1# frozen_string_literal: true
2
3# Contains functionality shared between `DiffDiscussion` and `LegacyDiffDiscussion`.
4module DiscussionOnDiff
5  extend ActiveSupport::Concern
6
7  NUMBER_OF_TRUNCATED_DIFF_LINES = 16
8
9  included do
10    delegate  :line_code,
11              :original_line_code,
12              :note_diff_file,
13              :diff_line,
14              :active?,
15              :created_at_diff?,
16              to: :first_note
17
18    delegate  :file_path,
19              :blob,
20              :highlighted_diff_lines,
21              :diff_lines,
22              to: :diff_file,
23              allow_nil: true
24  end
25
26  def diff_discussion?
27    true
28  end
29
30  def file_new_path
31    first_note.position.new_path
32  end
33
34  def on_merge_request_commit?
35    for_merge_request? && commit_id.present?
36  end
37
38  # Returns an array of at most 16 highlighted lines above a diff note
39  def truncated_diff_lines(highlight: true, diff_limit: nil)
40    return [] unless on_text?
41    return [] if diff_line.nil?
42
43    diff_limit = [diff_limit, NUMBER_OF_TRUNCATED_DIFF_LINES].compact.min
44    lines = highlight ? highlighted_diff_lines : diff_lines
45
46    initial_line_index = [diff_line.index - diff_limit + 1, 0].max
47
48    prev_lines = []
49
50    lines[initial_line_index..diff_line.index].each do |line|
51      if line.meta?
52        prev_lines.clear
53      else
54        prev_lines << line
55      end
56    end
57
58    prev_lines
59  end
60
61  def diff_file
62    strong_memoize(:diff_file) do
63      # Falling back here is important as `note_diff_files` are created async.
64      fetch_preloaded_diff_file || first_note.diff_file
65    end
66  end
67
68  def line_code_in_diffs(diff_refs)
69    if active?(diff_refs)
70      line_code
71    elsif diff_refs && created_at_diff?(diff_refs)
72      original_line_code
73    end
74  end
75
76  private
77
78  def fetch_preloaded_diff_file
79    fetch_preloaded_diff =
80      context_noteable &&
81      context_noteable.preloads_discussion_diff_highlighting? &&
82      note_diff_file
83
84    context_noteable.discussions_diffs.find_by_id(note_diff_file.id) if fetch_preloaded_diff
85  end
86end
87