#!/bin/sh

## TODO: add support for DLAGENT.
## TODO: add support for curl.

_printhelp()
{
    cat<<EOF
Usage: ${1##*/} [OPTIONS] PKGBUILDs

Convert an Arch Linux PKGBUILD to a universal standalone bash script. (The
infamous 'bash' is assumed because PKGBUILD are bash scripts, they strongly rely
on arrays.)  The resulting script tries to resemble makepkg build process where
it makes sense. There is no dependency resolution because we cannot guess the
package names of the target system.

Differences with makepkg
* Parameters may differ.
* The progress output may differ.
* Some features are not yet implemented (e.g. explicit source filename)

Options:

  -h:  Show this help.
  -f:  Overwrite existing builder.
  -l:  Install in usr/local/ instead of usr/.

EOF
}

OPT_LOCAL=false
OPT_OVERWRITE=false
while getopts ":flh" opt; do
    case $opt in
        h)
            _printhelp "$0"
            exit 1 ;;
        l)
            OPT_OVERWRITE=true ;;
        l)
            OPT_LOCAL=true ;;
        ?)
            _printhelp "$0"
            exit 1 ;;
        :)
            _printhelp "$0"
            exit 1 ;;
    esac
done

shift $(($OPTIND - 1))

if [ $# -eq 0 ]; then
    _printhelp "$0"
    exit 1
fi


if ! command -v realpath >/dev/null; then
    echo "You need 'realpath'"
    exit
fi


for i ; do
    if [ ! -f "$i" ]; then
        echo "$i must be a PKGBUILD file."
        continue
    fi

    OUTPATH="$(realpath "$i")"
    OUTPATH="${OUTPATH%/*}"
    PKGNAME="$(awk -F= '/^pkgname/{print $2}' "$i")"
    UBUILD="${OUTPATH}/$PKGNAME.sh"

    if [ -f "$UBUILD" ] && ! $OPT_OVERWRITE; then
        echo "$UBUILD already exists."
        continue
    fi

    cat<<"EOF" > "$UBUILD"
#!/bin/bash

if ! command -v realpath >/dev/null; then
    echo "You need 'realpath'."
    exit
fi
if ! command -v wget >/dev/null; then
    echo "You need 'wget'."
    exit
fi

################################################################################
EOF

    if $OPT_LOCAL; then
        sed -e 's|/usr|/usr/local|g' "$i" >> "$UBUILD"
    else
        cat "$i" >> "$UBUILD"
    fi

    cat  "${0%/*}/.${0##*/}.in" >> "$UBUILD"
    chmod +x "$UBUILD"
done