            if (0== a){
                System.out.println("Found!!!: "+Double.toString(start+i));
                return start+i;
            }
            else{
                return a;
            }

        }
        }

        catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        return 0;
    }

    private static String[] write_ffmpeg_info(String videofilename) {
        System.out.println("Video Input file: " + videofilename);
        try {
        String[] befehl = new String[] {"ffmpeg","-i",videofilename,"-f","wav","/dev/null"};
        ProcessBuilder builder = new ProcessBuilder(befehl);
        builder.redirectErrorStream(true);
        Process process = builder.start();

        OutputStream os = process.getOutputStream();
        OutputStreamWriter osr = new OutputStreamWriter(os);

        BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));

        try {
            Thread.sleep(500);
        } catch (InterruptedException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        osr.write("y\n");
        osr.flush();

        String line;
        ArrayList<String> output = new ArrayList<String>();
        String xy = null;
        while ((line = br.readLine()) != null) {

             if (line.startsWith("size=")){
                 xy=(line.substring(line.indexOf("time=")+5,line.indexOf("time=")+13));
             }
             if (line.contains("frame changed")){
                 System.out.println("Candidate found: "+xy);
                 output.add(xy);
             }

           }
        String[] arr = output.toArray(new String[output.size()]);
        return arr;
    }
    catch (IOException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }
        return null;

    }

}