1# frozen_string_literal: true
2
3class Projects::MergeRequests::DiffsController < Projects::MergeRequests::ApplicationController
4  include DiffHelper
5  include RendersNotes
6  include Gitlab::Cache::Helpers
7
8  before_action :commit
9  before_action :define_diff_vars
10  before_action :define_diff_comment_vars, except: [:diffs_batch, :diffs_metadata]
11  before_action :update_diff_discussion_positions!
12
13  around_action :allow_gitaly_ref_name_caching
14
15  after_action :track_viewed_diffs_events, only: [:diffs_batch]
16
17  urgency :low, [
18    :show,
19    :diff_for_path,
20    :diffs_batch,
21    :diffs_metadata
22  ]
23
24  def show
25    render_diffs
26  end
27
28  def diff_for_path
29    render_diffs
30  end
31
32  def diffs_batch
33    diff_options_hash = diff_options
34    diff_options_hash[:paths] = params[:paths] if params[:paths]
35
36    diffs = @compare.diffs_in_batch(params[:page], params[:per_page], diff_options: diff_options_hash)
37    unfoldable_positions = @merge_request.note_positions_for_paths(diffs.diff_file_paths, current_user).unfoldable
38    environment = @merge_request.environments_for(current_user, latest: true).last
39
40    diffs.unfold_diff_files(unfoldable_positions)
41    diffs.write_cache
42
43    options = {
44      environment: environment,
45      merge_request: @merge_request,
46      commit: commit,
47      diff_view: diff_view,
48      merge_ref_head_diff: render_merge_ref_head_diff?,
49      pagination_data: diffs.pagination_data,
50      allow_tree_conflicts: display_merge_conflicts_in_diff?
51    }
52
53    if diff_options_hash[:paths].blank?
54      # NOTE: Any variables that would affect the resulting json needs to be added to the cache_context to avoid stale cache issues.
55      cache_context = [
56        current_user&.cache_key,
57        environment&.cache_key,
58        unfoldable_positions.map(&:to_h),
59        diff_view,
60        params[:w],
61        params[:expanded],
62        params[:page],
63        params[:per_page],
64        options[:merge_ref_head_diff],
65        options[:allow_tree_conflicts]
66      ]
67
68      render_cached(
69        diffs,
70        with: PaginatedDiffSerializer.new(current_user: current_user),
71        cache_context: -> (_) { [Digest::SHA256.hexdigest(cache_context.to_s)] },
72        **options
73      )
74    else
75      render json: PaginatedDiffSerializer.new(current_user: current_user).represent(diffs, options)
76    end
77  end
78
79  def diffs_metadata
80    diffs = @compare.diffs(diff_options)
81
82    options = additional_attributes.merge(
83      only_context_commits: show_only_context_commits?,
84      merge_ref_head_diff: render_merge_ref_head_diff?,
85      allow_tree_conflicts: display_merge_conflicts_in_diff?
86    )
87
88    render json: DiffsMetadataSerializer.new(project: @merge_request.project, current_user: current_user)
89                   .represent(diffs, options)
90  end
91
92  private
93
94  def preloadable_mr_relations
95    [{ source_project: :namespace }, { target_project: :namespace }]
96  end
97
98  # Deprecated: https://gitlab.com/gitlab-org/gitlab/issues/37735
99  def render_diffs
100    diffs = @compare.diffs(diff_options)
101    @environment = @merge_request.environments_for(current_user, latest: true).last
102
103    diffs.unfold_diff_files(note_positions.unfoldable)
104    diffs.write_cache
105
106    request = {
107      current_user: current_user,
108      project: @merge_request.project,
109      render: ->(partial, locals) { view_to_html_string(partial, locals) }
110    }
111
112    options = additional_attributes.merge(
113      diff_view: "inline",
114      merge_ref_head_diff: render_merge_ref_head_diff?,
115      allow_tree_conflicts: display_merge_conflicts_in_diff?
116    )
117
118    if @merge_request.project.context_commits_enabled?
119      options[:context_commits] = @merge_request.recent_context_commits
120    end
121
122    render json: DiffsSerializer.new(request).represent(diffs, options)
123  end
124
125  # Deprecated: https://gitlab.com/gitlab-org/gitlab/issues/37735
126  def define_diff_vars
127    @merge_request_diffs = @merge_request.merge_request_diffs.viewable.order_id_desc
128    @compare = commit || find_merge_request_diff_compare
129    return render_404 unless @compare
130  end
131
132  # rubocop: disable CodeReuse/ActiveRecord
133  def commit
134    return unless commit_id = params[:commit_id].presence
135    return unless @merge_request.all_commits.exists?(sha: commit_id) || @merge_request.recent_context_commits.map(&:id).include?(commit_id)
136
137    @commit ||= @project.commit(commit_id)
138  end
139  # rubocop: enable CodeReuse/ActiveRecord
140
141  # rubocop: disable CodeReuse/ActiveRecord
142  #
143  # Deprecated: https://gitlab.com/gitlab-org/gitlab/issues/37735
144  def find_merge_request_diff_compare
145    @merge_request_diff =
146      if params[:diff_id].present?
147        @merge_request.merge_request_diffs.viewable.find_by(id: params[:diff_id])
148      else
149        @merge_request.merge_request_diff
150      end
151
152    return unless @merge_request_diff&.id
153
154    @comparable_diffs = @merge_request_diffs.select { |diff| diff.id < @merge_request_diff.id }
155
156    if @start_sha = params[:start_sha].presence
157      @start_version = @comparable_diffs.find { |diff| diff.head_commit_sha == @start_sha }
158
159      unless @start_version
160        @start_sha = @merge_request_diff.head_commit_sha
161        @start_version = @merge_request_diff
162      end
163    end
164
165    return @merge_request.context_commits_diff if show_only_context_commits? && !@merge_request.context_commits_diff.empty?
166    return @merge_request.merge_head_diff if render_merge_ref_head_diff?
167
168    if @start_sha
169      @merge_request_diff.compare_with(@start_sha)
170    else
171      @merge_request_diff
172    end
173  end
174  # rubocop: enable CodeReuse/ActiveRecord
175
176  def additional_attributes
177    {
178      environment: @environment,
179      merge_request: @merge_request,
180      merge_request_diff: @merge_request_diff,
181      merge_request_diffs: @merge_request_diffs,
182      start_version: @start_version,
183      start_sha: @start_sha,
184      commit: @commit,
185      latest_diff: @merge_request_diff&.latest?
186    }
187  end
188
189  # Deprecated: https://gitlab.com/gitlab-org/gitlab/issues/37735
190  def define_diff_comment_vars
191    @new_diff_note_attrs = {
192      noteable_type: 'MergeRequest',
193      noteable_id: @merge_request.id,
194      commit_id: @commit&.id
195    }
196
197    @diff_notes_disabled = false
198
199    @use_legacy_diff_notes = !@merge_request.has_complete_diff_refs?
200
201    @grouped_diff_discussions = @merge_request.grouped_diff_discussions(@compare.diff_refs)
202    @notes = prepare_notes_for_rendering(@grouped_diff_discussions.values.flatten.flat_map(&:notes), @merge_request)
203  end
204
205  def render_merge_ref_head_diff?
206    params[:diff_id].blank? &&
207      Gitlab::Utils.to_boolean(params[:diff_head]) &&
208      @merge_request.diffable_merge_ref? &&
209      @start_sha.nil?
210  end
211
212  def note_positions
213    @note_positions ||= Gitlab::Diff::PositionCollection.new(renderable_notes.map(&:position))
214  end
215
216  def renderable_notes
217    define_diff_comment_vars unless @notes
218
219    draft_notes =
220      if current_user
221        merge_request.draft_notes.authored_by(current_user)
222      else
223        []
224      end
225
226    @notes.concat(draft_notes)
227  end
228
229  def update_diff_discussion_positions!
230    return if @merge_request.has_any_diff_note_positions?
231
232    Discussions::CaptureDiffNotePositionsService.new(@merge_request).execute
233  end
234
235  def track_viewed_diffs_events
236    return if dnt_enabled?
237
238    Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter
239      .track_mr_diffs_action(merge_request: @merge_request)
240
241    return unless current_user&.view_diffs_file_by_file
242
243    Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter
244      .track_mr_diffs_single_file_action(merge_request: @merge_request, user: current_user)
245  end
246
247  def display_merge_conflicts_in_diff?
248    Feature.enabled?(:display_merge_conflicts_in_diff, @merge_request.project)
249  end
250end
251