# frozen_string_literal: true

module Ci
  class Runner < ApplicationRecord
    extend Gitlab::Ci::Model
    include Gitlab::SQL::Pattern
    include RedisCacheable
    include ChronicDurationAttribute
    include FromUnion
    include TokenAuthenticatable
    include IgnorableColumns
    include FeatureGate
    include Gitlab::Utils::StrongMemoize
    include TaggableQueries

    add_authentication_token_field :token, encrypted: :optional

    enum access_level: {
      not_protected: 0,
      ref_protected: 1
    }

    enum runner_type: {
      instance_type: 1,
      group_type: 2,
      project_type: 3
    }

    # This `ONLINE_CONTACT_TIMEOUT` needs to be larger than
    #   `RUNNER_QUEUE_EXPIRY_TIME+UPDATE_CONTACT_COLUMN_EVERY`
    #
    ONLINE_CONTACT_TIMEOUT = 2.hours

    # The `RUNNER_QUEUE_EXPIRY_TIME` indicates the longest interval that
    #   Runner request needs to be refreshed by Rails instead of being handled
    #   by Workhorse
    RUNNER_QUEUE_EXPIRY_TIME = 1.hour

    # The `UPDATE_CONTACT_COLUMN_EVERY` defines how often the Runner DB entry can be updated
    UPDATE_CONTACT_COLUMN_EVERY = (40.minutes..55.minutes).freeze

    AVAILABLE_TYPES_LEGACY = %w[specific shared].freeze
    AVAILABLE_TYPES = runner_types.keys.freeze
    AVAILABLE_STATUSES = %w[active paused online offline not_connected].freeze
    AVAILABLE_SCOPES = (AVAILABLE_TYPES_LEGACY + AVAILABLE_TYPES + AVAILABLE_STATUSES).freeze

    FORM_EDITABLE = %i[description tag_list active run_untagged locked access_level maximum_timeout_human_readable].freeze
    MINUTES_COST_FACTOR_FIELDS = %i[public_projects_minutes_cost_factor private_projects_minutes_cost_factor].freeze

    has_many :builds
    has_many :runner_projects, inverse_of: :runner, autosave: true, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
    has_many :projects, through: :runner_projects
    has_many :runner_namespaces, inverse_of: :runner, autosave: true
    has_many :groups, through: :runner_namespaces

    has_one :last_build, -> { order('id DESC') }, class_name: 'Ci::Build'

    before_save :ensure_token

    scope :active, -> { where(active: true) }
    scope :paused, -> { where(active: false) }
    scope :online, -> { where('contacted_at > ?', online_contact_time_deadline) }
    scope :recent, -> { where('ci_runners.created_at > :date OR ci_runners.contacted_at > :date', date: 3.months.ago) }
    # The following query using negation is cheaper than using `contacted_at <= ?`
    # because there are less runners online than have been created. The
    # resulting query is quickly finding online ones and then uses the regular
    # indexed search and rejects the ones that are in the previous set. If we
    # did `contacted_at <= ?` the query would effectively have to do a seq
    # scan.
    scope :offline, -> { where.not(id: online) }
    scope :not_connected, -> { where(contacted_at: nil) }
    scope :ordered, -> { order(id: :desc) }

    scope :with_recent_runner_queue, -> { where('contacted_at > ?', recent_queue_deadline) }

    # BACKWARD COMPATIBILITY: There are needed to maintain compatibility with `AVAILABLE_SCOPES` used by `lib/api/runners.rb`
    scope :deprecated_shared, -> { instance_type }
    scope :deprecated_specific, -> { project_type.or(group_type) }

    scope :belonging_to_project, -> (project_id) {
      joins(:runner_projects).where(ci_runner_projects: { project_id: project_id })
    }

    scope :belonging_to_group, -> (group_id, include_ancestors: false) {
      groups = ::Group.where(id: group_id)

      if include_ancestors
        groups = Gitlab::ObjectHierarchy.new(groups).base_and_ancestors
      end

      joins(:runner_namespaces).where(ci_runner_namespaces: { namespace_id: groups })
    }

    scope :belonging_to_group_or_project, -> (group_id, project_id) {
      groups = ::Group.where(id: group_id)

      group_runners = joins(:runner_namespaces).where(ci_runner_namespaces: { namespace_id: groups })
      project_runners = joins(:runner_projects).where(ci_runner_projects: { project_id: project_id })

      union_sql = ::Gitlab::SQL::Union.new([group_runners, project_runners]).to_sql

      from("(#{union_sql}) #{table_name}")
    }

    scope :belonging_to_parent_group_of_project, -> (project_id) {
      project_groups = ::Group.joins(:projects).where(projects: { id: project_id })
      hierarchy_groups = Gitlab::ObjectHierarchy.new(project_groups).base_and_ancestors

      joins(:groups).where(namespaces: { id: hierarchy_groups })
    }

    scope :owned_or_instance_wide, -> (project_id) do
      from_union(
        [
          belonging_to_project(project_id),
          belonging_to_parent_group_of_project(project_id),
          instance_type
        ],
        remove_duplicates: false
      )
    end

    scope :assignable_for, ->(project) do
      # FIXME: That `to_sql` is needed to workaround a weird Rails bug.
      #        Without that, placeholders would miss one and couldn't match.
      #
      # We use "unscoped" here so that any current Ci::Runner filters don't
      # apply to the inner query, which is not necessary.
      exclude_runners = unscoped { project.runners.select(:id) }.to_sql

      where(locked: false)
        .where.not("ci_runners.id IN (#{exclude_runners})")
        .project_type
    end

    scope :order_contacted_at_asc, -> { order(contacted_at: :asc) }
    scope :order_contacted_at_desc, -> { order(contacted_at: :desc) }
    scope :order_created_at_asc, -> { order(created_at: :asc) }
    scope :order_created_at_desc, -> { order(created_at: :desc) }
    scope :with_tags, -> { preload(:tags) }

    validate :tag_constraints
    validates :access_level, presence: true
    validates :runner_type, presence: true

    validate :no_projects, unless: :project_type?
    validate :no_groups, unless: :group_type?
    validate :any_project, if: :project_type?
    validate :exactly_one_group, if: :group_type?

    acts_as_taggable

    after_destroy :cleanup_runner_queue

    cached_attr_reader :version, :revision, :platform, :architecture, :ip_address, :contacted_at

    chronic_duration_attr :maximum_timeout_human_readable, :maximum_timeout,
        error_message: 'Maximum job timeout has a value which could not be accepted'

    validates :maximum_timeout, allow_nil: true,
                                numericality: { greater_than_or_equal_to: 600,
                                                message: 'needs to be at least 10 minutes' }

    validates :public_projects_minutes_cost_factor, :private_projects_minutes_cost_factor,
      allow_nil: false,
      numericality: { greater_than_or_equal_to: 0.0,
                      message: 'needs to be non-negative' }

    validates :config, json_schema: { filename: 'ci_runner_config' }

    # Searches for runners matching the given query.
    #
    # This method uses ILIKE on PostgreSQL for the description field and performs a full match on tokens.
    #
    # query - The search query as a String.
    #
    # Returns an ActiveRecord::Relation.
    def self.search(query)
      where(token: query).or(fuzzy_search(query, [:description]))
    end

    def self.online_contact_time_deadline
      ONLINE_CONTACT_TIMEOUT.ago
    end

    def self.recent_queue_deadline
      # we add queue expiry + online
      # - contacted_at can be updated at any time within this interval
      #   we have always accurate `contacted_at` but it is stored in Redis
      #   and not persisted in database
      (ONLINE_CONTACT_TIMEOUT + RUNNER_QUEUE_EXPIRY_TIME).ago
    end

    def self.order_by(order)
      case order
      when 'contacted_asc'
        order_contacted_at_asc
      when 'contacted_desc'
        order_contacted_at_desc
      when 'created_at_asc'
        order_created_at_asc
      else
        order_created_at_desc
      end
    end

    def self.runner_matchers
      unique_params = [
        :runner_type,
        :public_projects_minutes_cost_factor,
        :private_projects_minutes_cost_factor,
        :run_untagged,
        :access_level,
        Arel.sql("(#{arel_tag_names_array.to_sql})")
      ]

      group(*unique_params).pluck('array_agg(ci_runners.id)', *unique_params).map do |values|
        Gitlab::Ci::Matching::RunnerMatcher.new({
          runner_ids: values[0],
          runner_type: values[1],
          public_projects_minutes_cost_factor: values[2],
          private_projects_minutes_cost_factor: values[3],
          run_untagged: values[4],
          access_level: values[5],
          tag_list: values[6]
        })
      end
    end

    def runner_matcher
      strong_memoize(:runner_matcher) do
        Gitlab::Ci::Matching::RunnerMatcher.new({
          runner_ids: [id],
          runner_type: runner_type,
          public_projects_minutes_cost_factor: public_projects_minutes_cost_factor,
          private_projects_minutes_cost_factor: private_projects_minutes_cost_factor,
          run_untagged: run_untagged,
          access_level: access_level,
          tag_list: tag_list
        })
      end
    end

    def assign_to(project, current_user = nil)
      if instance_type?
        self.runner_type = :project_type
      elsif group_type?
        raise ArgumentError, 'Transitioning a group runner to a project runner is not supported'
      end

      begin
        transaction do
          self.projects << project
          self.save!
        end
      rescue ActiveRecord::RecordInvalid => e
        self.errors.add(:assign_to, e.message)
        false
      end
    end

    def display_name
      return short_sha if description.blank?

      description
    end

    def online?
      contacted_at && contacted_at > self.class.online_contact_time_deadline
    end

    def status
      if contacted_at.nil?
        :not_connected
      elsif active?
        online? ? :online : :offline
      else
        :paused
      end
    end

    def belongs_to_one_project?
      runner_projects.count == 1
    end

    def belongs_to_more_than_one_project?
      self.projects.limit(2).count(:all) > 1
    end

    def assigned_to_group?
      runner_namespaces.any?
    end

    def assigned_to_project?
      runner_projects.any?
    end

    # TODO: remove this method in favor of `matches_build?` once feature flag is removed
    # https://gitlab.com/gitlab-org/gitlab/-/issues/323317
    def can_pick?(build)
      if Feature.enabled?(:ci_runners_short_circuit_assignable_for, self, default_enabled: :yaml)
        matches_build?(build)
      else
        #  Run `matches_build?` checks before, since they are cheaper than
        # `assignable_for?`.
        #
        matches_build?(build) && assignable_for?(build.project_id)
      end
    end

    def match_build_if_online?(build)
      active? && online? && can_pick?(build)
    end

    def only_for?(project)
      projects == [project]
    end

    def short_sha
      token[0...8] if token
    end

    def tag_list
      return super unless Feature.enabled?(:ci_preload_runner_tags, default_enabled: :yaml)

      if tags.loaded?
        tags.map(&:name)
      else
        super
      end
    end

    def has_tags?
      tag_list.any?
    end

    def predefined_variables
      Gitlab::Ci::Variables::Collection.new
        .append(key: 'CI_RUNNER_ID', value: id.to_s)
        .append(key: 'CI_RUNNER_DESCRIPTION', value: description)
        .append(key: 'CI_RUNNER_TAGS', value: tag_list.to_s)
    end

    def tick_runner_queue
      ##
      # We only stick a runner to primary database to be able to detect the
      # replication lag in `EE::Ci::RegisterJobService#execute`. The
      # intention here is not to execute `Ci::RegisterJobService#execute` on
      # the primary database.
      #
      ::Gitlab::Database::LoadBalancing::Sticking.stick(:runner, id)

      SecureRandom.hex.tap do |new_update|
        ::Gitlab::Workhorse.set_key_and_notify(runner_queue_key, new_update,
          expire: RUNNER_QUEUE_EXPIRY_TIME, overwrite: true)
      end
    end

    def ensure_runner_queue_value
      new_value = SecureRandom.hex
      ::Gitlab::Workhorse.set_key_and_notify(runner_queue_key, new_value,
        expire: RUNNER_QUEUE_EXPIRY_TIME, overwrite: false)
    end

    def runner_queue_value_latest?(value)
      ensure_runner_queue_value == value if value.present?
    end

    def heartbeat(values)
      ##
      # We can safely ignore writes performed by a runner heartbeat. We do
      # not want to upgrade database connection proxy to use the primary
      # database after heartbeat write happens.
      #
      ::Gitlab::Database::LoadBalancing::Session.without_sticky_writes do
        values = values&.slice(:version, :revision, :platform, :architecture, :ip_address, :config) || {}
        values[:contacted_at] = Time.current

        cache_attributes(values)

        # We save data without validation, it will always change due to `contacted_at`
        self.update_columns(values) if persist_cached_data?
      end
    end

    def pick_build!(build)
      tick_runner_queue if matches_build?(build)
    end

    def uncached_contacted_at
      read_attribute(:contacted_at)
    end

    private

    def cleanup_runner_queue
      Gitlab::Redis::SharedState.with do |redis|
        redis.del(runner_queue_key)
      end
    end

    def runner_queue_key
      "runner:build_queue:#{self.token}"
    end

    def persist_cached_data?
      # Use a random threshold to prevent beating DB updates.
      contacted_at_max_age = Random.rand(UPDATE_CONTACT_COLUMN_EVERY)

      real_contacted_at = read_attribute(:contacted_at)
      real_contacted_at.nil? ||
        (Time.current - real_contacted_at) >= contacted_at_max_age
    end

    def tag_constraints
      unless has_tags? || run_untagged?
        errors.add(:tags_list,
          'can not be empty when runner is not allowed to pick untagged jobs')
      end
    end

    # TODO: remove this method once feature flag ci_runners_short_circuit_assignable_for
    # is removed. https://gitlab.com/gitlab-org/gitlab/-/issues/323317
    def assignable_for?(project_id)
      self.class.owned_or_instance_wide(project_id).where(id: self.id).any?
    end

    def no_projects
      if projects.any?
        errors.add(:runner, 'cannot have projects assigned')
      end
    end

    def no_groups
      if groups.any?
        errors.add(:runner, 'cannot have groups assigned')
      end
    end

    def any_project
      unless projects.any?
        errors.add(:runner, 'needs to be assigned to at least one project')
      end
    end

    def exactly_one_group
      unless groups.one?
        errors.add(:runner, 'needs to be assigned to exactly one group')
      end
    end

    def matches_build?(build)
      runner_matcher.matches?(build.build_matcher)
    end
  end
end

Ci::Runner.prepend_mod_with('Ci::Runner')