#!/bin/bash

# Relational pipes
# Copyright © 2020 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/>.


# This streamlet provides a single attribute: number of lines of given file
# Standard wc -l is used to count the lines.
# Directories are reported a 0 lines and with a null flag (will be supported in further Relational pipes versions).


. "$(dirname "$(realpath "$0")")/streamlet-common.sh"

processMessage_WAITING_FOR_OUTPUT_ATTRIBUTES_METADATA() {
	send OUTPUT_ATTRIBUTE_METADATA "${outputAttributeAliases[0]-lines_count}"    "integer"
	send WAITING_FOR_INPUT_ATTRIBUTES
}

processMessage_WAITING_FOR_OUTPUT_ATTRIBUTES() {
	if [[ -d "$currentFile" ]]; then
		isNull="true";
	else
		value=$(wc -l "$currentFile" | cut -d" " -f1);
		isNull="false";
	fi
	
	send OUTPUT_ATTRIBUTE "$value"    "$isNull";
	send WAITING_FOR_INPUT_ATTRIBUTES;
}

initialize
processMessages