#!/usr/bin/env bash

# Either set DIR to the same value as supybot.plugins.PackageInfo.aptdir,
# or use the --dir command-line option.
DIR=""

# Be quiet by default.
VERBOSE=0

## Please don't change anything below this line, unless you really know what
## you are doing and don't bother me with whatever errors it produces :)

# Print usage information.
usage() {
    cat <<EOF
Usage: $0 [OPTION]...

Updates the APT package cache for PackageInfo.

-d, --dir <DIR>       Specify directory for APT package cache.
-v, --verbose         Be more verbose than normal.
-V, --very-verbose    Be even more verbose than normal.
-h, --help            Display this message and exit.

Note:
  Please separate each option with a space, eg:
      $0 -v -d /home/bot/aptdir
  Rather than:
      $0 -vd /home/bot/aptdir

This script is intended to be run automatically (eg: cron), so it shows no output by default.
You can make the script more verbose with the -v/--verbose or -V/--very-verbose options.
The -d/--dir option sets the directory where this script looks for *.list files for apt-get.
EOF
}

# Prints an error message, usage (above), then exits with the specified exit value.
error() {
    local exit_val=$1
    shift
    echo "$@" >&2
    usage >&2
    exit $exit_val
}

# Runs apt-get update in the specified directory for the specified distribution.
update_apt() {
    if [ $VERBOSE -eq 0 ]; then
        apt_args="-qq"
    elif [ $VERBOSE -eq 1 ]; then
        apt_args="-q"
    fi

    apt-get $apt_args \
        -o="APT::Architecture=amd64" \
        -o="APT::Architectures::=i386" \
        -o="APT::Architectures::=amd64" \
        -o="Dir::State::Lists=$DIR/$DIST" \
        -o="Dir::State::Status=$DIR/$DIST.status" \
        -o="Dir::Etc::SourceList=$DIR/$DIST.list" \
        -o="Dir::Etc::SourceParts=''" \
        -o="Dir::Etc::trusted=/usr/share/keyrings/debian-archive-keyring.gpg" \
        -o="Dir::Etc::trusted=/usr/share/keyrings/ubuntu-archive-keyring.gpg" \
        -o="Dir::Cache=$DIR/cache" \
        update
}

# Check command-line arguments
while [ $# -gt 0 ]; do
    case $1 in
        -h|--help)
            usage
            exit 0
            ;;
        -v|--verbose)
            VERBOSE=1
            ;;
        -V|--very-verbose)
            VERBOSE=2
            ;;
        -d|--dir)
            [ -z "$2" ] && error 1 '"-d/--dir" requires an argument.'
            shift
            DIR="$1"
            ;;
        --dir=*)
            DIR="${1:6}"
            [ -z "$DIR" ] && error 1 '"--dir" requires an argument.'
            ;;
        -*)
            error 1 "Unknown option \"$1\"."
            ;;
        *)
            error 1 "This script takes no non-argument parameters."
            ;;
    esac
    shift
done

# Check if apt-get is installed and bail if not.
if ! which apt-get >/dev/null 2>&1; then
    echo "ERROR: apt-get not found. Please install apt-get in your PATH." >&2
    exit 1
fi

if [ -z "$DIR" ]; then
    error 1 "ERROR: No DIR set in the script and no -d/--dir option given."
fi

items=("$DIR"/*.list)
[ ! -e "${items[0]}" ] && error 1 "ERROR: Could not find any *.list files in \"$DIR\"."

for DIST in "${items[@]}"; do
    [ -h "$DIST" ] && continue # Ignore symbolic links
    # Extract the distribution name from the .list file name.
    DIST=${DIST##*/}
    DIST=${DIST%.list}

    [ $VERBOSE -gt 0 ] && echo "INFO: Processing $DIST"
    touch "$DIR/$DIST.status" # Create APT status file
    mkdir -p "$DIR/$DIST/partial" # APT needs this to exist
    update_apt # Update APT package cache
    if [ $? -ne 0 ]; then
        [ $VERBOSE -eq 0 ] && echo "Try passing -v or -V to get the error message." >&2
        echo "ERROR: apt-get update failed for $DIST." >&2
        exit_val=$?
    fi
done
exit $exit_val