#!/bin/sh

if [ $# -lt 2 ]
then
  echo "$0 <rate> <file>"
fi

RATE="$1"
FILE="$2"

OUTPUTFILE="$(echo "$2" | sed 's/\.osu//g' | cut -d']' -f1) x$RATE].osu"

AUDIO=$(grep "AudioFilename:" "$FILE" | cut -d' ' -f2- | tr -d '\n\r')
AUDIORATED=$(echo $AUDIO | cut -d'.' -f1)-x$RATE".mp3"

echo "" > $OUTPUTFILE
rm "$OUTPUTFILE"

output_line () {
  printf "%s\r\n" "$1" >> $OUTPUTFILE
}

audioRate () {
  ffmpeg -i "$AUDIO" -filter:a "asetrate=$(ffprobe -v error -show_entries stream=sample_rate -of default=noprint_wrappers=1:nokey=1 "$AUDIO")*$RATE" -y "$AUDIORATED"
}

LINES=$(wc -l "$FILE" | cut -d' ' -f1)
FFILE=$(cat "$FILE")

step_skip ()
{
  printf "$(echo "$FFILE" | grep -B $LINES "$1" | head -n -1)" >> $OUTPUTFILE
  FFILE=$(echo "$FFILE" | grep -A $LINES "$1" | tail -n +2)
}

step_skip "AudioFilename:"
output_line "AudioFilename: $AUDIORATED"

PREVIEW=$(echo "$FFILE" | grep "PreviewTime:" | cut -d' ' -f2 | tr -d '\r\n')
step_skip "PreviewTime:"
output_line "PreviewTime: $(echo "$PREVIEW / $RATE" | bc | cut -d '.' -f1)"
VERSION=$(echo "$FFILE" | grep "Version:" | cut -d':' -f2- | tr -d '\n\r')
step_skip "Version:"
output_line "Version:$VERSION x$RATE"

step_skip "BeatmapID:"
output_line "BeatmapID:0"

step_skip "\[TimingPoints\]"
TIMINGPOINTS=$(echo "$FFILE" | grep -B $LINES "\[HitObjects\]" | head -n -1)
OBJECTS=$(echo "$FFILE" | grep -A $LINES "\[HitObjects\]" | tail -n +2)

output_line "[TimingPoints]"

N=$(echo "$TIMINGPOINTS" | wc -l)
I=0
for LINE in $TIMINGPOINTS
do
  # TODO: ignore colors
  I=$((I + 1))
  printf "Timing:  %s%%\r" $(echo "$I * 100 / $N" | bc)
  if [ -n "$(echo $LINE | grep ",")" ]
  then
    VAL=$(echo "$(echo "$LINE" | cut -d ',' -f1) / $RATE" | bc | cut -d '.' -f1)
    BPM=$(echo "$LINE" | cut -d',' -f7)
    if [ $BPM -eq 1 ] ; then
      VAL2=$(echo "$(echo "$LINE" | cut -d ',' -f2) / $RATE" | bc -l)
      output_line "$VAL,$VAL2,$(echo "$LINE" | cut -d ',' -f3-)"
    else
      output_line "$VAL,$(echo "$LINE" | cut -d ',' -f2-)"
    fi
  else
    output_line "$LINE"
  fi
done
echo ""

output_line "[HitObjects]"
N=$(echo "$OBJECTS" | wc -l)
I=0
for LINE in $OBJECTS
do
  I=$((I + 1))
  printf "Objects: %s%%\r" $(echo "$I * 100 / $N" | bc)
  if [ -n "$(echo $LINE | grep ",")" ]
  then
    V12=$(echo $LINE | cut -d',' -f-2)
    V3=$(echo "$(echo "$LINE" | cut -d ',' -f3) / $RATE" | bc | cut -d '.' -f1)
    V45=$(echo $LINE | cut -d',' -f4-5)
    V6=$(echo "$(echo $LINE | cut -d',' -f6 | cut -d':' -f1) / $RATE" | bc | cut -d '.' -f1)
    CPM=$(echo $LINE | cut -d':' -f2-)
    output_line "$V12,$V3,$V45,$V6:$CPM"
  else
    output_line $LINE
  fi
done
echo ""
audioRate