# frozen_string_literal: true
require 'json'
require 'optimist'
require 'semantic_logger'

require_relative 'route_gatherer'
require_relative 'version'


module OpenVPNConfigurator
	class CLI
		include SemanticLogger::Loggable

		AWS_IP_RANGES_URL = 'https://ip-ranges.amazonaws.com/ip-ranges.json'.freeze


		def initialize
			setup_logger
		end


		# Expects to be invoked with <input path>, <output path>
		def invoke(arguments)
			options = parse_arguments arguments.dup
			logger.debug "Beginning CLI invocation run", options: options

			RouteGatherer.new.extend_template options
		end


		private


		def parse_arguments(original_arguments)
			arguments = original_arguments.dup
			logger.trace "Beginning command-line argument parsing", arguments: arguments
			options = Optimist.options(arguments) do
				synopsis 'Fetches IP block information from AWS and generates an OpenVPN configuration file'
				version "openvpn_configurator #{VERSION}"
				banner self.version
				banner self.synopsis
				banner "Usage: #{$0} [options] <input-path> <output-path>"
				banner 'Dynamic route collection options'
				opt :route_v4_aws_region, "Add IPv4 routes for an AWS region (like 'us-west-2')", type: :string, multi: true
				opt :route_v4_dns, 'Add IPv4 routes for A record(s) returned by the specified DNS query', type: :string, multi: true
				banner 'Actions'
				opt :restart_systemd, 'Restart the specified systemd service when the generated configuration changes (including the first time we run)', type: :string, multi: true
			end
			if arguments.length != 2
				Optimist.die 'Must specify input and output file paths', -2
			end
			options[:input_path] = arguments[0]
			options[:output_path] = arguments[1]
			options
		end


		def setup_logger
			# Reset the logger so we can reconfigure it if it was configured before.
			::SemanticLogger.flush
			::SemanticLogger.close unless ::SemanticLogger.appenders.empty?

			# Do setup
			::SemanticLogger.application = 'openvpn-configurator'
			::SemanticLogger.default_level = ENV.fetch('LOG_LEVEL', 'info').downcase.to_sym

			# Don't colorize output in lambda contexts
			formatter_options = ENV.has_key?('AWS_EXECUTION_ENV') ? {} : { formatter: :color }

			if ENV.has_key?('LOG_FILE_PATH') && ENV['LOG_FILE_PATH'] != '-'
				puts "INFO: Logging to file at #{ENV['LOG_FILE_PATH'].inspect}."
				::SemanticLogger.add_appender file_name: ENV['LOG_FILE_PATH'], **formatter_options
			end

			if ENV['LOG_FILE_PATH'] == '-' || $stdout.tty? || ENV['LOG_TO_STDOUT'] == 'true'
				puts "INFO: Logging to stdout."
				::SemanticLogger.add_appender io: $stdout, **formatter_options
			else
				puts "INFO: stdout is not a TTY, and LOG_TO_STDOUT is not true. No logs will be sent to stdout."
			end

			if ENV.has_key? 'GRAYLOG_URL'
				puts "INFO: Logging to Graylog at #{ENV['GRAYLOG_URL'].inspect}."
				::SemanticLogger.add_appender appender: :graylog, url: ENV['GRAYLOG_URL']
			end

			if ENV.has_key? 'STATSD_URL'
				logger.info "Sending metrics to Statsd at #{ENV['STATSD_URL'].inspect}."
				subscriber = ::SemanticLogger::Metrics::Statsd.new url: ENV['STATSD_URL']
				::SemanticLogger.on_metric subscriber
			end
		end
	end
end