#!/bin/bash
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2017  IPFire Network Development Team                         #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

WIRELESS_NETWORK_CONFIG_SETTINGS="ENCRYPTION_MODE KEY PRIORITY SSID"

WIRELESS_NETWORKS_VALID_ENCRYPTION_MODES="WPA2-PSK"

cli_wireless_network() {
	if wireless_network_exists "${1}"; then
		local ssid="${1}"
		local key="${2}"
		key=${key//-/_}
		shift 2

		case "${key}" in
			encryption_mode|key|priority)
				wireless_network_${key} "${ssid}" "$@"
				;;
			show)
				wireless_network_show "${ssid}"
				exit $?
				;;
			*)
				error "Unrecognized argument: ${key}"
				exit ${EXIT_ERROR}
				;;
		esac
	else
		local action=${1}
		shift

		case "${action}" in
			new)
				wireless_network_new "$@"
				;;
			destroy)
				wireless_network_destroy "$@"
				;;
			""|*)
				if [ -n "${action}" ]; then
					error "Unrecognized argument: '${action}'"
				fi
				exit ${EXIT_ERROR}
				;;
		esac
	fi
}

# This function writes all values to a via ${ssid} specificated wireless network configuration file
wireless_network_write_config() {
	assert [ $# -ge 1 ]

	local ssid="${1}"

	local ssid_hash="$(wireless_network_hash "${ssid}")"
	assert isset ssid_hash

	if ! wireless_network_exists "${ssid}"; then
		log ERROR "No such wireless network: '${ssid}'"
		return ${EXIT_ERROR}
	fi

	local path="${NETWORK_WIRELESS_NETWORKS_DIR}/${ssid_hash}/settings"

	if ! settings_write "${path}" ${WIRELESS_NETWORK_CONFIG_SETTINGS}; then
		log ERROR "Could not write configuration settings for wireless network ${ssid}"
		return ${EXIT_ERROR}
	fi

	# When we get here the writing of the config file was successful
	return ${EXIT_OK}
}

# This funtion writes the value for one key to a via ${ssid} specificated
# wireless network configuration file
wireless_network_write_config_key() {
	assert [ $# -ge 3 ]

	local ssid="${1}"
	local key="${2}"
	shift 2

	local value="$@"

	if ! wireless_network_exists "${ssid}"; then
		log ERROR "No such wireless network: ${ssid}"
		return ${EXIT_ERROR}
	fi

	log DEBUG "Set '${key}' to new value '${value}' in wireless network '${ssid}'"

	local ${WIRELESS_NETWORK_CONFIG_SETTINGS}

	# Read the config settings
	if ! wireless_network_read_config "${ssid}"; then
		return ${EXIT_ERROR}
	fi

	# Set the key to a new value
	assign "${key}" "${value}"

	if ! wireless_network_write_config "${ssid}"; then
		return ${EXIT_ERROR}
	fi

	return ${EXIT_OK}
}

# Reads one or more keys out of a settings file or all if no key is provided.
wireless_network_read_config() {
	assert [ $# -ge 1 ]

	local ssid="${1}"
	shift 1

	local ssid_hash="$(wireless_network_hash "${ssid}")"
	assert isset ssid_hash

	if ! wireless_network_exists "${ssid}"; then
		log ERROR "No such wireless network : ${ssid}"
		return ${EXIT_ERROR}
	fi

	local args
	if [ $# -eq 0 ] && [ -n "${WIRELESS_NETWORK_CONFIG_SETTINGS}" ]; then
		list_append args ${WIRELESS_NETWORK_CONFIG_SETTINGS}
	else
		list_append args "$@"
	fi

	local path="${NETWORK_WIRELESS_NETWORKS_DIR}/${ssid_hash}/settings"

	if ! settings_read "${path}" ${args}; then
		log ERROR "Could not read settings for wireless network ${ssid}"
		return ${EXIT_ERROR}
	fi
}

# This function checks if a wireless network exists
# Returns True when yes and false when not
wireless_network_exists() {
	assert [ $# -eq 1 ]

	local ssid="${1}"
	local ssid_hash="$(wireless_network_hash "${ssid}")"
	assert isset ssid_hash

	local path="${NETWORK_WIRELESS_NETWORKS_DIR}/${ssid_hash}"

	# We cannot use wireless_network_read_config here beacuse we would end in a loop
	local SSID

	local path_settings="${NETWORK_WIRELESS_NETWORKS_DIR}/${ssid_hash}/settings"

	if ! settings_read "${path_settings}" SSID; then
		return ${EXIT_FALSE}
	fi

	assert isset SSID

	if [ -d "${path}" ] && [[ "${ssid}" = "${SSID}" ]]; then
		return ${EXIT_TRUE}
	else
		return ${EXIT_FALSE}
	fi
}

wireless_network_hash() {
	assert [ $# -eq 1 ]

	local string="${1}"

	local hash=$(echo -n "${string}" | md5sum )
	hash=${hash%%  -}

	local path="${NETWORK_WIRELESS_NETWORKS_DIR}/*${hash}"

	if [ -d "${path}" ]; then
		basename "${path}"
	else
		local normalized=$(normalize "${string}")
		normalized=${normalized%-}
		echo "${normalized}-${hash}"
	fi
}

wireless_network_new() {
	if [ $# -gt 1 ]; then
		error "Too many arguments"
		return ${EXIT_ERROR}
	fi

	local ssid="${1}"
	if ! isset ssid; then
		error "Please provide a SSID"
		return ${EXIT_ERROR}
	fi

	local ssid_hash="$(wireless_network_hash "${ssid}")"
	assert isset ssid_hash

	# Check for duplicates
	if wireless_network_exists "${ssid}"; then
		error "The wireless network ${ssid} already exists"
		return ${EXIT_ERROR}
	fi

	log DEBUG "Creating wireless network '${ssid}'"

	if ! mkdir -p "${NETWORK_WIRELESS_NETWORKS_DIR}/${ssid_hash}"; then
		log ERROR "Could not create config directory for wireless network ${ssid}"
		return ${EXIT_ERROR}
	fi

	# When the ssid is not set in the settings file we cannot write it because wireless_network_exists fails
	echo "SSID=\"${ssid}\"" >>"${NETWORK_WIRELESS_NETWORKS_DIR}/${ssid_hash}/settings"

	local ${WIRELESS_NETWORK_CONFIG_SETTINGS}
	SSID="${ssid}"
	PRIORITY=500

	if ! wireless_network_write_config "${ssid}"; then
		log ERROR "Could not write new config file"
		return ${EXIT_ERROR}
	fi
}

# Function that deletes based on the passed parameters
# one ore more wireless networks
wireless_network_destroy() {
	local ssid
	for ssid in "$@"; do
		local ssid_hash="$(wireless_network_hash "${ssid}")"
		assert isset ssid_hash

		if ! wireless_network_exists "${ssid}"; then
			log ERROR "The wireless network ${ssid} does not exist."
			continue
		fi

		log DEBUG "Deleting wireless network ${ssid}"

		if ! rm -rf "${NETWORK_WIRELESS_NETWORKS_DIR}/${ssid_hash}"; then
			log ERROR "Deleting the wireless network ${ssid} was not sucessful"
			return ${EXIT_ERROR}
		fi
	done
}

wireless_network_encryption_mode() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local ssid="${1}"
	local mode="${2}"

	if ! isoneof mode ${WIRELESS_NETWORKS_VALID_ENCRYPTION_MODES}; then
		log ERROR "Encryption mode '${mode}' is invalid"
		return ${EXIT_ERROR}
	fi

	if ! wireless_network_write_config_key "${ssid}" "ENCRYPTION_MODE" ${mode^^}; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi
}

wireless_network_key() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local ssid="${1}"
	local key="${2}"

	if ! wireless_network_write_config_key "${ssid}" "KEY" "${key}"; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi
}

wireless_network_priority() {
	if [ ! $# -eq 2 ]; then
		log ERROR "Not enough arguments"
		return ${EXIT_ERROR}
	fi
	local ssid="${1}"
	local priority=${2}

	if ! isinteger priority && [ ! ${priority} -ge 0 ]; then
		log ERROR "The priority must be an integer greater or eqal zero"
		return ${EXIT_ERROR}
	fi

	if ! wireless_network_write_config_key "${ssid}" "PRIORITY" "${priority}"; then
		log ERROR "Could not write configuration settings"
		return ${EXIT_ERROR}
	fi
}