# Relational pipes
# Copyright © 2019 František Kučera (Frantovo.cz, GlobalCode.info)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

_relpipe_tr_xpath_completion() {
	local w0 w1 w2 w3

	COMPREPLY=()
	w0=${COMP_WORDS[COMP_CWORD]}
	w1=${COMP_WORDS[COMP_CWORD-1]}
	w2=${COMP_WORDS[COMP_CWORD-2]}
	w3=${COMP_WORDS[COMP_CWORD-3]}

	DATA_TYPE=(
		"string"
		"integer"
		"boolean"
	)

	INPUT_ATTRIBUTE_POLICY=(
		"append"
		"prepend"
		"auto"
	)

	# FIXME: user must type " and then press TAB otherwise the completion is broken due to the : colon
	#
	# can be fixed by global modification of environment variable:
	#	COMP_WORDBREAKS=${COMP_WORDBREAKS//:}
	# but it will affect other completions (where : is a separator)
	#
	# these functions should help:
	#	_get_comp_words_by_ref -n : cur
	#	__ltrim_colon_completions "$cur"
	# but was not working (despite w0 renamed to cur)
	XMLNS=(
		"tag:globalcode.info,2018:relpipe"
		"http://www.w3.org/1999/xhtml"
		"http://www.w3.org/2000/svg"
		"http://www.w3.org/2005/Atom"
		"http://docbook.org/ns/docbook"
	)


	if   [[ "$w1" == "--relation"                      && "x$w0" == "x" ]];    then COMPREPLY=("'.*'")
	elif [[ "$w1" == "--where"                         && "x$w0" == "x" ]];    then COMPREPLY=("''")
	elif [[ "$w1" == "--xml-attribute"                 && "x$w0" == "x" ]];    then COMPREPLY=("''")
	elif [[ "$w1" == "--output-attribute"              && "x$w0" == "x" ]];    then COMPREPLY=("''")
	elif [[ "$w2" == "--output-attribute"                               ]];    then COMPREPLY=($(compgen -W "${DATA_TYPE[*]}" -- "$w0"))
	elif [[ "$w3" == "--output-attribute"              && "x$w0" == "x" ]];    then COMPREPLY=("''")
	elif [[ "$w1" == "--namespace"                     && "x$w0" == "x" ]];    then COMPREPLY=("''")
	elif [[ "$w2" == "--namespace"                                      ]];    then COMPREPLY=($(compgen -W "${XMLNS[*]}" -- "$w0"))
	elif [[ "$w1" == "--input-attributes"                               ]];    then COMPREPLY=($(compgen -W "${INPUT_ATTRIBUTE_POLICY[*]}" -- "$w0"))
	else
		OPTIONS=(
			"--namespace"
			"--relation"
			"--where"
			"--output-attribute"
			"--input-attributes"
			"--xml-attribute"
		)
		COMPREPLY=($(compgen -W "${OPTIONS[*]}" -- "$w0"))
	fi
}

complete -F _relpipe_tr_xpath_completion relpipe-tr-xpath
