#!/bin/bash

shellfu import pretty

#
# Poor man's xpath tool
#
# Most good xpath qruery tools won't work on RHEL5; Perl's XML::XPath
# is even missing aarch64 in RHEL7 (not sure if this is intentional).
#
# For this reason this simple script exists; it should only require
# libxml2 and its Python bindings.
#

pxpath() {
    #
    # Run XPath query $1 on file $2, register namespaces $3..
    #
    # Usage:
    #
    #     pxpath [-f FMT] EXPR FILE [NSNAME:NSURI]..
    #
    # Run EXPR expression on XML FILE using Python bindings to libxml2.
    # Optionally, you can specify own namespaces; each has to have name
    # and reference URI.
    #
    # FMT is printf-like format string with single '%s' to which every
    # match is inserted prior to printing.  Default is '%s\n', that is.
    # each match is terminated with single newline.
    #
    # FILE can be '-' (single dash), in which case standard input
    # is (cached and) parsed.
    #
    # If DEBUG environment variable is set to '1', will print match
    # debug info to standard error output.
    #
    local query
    local file
    local tmp
    local es=0
    while true; do case $1 in
        -f) fmt+=("$2");        shift 2 || { __pxpath__usage; return 2; } ;;
        -*) __pxpath__usage; return 2 ;;
        *)  break ;;
    esac done
    query=$1; file=$2; shift 2
    test -n "$query" || { __pxpath__usage; return 2; }
    case $file in
        "")
            __pxpath__usage
            return 2
            ;;
        -)
            tmp=$(mktemp -t pxpath.stdin.XXXXXXXX)
            cat > "$tmp"
            file=$tmp
            ;;
        *)
            test -f "$file" || {
                warn "no such file, ignoring query: $file"
                return 1
            }
    esac
    #shellcheck disable=SC2154
    "$_PXPATH__BIN" \
        "$query" "$file" "$@"; es=$?
    test -n "$tmp" && rm "$tmp"
    return $es
}

#          #                             code below should not be called #
# INTERNAL # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
#          #                                not even as XPath expression #

#
# Path to pxpath python script
#
_PXPATH__BIN=${_PXPATH__BIN:-__SHELLFU_LIBEXEC__/pxpath}

__pxpath__usage() {
    #
    # Print usage message for function pxpath__$1
    #
    local base="usage: pxpath"
    mkusage -E "$base [-f FMT] EXPR FILE [NSNAME:NSURI]"
}

#shellfu module-version=__MKIT_PROJ_VERSION__