#!/bin/sh

set -o errexit
set -o nounset

SCRIPTS_DIR="$(CDPATH= cd -- "$(dirname -- "${0}")" && pwd)"
ROOT_DIR="$(dirname -- "${SCRIPTS_DIR}")"
DATA_DIR="${ROOT_DIR}/data"

. "${SCRIPTS_DIR}/common"


# Get the list of PHP extensions from the data file
#
# Arguments:
# $1: the path to the data file
#
# Output:
# the list of PHP extensions
getExtensionList () {
	getExtensionList_extensions=''
	IFS='
'
	for getExtensionList_line in $(cat -- "${1}" | sort)
	do
		getExtensionList_extension=''
		IFS=' 	'
		for getExtensionList_chunk in ${getExtensionList_line}
		do
			if test -z "${getExtensionList_extensions}"
			then
				getExtensionList_extensions="${getExtensionList_chunk}"
			else
				getExtensionList_extensions="${getExtensionList_extensions} ${getExtensionList_chunk}"
			fi
			break
		done
	done
	printf '%s' "${getExtensionList_extensions}"
}


# Get the list of PHP versions from the data file
#
# Arguments:
# $1: the path to the data file
#
# Output:
# the list of PHP versions
getVersionList () {
	getVersionList_versions=''
	IFS='
'
	for getVersionList_line in $(cat -- "${1}" | sort)
	do
		getVersionList_extension=''
		IFS=' 	'
		for getVersionList_chunk in ${getVersionList_line}
		do
			if test -z "${getVersionList_extension}"
			then
				getVersionList_extension="${getVersionList_chunk}"
			elif test -z "${getVersionList_versions}"
			then
				getVersionList_versions="${getVersionList_chunk}"
			elif ! stringInList "${getVersionList_chunk}" "${getVersionList_versions}"
			then
				getVersionList_versions="${getVersionList_versions} ${getVersionList_chunk}"
			fi
		done
	done
	sortVersionList "${getVersionList_versions}"
}


# Sort the list of PHP versions
#
# Arguments:
# $1: the list of PHP versions
#
# Output:
# the sorted list of PHP versions
sortVersionList () {
	sortVersionList_list=''
	IFS='
'
	for sortVersionList_version in $(printf '%s' "${1}" | tr ' ' '\n' | sort -t '.' -k 1,1n -k 2,2n -k 3,3n)
	do
		if test -z "${sortVersionList_list}"
		then
			sortVersionList_list="${sortVersionList_version}"
		else
			sortVersionList_list="${sortVersionList_list} ${sortVersionList_version}"
		fi
	done
	printf '%s' "${sortVersionList_list}"
}


# Generate the markdown table with the supported PHP extensions
#
# Arguments:
# $1: the path to the data file
#
# Output:
# the markdown table
generateExtensionsTable () {
	generateExtensionsTable_data=$(cat "${1}")
	generateExtensionsTable_extensions="$(getExtensionList "${1}")"
	generateExtensionsTable_versions="$(getVersionList "${1}")"
	printf '| Extension |'
	IFS=' '
	for generateExtensionsTable_version in ${generateExtensionsTable_versions}
	do
		printf ' PHP %s |' "${generateExtensionsTable_version}"
	done
	printf '\n'
	printf '|:---:|'
	for generateExtensionsTable_version in ${generateExtensionsTable_versions}
	do
		printf -- ':---:|'
	done
	printf '\n'
	IFS=' '
	for generateExtensionsTable_extension in ${generateExtensionsTable_extensions}
	do
		printf '| %s |' "${generateExtensionsTable_extension}"
		IFS=' '
		for generateExtensionsTable_version in ${generateExtensionsTable_versions}
		do
			printf ' '
			generateExtensionsTable_versionOk=''
			IFS='
'
			for generateExtensionsTable_dataLine in ${generateExtensionsTable_data}
			do
				if stringInList "${generateExtensionsTable_extension}" "${generateExtensionsTable_dataLine}"
				then
					if stringInList "${generateExtensionsTable_version}" "${generateExtensionsTable_dataLine}"
					then
						generateExtensionsTable_versionOk='y'
					fi
					break
				fi
			done
			if test -n "${generateExtensionsTable_versionOk}"
			then
				printf 'V'
			fi
			printf ' |'
		done
		printf '\n'
	done
}


# Generate the markdown table with the special requirements for the PHP extensions
#
# Arguments:
# $1: the path to the data file
#
# Output:
# the markdown table
generateSpecialRequirementsTable () {
	generateSpecialRequirementsTable_started=''
	IFS='
'
	for generateSpecialRequirementsTable_line in $(cat -- "${1}" | sort)
	do
		if test -z "${generateSpecialRequirementsTable_started}"
		then
			printf '| Extension | Requirements |\n'
			printf '|:---:|:---:|\n'
			generateSpecialRequirementsTable_started='y'
		fi
		resetIFS
		generateSpecialRequirementsTable_requirement="$(echo "${generateSpecialRequirementsTable_line}" | sed -E 's/^\s*\w+\s+//')"
		case "${generateSpecialRequirementsTable_requirement}" in
			zts)
				generateSpecialRequirementsTable_requirement='Requires images with PHP compiled with thread-safety enabled (`zts`).'
				;;
		esac
		printf '| %s | %s |\n' \
			"$(echo "${generateSpecialRequirementsTable_line}" | awk '{print $1;}')" \
			"${generateSpecialRequirementsTable_requirement}"
	done
}


# Generate the contents of README.md
#
# Arguments:
# $1: the path to the README file
# $2: the path to the extensions data file
# $3: the path to the special requirements data file
#
# Output:
# the markdown table
generateReadme () {
	generateReadme_ph_ExtensionsStart='<!-- START OF EXTENSIONS TABLE -->'
	generateReadme_ph_ExtensionsEnd='<!-- END OF EXTENSIONS TABLE -->'
	generateReadme_ph_SpecialStart='<!-- START OF SPECIAL REQUIREMENTS -->'
	generateReadme_ph_SpecialEnd='<!-- END OF SPECIAL REQUIREMENTS -->'
	generateReadme_skip=''
	while IFS= read -r generateReadme_line
	do
		if test "${generateReadme_line}" = "${generateReadme_ph_ExtensionsEnd}" || test "${generateReadme_line}" = "${generateReadme_ph_SpecialEnd}"
		then
			generateReadme_skip=''
		fi
		if test -z "${generateReadme_skip}"
		then
			printf '%s\n' "${generateReadme_line}"
		fi
		if test "${generateReadme_line}" = "${generateReadme_ph_ExtensionsStart}"
		then
			generateReadme_skip='y'
			printf '<!-- ########################################################### -->\n'
			printf '<!-- #                                                         # -->\n'
			printf '<!-- #  DO NOT EDIT THIS TABLE: IT IS GENERATED AUTOMATICALLY  # -->\n'
			printf '<!-- #                                                         # -->\n'
			printf '<!-- #  EDIT THE data/supported-extensions FILE INSTEAD        # -->\n'
			printf '<!-- #                                                         # -->\n'
			printf '<!-- ########################################################### -->\n'
			generateExtensionsTable "${2}"
		elif test "${generateReadme_line}" = "${generateReadme_ph_SpecialStart}"
		then
			generateReadme_skip='y'
			printf '<!-- ########################################################### -->\n'
			printf '<!-- #                                                         # -->\n'
			printf '<!-- #  DO NOT EDIT THIS TABLE: IT IS GENERATED AUTOMATICALLY  # -->\n'
			printf '<!-- #                                                         # -->\n'
			printf '<!-- #  EDIT THE data/special-requirements FILE INSTEAD        # -->\n'
			printf '<!-- #                                                         # -->\n'
			printf '<!-- ########################################################### -->\n'
			generateSpecialRequirementsTable "${3}"
		fi
	done < "${1}"
	printf '%s' "${generateReadme_line}"
}

NEW_README="$(generateReadme "${ROOT_DIR}/README.md" "${DATA_DIR}/supported-extensions" "${DATA_DIR}/special-requirements")"
printf '%s\n' "${NEW_README}" > "${ROOT_DIR}/README.md"