module Awsecrets

# File lib/awsecrets.rb, line 148
def self.current_region
  metadata_endpoint = 'http://169.254.169.254/latest/meta-data/'
  az = Net::HTTP.get(URI.parse(metadata_endpoint + 'placement/availability-zone'))
  az[0...-1]
end

# File lib/awsecrets.rb, line 144
def self.generate_session_name
  "awsecrets-session-#{Time.now.to_i}"
end

# File lib/awsecrets.rb, line 9
def self.load(profile: nil, region: nil, secrets_path: nil, disable_load_secrets: false)
  @profile              = profile
  @region               = region
  @secrets_path         = secrets_path
  @disable_load_secrets = disable_load_secrets
  @disable_load_secrets = true if secrets_path == false

  @credentials       = nil
  @access_key_id     = nil
  @secret_access_key = nil
  @session_token     = nil
  @role_arn          = nil
  @external_id       = nil
  @source_profile    = nil
  @role_session_name = nil

  # 1. Command Line Options
  load_options if load_method_args
  # 2. Environment Variables
  load_env
  # 3. YAML file (secrets.yml)
  load_yaml
  # 4. The AWS credentials file
  # load_creds
  # 5. The CLI configuration file
  load_config

  set_aws_config
end

# File lib/awsecrets.rb, line 100
def self.load_config
  @region ||= if AWSConfig[@profile] && AWSConfig[@profile]['region']
                AWSConfig[@profile]['region']
              elsif AWSConfig['default']
                AWSConfig['default']['region']
              end

  @role_arn          ||= AWSConfig[@profile]['role_arn'] if AWSConfig[@profile]
  @role_session_name ||= AWSConfig[@profile]['role_session_name'] if AWSConfig[@profile]
  @external_id       ||= AWSConfig[@profile]['external_id'] if AWSConfig[@profile]
  @source_profile    ||= AWSConfig[@profile]['source_profile'] if AWSConfig[@profile]
end

# File lib/awsecrets.rb, line 58
def self.load_env
  @region       ||= ENV['AWS_REGION']
  @region       ||= ENV['AWS_DEFAULT_REGION']
  @profile      ||= ENV['AWS_PROFILE']
  @secrets_path ||= ENV['AWS_SECRETS_PATH']
  return if @access_key_id
  return unless ENV['AWS_ACCESS_KEY_ID'] && ENV['AWS_SECRET_ACCESS_KEY']
  @access_key_id     ||= ENV['AWS_ACCESS_KEY_ID']
  @secret_access_key ||= ENV['AWS_SECRET_ACCESS_KEY']
  @session_token     ||= ENV['AWS_SESSION_TOKEN']
end

# File lib/awsecrets.rb, line 39
def self.load_method_args
  return false unless @profile
  @region ||= AWSConfig[@profile]['region'] if AWSConfig[@profile]['region']
  true
end

# File lib/awsecrets.rb, line 45
def self.load_options
  opt = OptionParser.new
  opt.on('--profile PROFILE') { |v| @profile ||= v }
  opt.on('--region REGION') { |v| @region ||= v }
  opt.on('--secrets_path SECRETS_PATH') { |v| @secrets_path ||= v }
  begin
    opt.parse!(ARGV)
  rescue OptionParser::InvalidOption
  end
  return unless @profile
  @region ||= AWSConfig[@profile]['region']
end

# File lib/awsecrets.rb, line 70
def self.load_yaml
  return if @disable_load_secrets
  @secrets_path ||= 'secrets.yml'
  creds = YAML.load_file(@secrets_path) if File.exist?(File.expand_path(@secrets_path))
  @region ||= creds['region'] if creds && creds.include?('region')
  return if @access_key_id
  return unless creds &&
                creds.include?('aws_access_key_id') &&
                creds.include?('aws_secret_access_key')
  @access_key_id     ||= creds['aws_access_key_id']
  @secret_access_key ||= creds['aws_secret_access_key']
  @session_token     ||= creds['aws_session_token'] if creds.include?('aws_session_token')
  @role_arn          ||= creds['role_arn'] if creds.include?('role_arn')
  @external_id       ||= creds['external_id'] if creds.include?('external_id')
  @role_session_name ||= creds['role_session_name'] if creds.include?('role_session_name')

  return unless @role_arn
  @role_session_name ||= generate_session_name
  @credentials ||= role_creds(
    client: Aws::STS::Client.new(
      region: @region,
      access_key_id: @access_key_id,
      secret_access_key: @secret_access_key
    ),
    role_arn: @role_arn,
    role_session_name: @role_session_name,
    external_id: @external_id
  )
end

# File lib/awsecrets.rb, line 154
def self.role_creds(args)
  Aws::AssumeRoleCredentials.new(args)
end

# File lib/awsecrets.rb, line 113
def self.set_aws_config
  @region ||= self.current_region
  Aws.config[:region] = @region

  if @role_arn && @source_profile
    @role_session_name ||= generate_session_name
    region = if AWSConfig[@source_profile.name] && AWSConfig[@source_profile.name]['region']
               AWSConfig[@source_profile.name]['region']
             else
               AWSConfig['default']['region']
             end

    @credentials ||= role_creds(
      client: Aws::STS::Client.new(
        region: region,
        credentials: Aws::SharedCredentials.new(profile_name: @source_profile.name)
      ),
      role_arn: @role_arn,
      role_session_name: @role_session_name,
      external_id: @external_id
    )
  end

  @credentials ||= Aws::SharedCredentials.new(profile_name: @profile) if @profile
  @credentials ||= Aws::SharedCredentials.new(profile_name: 'default') if AWSConfig['default'] && !@access_key_id
  @credentials ||= Aws::Credentials.new(@access_key_id, @secret_access_key, @session_token) if @access_key_id
  @credentials ||= Aws::InstanceProfileCredentials.new

  Aws.config[:credentials] = @credentials
end