class CfndslConverger

# File lib/cfndsl_converger.rb, line 8
def chain_converge(cfndsl_stacks:,
                   input_bindings: nil)

  previous_output_bindings = input_bindings
  cfndsl_stacks.each do |cfndsl_stack|
    previous_output_bindings = converge stack_name: cfndsl_stack[:stack_name],
                                        path_to_stack: cfndsl_stack[:path_to_stack],
                                        bindings: previous_output_bindings.merge(input_bindings)
  end
  previous_output_bindings
end

# File lib/cfndsl_converger.rb, line 57
def cleanup(cloudformation_stack_name)
  resource = Aws::CloudFormation::Resource.new
  stack_to_delete = resource.stack(cloudformation_stack_name)

  stack_to_delete.delete
  begin
    stack_to_delete.wait_until(max_attempts:100, delay:15) do |stack|
      stack.stack_status.match /DELETE_COMPLETE/
    end
  rescue
    #squash any errors - when stack is gone, the waiter might freak
  end
end

# File lib/cfndsl_converger.rb, line 20
def converge(stack_name:,
             path_to_stack:,
             bindings: nil,
             fail_on_changes_to_immutable_resource: false)
  extras = []
  unless bindings.nil?
    temp_file = Tempfile.new(['cfnstackfortesting', '.yml'])
    temp_file.write bindings.to_yaml
    temp_file.close

    extras << [:yaml,File.expand_path(temp_file)]
  end

  verbose = false
  model = CfnDsl::eval_file_with_extras(File.expand_path(path_to_stack),
                                        extras,
                                        verbose)

  if fail_on_changes_to_immutable_resource and stack_exists?(stack_name)
    unsafe_logical_resource_id = ChangesetUtil.new.immutable_resources_that_would_change stack_name: stack_name,
                                                                                         template_body: model.to_json
    if unsafe_logical_resource_id.nil?
      outputs = converge_stack stack_name: stack_name,
                               stack_body: model.to_json
    else
      raise "update would modify or delete immutable resource #{unsafe_logical_resource_id}"
    end
  else
    outputs = converge_stack stack_name: stack_name,
                             stack_body: model.to_json
  end
  outputs
end

# File lib/cfndsl_converger.rb, line 79
def converge_stack(stack_name:,
                   stack_body:)

  cloudformation_client = Aws::CloudFormation::Client.new
  resource = Aws::CloudFormation::Resource.new(client: cloudformation_client)
  if stack_exists?(stack_name)
    stack = resource.stack(stack_name)
    begin
      stack.update(template_body: stack_body,
                   capabilities: %w(CAPABILITY_IAM))
    rescue Exception => error
      if error.to_s =~ /No updates are to be performed/
        STDERR.puts 'no updates necessary'
        return stack_outputs_hash(stack) if stack.stack_status =~ /COMPLETE/
      else
        raise error
      end
    end

  else
    stack = resource.create_stack(stack_name: stack_name,
                                  template_body: stack_body,
                                  capabilities: %w(CAPABILITY_IAM))
  end

  stack.wait_until(max_attempts:360, delay:15) do |stack|
    stack.stack_status =~ /COMPLETE/ or stack.stack_status =~ /FAILED/
  end

  if stack.stack_status =~ /FAILED/ or stack.stack_status =~ /ROLLBACK_COMPLETE/
    raise "#{stack_name} failed to converge: #{stack.stack_status}"
  end

  stack_outputs_hash(stack)
end

# File lib/cfndsl_converger.rb, line 73
def stack_exists?(stack_name)
  cloudformation_client = Aws::CloudFormation::Client.new
  resource = Aws::CloudFormation::Resource.new(client: cloudformation_client)
  resource.stacks.find {|stack| stack.name == stack_name }
end

# File lib/cfndsl_converger.rb, line 115
def stack_outputs_hash(stack)
  stack.outputs.inject({}) do |hash, output|
    hash[output.output_key] = output.output_value
    hash
  end
end