require "inifile"
require "csv"
require "chef/mixin/deep_merge"

class Chef
  module Provisioning
    module FogDriver
      module Providers
        class AWS
          # Reads in a credentials file in Amazon's download format and presents the credentials to you
          class Credentials
            def initialize
              @credentials = {}
            end

            include Enumerable
            include Chef::Mixin::DeepMerge

            def default
              if @credentials.empty?
                raise "No credentials loaded!  Do you have one of ~/.aws/credentials or ~/.aws/config?"
              end
              @credentials[ENV["AWS_DEFAULT_PROFILE"] || "default"] || @credentials.first[1]
            end

            def keys
              @credentials.keys
            end

            def [](name)
              @credentials[name]
            end

            def each(&block)
              @credentials.each(&block)
            end

            def load_inis(config_ini_file, credentials_ini_file = nil)
              @credentials = load_config_ini(config_ini_file)
              if credentials_ini_file
                @credentials = deep_merge!(@credentials,
                                           load_credentials_ini(credentials_ini_file))
              end
            end

            def load_config_ini(config_ini_file)
              inifile = IniFile.load(File.expand_path(config_ini_file))
              config = {}
              if inifile
                inifile.each_section do |section|
                  next unless section =~ /^\s*profile\s+(.+)$/ || section =~ /^\s*(default)\s*/
                  profile_name = Regexp.last_match(1).strip
                  profile = inifile[section].each_with_object({}) do |pair, result|
                    result[pair[0].to_sym] = pair[1]
                  end
                  profile[:name] = profile_name
                  config[profile_name] = profile
                end
              end
              config
            end

            def load_credentials_ini(credentials_ini_file)
              inifile = IniFile.load(File.expand_path(credentials_ini_file))
              config = {}
              if inifile
                inifile.each_section do |section|
                  profile = inifile[section].each_with_object({}) do |pair, result|
                    result[pair[0].to_sym] = pair[1]
                  end
                  profile[:name] = section
                  config[section] = profile
                end
              end
              config
            end

            def load_csv(credentials_csv_file)
              CSV.new(File.open(credentials_csv_file), headers: :first_row).each do |row|
                @credentials[row["User Name"]] = {
                  name: row["User Name"],
                  user_name: row["User Name"],
                  aws_access_key_id: row["Access Key Id"],
                  aws_secret_access_key: row["Secret Access Key"]
                }
              end
            end

            def load_default
              config_file = ENV["AWS_CONFIG_FILE"] || File.expand_path("~/.aws/config")
              credentials_file = ENV["AWS_CREDENTIAL_FILE"] || File.expand_path("~/.aws/credentials")
              if File.file?(config_file)
                if File.file?(credentials_file)
                  load_inis(config_file, credentials_file)
                else
                  load_inis(config_file)
                end
              end
            end

            def self.method_missing(name, *args, &block)
              singleton.send(name, *args, &block)
            end

            def self.singleton
              @aws_credentials ||= Credentials.new
            end
          end
        end
      end
    end
  end
end