# frozen_string_literal: true

# To add new service you should build a class inherited from Service
# and implement a set of methods
class Service < ApplicationRecord
  include Sortable
  include Importable
  include ProjectServicesLoggable
  include DataFields
  include FromUnion
  include EachBatch

  SERVICE_NAMES = %w[
    alerts asana assembla bamboo bugzilla buildkite campfire confluence custom_issue_tracker discord
    drone_ci emails_on_push ewm external_wiki flowdock hangouts_chat hipchat irker jira
    mattermost mattermost_slash_commands microsoft_teams packagist pipelines_email
    pivotaltracker prometheus pushover redmine slack slack_slash_commands teamcity unify_circuit webex_teams youtrack
  ].freeze

  DEV_SERVICE_NAMES = %w[
    mock_ci mock_deployment mock_monitoring
  ].freeze

  serialize :properties, JSON # rubocop:disable Cop/ActiveRecordSerialize

  default_value_for :active, false
  default_value_for :alert_events, true
  default_value_for :category, 'common'
  default_value_for :commit_events, true
  default_value_for :confidential_issues_events, true
  default_value_for :confidential_note_events, true
  default_value_for :issues_events, true
  default_value_for :job_events, true
  default_value_for :merge_requests_events, true
  default_value_for :note_events, true
  default_value_for :pipeline_events, true
  default_value_for :push_events, true
  default_value_for :tag_push_events, true
  default_value_for :wiki_page_events, true

  after_initialize :initialize_properties

  after_commit :reset_updated_properties
  after_commit :cache_project_has_external_issue_tracker
  after_commit :cache_project_has_external_wiki

  belongs_to :project, inverse_of: :services
  belongs_to :group, inverse_of: :services
  has_one :service_hook

  validates :project_id, presence: true, unless: -> { template? || instance? || group_id }
  validates :group_id, presence: true, unless: -> { template? || instance? || project_id }
  validates :project_id, :group_id, absence: true, if: -> { template? || instance? }
  validates :type, uniqueness: { scope: :project_id }, unless: -> { template? || instance? || group_id }, on: :create
  validates :type, uniqueness: { scope: :group_id }, unless: -> { template? || instance? || project_id }
  validates :type, presence: true
  validates :template, uniqueness: { scope: :type }, if: -> { template? }
  validates :instance, uniqueness: { scope: :type }, if: -> { instance? }
  validate :validate_is_instance_or_template
  validate :validate_belongs_to_project_or_group

  scope :external_issue_trackers, -> { where(category: 'issue_tracker').active }
  scope :external_wikis, -> { where(type: 'ExternalWikiService').active }
  scope :active, -> { where(active: true) }
  scope :by_type, -> (type) { where(type: type) }
  scope :by_active_flag, -> (flag) { where(active: flag) }
  scope :inherit_from_id, -> (id) { where(inherit_from_id: id) }
  scope :for_group, -> (group) { where(group_id: group, type: available_services_types) }
  scope :for_template, -> { where(template: true, type: available_services_types) }
  scope :for_instance, -> { where(instance: true, type: available_services_types) }

  scope :push_hooks, -> { where(push_events: true, active: true) }
  scope :tag_push_hooks, -> { where(tag_push_events: true, active: true) }
  scope :issue_hooks, -> { where(issues_events: true, active: true) }
  scope :confidential_issue_hooks, -> { where(confidential_issues_events: true, active: true) }
  scope :merge_request_hooks, -> { where(merge_requests_events: true, active: true) }
  scope :note_hooks, -> { where(note_events: true, active: true) }
  scope :confidential_note_hooks, -> { where(confidential_note_events: true, active: true) }
  scope :job_hooks, -> { where(job_events: true, active: true) }
  scope :pipeline_hooks, -> { where(pipeline_events: true, active: true) }
  scope :wiki_page_hooks, -> { where(wiki_page_events: true, active: true) }
  scope :deployment_hooks, -> { where(deployment_events: true, active: true) }
  scope :alert_hooks, -> { where(alert_events: true, active: true) }
  scope :deployment, -> { where(category: 'deployment') }

  # Provide convenient accessor methods for each serialized property.
  # Also keep track of updated properties in a similar way as ActiveModel::Dirty
  def self.prop_accessor(*args)
    args.each do |arg|
      class_eval <<~RUBY, __FILE__, __LINE__ + 1
        unless method_defined?(arg)
          def #{arg}
            properties['#{arg}']
          end
        end

        def #{arg}=(value)
          self.properties ||= {}
          updated_properties['#{arg}'] = #{arg} unless #{arg}_changed?
          self.properties['#{arg}'] = value
        end

        def #{arg}_changed?
          #{arg}_touched? && #{arg} != #{arg}_was
        end

        def #{arg}_touched?
          updated_properties.include?('#{arg}')
        end

        def #{arg}_was
          updated_properties['#{arg}']
        end
      RUBY
    end
  end

  # Provide convenient boolean accessor methods for each serialized property.
  # Also keep track of updated properties in a similar way as ActiveModel::Dirty
  def self.boolean_accessor(*args)
    self.prop_accessor(*args)

    args.each do |arg|
      class_eval <<~RUBY, __FILE__, __LINE__ + 1
        def #{arg}?
          # '!!' is used because nil or empty string is converted to nil
          !!ActiveRecord::Type::Boolean.new.cast(#{arg})
        end
      RUBY
    end
  end

  def self.to_param
    raise NotImplementedError
  end

  def self.event_names
    self.supported_events.map { |event| ServicesHelper.service_event_field_name(event) }
  end

  def self.supported_event_actions
    %w[]
  end

  def self.supported_events
    %w[commit push tag_push issue confidential_issue merge_request wiki_page]
  end

  def self.event_description(event)
    ServicesHelper.service_event_description(event)
  end

  def self.find_or_create_templates
    create_nonexistent_templates
    for_template
  end

  def self.create_nonexistent_templates
    nonexistent_services = list_nonexistent_services_for(for_template)
    return if nonexistent_services.empty?

    # Create within a transaction to perform the lowest possible SQL queries.
    transaction do
      nonexistent_services.each do |service_type|
        service_type.constantize.create(template: true)
      end
    end
  end
  private_class_method :create_nonexistent_templates

  def self.find_or_initialize_integration(name, instance: false, group_id: nil)
    if name.in?(available_services_names)
      "#{name}_service".camelize.constantize.find_or_initialize_by(instance: instance, group_id: group_id)
    end
  end

  def self.find_or_initialize_all(scope)
    scope + build_nonexistent_services_for(scope)
  end

  def self.build_nonexistent_services_for(scope)
    list_nonexistent_services_for(scope).map do |service_type|
      service_type.constantize.new
    end
  end
  private_class_method :build_nonexistent_services_for

  def self.list_nonexistent_services_for(scope)
    # Using #map instead of #pluck to save one query count. This is because
    # ActiveRecord loaded the object here, so we don't need to query again later.
    available_services_types - scope.map(&:type)
  end
  private_class_method :list_nonexistent_services_for

  def self.available_services_names
    service_names = services_names
    service_names += dev_services_names

    service_names.sort_by(&:downcase)
  end

  def self.services_names
    SERVICE_NAMES
  end

  def self.dev_services_names
    return [] unless Rails.env.development?

    DEV_SERVICE_NAMES
  end

  def self.project_specific_services_names
    []
  end

  def self.available_services_types
    available_services_names.map { |service_name| "#{service_name}_service".camelize }
  end

  def self.services_types
    services_names.map { |service_name| "#{service_name}_service".camelize }
  end

  def self.build_from_integration(integration, project_id: nil, group_id: nil)
    service = integration.dup

    if integration.supports_data_fields?
      data_fields = integration.data_fields.dup
      data_fields.service = service
    end

    service.template = false
    service.instance = false
    service.project_id = project_id
    service.group_id = group_id
    service.inherit_from_id = integration.id if integration.instance? || integration.group
    service.active = false if service.invalid?
    service
  end

  def self.instance_exists_for?(type)
    exists?(instance: true, type: type)
  end

  def self.default_integration(type, scope)
    closest_group_integration(type, scope) || instance_level_integration(type)
  end

  def self.closest_group_integration(type, scope)
    group_ids = scope.ancestors.select(:id)
    array = group_ids.to_sql.present? ? "array(#{group_ids.to_sql})" : 'ARRAY[]'

    where(type: type, group_id: group_ids, inherit_from_id: nil)
      .order(Arel.sql("array_position(#{array}::bigint[], services.group_id)"))
      .first
  end
  private_class_method :closest_group_integration

  def self.instance_level_integration(type)
    find_by(type: type, instance: true)
  end
  private_class_method :instance_level_integration

  def self.create_from_active_default_integrations(scope, association, with_templates: false)
    group_ids = scope.ancestors.select(:id)
    array = group_ids.to_sql.present? ? "array(#{group_ids.to_sql})" : 'ARRAY[]'

    from_union([
      with_templates ? active.where(template: true) : none,
      active.where(instance: true),
      active.where(group_id: group_ids, inherit_from_id: nil)
    ]).order(Arel.sql("type ASC, array_position(#{array}::bigint[], services.group_id), instance DESC")).group_by(&:type).each do |type, records|
      build_from_integration(records.first, association => scope.id).save!
    end
  end

  def self.inherited_descendants_from_self_or_ancestors_from(integration)
    inherit_from_ids =
      where(type: integration.type, group: integration.group.self_and_ancestors)
        .or(where(type: integration.type, instance: true)).select(:id)

    from_union([
      where(type: integration.type, inherit_from_id: inherit_from_ids, group: integration.group.descendants),
      where(type: integration.type, inherit_from_id: inherit_from_ids, project: Project.in_namespace(integration.group.self_and_descendants))
    ])
  end

  def activated?
    active
  end

  def operating?
    active && persisted?
  end

  def show_active_box?
    true
  end

  def editable?
    true
  end

  def category
    read_attribute(:category).to_sym
  end

  def initialize_properties
    self.properties = {} if has_attribute?(:properties) && properties.nil?
  end

  def title
    # implement inside child
  end

  def description
    # implement inside child
  end

  def help
    # implement inside child
  end

  def to_param
    # implement inside child
    self.class.to_param
  end

  def fields
    # implement inside child
    []
  end

  # Expose a list of fields in the JSON endpoint.
  #
  # This list is used in `Service#as_json(only: json_fields)`.
  def json_fields
    %w[active]
  end

  def to_service_hash
    as_json(methods: :type, except: %w[id template instance project_id group_id])
  end

  def to_data_fields_hash
    data_fields.as_json(only: data_fields.class.column_names).except('id', 'service_id')
  end

  def event_channel_names
    []
  end

  def event_names
    self.class.event_names
  end

  def event_field(event)
    nil
  end

  def api_field_names
    fields.map { |field| field[:name] }
      .reject { |field_name| field_name =~ /(password|token|key|title|description)/ }
  end

  def global_fields
    fields
  end

  def configurable_events
    events = supported_events

    # No need to disable individual triggers when there is only one
    if events.count == 1
      []
    else
      events
    end
  end

  def configurable_event_actions
    self.class.supported_event_actions
  end

  def supported_events
    self.class.supported_events
  end

  def execute(data)
    # implement inside child
  end

  def test(data)
    # default implementation
    result = execute(data)
    { success: result.present?, result: result }
  end

  # Disable test for instance-level and group-level services.
  # https://gitlab.com/gitlab-org/gitlab/-/issues/213138
  def can_test?
    !instance? && !group_id
  end

  # Returns a hash of the properties that have been assigned a new value since last save,
  # indicating their original values (attr => original value).
  # ActiveRecord does not provide a mechanism to track changes in serialized keys,
  # so we need a specific implementation for service properties.
  # This allows to track changes to properties set with the accessor methods,
  # but not direct manipulation of properties hash.
  def updated_properties
    @updated_properties ||= ActiveSupport::HashWithIndifferentAccess.new
  end

  def reset_updated_properties
    @updated_properties = nil
  end

  def async_execute(data)
    return unless supported_events.include?(data[:object_kind])

    ProjectServiceWorker.perform_async(id, data)
  end

  def external_issue_tracker?
    category == :issue_tracker && active?
  end

  def external_wiki?
    type == 'ExternalWikiService' && active?
  end

  # override if needed
  def supports_data_fields?
    false
  end

  private

  def validate_is_instance_or_template
    errors.add(:template, 'The service should be a service template or instance-level integration') if template? && instance?
  end

  def validate_belongs_to_project_or_group
    errors.add(:project_id, 'The service cannot belong to both a project and a group') if project_id && group_id
  end

  def cache_project_has_external_issue_tracker
    if project && !project.destroyed?
      project.cache_has_external_issue_tracker
    end
  end

  def cache_project_has_external_wiki
    if project && !project.destroyed?
      project.cache_has_external_wiki
    end
  end

  def valid_recipients?
    activated? && !importing?
  end
end

Service.prepend_if_ee('EE::Service')
