require 'workers/stack_bootstrap/chef_node_name_builder'

# Fetches info about stack servers from provider and then persist them in mongo.
class StackServersPersister
  include PutsAndFlush
  attr_reader :stack, :out, :deleted, :servers_info

  NEW = 'new'
  DELETED = 'deleted'
  PERSISTED = 'persisted'
  JUST_PERSISTED = 'just_persisted'

  def initialize(stack, out)
    @stack, @out = stack, out
    @project = mongo.project(stack.project)
    @deploy_env = @project.deploy_env(stack.deploy_env)
    fetch_provider_servers_info
    set_servers_states
  end

  def persist_new_servers
    with_state(NEW).each do |info|
      info[:server] = persist_stack_server(info[:provider_info])
      info[:state] = JUST_PERSISTED
    end
  end

  # returns: { priority_as_integer => [Servers] }
  def just_persisted_by_priority
    stack_servers_with_priority = {}
    with_state(JUST_PERSISTED).each do |info|
      stack_servers_with_priority[info[:priority]] ||= []
      stack_servers_with_priority[info[:priority]] << info[:server]
    end
    stack_servers_with_priority
  end

  private

  def fetch_provider_servers_info
    @servers_info = stack.provider_instance.stack_servers(stack).map do |provider_info|
      {
        id: provider_info['id'],
        provider_info: provider_info,
        priority: provider_info['tags']['cid:priority'].to_i
      }
    end
  end

  def set_servers_states
    persisted = Devops::Db.connector.stack_servers(stack.id)
    persisted_ids = persisted.map(&:id)
    in_cloud_ids = @servers_info.map {|info| info[:id]}
    new_ids = in_cloud_ids - persisted_ids
    deleted_ids = persisted_ids - in_cloud_ids

    @servers_info.each do |info|
      if new_ids.include?(info[:id])
        info[:state] = NEW
      else
        info[:state] = PERSISTED
      end
    end

    @deleted = persisted.select { |server| deleted_ids.include?(server.id) }
  end

  def with_state(state)
    @servers_info.select { |info| info[:state] == state }
  end

  # takes a hash, returns Server model
  def persist_stack_server(server_info)
    server_attrs = {
      '_id' => server_info['id'],
      'chef_node_name' => get_name_builder(server_info).build_node_name!(incrementers_values),
      'created_by' => stack.owner,
      'deploy_env' => @deploy_env.identifier,
      'key' => server_info['key_name'] || stack.provider_instance.ssh_key,
      'project' => @project.id,
      'provider' => @stack.provider,
      'provider_account' => @stack.provider_account,
      'remote_user' => mongo.image(@deploy_env.image).remote_user,
      'private_ip' => server_info['private_ip'],
      'public_ip' => server_info['public_ip'],
      'run_list' => stack.run_list || [],
      'stack' => stack.name
    }

    server = ::Devops::Model::Server.new(server_attrs)
    mongo.server_insert(server)
    server
  end

  def get_name_builder(server_info)
    ChefNodeNameBuilder.new(
      provider_server_info: server_info,
      project_id: @project.id,
      env_id: @deploy_env.identifier,
      owner: stack.owner
    )
  end

  def incrementers_values
    @incrementers_values ||= {}
  end

  def mongo
    Devops::Db.connector
  end
end