require 'etc'
require 'yaml'
require 'rest' # from nap gem
require 'active_support'
require 'active_support/version'
%w{
  active_support/json
}.each do |active_support_3_requirement|
  require active_support_3_requirement
end if ActiveSupport::VERSION::MAJOR == 3

module EY
  module Metadata
    # An adapter that reads from the public EngineYard Cloud API (https://cloud.engineyard.com). Available from anywhere.
    #
    # See README for what environment variables and/or files you need to have in place for this to work.
    class EngineYardCloudApi
      URL = 'https://cloud.engineyard.com/api/v2/environments'
      
      # Currently the same as the SSH username.
      def database_username
        data['ssh_username']
      end
      
      # The username for connecting by SSH.
      def ssh_username
        data['ssh_username']
      end
      
      # Currently the same as the app name, at least for recently-created environments.
      #
      # It used to be named after the environment.
      def database_name
        data['apps'][0]['name']
      end
      
      # The hostname of the database host.
      def database_host
        db_master
      end

      # The public hostname of the db_master.
      #
      # If you're on a solo app, it counts the solo as the app_master.
      def db_master
        if x = data['instances'].detect { |i| i['role'] == 'db_master' }
          x['public_hostname']
        else
          solo
        end
      end
      
      # The public hostnames of all the app servers.
      #
      # If you're on a solo app, it counts the solo as an app server.
      def app_servers
        data['instances'].select { |i| %w{ app_master app solo }.include? i['role'] }.map { |i| i['public_hostname'] }.sort
      end
      
      # The public hostnames of all the db servers.
      #
      # If you're on a solo app, it counts the solo as a db server.
      def db_servers
        data['instances'].select { |i| %w{ db_master db_slave solo }.include? i['role'] }.map { |i| i['public_hostname'] }.sort
      end
      
      # The public hostnames of all the utility servers.
      #
      # If you're on a solo app, it counts the solo as a utility.
      def utilities
        data['instances'].select { |i| %w{ util solo }.include? i['role'] }.map { |i| i['public_hostname'] }.sort
      end
      
      # The public hostnames of all the app slaves.
      def app_slaves
        data['instances'].select { |i| %w{ app }.include? i['role'] }.map { |i| i['public_hostname'] }.sort
      end
  
      # The public hostnames of all the db slaves.
      def db_slaves
        data['instances'].select { |i| %w{ db_slave }.include? i['role'] }.map { |i| i['public_hostname'] }.sort
      end
      
      # The public hostname of the app_master.
      #
      # If you're on a solo app, it counts the solo as the app_master.
      def app_master
        if x = data['instances'].detect { |i| i['role'] == 'app_master' }
          x['public_hostname']
        else
          solo
        end
      end

      # The public hostname of the solo.
      def solo
        if x = data['instances'].detect { |i| i['role'] == 'solo' }
          x['public_hostname']
        end
      end

      # The name of the EngineYard AppCloud environment.
      def environment_name
        data['name']
      end
      
      # The stack in use, like nginx_passenger.
      def stack_name
        data['stack_name']
      end
      
      # The secret API token to access https://cloud.engineyard.com
      def ey_cloud_token
        @ey_cloud_token ||= if ENV['EY_CLOUD_TOKEN'].to_s.strip.length > 0
          ENV['EY_CLOUD_TOKEN']
        elsif File.exist? EY::Metadata.eyrc_path
          YAML.load(File.read(EY::Metadata.eyrc_path))['api_token']
        else
          raise RuntimeError, "[engineyard-metadata gem] You need to download #{eyrc_path} or set ENV['EY_CLOUD_TOKEN']"
        end
      end
      
      # The URL that EngineYard has on file for your application.
      def repository_uri
        @repository_uri ||= if ENV['REPOSITORY_URI'].to_s.strip.length > 0
          ENV['REPOSITORY_URI']
        elsif File.exist? EY::Metadata.git_config_path
          `git config --get remote.origin.url`
        else
          raise RuntimeError, "[engineyard-metadata gem] You need to be inside a app's git repo or set ENV['REPOSITORY_URI']"
        end
      end
      
      def data
        return @data if @data.is_a? Hash
        raw_json = REST.get(URL, 'X-EY-Cloud-Token' => ey_cloud_token).body
        raw_data = ActiveSupport::JSON.decode raw_json
        catch :found_environment_by_repository_uri do
          raw_data['environments'].each do |environment_hsh|
            if environment_hsh['apps'].any? { |app_hsh| app_hsh['repository_uri'] == repository_uri }
              @data = environment_hsh
              throw :found_environment_by_repository_uri
            end
          end
        end
        raise RuntimeError, "[engineyard-metadata gem] Couldn't find an EngineYard environment with the repository uri #{repository_uri}" unless @data.is_a? Hash
        @data
      end
    end
  end
end