# Copyright 1999-2014 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id: $

DESCRIPTION="Manage active Python interpreter"
MAINTAINER="python@gentoo.org"
SVN_DATE='$Date$'
VERSION=$(svn_date_to_version "${SVN_DATE}" )

ENV_D_PATH="${EROOT%/}/etc/env.d"
INTERPRETER_PATH="${EROOT%/}/usr/bin/"
MAN_PATH="${EROOT%/}/usr/share/man/man1/"

PYTHON_INTERPRETERS_GROUP=""

# Find a list of Python versions
find_targets() {
	local interpreter interpreters="python?.?@EXEEXT@"

	if [[ "${PYTHON_INTERPRETERS_GROUP}" == "2" ]]; then
		interpreters="python2.?@EXEEXT@"
	elif [[ "${PYTHON_INTERPRETERS_GROUP}" == "3" ]]; then
		interpreters="python3.?@EXEEXT@"
	fi

	# Think twice before adding jython to this list. /usr/bin/jython
	# is a bash wrapper that calls java-config, which is a Python
	# script, so you need a valid /usr/bin/python to start jython.
	for interpreter in "${INTERPRETER_PATH}"${interpreters}; do
		if [[ -f "${interpreter}" ]]; then
			echo ${interpreter#${INTERPRETER_PATH}}
		fi
	done
}

set_python_subver() {
	local target=${1}
	local subver=${target%.*}
	mkdir -p "${ENV_D_PATH}/python"
	echo "${target}" > "${ENV_D_PATH}/python/${subver}"
}

set_python() {
	local target="${1}"
	mkdir -p "${ENV_D_PATH}/python"
	echo "${target}" > "${ENV_D_PATH}/python/config"
}

# Try to remove python and python.1 symlinks
remove_symlinks() {
	local symlink symlink_target symlink_target_found
	if [[ "${SET_MAIN_ACTIVE_PYTHON_INTERPRETER}" == "1" ]]; then
		rm -f "${MAN_PATH}"python.1{,.gz,.bz2,.lzma,.xz,.lz} &> /dev/null || return 1
	fi

	# Files of Mac OS X framework
	rm -f "${INTERPRETER_PATH%/bin/}/lib/Python.framework}"/{Headers,Python,Resources}
}

# Set a man page symlink
set_man_symlink() {
	local target="${1}" x extension

	for x in ".1" ".1.bz2" ".1.gz" ".1.lzma" ".1.xz" ".1.lz"; do
		if [[ -e "${MAN_PATH}${target}${x}" ]]; then
			extension="${x}"
			break
		fi
	done

	if [[ -z "${extension}" ]]; then
		echo "Couldn't find a man page for ${target}; skipping." 1>&2
		return 1
	fi

	pushd "${MAN_PATH}" 1> /dev/null
	ln -nfs "${target}${extension}" "python${extension}"
	popd 1> /dev/null
}

# Set python-config script and appropriate symlinks
set_scripts_and_symlinks() {
	local target="${1}" targets=($(find_targets))
	if is_number "${target}" && [[ ${target} -ge 1 ]]; then
		target=${targets[$((${target} - 1))]}
	fi

	if ! has ${target} "${targets[@]}"; then
		die -q "Invalid target ${target}"
	fi
	if [[ -f "${INTERPRETER_PATH}${target}" ]]; then
		if ! remove_symlinks; then
			die -q "Cannot remove symlinks"
		fi

		if [[ "${SET_MAIN_ACTIVE_PYTHON_INTERPRETER}" == "1" ]]; then
			set_man_symlink "${target}"
		fi

		pushd "${INTERPRETER_PATH}" 1> /dev/null

		set_python_subver "${target}"
		if [[ "${SET_MAIN_ACTIVE_PYTHON_INTERPRETER}" == "1" ]]; then
			set_python "${target}"

			# Files of Mac OS X framework
			local framework_dir="${INTERPRETER_PATH%/bin/}/lib/Python.framework"
			if [[ -d "${framework_dir}" ]]; then
				local version="${target#python}"
				pushd "${framework_dir}" 1> /dev/null
				ln -nfs "Versions/${version}/Headers"
				ln -nfs "Versions/${version}/Python"
				ln -nfs "Versions/${version}/Resources"
				popd 1> /dev/null
			fi
		fi

		popd 1> /dev/null
	else
		die -q "Target \"${1}\" doesn't appear to be valid!"
	fi
}

# Set the content of /etc/env.d/65python-docs
set_python_docs() {
	local path target="${1#python}" variable
	rm -f "${ENV_D_PATH}/65python-docs"
	if [[ -f "${ENV_D_PATH}/60python-docs-${target}" ]]; then
		variable="PYTHONDOCS_${target//./_}"
		path="$(. "${ENV_D_PATH}/60python-docs-${target}"; echo -n "${!variable}")"
		if [[ -d "${path}" ]]; then
			echo "PYTHONDOCS=\"${path}\"" > "${ENV_D_PATH}/65python-docs"
		fi
	fi
}

### show action ###

describe_show() {
	echo "Show main active Python interpreter"
}

describe_show_options() {
	echo "--ABI         : Show Python ABI in format of PYTHON_ABI variable"
	echo "--python2     : Show active Python 2 interpreter"
	echo "--python3     : Show active Python 3 interpreter"
}

do_show() {
	local ABI="0" interpreter python2="0" python3="0"
	while [[ $# > 0 ]]; do
		case "$1" in
			--ABI)
				ABI="1"
				;;
			--python2)
				python2="1"
				;;
			--python3)
				python3="1"
				;;
			*)
				die -q "Unrecognized argument '$1'"
				;;
		esac
		shift
	done

	if [[ "${python2}" == "1" && "${python3}" == "1" ]]; then
		die -q "'--python2' and '--python3' options cannot be specified simultaneously"
	fi

	if [[ "${python2}" == "1" ]]; then
		if [[ -f ${ENV_D_PATH}/python/python2 ]]; then
			interpreter="$(<"${ENV_D_PATH}/python/python2")"
		fi
	elif [[ "${python3}" == "1" ]]; then
		if [[ -f ${ENV_D_PATH}/python/python3 ]]; then
			interpreter="$(<"${ENV_D_PATH}/python/python3")"
		fi
	elif [[ -f "${ENV_D_PATH}/python/config" ]]; then
		interpreter="$(<"${ENV_D_PATH}/python/config")"
	fi

	if [[ "${ABI}" == "1" ]]; then
		echo -n "${interpreter#python}"
	else
		echo -n "${interpreter}"
	fi

	if [[ -n "${interpreter}" ]]; then
		echo
	fi
}

### list action ###

describe_list() {
	echo "List installed Python interpreters"
}

describe_list_options() {
	echo "--python2     : List installed Python 2 interpreters"
	echo "--python3     : List installed Python 3 interpreters"
}

do_list() {
	local active i python_descriptive_name="Python" python_version_option= python2="0" python3="0" targets=()
	while [[ $# > 0 ]]; do
		case "$1" in
			--python2)
				python2="1"
				python_descriptive_name="Python 2"
				python_version_option="--python2"
				PYTHON_INTERPRETERS_GROUP="2"
				;;
			--python3)
				python3="1"
				python_descriptive_name="Python 3"
				python_version_option="--python3"
				PYTHON_INTERPRETERS_GROUP="3"
				;;
			*)
				die -q "Unrecognized argument '$1'"
				;;
		esac
		shift
	done

	if [[ "${python2}" == "1" && "${python3}" == "1" ]]; then
		die -q "'--python2' and '--python3' options cannot be specified simultaneously"
	fi

	targets=($(find_targets))

	write_list_start "Available ${python_descriptive_name} interpreters:"

	active="$(do_show ${python_version_option})"
	for ((i = 0; i < ${#targets[@]}; i++)); do
		if [[ ${targets[${i}]} == ${active} ]]; then
			targets[${i}]="$(highlight_marker "${targets[${i}]}")"
		fi
	done
	write_numbered_list -m "(none found)" "${targets[@]}"
}

### set action ###

describe_set() {
	echo "Set main active Python interpreter"
}

describe_set_options() {
	echo "--python2     : Set active Python 2 interpreter without setting of main active Python interpreter if it is not set to Python 2"
	echo "--python3     : Set active Python 3 interpreter without setting of main active Python interpreter if it is not set to Python 3"
}

describe_set_parameters() {
	echo "<target>"
}

do_set() {
	local main_active_python_interpreter python2="0" python3="0"
	SET_MAIN_ACTIVE_PYTHON_INTERPRETER="1"
	while [[ $# > 0 ]]; do
		case "$1" in
			--python2)
				python2="1"
				PYTHON_INTERPRETERS_GROUP="2"
				;;
			--python3)
				python3="1"
				PYTHON_INTERPRETERS_GROUP="3"
				;;
			*)
				break
				;;
		esac
		shift
	done

	if [[ "${python2}" == "1" && "${python3}" == "1" ]]; then
		die -q "'--python2' and '--python3' options cannot be specified simultaneously"
	fi

	if [[ $# -lt 1 ]]; then
		die -q "'eselect python set' requires Python interpreter filename"
	elif [[ $# -gt 1 ]]; then
		die -q "'eselect python set' requires 1 argument"
	else
		main_active_python_interpreter="$(do_show)"
		if [[ "${python2}" == "1" && "${main_active_python_interpreter}" != "python2."* ]]; then
			SET_MAIN_ACTIVE_PYTHON_INTERPRETER="0"
		elif [[ "${python3}" == "1" && "${main_active_python_interpreter}" != "python3."* ]]; then
			SET_MAIN_ACTIVE_PYTHON_INTERPRETER="0"
		fi

		if ! set_scripts_and_symlinks "${1}"; then
			die -q "Can't set new provider"
		fi

		if [[ "${SET_MAIN_ACTIVE_PYTHON_INTERPRETER}" == "1" ]]; then
			set_python_docs "${1}"
		fi
	fi
}

### update action ###

describe_update() {
	echo "Switch to the most recent CPython interpreter"
}

describe_update_options() {
	echo "--if-unset    : Do not override existing implementation"
	echo "--ignore SLOT : Ignore SLOT when setting symlinks"
	echo "--python2     : Set active Python 2 interpreter without setting of main active Python interpreter if it is not set to Python 2"
	echo "--python3     : Set active Python 3 interpreter without setting of main active Python interpreter if it is not set to Python 3"
}

do_update() {
	local if_unset="0" ignored_slots=() interpreters="python?.?@EXEEXT@" python2="0" python3="0" python_version_option= slot= target targets=()
	while [[ $# > 0 ]]; do
		case "$1" in
			--if-unset)
				if_unset="1"
				;;
			--ignore)
				ignored_slots+=("${2}")
				shift;;
			--python2)
				python2="1"
				python_version_option="--python2"
				;;
			--python3)
				python3="1"
				python_version_option="--python3"
				;;
			*)
				die -q "Unrecognized argument '$1'"
				;;
		esac
		shift
	done

	if [[ "${python2}" == "1" && "${python3}" == "1" ]]; then
		die -q "'--python2' and '--python3' options cannot be specified simultaneously"
	fi

	if [[ "${if_unset}" == "1" && -f "${ENV_D_PATH}/python/config" ]]; then
		if [[ "${python2}" == "1" && -f "${ENV_D_PATH}/python/python2" ]]; then
			return
		elif [[ "${python3}" == "1" && -f "${ENV_D_PATH}/python/python3" ]]; then
			return
		elif [[ "${python2}" == "0" && "${python3}" == "0" ]]; then
			return
		fi
	fi

	if [[ "${python2}" == "1" ]]; then
		interpreters="python2.?@EXEEXT@"
	elif [[ "${python3}" == "1" ]]; then
		interpreters="python3.?@EXEEXT@"
	fi

	targets=($(cd "${INTERPRETER_PATH}"; ls ${interpreters} 2> /dev/null | sort -r))

	# Ignore slots
	for slot in ${ignored_slots[@]}; do
		targets=(${targets[@]/python${slot}/})
	done

	if [[ ${#targets[@]} -gt 0 ]]; then
		target=${targets[0]}
		echo "Switching to ${target}"
		do_set ${python_version_option} ${target}
	else
		die -q "No Python interpreter available"
	fi
}

# vim: set ft=eselect :