# Copyright 1999-2010 Gentoo Foundation
# Copyright 2013 Ryan P. Harris
# Distributed under the terms of the GNU General Public License v2
# $Id: $


DESCRIPTION="Manage Jython symlinks"
MAINTAINER="rh1@funtoo.org"
VERSION="1.0"

INTERPRETER_PATH="${EROOT%/}/usr/bin/"


### HELPER FUNCTIONS ###

# PUBLIC
# Converts number from list to jython version
# $1 = number to convert
convert_list_number() {
	local number="${1}"
	local interpreters=( $(find_targets) )
	if [[ "${number}" < 0 || "${number}" == 0 || "${number}" > "${#interpreters[@]}" ]] ; then
		die -q "Invalid number. No matching entry."
	fi
	number=$(( ${1} - 1 ))
	echo "${interpreters[number]}"
}


# PUBLIC
# Finds jython targets.
find_targets() {
	local interpreters="jython?.?"

	for interpreter in "${INTERPRETER_PATH}"${interpreters}; do
		if [[ -f "${interpreter}" ]]; then
			echo ${interpreter#${INTERPRETER_PATH}}
		fi
	done
}


### LIST ACTION ###

# PUBLIC
# Descritpion of list action
describe_list() {
	echo "Lists installed Jython versions"
}


# PUBLIC
# Called by eselect when passed list as an action
do_list() {
	local interpreters=( $(find_targets) )
	write_list_start "Available Jython targets:"
	for (( i = 0; i < ${#interpreters[@]}; i++ )) ; do
		local number=$(( ${i} + 1 ))
		if [[ "${interpreters[${i}]}" == "$(do_show)" ]] ; then
			write_numbered_list_entry "${number}" "${interpreters[${i}]} *"
		else
			write_numbered_list_entry "${number}" "${interpreters[${i}]}"
		fi
	done
}


### SHOW ACTION ###

# PUBLIC
# Description of show action.
describe_show() {
	echo "Show main active Jython version"
}


# PUBLIC
# Called by eselect when passed show as an action.
do_show() {
	echo "$(basename $(readlink -e ${INTERPRETER_PATH}jython))"
}


### SET ACTION ###

# PUBLIC
# Removes the old jython symlink and sets the new one.
# $1 = Target version for new symlink. (Ex: jython2.5)
set_jython_symlink() {
	local target="${1}"
	cd "${INTERPRETER_PATH}"

	if [[ ! -e "${target}" ]] ; then
		die -q "Target ${target} does not exist"
	fi

	if [[ -e jython ]] ; then
		if [[ -h jython ]] ; then
			rm jython
		else
			die -q "'${INTERPRETER_PATH}jython' is not a symlink."
		fi
	fi
	ln -sf "${target}" jython
}


# PUBLIC
# Description of set action
describe_set() {
	echo "Set the main active Jython version"
}


# PUBLIC
# Desciption of set parameters
describe_set_parameters() {
	echo "<target>"
}


# PUBLIC
# Called by eselect when passed set as an action
do_set() {

	local target="${1}"
	if [[ ${#} != 1 ]] ; then
		die -q "'eselect jython set' requires 1 argument"
	fi

	if is_number "${target}" ; then
		target="$(convert_list_number ${target})"
		if [[ $? != 0 ]] ; then
			exit 1
		fi
	fi

	set_jython_symlink "${target}"
}