#!/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: OCR recognized texf of given image file. It calls the tool tesseract.

# Languages can be specified by: --option "language" "eng" --option "language" "ces"

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

processMessage_WAITING_FOR_OUTPUT_ATTRIBUTES_METADATA() {

	tesseractLanguage="";

	for (( i=0; i<${#optionNames[@]}; i++)); do

		if [[ "x${optionNames[$i]}" == "xlanguage" ]]; then

			tesseractLanguage+="+${optionValues[$i]}";

		else

			echo "Unsupported option: ${optionNames[$i]}" >&2

		fi

	done

	send OUTPUT_ATTRIBUTE_METADATA "${outputAttributeAliases[0]-tesseract}"    "string"

	send WAITING_FOR_INPUT_ATTRIBUTES

}

processMessage_WAITING_FOR_OUTPUT_ATTRIBUTES() {

	value="$(cat "$currentFile" | tesseract stdin stdout "${tesseractLanguage:+-l}" "${tesseractLanguage}")";

	if   [[ "x$?" == "x0" ]]; then isNull="false"; else value=""; isNull="true"; fi

	value="$(echo "$value" | tr -d \\f)"

	send OUTPUT_ATTRIBUTE "$value"    "$isNull";

	send WAITING_FOR_INPUT_ATTRIBUTES;

}

initialize

processMessages