#!/usr/bin/env ruby

require 'optparse'
require 'methadone'
require 'generator.rb'
require 'yaml'
require 'nokogiri'
require 'generator'
require 'validator'
require 'api'
require 'login'
require 'diffy'
require 'pp'
require 'fileutils'

class App
  include Methadone::Main
  include Methadone::CLILogging

# the main block
  main do
    @api = Vpnconfig::Api.new
    @verbose = !options['v'].nil?
    self.check_mandatory_inputs
    input_config = self.validate_yaml_if_present(options['w'])

    puts 'Logging in' if @verbose
    conn = Vpnconfig::Login.new.login(options['u'])
    puts "\nReading configuration...."
    dc_details = @api.get_dc_details(conn, options['d'])
    puts 'Found data centre: '+dc_details['name'] if @verbose
    current_config, edgegw_href = @api.read_edgegw_config(dc_details, conn)

    unless options['b'].nil?
      self.backup_current_config(current_config, options['b'], options['d'])
    end

    puts 'Current configuration is:' if @verbose
    puts current_config if @verbose
    puts if @verbose

    unless options['w'].nil?
      puts 'Reading in your yaml file...' if @verbose

      puts 'Generating XML...' if @verbose
      new_config = Vpnconfig::Generator.new.generate_xml(input_config)
      puts 'Generated XML is:' if @verbose
      puts new_config if @verbose
      puts if @verbose

      if configs_match(current_config, new_config)
        puts 'Old and new configuration are identical, no changes to make'
      else
        puts "Posting new configuration to skyscape"
        puts "href: #{edgegw_href}..." if @verbose
        task_href = @api.post_to_api(edgegw_href, conn, new_config)
        puts 'Task has been created to update config, tracking progress....' if @verbose
        report_task_status(task_href, conn)
      end
    end

  end

# Supplemental methods
  def self.validate_yaml_if_present(yaml_path)
    if !yaml_path.nil?
      input_config = YAML.load_file(yaml_path)
      validation_errors = Vpnconfig::Validator.new.validate_yaml(input_config)

      if !validation_errors.empty?
        display_errors_and_abort(validation_errors)
      end
    end
    input_config
  end

  def self.backup_current_config(current_config, backup_path, datacentre)
    puts 'Creating backup of current configuration...' if @verbose
    filename = Time.now.strftime("%Y%m%d%H%M%S") + '_' + datacentre + '_VPN_Config'
    backup_path = backup_path + '/' if backup_path[-1] != '/'
    filepath = backup_path + filename
    unless File.directory?(filepath)
      FileUtils.mkdir_p(backup_path)
      puts 'Created directory for backup' if @verbose
    end
    File.write(filepath, current_config)
    puts "Created backup file at: #{filepath}" if @verbose
  end

  def self.report_task_status(task_href, conn)
    completed_task = @api.get_completed_task(task_href, conn)
    if completed_task['status'] == 'success'
      puts 'New config has been successfully written to Skyscape'
    else
      api_error_message = completed_task.at('Error')['message']
      api_error_code= completed_task.at('Error')['majorErrorCode']
      Kernel.abort("The task returned with status code #{api_error_code} and the following error: #{api_error_message}")
    end
  end

  def self.check_mandatory_inputs
    if options['d'].nil?
      Kernel.abort('You must define a datacentre')
    end
    if options['u'].nil?
      Kernel.abort('You must provide a username')
    end
  end

  def self.save_config(xml_obj, filename)
    file = File.open(filename, "w")
    xml_obj.write_xml_to(file, options={})
    file.close
  end

  def self.display_errors_and_abort(errors)
    errors.each{|e| puts "#{e.message}"}
    puts 'The schema to match against is:'
    pp YAML.load_file('./lib/vpn-configuration-schema.yaml')
    Kernel.abort('ERROR: Invalid yaml input does not match the schema, see validation_errors above.')
  end

  def self.configs_match(current_config, new_config)
    new_config.delete(' ').lines.drop(1).join() == current_config.delete(' ')
  end


# Command line interface details
  description "Updates VPN configuration for given datacentre based on a yaml input file"

  on("-w VAL", "--write", "Writes configuration to the VDC as per specified XML file")
  on("-d VAL", "--datacentre", "Name of the skyscape datacentre")
  on("-u VAL", "--user", "Username to connect to the Skyscape Datacenter(check API tab)")
  on("-b VAL", "--backup", "Optionally specify the location to store a backup of the current configuration")
  on("-v", "--verbose", "Verbose logging")

  version Vpnconfig::VERSION

  use_log_level_option :toggle_debug_on_signal => 'USR1'

  go!
end