#!/bin/sh

version='1.1'

rick='https://f.freya.cat/rick'
video="$rick/astley80.full.bz2"
audio_gsm="$rick/roll.gsm"
audio_raw="$rick/roll.s16"
audpid=0

red='\x1b[38;5;9m'
yell='\x1b[38;5;216m'
green='\x1b[38;5;10m'
purp='\x1b[38;5;171m'
echo -en '\x1b[s'

has() { hash $1 2>/dev/null; }
cleanup() { (( audpid > 1 )) && kill $audpid 2>/dev/null; }
quit() { echo -e "\x1b[2J \x1b[0H ${purp}<3 \x1b[?25h \x1b[u \x1b[m"; }

trap "cleanup" INT
trap "quit" EXIT

obtainium() {
  if has curl; then curl -L -s "$1"
  elif has wget; then wget -q -O - "$1"
  else echo "Cannot has internets. :(" && exit
  fi
}

if ! has bunzip2; then
	echo "Cannot has decompression. :(" && exit
fi

echo -en "\x1b[?25l \x1b[2J \x1b[H"

if has afplay; then
  # On Mac OS, if |afplay| available, pre-fetch compressed audio.
  [ -f /tmp/roll.s16 ] || obtainium "$audio_raw" >/tmp/roll.s16
  afplay /tmp/roll.s16 &
elif has aplay; then
  # On Linux, if |aplay| available, stream raw sound.
  obtainium "$audio_raw" | aplay -Dplug:default -q -f S16_LE -r 8000 &
elif has play; then
  # On Cygwin, if |play| is available (via sox), pre-fetch compressed audio.
  obtainium "$audio_gsm" >/tmp/roll.gsm.wav
  play -q /tmp/roll.gsm.wav &
fi
audpid="$!"

# Sync FPS to reality as best as possible. Mac's freebsd version of date cannot
# has nanoseconds so inject python. :/
python <(cat <<EOF
import sys
import time
fps = 25; time_per_frame = 1.0 / fps
buf = ''; frame = 0; next_frame = 0
begin = time.time()
try:
  for i, line in enumerate(sys.stdin):
    if i % 32 == 0:
      frame += 1
      sys.stdout.write(buf); buf = ''
      elapsed = time.time() - begin
      repose = (frame * time_per_frame) - elapsed
      if repose > 0.0:
        time.sleep(repose)
      next_frame = elapsed / time_per_frame
    if frame >= next_frame:
      buf += line
except KeyboardInterrupt:
  pass
EOF
) < <(obtainium $video | bunzip2 -q 2> /dev/null)