# Copyright 1999-2005 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id: php.eselect,v 1.1 2005/09/04 09:47:51 stuart Exp $

DESCRIPTION="Manage the talled gnat compilers"
MAINTAINER="ada@gentoo.org"
SVN_DATE='$Date: $'
VERSION=$(svn_date_to_version "${SVN_DATE}" )

SPECSDIR="/etc/eselect/gnat"
ENVDIR="/etc/env.d"
MARKER="55gnat-"

### Helpers

# create a list of all gnat env.d files
# for now use trivial implementation - store name of active profile in the
# env file name, so it gets called 55gnat-${ARCH}-${PN}-${SLOT}
get_env_list() {
	for fn in ${ENVDIR}/${MARKER}*; do
		echo $(basename ${fn})
	done
}

# return *the* name of the active profile, checking that we do not have multiple
# env files.
# There can be only one!
get_current_gnat() {
	local profiles=( $(get_env_list) ) 

	if [ ${profiles[@]} == "${MARKER}*" ]; then exit; fi

	if (( 1 == ${#profiles[@]} )); then
		local active=${profiles[0]#${MARKER}}
	else
		die -q "${ENVDIR} contains multiple gnat profiles, please cleanup!"
	fi

	if [ -f ${SPECSDIR}/${active} ]; then
		echo ${active}
	else
		die -q "the active env.d profile does not correspond to any installed gnat!"
	fi
}

# find installed compilers and return a list
find_compilers() {
	for fn in ${SPECSDIR}/*; do
		echo $(basename ${fn});
	done
}

# check if the passed arg represents the installed gnat and return it or
# not_found
# takes args:
# $1 - list ID to check
get_name_from_list() {
    compiler=$1

    compilers=( $(find_compilers) )
    for (( i = 0 ; i < ${#compilers[@]} ; i = i + 1 )) ; do
        if [[ ${compilers[$i]} == ${compiler} ]] ; then
            echo ${compiler}
            return
        fi
    done

    echo "(not-found)"
}


# extracts values of the passed var definition from given spec file
# params:
# $1: spec file (as generated by gnabuild.eclass)
# $2: variable name
get_var_from_spec() {
	local var=$(grep $2 $1|cut -d= -f2)
	echo ${var}
}


# removes env file
# params:
# $1: the name of profile for which to remove env file
unset_env() {
	rm -f ${ENVDIR}/${MARKER}$1 &> /dev/null
}

### show action ###

describe_show() {
	echo "Show the active gnat compiler/profile"
}

do_show() {
	write_list_start "Current gnat version:"
	active=$(get_current_gnat)
	[ -z $active ] && active="(none set)"
	write_kv_list_entry "$active" ""
}

### list action ###

describe_list() {
	echo "List installed gnat compilers"
}

do_list() {
	compilers=( $(find_compilers ) )
	active=$(get_current_gnat)

	write_list_start "Available gnat compilers:"

	if [[ -n ${compilers[@]} ]] ; then
		local i
		for (( i = 0 ; i < ${#compilers[@]} ; i = i + 1 )) ; do
			linkversion=${compilers[${i}]}

			[[ $linkversion == $active ]] && \
				compilers[${i}]="${compilers[${i}]} $(highlight '*' )"
		done
		write_numbered_list "${compilers[@]}"
	else
		write_kv_list_entry "(none found)" ""
	fi
}

### set action ###

describe_set() {
	echo "Set active gnat compiler"
}

do_set() {
	if [[ -z ${1} ]] ; then
		# no parameter
		die -q "You didn't tell me which gnat to use"
	fi

	local toset=$(get_name_from_list $1)
	if [[ ${toset} == "(not-found)" ]] ; then
		die -q "I don't recognise the selection"
	fi

	# the action!
	# in this implementation simply create an appropriate env file
	local active=$(get_current_gnat)
	local envfile="${ENVDIR}/${MARKER}${toset}"

	# now we need to remove an old env file, which is guaranteed to 
	# be unique by get_current_gnat above
	unset_env ${active}
	# just for a good measure remove the one we are going to write
	unset_env ${toset}

	local binpath="$(get_var_from_spec ${SPECSDIR}/${toset} binpath)"
	local libexecpath="$(get_var_from_spec ${SPECSDIR}/${toset} libexecpath)"
	echo "PATH=${binpath}:${libexecpath}" >> "${envfile}"
	echo "MANPATH=$(get_var_from_spec ${SPECSDIR}/${toset}	manpath)" >> "${envfile}"
	echo "INFOPATH=$(get_var_from_spec ${SPECSDIR}/${toset}	infopath)" >> "${envfile}"
	echo "ADA_INCLUDE_PATH=$(get_var_from_spec ${SPECSDIR}/${toset}	ldpath)/adainclude" >> "${envfile}"
	echo "ADA_OBJECTS_PATH=$(get_var_from_spec ${SPECSDIR}/${toset}	ldpath)/adalib" >> "${envfile}"
}


### unset action ###

describe_unset() {
	echo "Remove settings for currently active gnat"
}

do_unset() {
	local active=$(get_current_gnat)
	unset_env ${active}
}