# frozen_string_literal: true

module Clusters
  module Applications
    class Knative < ApplicationRecord
      VERSION = '0.9.0'
      REPOSITORY = 'https://charts.gitlab.io'
      METRICS_CONFIG = 'https://gitlab.com/gitlab-org/charts/knative/-/raw/v0.9.0/vendor/istio-metrics.yml'
      FETCH_IP_ADDRESS_DELAY = 30.seconds
      API_GROUPS_PATH = 'config/knative/api_groups.yml'

      self.table_name = 'clusters_applications_knative'

      has_one :serverless_domain_cluster, class_name: '::Serverless::DomainCluster', foreign_key: 'clusters_applications_knative_id', inverse_of: :knative

      include ::Clusters::Concerns::ApplicationCore
      include ::Clusters::Concerns::ApplicationStatus
      include ::Clusters::Concerns::ApplicationVersion
      include ::Clusters::Concerns::ApplicationData
      include AfterCommitQueue

      alias_method :original_set_initial_status, :set_initial_status
      def set_initial_status
        return unless cluster&.platform_kubernetes_rbac?

        original_set_initial_status
      end

      state_machine :status do
        after_transition any => [:installed] do |application|
          application.run_after_commit do
            ClusterWaitForIngressIpAddressWorker.perform_in(
              FETCH_IP_ADDRESS_DELAY, application.name, application.id)
          end
        end

        after_transition any => [:installed, :updated] do |application|
          application.run_after_commit do
            ClusterConfigureIstioWorker.perform_async(application.cluster_id)
          end
        end
      end

      default_value_for :version, VERSION

      validates :hostname, presence: true, hostname: true

      scope :for_cluster, -> (cluster) { where(cluster: cluster) }

      has_one :pages_domain, through: :serverless_domain_cluster

      def chart
        'knative/knative'
      end

      def values
        { "domain" => hostname }.to_yaml
      end

      def available_domains
        PagesDomain.instance_serverless
      end

      def find_available_domain(pages_domain_id)
        available_domains.find_by(id: pages_domain_id)
      end

      def allowed_to_uninstall?
        !pre_installed?
      end

      def install_command
        helm_command_module::InstallCommand.new(
          name: name,
          version: VERSION,
          rbac: cluster.platform_kubernetes_rbac?,
          chart: chart,
          files: files,
          repository: REPOSITORY,
          postinstall: install_knative_metrics
        )
      end

      def schedule_status_update
        return unless installed?
        return if external_ip
        return if external_hostname

        ClusterWaitForIngressIpAddressWorker.perform_async(name, id)
      end

      def ingress_service
        cluster.kubeclient.get_service('istio-ingressgateway', Clusters::Kubernetes::ISTIO_SYSTEM_NAMESPACE)
      end

      def uninstall_command
        helm_command_module::DeleteCommand.new(
          name: name,
          rbac: cluster.platform_kubernetes_rbac?,
          files: files,
          predelete: delete_knative_services_and_metrics,
          postdelete: delete_knative_istio_leftovers
        )
      end

      private

      def delete_knative_services_and_metrics
        delete_knative_services + delete_knative_istio_metrics
      end

      def delete_knative_services
        cluster.kubernetes_namespaces.map do |kubernetes_namespace|
          Gitlab::Kubernetes::KubectlCmd.delete("ksvc", "--all", "-n", kubernetes_namespace.namespace)
        end
      end

      def delete_knative_istio_leftovers
        delete_knative_namespaces + delete_knative_and_istio_crds
      end

      def delete_knative_namespaces
        [
          Gitlab::Kubernetes::KubectlCmd.delete("--ignore-not-found", "ns", "knative-serving"),
          Gitlab::Kubernetes::KubectlCmd.delete("--ignore-not-found", "ns", "knative-build")
        ]
      end

      def delete_knative_and_istio_crds
        api_groups.map do |group|
          Gitlab::Kubernetes::KubectlCmd.delete_crds_from_group(group)
        end
      end

      # returns an array of CRDs to be postdelete since helm does not
      # manage the CRDs it creates.
      def api_groups
        @api_groups ||= YAML.safe_load(File.read(Rails.root.join(API_GROUPS_PATH)))
      end

      def install_knative_metrics
        return [] unless cluster.application_prometheus_available?

        [Gitlab::Kubernetes::KubectlCmd.apply_file(METRICS_CONFIG)]
      end

      def delete_knative_istio_metrics
        return [] unless cluster.application_prometheus_available?

        [Gitlab::Kubernetes::KubectlCmd.delete("--ignore-not-found", "-f", METRICS_CONFIG)]
      end
    end
  end
end
