Dear List,

This module is to replace the existing one that is shipped with
<app-admin/eselect-postgresql-1.0.3. It is an entire rewrite.

Changes can be tracked at:
http://git.overlays.gentoo.org/gitweb/?p=proj/pgsql-patches.git;a=shortlog;h=refs/heads/eselect

Before you start reading the attached module, please bear in mind that I
am a novice at writing BASH scripts, and am not intimately familiar with
all the nuances of the language.

There is some duplication of work within the module when compared with
the current postgresql-{base,server}-*.ebuilds in the tree. The plan is
to move that work being handled in the ebuilds to the module.

Setting a service slot has been dropped from the module as it is no
longer necessary.

Features:
* Supports --brief output
* Prefix compatible
* Slot specific application links (e.g., psql90, createdb84)
* Automatically sets the highest slot available as the default unless a
  valid slot is already set
* Properly orders LDPATH giving preference to the set slot and then
  lists the other slots in descending order

Thank you.

Sincerely,
  Mr. Aaron W. Swenson (TitanOfOld)

# Copyright 1999-2011 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id: $

inherit config multilib output package-manager path-manipulation

DESCRIPTION="Manage active PostgreSQL client applications and libraries"
MAINTAINER="pgsql-bugs@g.o"
SVN_DATE='$Date: $'
VERSION="1.0.4"

# Global Data
B_PATH="${EROOT%/}/usr"
E_PATH="${EROOT%/}/etc/eselect/postgresql"
ENV_FILE="${EROOT%/}/etc/env.d/50postgresql"
if [ -r ${E_PATH}/active -a -n ${E_PATH}/active ] ; then
	ACTIVE_SLOT=$(<${E_PATH}/active)
else
	ACTIVE_SLOT="(none)"
fi
LIB_LIST=$(list_libdirs)
if [[ ${LIB_LIST} =~ .*lib64.* && "$(ls -d ${B_PATH}/lib64/postgresql-*/lib)" != "" ]] ; then
	LIBDIR="lib64"
elif [[ ${LIB_LIST} =~ .*lib32.* && "$(ls -d ${B_PATH}/lib32/postgresql-*/lib)" != "" ]] ; then
	LIBDIR="lib32"
else
	LIBDIR="lib"
fi

### Linker Function ###
# Takes three arguments:
#   - Full source path (e.g. /usr/lib/postgresql-9.0/lib/lib*.{a,so})
#   - Full target directory path (e.g. /usr/bin)
#   - Suffix (Optional) (e.g 84 to make /usr/bin/psql84)
linker() {
	local source_dir=$1
	local target_dir=$2
	local suffix=$3
	local link_source

	for link_source in $(eval ls ${source_dir} 2> /dev/null) ; do
		local link_target="${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!"

		ln -s ${link_source} ${link_target} || die -q "Unable to create link!"
		echo ${link_target} >> ${E_PATH}/active.links${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 ${active_links[$i]} ] && rm -f ${active_links[$i]}
			[ -e ${active_links[$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 LIBDIR and return them.
get_slots() {
	echo $(ls -dv ${B_PATH}/${LIBDIR}/postgresql-* 2> /dev/null | sed -re 's#^.+-##')
}

### 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 ${B_PATH}/${LIBDIR}/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 i
	for (( i=0; $i < ${#sources[@]}; i++ )) ; do
		# Remove target before creating the symlink
		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!"

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

	# Link modules to /usr/lib{,lib32,lib64}/
	local x
	for x in ${LIB_LIST} ; do
		if [ -d ${B_PATH}/${x}/postgresql-${SLOT}/${x} ] ; then
			# 'linker' function doesn't work for linking directories.
			# Default lib path
			ln -s ${B_PATH}/${x}/postgresql-${SLOT}/${x} ${B_PATH}/${x}/postgresql
			echo ${B_PATH}/${x}/postgresql >> ${E_PATH}/active.links
			# Linker works for files
			linker "${B_PATH}/${x}/postgresql-${SLOT}/${x}/lib*.{a,dylib,so}" "${B_PATH}/${x}"
		fi
	done

	# Link binaries to /usr/bin/
	linker "${B_PATH}/${LIBDIR}/postgresql-${SLOT}/bin/*" "${B_PATH}/bin"

	# Default share path
	ln -s ${B_PATH}/share/postgresql-${SLOT} ${B_PATH}/share/postgresql
	echo ${B_PATH}/share/postgresql >> ${E_PATH}/active.links

	echo ${SLOT} > ${E_PATH}/active
	echo "done."
	echo -e "\033[1mSetting ${SLOT} as default was successful!\033[0m"
}

### 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."
	else
		echo "Inactive slot selected. No work to do."
	fi
}

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

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

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

do_update() {
	# Check for files managed by postgresql.eselect before 1.0
	[ -h /etc/eselect/postgresql/active ] && ACTIVE_SLOT="$(basename $(canonicalise /etc/eselect/postgesql/active))"
	# Remove service file outright.
	[ -h /etc/eselect/postgresql/service ] && rm -f /etc/eselect/postgresql/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
		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[@]} =~ ${ACTIVE_SLOT} ]] ; then
		do_reset
	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 ${LIB_LIST} ; do
		[ -h ${B_PATH}/${x}/postgresql ] && ldpath+="${B_PATH}/${x}/postgresql:"
	done
	ldpath="${ldpath%:}"
	local manpath="${B_PATH}/share/postgresql/"
	while [ $[--index] -gt -1 ] ; do
		local curslot="${slots[$index]}"
		echo -n "Refreshing symbolic links for ${curslot} applications (like /usr/bin/psql${curslot//.})..."
		for x in ${LIB_LIST} ; do
			local lib_path="${B_PATH}/${x}/postgresql-${curslot}/${x}/"
			[ -d ${lib_path} ] && ldpath+=":${lib_path}"
		done
		local share_path="${B_PATH}/share/postgresql-${curslot}/"
		[ -d ${share_path} ] && manpath+=":${share_path}"
		linker "${B_PATH}/${LIBDIR}/postgresql-${curslot}/bin/*" "${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
}