# frozen_string_literal: true

require 'spec_helper'

# We want to test Import on "complete" data set,
# which means that every relation (as in our Import/Export definition) is covered.
# Fixture JSONs we use for testing Import such as
# `spec/fixtures/lib/gitlab/import_export/complex/project.json`
# should include these relations being non-empty.
RSpec.describe 'Test coverage of the Project Import' do
  include ConfigurationHelper

  # `muted_relations` is a technical debt.
  # This list expected to be empty or used as a workround
  # in case this spec blocks an important urgent MR.
  # It is also expected that adding a relation in the list should lead to
  # opening a follow-up issue to fix this.
  let(:muted_relations) do
    %w[
      project.milestones.events.push_event_payload
      project.issues.events
      project.issues.events.push_event_payload
      project.issues.notes.events
      project.issues.notes.events.push_event_payload
      project.issues.milestone.events.push_event_payload
      project.issues.issuable_sla
      project.issues.issue_milestones
      project.issues.issue_milestones.milestone
      project.issues.resource_label_events.label.priorities
      project.issues.designs.notes
      project.issues.designs.notes.author
      project.issues.designs.notes.events
      project.issues.designs.notes.events.push_event_payload
      project.merge_requests.metrics
      project.merge_requests.notes.events.push_event_payload
      project.merge_requests.events.push_event_payload
      project.merge_requests.timelogs
      project.merge_requests.label_links
      project.merge_requests.label_links.label
      project.merge_requests.label_links.label.priorities
      project.merge_requests.milestone
      project.merge_requests.milestone.events
      project.merge_requests.milestone.events.push_event_payload
      project.merge_requests.merge_request_milestones
      project.merge_requests.merge_request_milestones.milestone
      project.merge_requests.resource_label_events.label
      project.merge_requests.resource_label_events.label.priorities
      project.ci_pipelines.notes.events
      project.ci_pipelines.notes.events.push_event_payload
      project.protected_branches.unprotect_access_levels
      project.prometheus_metrics
      project.metrics_setting
      project.boards.lists.label.priorities
      project.service_desk_setting
      project.security_setting
    ].freeze
  end

  # A list of JSON fixture files we use to test Import.
  # Most of the relations are present in `complex/project.json`
  # which is our main fixture.
  let(:project_json_fixtures) do
    [
      'spec/fixtures/lib/gitlab/import_export/complex/project.json',
      'spec/fixtures/lib/gitlab/import_export/group/project.json',
      'spec/fixtures/lib/gitlab/import_export/light/project.json',
      'spec/fixtures/lib/gitlab/import_export/milestone-iid/project.json',
      'spec/fixtures/lib/gitlab/import_export/designs/project.json'
    ].freeze
  end

  it 'ensures that all imported/exported relations are present in test JSONs' do
    not_tested_relations = (relations_from_config - tested_relations) - muted_relations

    expect(not_tested_relations).to be_empty, failure_message(not_tested_relations)
  end

  def relations_from_config
    relation_paths_for(:project)
      .map { |relation_names| relation_names.join(".") }
      .to_set
  end

  def tested_relations
    project_json_fixtures.flat_map(&method(:relations_from_json)).to_set
  end

  def relations_from_json(json_file)
    json = Gitlab::Json.parse(File.read(json_file))

    [].tap { |res| gather_relations({ project: json }, res, []) }
      .map { |relation_names| relation_names.join('.') }
  end

  def gather_relations(item, res, path)
    case item
    when Hash
      item.each do |k, v|
        next unless (v.is_a?(Array) || v.is_a?(Hash)) && v.present?

        new_path = path + [k]
        res << new_path
        gather_relations(v, res, new_path)
      end
    when Array
      item.each { |i| gather_relations(i, res, path) }
    end
  end

  def failure_message(not_tested_relations)
    <<~MSG
      These relations seem to be added recently and
      they expected to be covered in our Import specs: #{not_tested_relations}.

      To do that, expand one of the files listed in `project_json_fixtures`
      (or expand the list if you consider adding a new fixture file).

      After that, add a new spec into
      `spec/lib/gitlab/import_export/project/tree_restorer_spec.rb`
      to check that the relation is being imported correctly.

      In case the spec breaks the master or there is a sense of urgency,
      you could include the relations into the `muted_relations` list.

      Muting relations is considered to be a temporary solution, so please
      open a follow-up issue and try to fix that when it is possible.
    MSG
  end
end