# Copyright 1999-2013 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id: $

inherit config multilib

DESCRIPTION="Manage active PostgreSQL client applications and libraries"
MAINTAINER="pgsql-bugs@gentoo.org"
VERSION="1.0.11"

# Global Data
B_PATH="${EROOT%/}/usr"
E_PATH="${EROOT%/}/etc/eselect/postgresql"
ENV_FILE="${EROOT%/}/etc/env.d/50postgresql"

active_slot() {
	if [[ -r ${E_PATH}/active && -n ${E_PATH}/active ]] ; then
		echo $( <"${E_PATH}"/active )
	else
		echo "(none)"
	fi
}

lib_dir() {
	local lib_list=$(list_libdirs)
	if [[ ${lib_list} =~ .*lib64.* && \
		-n $(ls -d ${B_PATH}/lib64/postgresql-*/lib64 2> /dev/null) ]] ; then
		echo "lib64"
	elif [[ ${lib_list} =~ .*lib32.* && \
		-n $(ls -d ${B_PATH}/lib32/postgresql-*/lib32 2> /dev/null) ]] ; then
		echo "lib32"
	else
		echo "lib"
	fi
}

### Linker Function ###
# Takes four arguments:
#   - Full source path (e.g. /usr/lib/postgresql-9.0/lib)
#   - Pattern to search for
#   - Full target directory path (e.g. /usr/bin)
#   - Suffix (Optional) (e.g 84 to make /usr/bin/psql84)
linker() {
	local source_dir=$1
	local pattern=$2
	local target_dir=$3
	local suffix=$4
	local link_source
	local findings
	local rel_source

	# Prevent passed patterns from being globbed
	# If this module is run in /usr, '-name lib*' ends up globbing 'lib*',
	# passing to 'find' the pattern '-name lib lib32 lib64' and find interprets
	# those as path arguments causing failure.
	set -f
	findings=$(find -L "${source_dir}" -maxdepth 1 -mindepth 1 ${pattern})
	set +f

	for link_source in ${findings} ; do
		local link_target="${target_dir%/}/$(basename ${link_source})${suffix}"

		# For good measure, remove target before creating the symlink
		[[ -h ${link_target} ]] && rm -f "${link_target}"
		[[ -e ${link_target} ]] && \
			die -q "The target '${link_target}' still exists and could not be removed!"

		# Create relative links so that they work both here and inside the new
		# root if $ROOT is not "/".
		rel_source=$(relative_name "${link_source}" "${target_dir}")
		ln -s "${rel_source}" "${link_target}" || die -q "Unable to create link!"
		echo "${link_target##${ROOT%/}/}" >> "${E_PATH}"/active.links${suffix}
	done
}

### Unlinker Function ###
# Takes one argument:
#   - Full path to active links file (e.g. /etc/eselect/postgresql/active.links)
unlinker() {
	local active_link_file=$1
	if [[ -r ${active_link_file} ]] ; then
		local active_links=($(<"${active_link_file}"))
		for (( i=0; $i < ${#active_links[@]}; i++ )) ; do
			[[ -h "${ROOT%/}/${active_links[$i]}" ]] && \
				rm -f "${ROOT%/}/${active_links[$i]}"
			[[ -e "${ROOT%/}/${active_links[$i]}" ]] && \
				die -q "The target '${active_links[$i]}' still exists and could not be removed!"
		done

		rm -f "${active_link_file}"
	fi
}

### Get Slots Function ###
# Find all available slots in the preferred lib_dir() and return them.
get_slots() {
	local slot
	local found_slots

	for slot in $(find "${B_PATH}/$(lib_dir)/" -maxdepth 1 -type d \
		-regex '.*postgresql-[0-9][0-9]*\.[0-9][0-9]*' | \
		sed -re 's#.*([0-9]+\.[0-9]+)$#\1#' | sort -n)
	do
		# Check that pg_config exists for this slot, otherwise we have
		# a false positive.
		[[ -x "${B_PATH}/$(lib_dir)/postgresql-${slot}/bin/pg_config" ]] && \
			found_slots+=( ${slot} )
	done

	echo ${found_slots[@]}
}

### List Action ###
describe_list() {
	echo "List available PostgreSQL slots."
}

do_list() {
	write_list_start "Available PostgreSQL Slots"

	if $(is_output_mode brief) ; then
		echo $(get_slots)
	else
		local slot
		for slot in $(get_slots) ; do
			local postgres_ebuilds=""
			local src
			for src in "${E_PATH}"/slots/${slot}/{server,service,base,docs} ; do
				[[ -r ${src} ]] && source "${src}"
			done

			case "${slot}" in
				"$(active_slot)" ) write_kv_list_entry \
					"$(highlight_marker ${slot})" "${postgres_ebuilds//postgresql-/}";;
				*                ) write_kv_list_entry \
					"${slot}" "${postgres_ebuilds//postgresql-/}";;
			esac
		done

		[[ -z ${postgres_ebuilds} ]] && write_warning_msg "No slots available."
	fi
}

### Show Action ###
describe_show() {
	echo "Show which slot is currently active."
}

do_show() {
	echo $(active_slot)
}

### Show Service Action ###
# Here for backwards compatibility with ebuilds
describe_show-service()  {
	echo "Deprecated. For ebuild use; returns no useful information."
}

do_show-service() {
	echo 1
}

### Set Action ###
describe_set() {
	echo "Create symbolic links for PostgreSQL libraries and applications."
}

do_set() {
	local SLOT=$1
	if [[ ! -d ${B_PATH}/$(lib_dir)/postgresql-${SLOT} ]] ; then
		die -q "Not a valid slot."
	fi

	echo "Setting ${SLOT} as the default installation..."

	# Remove the active links to start a fresh list
	echo -ne "\tRemoving old links..."
	unlinker ${E_PATH}/active.links
	echo "done."

	echo -ne "\tGenerating new links..."
	# Sources and targets for header files
	local sources=(
		"${B_PATH}"/include/postgresql-${SLOT}
		"${B_PATH}"/include/postgresql-${SLOT}/libpq-fe.h
		"${B_PATH}"/include/postgresql-${SLOT}/pg_config_manual.h
		"${B_PATH}"/include/postgresql-${SLOT}/libpq
		"${B_PATH}"/include/postgresql-${SLOT}/postgres_ext.h
	)
	local targets=(
		"${B_PATH}"/include/postgresql
		"${B_PATH}"/include/libpq-fe.h
		"${B_PATH}"/include/pg_config_manual.h
		"${B_PATH}"/include/libpq
		"${B_PATH}"/include/postgres_ext.h
	)

	# The linker function cannot accomadate this special purpose.
	local rel_source
	local i
	for (( i=0; $i < ${#sources[@]}; i++ )) ; do
		# Remove target before creating the symlink
		[[ -h ${targets[$i]} ]] && rm -f "${targets[$i]}"

		# Check if link_target still exists
		[[ -e ${targets[$i]} ]] && \
			die -q "The target '${targets[$i]}' exists and could not be removed!"

		# Create relative links so that they work both here and inside the new
		# root if $ROOT is not "/"
		rel_source=$(relative_name "${sources[$i]}" "$(dirname "${targets[$i]}")")

		ln -s "$rel_source" "${targets[$i]}" || die -q "Unable to create link!"
		echo "${targets[$i]##${ROOT%/}/}" >> "${E_PATH}"/active.links
	done

	# Link modules to /usr/lib{,32,64}/
	local x
	for x in $(list_libdirs) ; do
		if [[ -d ${B_PATH}/${x}/postgresql-${SLOT}/${x} ]] ; then
			# 'linker' function doesn't work for linking directories.
			# Default lib path - create a relative link
			ln -s "postgresql-${SLOT}/${x}" "${B_PATH}/${x}/postgresql"
			echo "${B_PATH##${ROOT%/}/}/${x}/postgresql" >> \
				"${E_PATH}"/active.links
			# Linker works for files
			linker "${B_PATH}/${x}/postgresql-${SLOT}/${x}/" \
				"-name lib*" "${B_PATH}/${x}"
		fi
	done

	# Link binaries to /usr/bin/
	linker "${B_PATH}/$(lib_dir)/postgresql-${SLOT}/bin/" \
		"-type f" "${B_PATH}/bin"

	# Default share path - use a relative link here by just specifying the
	# base name
	ln -s "postgresql-${SLOT}" "${B_PATH}/share/postgresql"
	echo "${B_PATH##${ROOT%/}/}/share/postgresql" >> "${E_PATH}/active.links"

	echo ${SLOT} > "${E_PATH}/active"
	echo "done."
	echo "Setting ${SLOT} as default was successful!"
}

### Unset Action ###
describe_unset() {
	echo "Remove symbolic links."
}

do_unset() {
	local SLOT=$1
	if [[ ${SLOT} = $(active_slot) ]] ; then
		echo -n "Unsetting ${SLOT} as the default installation..."
		unlinker "${E_PATH}/active.links"
		rm -f "${E_PATH}/active"
		echo "done."
		echo "Setting a new slot as the default."
		do_update
	else
		echo "Inactive slot selected. No work to do."
	fi
}

### Reset Action ###
describe_reset() {
	echo "Recreate symbolic links for currently active slot."
}

do_reset() {
	local SLOT=$(active_slot)
	[[ ${SLOT} = "(none)" ]] && die -q "No active slot to reset."
	do_unset ${SLOT}
	do_set ${SLOT}
}

### Update Action ###
describe_update() {
	echo "Refreshes all symbolic links managed by this module"
}

do_update() {
	local slot=$(active_slot)
	# Check for files managed by postgresql.eselect before 1.0
	if [[ -h ${E_PATH}/active ]] ; then
		slot="$(basename $(canonicalise ${E_PATH}/active)))"
		rm -f "${E_PATH}/active"
	fi
	# Remove service file outright.
	[[ -h ${E_PATH}/service ]] && rm -f "${E_PATH}/service"

	local slots=($(get_slots))
	local index=${#slots[@]}

	# In case all slots have been unmerged
	if [[ ${index} -eq 0 ]] ; then
		write_warning_msg "No slots found!"
		write_warning_msg "Removing files (Control-C to abort) in..."
		local i=6
		while [[ $[i--] -gt 0 ]] ; do
			echo -n " $i"
			sleep 1
		done
		local sym_links
		for sym_links in "${E_PATH}"/active.links* ; do
			unlinker "${sym_links}"
		done
		rm -f "${E_PATH}/active"
		rm -f "${ENV_FILE}"
		do_action env update &> /dev/null
		echo "Done!"
		return 0
	fi

	# Reset, otherwise set the highest slot available.
	if [[ ${slots[@]} =~ ${slot} ]] ; then
		do_set ${slot}
	else
		# best_version doesn't work here as pkg_postrm runs before the world
		# file is updated, thereby returning a false positive.
		do_set ${slots[$index-1]}
	fi

	echo -en "\nCleaning out old links before refreshing..."
	local sym_links
	for sym_links in "${E_PATH}"/active.links?* ; do
		unlinker "${sym_links}"
	done
	echo "done."

	# Update paths to libs and docs
	local ldpath
	local x
	for x in $(list_libdirs) ; do
		[[ -h ${B_PATH}/${x}/postgresql ]] && \
			ldpath+="${B_PATH}/${x}/postgresql:"
	done
	ldpath="${ldpath%:}"
	local manpath="${B_PATH}/share/postgresql/man/"
	while [[ $[--index] -gt -1 ]] ; do
		local curslot="${slots[$index]}"
		echo -n "Refreshing symbolic links for ${curslot} applications (like "
		echo -n "/usr/bin/psql${curslot//.})..."
		for x in $(list_libdirs) ; do
			local lib_path="${B_PATH}/${x}/postgresql-${curslot}/${x}/"
			[[ -d ${lib_path} ]] && ldpath+=":${lib_path}"
		done
		local tmp_manpath="${B_PATH}/share/postgresql-${curslot}/man/"
		[[ -d ${tmp_manpath} ]] && manpath+=":${tmp_manpath}"
		linker "${B_PATH}/$(lib_dir)/postgresql-${curslot}/bin/" \
			"-type f" "${B_PATH}/bin" "${curslot//.}"
		echo "done."
	done

	# Remove environment files that have been generated by the ebuilds
	rm -f "${ENV_FILE}"-*

	store_config "${ENV_FILE}" LDPATH "${ldpath}"
	store_config "${ENV_FILE}" MANPATH "${manpath}"
	do_action env update &> /dev/null
}