#!/bin/bash

set -o errexit
set -o errtrace
set -o pipefail
set -o nounset

readonly progpath="$(realpath "$0")"
readonly progname="$(basename "$progpath")"
readonly progdir="$(dirname "$progpath")"

perl_corelist() {
    PATH="${prefix}/bin:${prefix}/bin/core_perl" corelist -v "$1" \
    | dos2unix \
    | tail -n+3 \
    | awk '{
        if ( $1 !~ /^\s*$/ ) {
            gsub(/::/, "-", $1)
            if ( $2 !~ /^\s*$/ ) {
                printf "perl-%s=%s\n", $1, $2
            } else {
                printf "perl-%s\n", $1
            }
        }
    }'
}

usage() {
    echo "   Usage: $progname <PKGBUILD> [<perl version>]"
    echo
    echo "   Perl and gawk (mingw-w64) needs to be installed"
    echo
    [[ "${1:-}" =~ ^[0-9]{1,3}$ ]] && exit $1
}

pkgbuild="${1:-}"
[[ -f "$pkgbuild" ]] || usage 1

if [[ -n "${MINGW_PREFIX:-}" ]]; then
    if [[ -x "${MINGW_PREFIX}/bin/perl" ]]; then
        prefix="${MINGW_PREFIX}"
    fi
elif [[ -x "/mingw64/bin/perl" ]]; then
    prefix="/mingw64"
elif [[ -x "/mingw32/bin/perl" ]]; then
    prefix="/mingw32"
fi
[[ -n "${prefix:-}" ]] || usage 1

command -v gawk &>/dev/null || usage 1

version="${2:-}"
if [[ -n "$version" ]]; then
    [[ "$version" =~ ^[1-9][0-9]*(\.[0-9]+)*$ ]] || usage 1
else
    [[ "$("${prefix}/bin/perl" -V:version)" =~ ^version=\'(.*)\'\; ]]
    version="${BASH_REMATCH[1]}"
fi

declare -r tmpfile="$(mktemp)"
perl_corelist "$version" \
| while IFS='' read -r line; do
    if [[ "$line" =~ ^perl-[[:alnum:]_\-]+=(v?[0-9_\.]+)$ ]]; then
        ver="$(perl -Mversion -le 'print version->parse("'"${BASH_REMATCH[1]}"'")->normal;')"
        line="${line/%"${BASH_REMATCH[1]}"/"${ver#"v"}"}"
    fi
    echo "${line,,}"
done \
| sort -f > "$tmpfile"

mv "$pkgbuild" "$pkgbuild~"

gawk '
/^provides=/ { s = 1 }
s && /)/ {
    s = 0
    print "provides=("
    while ( (getline line < "'"$tmpfile"'") > 0 ) {
        print "    \"${MINGW_PACKAGE_PREFIX}-" line "\""
    }
    print ")"
    next
}
s { next }
! s { print }
' "$pkgbuild~" > "$pkgbuild"

rm "$tmpfile"

# vim: set ts=4 sw=4 et ai: