class CapistranoAwsAutodiscover

# File lib/capistrano-aws-autodiscover.rb, line 8
def self.define_servers
  instances = CapistranoAwsAutodiscover.new(fetch(:aws_key_id), fetch(:secret_access_key), fetch(:aws_region), fetch(:ec2_project), fetch(:ec2_env)).execute
  instances.each do |s| 
    server s.dns, roles: s.roles, user: fetch(:user)
  end
end

# File lib/capistrano-aws-autodiscover.rb, line 15
def initialize(key, secret, aws_region, project, environment)
  @key = key
  @secret = secret
  @region = aws_region
  @project = project.to_s
  @environment = environment.to_s
end

# File lib/capistrano-aws-autodiscover.rb, line 23
def execute
  instances = ec2.describe_instances(instance_ids: tagged_instances,
                                     filters: [
                                       {name: "instance-state-name", values: ["running"]},
                                       {name: "tag:Env", values: [@environment]},
                                       {name: "tag:Project", values: [@project]},
                                       {name: "tag-key", values: ["Roles"]}
                                      ]
                                    )
  instances = instances.reservations.map {|r| r.instances }.flatten

  server_definitions(instances)
end

# File lib/capistrano-aws-autodiscover.rb, line 39
def ec2
  @ec2 ||= begin
            Aws.config = { access_key_id: @key,
                           secret_access_key: @secret,
                           region: @region }
            Aws::EC2::Client.new
           end
end

# File lib/capistrano-aws-autodiscover.rb, line 61
def make_args(instance)
  dns = instance.public_dns_name
  roles_tag = instance.tags.find {|t| t.key == "Roles"}.value
  roles = roles_tag.split(/,|;/)
  Instance.new(dns, roles)
end

# File lib/capistrano-aws-autodiscover.rb, line 57
def server_definitions(instances)
  instances.map {|i| make_args(i)}
end

# File lib/capistrano-aws-autodiscover.rb, line 48
def tagged_instances
  tags = ec2.describe_tags({filters: [
    {name: "resource-type", values: ["instance"]},
    {name: "key", values: ["Project"]}]
  })

  tags.tags.map(&:resource_id)
end