require 'ami_spec/aws_instance'
require 'ami_spec/aws_instance_options'
require 'ami_spec/server_spec'
require 'ami_spec/server_spec_options'
require 'ami_spec/wait_for_ssh'
require 'trollop'

module AmiSpec
  class InstanceConnectionTimeout < StandardError; end
  # == Parameters:
  # amis::
  #   A hash of roles and amis in the format of:
  #   {role => ami_id}. i.e.
  #   {'web_server' => 'ami-abcd1234'}
  # specs::
  #   A string of the directory to find ServerSpecs.
  #   There should be a folder in this directory for each role found in ::amis
  # subnet_id::
  #   The subnet_id to start instances in.
  # key_name::
  #   The SSH key name to assign to instances. This key name must exist on the executing host for passwordless login.
  # key_file::
  #   The SSH key file to use to connect to the host.
  # aws_region::
  #   AWS region to connect to
  #   Defaults to AWS_DEFAULT_REGION
  # aws_security_group_ids::
  #   AWS Security groups to assign to the instances
  #   Defaults to the default security group for the VPC
  # aws_instance_type::
  #   AWS ec2 instance type
  # aws_public_ip::
  #   Should the instances get a public IP address
  # ssh_user::
  #   The username to SSH to the AMI with.
  # ssh_retries::
  #   Set the maximum number of ssh retries while waiting for the instance to boot.
  # debug::
  #   Don't terminate the instances on exit
  # == Returns:
  # Boolean - The result of all the server specs.
  def self.run(options)
    instances = []
    options[:amis].each_pair do |role, ami|
      aws_instance_options = AwsInstanceOptions.new(options.merge(role: role, ami: ami))
      instances << AwsInstance.start(aws_instance_options)
    end

    results = []
    instances.each do |instance|
      ip_address = options[:aws_public_ip] ? instance.public_ip_address : instance.private_ip_address
      WaitForSSH.wait(ip_address, options[:ssh_user], options[:key_file], options[:ssh_retries])

      server_spec_options = ServerSpecOptions.new(options.merge(instance: instance))
      results << ServerSpec.new(server_spec_options).run
     end

    results.all?
  ensure
    stop_instances(instances, options[:debug])
  end

  def self.stop_instances(instances, debug)
    instances.each do |instance|
      begin
        if debug
          puts "EC2 instance ##{instance.instance_id} has not been stopped due to debug mode."
        else
          instance.terminate
        end
      rescue Aws::EC2::Errors::InvalidInstanceIDNotFound
        puts "Failed to stop EC2 instance ##{instance.instance_id}"
      end
    end
  end

  private_class_method :stop_instances

  def self.invoke
    options = Trollop::options do
      opt :role, "The role to test, this should map to a directory in the spec folder", type: :string
      opt :ami, "The ami ID to run tests against", type: :string
      opt :role_ami_file, "A file containing comma separated roles and amis. i.e.\nweb_server,ami-id.",
          type: :string
      opt :specs, "The directory to find ServerSpecs", type: :string, required: true
      opt :subnet_id, "The subnet to start the instance in", type: :string, required: true
      opt :key_name, "The SSH key name to assign to instances", type: :string, required: true
      opt :key_file, "The SSH private key file associated to the key_name", type: :string, required: true
      opt :ssh_user, "The user to ssh to the instance as", type: :string, required: true
      opt :aws_region, "The AWS region, defaults to AWS_DEFAULT_REGION environment variable", type: :string
      opt :aws_instance_type, "The ec2 instance type, defaults to t2.micro", type: :string, default: 't2.micro'
      opt :aws_security_groups, "Security groups to associate to the launched instances. May be specified multiple times",
          type: :strings, default: nil
      opt :aws_public_ip, "Launch instances with a public IP"
      opt :ssh_retries, "The number of times we should try sshing to the ec2 instance before giving up. Defaults to 30",
          type: :int, default: 30
      opt :debug, "Don't terminate instances on exit"
    end

    if options[:role] && options[:ami]
      options[:amis] = { options[:role] => options[:ami] }
      options.delete(:role)
      options.delete(:ami)
    elsif options[:role_ami_file]
      file_lines = File.read(options[:role_ami_file]).split("\n")
      file_array = file_lines.collect { |line| line.split(',') }.flatten
      options[:amis] = Hash[*file_array]
      options.delete(:role_ami_file)
    else
      fail "You must specify either role and ami or role_ami_file"
    end

    exit run(options)
  end
end