#!/usr/bin/env bash
# YouStore: convert any set of files/dirs into a video file
# that's also (somewhat) resistant to re-encoding
# Usage: ys [e|d] [vidfile] [path...] [path...]
# Dependencies: tar, zstd, truncate (coreutils), xpar, openssl, ffmpeg
# Created by Luxferre in 2026, released into the public domain

BASEW=320  # base frame width
BASEH=180  # base frame height
SCL=4      # frame scale factor
FR=60      # frame rate in the output video
CODEC_PARAMS='-c:v libvpx-vp9 -lossless 1 -deadline realtime -speed 8 -row-mt 1 -aq-mode 0 -pix_fmt yuv420p -f webm'

BPF=$(( BASEW * BASEH / 8 )) # bytes per frame
if [[ "$1" = "e" ]]; then
  OUTFILE="$2"
  shift
  shift
  ARCHFILE="$(mktemp -u)"
  PARFILE="$(mktemp -u)"
  ENCFILE="$(mktemp -u)"
  echo "Compressing..."
  tar --use-compress-program='zstd -19' -cf "$ARCHFILE" -- $*
  echo "Encrypting..."
  [[ -z "$YS_PASS" ]] && read -rs -p 'Password: ' YS_PASS
  openssl aes-256-cbc -e -pbkdf2 -in "$ARCHFILE" -out "$ENCFILE" -pass "pass:$YS_PASS"
  echo "Adding redundancy..."
  xpar -Je -i 3 -H blake2b "$ENCFILE" "$PARFILE"
  truncate -s $(( ( $(stat -c%s "$PARFILE") + BPF - 1 ) / BPF * BPF )) "$PARFILE"
  echo "Encoding video..."
  ffmpeg -hide_banner -f rawvideo -pixel_format monob -video_size ${BASEW}x${BASEH} -framerate $FR -i "$PARFILE" -vf "scale=iw*${SCL}:ih*${SCL}:flags=neighbor,format=monob" $CODEC_PARAMS "${OUTFILE}.webm"
  rm -f "$ARCHFILE" "$PARFILE" "$ENCFILE"
  echo "Done!"
elif [[ "$1" = "d" ]]; then
  PARFILE="$(mktemp -u)"
  echo "Decoding video..."
  ffmpeg -hide_banner -i "$2" -vf "scale=${BASEW}:${BASEH}:flags=neighbor,format=monob" -f rawvideo "$PARFILE"
  echo "Restoring, decrypting and decompressing..."
  [[ -z "$YS_PASS" ]] && read -rs -p 'Password: ' YS_PASS
  xpar -Jdc "$PARFILE" | openssl aes-256-cbc -d -pbkdf2 -pass "pass:$YS_PASS" | tar --use-compress-program='zstd' -xf -
  rm -f "$PARFILE"
  echo "Done!"
else
  echo "Invalid mode! Use e or d"
fi