# frozen_string_literal: true

module GoogleCloud
  class SetupCloudsqlInstanceService < ::GoogleCloud::BaseService
    INSTANCE_STATE_RUNNABLE = 'RUNNABLE'
    OPERATION_STATE_DONE = 'DONE'
    DEFAULT_DATABASE_NAME = 'main_db'
    DEFAULT_DATABASE_USER = 'main_user'

    def execute
      return error('Unauthorized user') unless Ability.allowed?(current_user, :admin_project_google_cloud, project)

      get_instance_response = google_api_client.get_cloudsql_instance(gcp_project_id, instance_name)

      if get_instance_response.state != INSTANCE_STATE_RUNNABLE
        return error("CloudSQL instance not RUNNABLE: #{Gitlab::Json.dump(get_instance_response)}")
      end

      save_instance_ci_vars(get_instance_response)

      list_database_response = google_api_client.list_cloudsql_databases(gcp_project_id, instance_name)
      list_user_response = google_api_client.list_cloudsql_users(gcp_project_id, instance_name)

      existing_database = list_database_response.items.find { |database| database.name == database_name }
      existing_user = list_user_response.items.find { |user| user.name == username }

      if existing_database && existing_user
        save_database_ci_vars
        save_user_ci_vars(existing_user)
        return success
      end

      database_response = execute_database_setup(existing_database)
      return database_response if database_response[:status] == :error

      save_database_ci_vars

      user_response = execute_user_setup(existing_user)
      return user_response if user_response[:status] == :error

      save_user_ci_vars(existing_user)

      success
    rescue Google::Apis::Error => err
      error(message: Gitlab::Json.dump(err))
    end

    private

    def instance_name
      @params[:instance_name]
    end

    def database_version
      @params[:database_version]
    end

    def database_name
      @params.fetch(:database_name, DEFAULT_DATABASE_NAME)
    end

    def username
      @params.fetch(:username, DEFAULT_DATABASE_USER)
    end

    def password
      @password ||= SecureRandom.hex(16)
    end

    def save_ci_var(key, value, is_masked = false)
      create_or_replace_project_vars(environment_name, key, value, @params[:is_protected], is_masked)
    end

    def save_instance_ci_vars(cloudsql_instance)
      primary_ip_address = cloudsql_instance.ip_addresses.first.ip_address
      connection_name = cloudsql_instance.connection_name

      save_ci_var('GCP_PROJECT_ID', gcp_project_id)
      save_ci_var('GCP_CLOUDSQL_INSTANCE_NAME', instance_name)
      save_ci_var('GCP_CLOUDSQL_CONNECTION_NAME', connection_name)
      save_ci_var('GCP_CLOUDSQL_PRIMARY_IP_ADDRESS', primary_ip_address)
      save_ci_var('GCP_CLOUDSQL_VERSION', database_version)
    end

    def save_database_ci_vars
      save_ci_var('GCP_CLOUDSQL_DATABASE_NAME', database_name)
    end

    def save_user_ci_vars(user_exists)
      save_ci_var('GCP_CLOUDSQL_DATABASE_USER', username)
      save_ci_var('GCP_CLOUDSQL_DATABASE_PASS', user_exists ? user_exists.password : password, true)
    end

    def execute_database_setup(database_exists)
      return success if database_exists

      database_response = google_api_client.create_cloudsql_database(gcp_project_id, instance_name, database_name)

      if database_response.status != OPERATION_STATE_DONE
        return error("Database creation failed: #{Gitlab::Json.dump(database_response)}")
      end

      success
    end

    def execute_user_setup(existing_user)
      return success if existing_user

      user_response = google_api_client.create_cloudsql_user(gcp_project_id, instance_name, username, password)

      if user_response.status != OPERATION_STATE_DONE
        return error("User creation failed: #{Gitlab::Json.dump(user_response)}")
      end

      success
    end
  end
end