#!/bin/bash

# eccc_to_commons - Batch convert Environment and Climate change Canada
#                   historical XML data into a JSON format suitable for
#                   Wikimedia Commons.
# Copyright (C) 2019-2020  Pierre Choffet
#
# 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, either version 3 of the License, or
# (at your option) any later version.
#
# 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/>.

set -e

SOURCE="${1}"
DESTINATION="${2}"

if [ -z "${SOURCE}" ]||[ -z "${DESTINATION}" ]||[ ! -d "${DESTINATION}" ]
then
	echo 'Fix XMLs provided by Environment and Climate change Canada'
	echo 'Usage: eccc_to_commons.sh <source folder> <destination folder>'
	exit 1
fi

# Loop on xml files in source folder
while IFS= read -r -d '' -u 9
do
	# Check XML type
	declare -i STATIONDATA_COUNT=$(xmlstarlet sel -t -v 'count(//stationdata)' "${REPLY}")
	declare -i YEAR_COUNT=$(xmlstarlet sel -t -v 'count(//stationdata[@year])' "${REPLY}")
	declare -i MONTH_COUNT=$(xmlstarlet sel -t -v 'count(//stationdata[@month])' "${REPLY}")
	declare -i DAY_COUNT=$(xmlstarlet sel -t -v 'count(//stationdata[@day])' "${REPLY}")
	declare -i HOUR_COUNT=$(xmlstarlet sel -t -v 'count(//stationdata[@hour])' "${REPLY}")
	declare -i MINUTE_COUNT=$(xmlstarlet sel -t -v 'count(//stationdata[@minute])' "${REPLY}")
	declare -i AL_MONTH_COUNT=$(xmlstarlet sel -t -v 'count(//month)' "${REPLY}")

	# Detect climate id
	declare LAST_DIR=$(basename $(dirname "${REPLY}"))
	declare FILENAME=$(basename "${REPLY%.*}")

	if [[ "${LAST_DIR}" =~ ^[A-Z0-9]{7}$ ]]
	then
		# Climate id is in last directory name
		CLIMATE_ID="${LAST_DIR}"
	elif [[ "${FILENAME}" =~ ^[A-Z0-9]{7}$ ]]
	then
		# Climate id is in file name
		CLIMATE_ID="${FILENAME}"
	else
		echo "${REPLY}: Cannot detect climate id"
		exit 1
	fi

	if [ ${AL_MONTH_COUNT} -eq 0 ]&& \
	   [ ${STATIONDATA_COUNT} -gt 0 ]&& \
	   [ ${STATIONDATA_COUNT} -eq ${YEAR_COUNT} ]&& \
	   [ ${STATIONDATA_COUNT} -eq ${MONTH_COUNT} ]&& \
	   [ ${STATIONDATA_COUNT} -eq ${DAY_COUNT} ]&& \
	   [ ${STATIONDATA_COUNT} -eq ${HOUR_COUNT} ]&& \
	   [ ${STATIONDATA_COUNT} -eq ${MINUTE_COUNT} ]
	then
		echo "${REPLY}: Hourly data not compatible yet. Ignoring." >&2
		continue
	elif [ ${AL_MONTH_COUNT} -eq 0 ]&& \
	     [ ${STATIONDATA_COUNT} -gt 0 ]&& \
	     [ ${STATIONDATA_COUNT} -eq ${YEAR_COUNT} ]&& \
	     [ ${STATIONDATA_COUNT} -eq ${MONTH_COUNT} ]&& \
	     [ ${STATIONDATA_COUNT} -eq ${DAY_COUNT} ]&& \
	     [ ${HOUR_COUNT} -eq 0 ]&& \
	     [ ${MINUTE_COUNT} -eq 0 ]
	then
		echo "${REPLY}: Daily data not compatible yet. Ignoring." >&2
		continue
	elif [ ${AL_MONTH_COUNT} -eq 0 ]&& \
	     [ ${STATIONDATA_COUNT} -gt 0 ]&& \
	     [ ${STATIONDATA_COUNT} -eq ${YEAR_COUNT} ]&& \
	     [ ${STATIONDATA_COUNT} -eq ${MONTH_COUNT} ]&& \
	     [ ${DAY_COUNT} -eq 0 ]&& \
	     [ ${HOUR_COUNT} -eq 0 ]&& \
	     [ ${MINUTE_COUNT} -eq 0 ]
	then
		STYLESHEET_PATH='monthly_to_commons.xslt'
		DESTINATION_PATH="${DESTINATION}/weather.gc.ca/Monthly/${CLIMATE_ID}.tab"
	elif [ ${STATIONDATA_COUNT} -eq 0 ]&& \
	     [ ${AL_MONTH_COUNT} -gt 0 ]
	then
		STYLESHEET_PATH='almanac_to_commons.xslt'
		DESTINATION_PATH="${DESTINATION}/weather.gc.ca/Almanac/${CLIMATE_ID}.tab"
	else
		echo "${REPLY}: Cannot detect file type. Exiting."
		exit 1
	fi

	echo "Processing ${REPLY} to ${DESTINATION_PATH}…" >&2
	mkdir -p "$(dirname "${DESTINATION_PATH}")"
	xmlstarlet tr "${STYLESHEET_PATH}" "${REPLY}" | jq > "${DESTINATION_PATH}"
done 9< <( find "${SOURCE}" -type f -name '*.xml' -print0 )