#!/bin/bash
# License: Unspecified

shopt -s extglob

m4_include(lib/common.sh)

# Source makepkg.conf; fail if it is not found
if [[ -r '/etc/makepkg.conf' ]]; then
	# shellcheck source=makepkg-x86_64.conf
	source '/etc/makepkg.conf'
else
	die '/etc/makepkg.conf not found!'
fi

# Source user-specific makepkg.conf overrides
if [[ -r "${XDG_CONFIG_HOME:-$HOME/.config}/pacman/makepkg.conf" ]]; then
	# shellcheck source=/dev/null
	source "${XDG_CONFIG_HOME:-$HOME/.config}/pacman/makepkg.conf"
elif [[ -r "$HOME/.makepkg.conf" ]]; then
	# shellcheck source=/dev/null
	source "$HOME/.makepkg.conf"
fi

usage() {
    cat <<- _EOF_
		Usage: ${BASH_SOURCE[0]##*/} [OPTIONS]

		Searches for a locally built package corresponding to the PKGBUILD, and
		downloads the last version of that package from the Pacman repositories.
		It then compares the list of .so files provided by each version of the
		package and outputs if there are soname differences for the new package.
		A directory is also created using mktemp with files containing a file
		list for both packages and a library list for both packages.

		OPTIONS
		    -r, --rmdir     Remove the temporary directory
		    -w, --warn      Print a warning in case of differences
		    -h, --help      Show this help text
_EOF_
}

RMDIR=0
WARN=0

OPT_SHORT='rwh'
OPT_LONG=('rmdir' 'warn' 'help')
if ! parseopts "$OPT_SHORT" "${OPT_LONG[@]}" -- "$@"; then
    exit 1
fi
set  -- "${OPTRET[@]}"

while :; do
    case $1 in
        -r|--rmdir)
            RMDIR=1
            ;;
        -w|--warn)
            WARN=1
            ;;
        -h|--help)
            usage
            exit 0
            ;;
        --)
            shift; break
            ;;
    esac
    shift
done

if [[ ! -f PKGBUILD ]]; then
	die 'This must be run in the directory of a built package.'
fi

# shellcheck source=PKGBUILD.proto
. ./PKGBUILD
if [[ ${arch[0]} == 'any' ]]; then
	CARCH='any'
fi

STARTDIR=$(pwd)
(( RMDIR )) && trap 'rm -rf $TEMPDIR' EXIT INT TERM QUIT
TEMPDIR=$(mktemp -d --tmpdir checkpkg-script.XXXX)

for _pkgname in "${pkgname[@]}"; do
	comparepkg=$_pkgname
	pkgurl=
	target_pkgver=$(get_full_version "$_pkgname")
	if ! pkgfile=$(find_cached_package "$_pkgname" "$target_pkgver" "$CARCH"); then
		die 'tarball not found for package: %s' "${_pkgname}-$target_pkgver"
	fi

	ln -s "$pkgfile" "$TEMPDIR"

	if (( $# )); then
		case $1 in
			*://*)
				pkgurl=$1 ;;
			/*|*/*)
				pkgurl=$(readlink -m "$1") ;;
			*.pkg.tar*)
				pkgurl=$1 ;;
			'')
				;;
			*)
				comparepkg=$1 ;;
		esac
		shift
	fi
	[[ -n $pkgurl ]] || pkgurl=$(pacman -Spdd --print-format '%l' --noconfirm "$comparepkg") ||
		die "Couldn't download previous package for %s." "$comparepkg"

	oldpkg=${pkgurl##*/}

	if [[ ${oldpkg} = "${pkgfile##*/}" ]]; then
		die "The built package (%s) is the one in the repo right now!" "$_pkgname"
	fi

	if [[ $pkgurl = file://* || ( $pkgurl = /* && -f $pkgurl ) ]]; then
		ln -s "${pkgurl#file://}" "$TEMPDIR/$oldpkg"
	elif [[ -f "$PKGDEST/$oldpkg" ]]; then
		ln -s "$PKGDEST/$oldpkg" "$TEMPDIR/$oldpkg"
	elif [[ -f "$STARTDIR/$oldpkg" ]]; then
		ln -s "$STARTDIR/$oldpkg" "$TEMPDIR/$oldpkg"
	else
		curl -fsLC - --retry 3 --retry-delay 3 -o "$TEMPDIR/$oldpkg" "$pkgurl"
	fi

	bsdtar tf "$TEMPDIR/$oldpkg" | sort > "$TEMPDIR/filelist-$_pkgname-old"
	bsdtar tf "$pkgfile" | sort > "$TEMPDIR/filelist-$_pkgname"

	sdiff -s "$TEMPDIR/filelist-$_pkgname-old" "$TEMPDIR/filelist-$_pkgname"

	find-libprovides "$TEMPDIR/$oldpkg" 2>/dev/null | sort > "$TEMPDIR/libraries-$_pkgname-old"
	find-libprovides "$pkgfile" 2>/dev/null | sort > "$TEMPDIR/libraries-$_pkgname"
	if ! diff_output="$(sdiff -s "$TEMPDIR/libraries-$_pkgname-old" "$TEMPDIR/libraries-$_pkgname")"; then
		message="Sonames differ in $_pkgname!"
		(( WARN )) && warning "$message" || msg "$message"
		echo "$diff_output"
	else
		msg "No soname differences for %s." "$_pkgname"
	fi
done

(( RMDIR )) || msg "Files saved to %s" "$TEMPDIR"