expac

#!/usr/bin/env bash
set -eu

script_path="$( cd -P "$( dirname "$(readlink -f "${0}")" )" && pwd )"
pacman_dbpath="$(pacman-conf "DBPath")"
debug=false
work_dir="/tmp/expac"
expac_version="0.1"

msg_error(){ echo "[expac] Error ${*}" 1>&2; }
msg_info (){ echo "[expac]  Info ${*}" 1>&2; }
msg_warn (){ echo "[expac]  Warn ${*}" 1>&2; }
msg_debug(){ [[ "${debug}" = true ]] && echo "[expac] Debug ${*}" 1>&2; return 0;}

_help() {
    echo "usage ${0} [options] [package]"
    echo
    echo " General options:"
    echo "    -h | --help               This help message"
    echo
    echo "         --debug              Enable debug mode"
    echo "         --dbpath             Set datebase dir"
}

# readdb <file> <section>
readdb(){
    local _path="${1}" _section="${2}" _dblines _line _in_section=false
    readarray -t _dblines < "${_path}"
    for _line in "${_dblines[@]}"; do
        case "${_line}" in
            "%${_section}%")
                _in_section=true
                continue
                ;;
            "%"*"%")
                _in_section=false
                continue
                ;;
        esac
        [[ "${_in_section}" = true ]] && [[ -n "${_line}" ]] && echo "${_line}"
    done
}


# exportpkg <package>cat 
exportpkg(){
    local _version _package="${1}" _datebase _filelist=()

    # Check package
    if ! pacman -Qq "${_package}" 1> /dev/null 2>&1; then
        msg_error "${_package} is not installed"
        exit 1
    fi

    # Set package info
    _package="$(pacman -Q "${_package}" 2> /dev/null | cut -d " " -f 1)"
    _version="$(pacman -Q "${_package}" 2> /dev/null | cut -d " " -f 2)"
    _datebase="${pacman_dbpath}/local/${_package}-${_version}"
    msg_debug "Package datebase is ${_datebase}"

    # Read datebase
    msg_info "Loading package datebase ..."
    readarray -t _db_filelist < <(readdb "${_datebase}/files" FILES | grep -v "/$")
    readarray -t _db_depends < <(readdb "${_datebase}/desc" "DEPENDS")
    for _data in "NAME" "VERSION" "BASE" "DESC" "URL" "ARCH" "BUILDDATE" "INSTALLDATE" "PACKAGER" "SIZE" "LICENSE" "VALIDATION"; do
        #readarray -t "_db_${_data,,}" < <(readdb "${_datebase}/desc" "${_data}")
        printf -v "_db_${_data,,}" "$(readdb "${_datebase}/desc" "${_data}")"
    done

    # Create BUILDINFO
    msg_info "Creating .BUILDINFO ..."
    mkdir -p "${work_dir}/${_package}"
    local _buildinfo="${work_dir}/${_package}/.BUILDINFO" _write_buildinfo
    function _write_buildinfo(){ echo "${1} = ${2}" >> "${_buildinfo}"; }
    echo -n > "${_buildinfo}"
    _write_buildinfo "format" "1"
    _write_buildinfo "pkgname" "${_package}"
    _write_buildinfo "pkgbase" "${_db_base}"
    _write_buildinfo "pkgver" "${_db_version}"
    _write_buildinfo "pkgarch" "${_db_arch}"
    _write_buildinfo "packager" "${_db_packager}"
    _write_buildinfo "builddate" "${_db_builddate}"
    _write_buildinfo "builddir" "${work_dir}/${_package}"

    while read -r _pkg; do
        _write_buildinfo "installed" "${_pkg}-$(readdb "${pacman_dbpath}/local/${_pkg}/desc" "ARCH")"
    done < <(pacman -Q --color never | tr " " "-")

    # Create PKGINFO
    msg_info "Creating .PKGINFO ..."
    local _write_pkginfo _pkginfo="${work_dir}/${_package}/.PKGINFO"
    function _write_pkginfo(){ echo "${1} = ${2}" >> "${_pkginfo}"; }
    echo "# Generated by expac ${expac_version}" > "${_pkginfo}"
    _write_pkginfo "pkgname" "${_package}"
    _write_pkginfo "pkgbase" "${_db_base}"
    _write_pkginfo "pkgver" "${_db_version}"
    _write_pkginfo "pkgdesc" "${_db_desc}"
    _write_pkginfo "url" "${_db_url}"
    _write_pkginfo "builddate" "${_db_builddate}"
    _write_pkginfo "packager" "${_db_packager}"
    _write_pkginfo "size" "${_db_size}"
    _write_pkginfo "arch" "${_db_arch}"
    _write_pkginfo "license" "${_db_license}"

    for _pkg in "${_db_depends[@]}"; do
        _write_pkginfo "depend" "${_pkg}"
    done

    # Create MTREE
    msg_info "Creating .MTRE ..."
    cp -a "${_datebase}/mtree" "${work_dir}/${_package}/.MTREE"

    # Copy files
    for _file in "${_db_filelist[@]}"; do
        if [[ -f "/${_file}" ]]; then
            msg_info "Copying ${_file}"
            mkdir -p "${work_dir}/${_package}/$(dirname "${_file}")"
            cp -a "/${_file}" "${work_dir}/${_package}/$(dirname "${_file}")"
        else
            msg_warn "${_file} was not found"
        fi
    done

    # Create archive
    (
        cd "${work_dir}/${_package}"
        readarray -t _archive_list < <(find ./ -mindepth 1 -maxdepth 1 -printf "%P\n")
        tar -v -c -I zstd -f "${script_path}/${_package}-${_db_version}-${_db_arch}.pkg.tar.zst" "${_archive_list[@]}"
    
    )
    
}

# Parse options
OPTS=("h")
OPTL=("debug" "help" "dbpath:")
if ! OPT=$(getopt -o "$(printf "%s," "${OPTS[@]}")" -l "$(printf "%s," "${OPTL[@]}")" --  "${@}"); then
    exit 1
fi

eval set -- "${OPT}"
msg_debug "Argument: ${OPT}"
unset OPT OPTS OPTL

while true; do
    case "${1}" in
        --debug)
            debug=true
            shift 1
            ;;
        --dbpath)
            pacman_dbpath="${2}"
            shift 2
            ;;
        -h | --help)
            _help
            exit 0
            ;;
        --)
            shift
            break
            ;;
        *)
            msg_error "Invalid argument '${1}'"
            _help
            exit 1
            ;;
    esac
done

for pkg in "${@}"; do
    exportpkg "${pkg}"
done