#!/bin/sh
set -e

NOW=$(date +'%Y-%m-%d')

# Raspberry Pi images are built by modifying a Debian 12 image for the Raspberry
# Pi 4 family:
RASPBERRYPI_IMG_URL=https://pirogue.apt.debamax.com/raspi-images/raspi_4_bookworm.img.xz
RASPBERRYPI_SHA_URL="$RASPBERRYPI_IMG_URL.sha256"

# Use a stable name to avoid leaving various files behind when the URL gets
# updated:
RASPBERRYPI_IMG=raspi_4_bookworm.img

# Basename for the target images:
PIROGUE34_IMG="PiRogue-OS-12-Pi3_and_Pi4-$NOW.img"
PIROGUE5E_IMG="PiRogue-OS-12-Pi5-Experimental-$NOW.img"

# List of things we produce:
MANIFEST=$(realpath MANIFEST.txt)
TOP_DIR=$(pwd)


# Helpers:
#  - prefer parallel compression if available:
xz_compress() {
  FILE="$1"

  # PTS images are published as compressed images alongside checksums for those
  # compressed images (as opposed to checksums for the uncompressed images). To
  # make sure everything is consistent, compare checksum of the original file
  # vs. checksum of a decompressed compressed image:
  echo "Computing checksum for $FILE..."
  SUM1=$(sha256sum "$FILE" | awk '{print $1}')
  echo "  $SUM1"

  if which pixz >/dev/null 2>&1; then
    echo "Compressing $FILE with pixz..."
    pixz "$FILE"
    echo '  done'
  else
    echo "Compressing $FILE with xz..."
    xz "$FILE"
    echo '  done'
  fi

  echo "Computing checksum for $FILE after decompression..."
  SUM2=$(xz -c -d "$FILE.xz" | sha256sum | awk '{print $1}')
  if [ "$SUM1" = "$SUM2" ]; then
    echo "  $SUM2 (match)"
  else
    echo "  $SUM2 (NO MATCH), exiting!"
    exit 1
  fi
}

#  - compute checksum and remember both target file and checksum file:
checksum_and_publish() {
  FILE="$1"
  sha256sum "$FILE" > "$FILE.sha256"
  SUB_DIR=$(pwd | sed "s,^$TOP_DIR/,,")
  echo "$SUB_DIR/$FILE"        >> "$MANIFEST"
  echo "$SUB_DIR/$FILE.sha256" >> "$MANIFEST"
}


# Start afresh, manifest-wise:
rm -f "$MANIFEST"

# We might need to descend into different directories, subshells are
# a way to do that:
(
  # Download and check (after switching to the stable name):
  cd raspberrypi
  wget -O $RASPBERRYPI_IMG.xz        "$RASPBERRYPI_IMG_URL"
  wget -O $RASPBERRYPI_IMG.xz.sha256 "$RASPBERRYPI_SHA_URL"
  sed "s/  .*$/  $RASPBERRYPI_IMG.xz/" -i $RASPBERRYPI_IMG.xz.sha256
  shasum -c $RASPBERRYPI_IMG.xz.sha256

  # Modify, compress, and checksum:
  sudo ./toaster $RASPBERRYPI_IMG.xz "$PIROGUE34_IMG" recipes/pi3-pi4.sh
  sudo ./toaster $RASPBERRYPI_IMG.xz "$PIROGUE5E_IMG" recipes/pi5.sh
  xz_compress "$PIROGUE34_IMG"
  xz_compress "$PIROGUE5E_IMG"
  checksum_and_publish "$PIROGUE34_IMG.xz"
  checksum_and_publish "$PIROGUE5E_IMG.xz"
)