1 files changed, 75 insertions, 0 deletions
diff --git a/app/helpers/snippets_helper.rb b/app/helpers/snippets_helper.rb
index 906cb12cd48..bc36434f549 100644
--- a/app/helpers/snippets_helper.rb
+++ b/app/helpers/snippets_helper.rb
@@ -17,4 +17,79 @@ module SnippetsHelper
       snippet_path(snippet)
     end
   end
+
+  # Get an array of line numbers surrounding a matching
+  # line, bounded by min/max.
+  #
+  # @returns Array of line numbers
+  def bounded_line_numbers(line, min, max, surrounding_lines)
+    lower = line - surrounding_lines > min ? line - surrounding_lines : min
+    upper = line + surrounding_lines < max ? line + surrounding_lines : max
+    (lower..upper).to_a
+  end
+
+  # Returns a sorted set of lines to be included in a snippet preview.
+  # This ensures matching adjacent lines do not display duplicated
+  # surrounding code.
+  #
+  # @returns Array, unique and sorted.
+  def matching_lines(lined_content, surrounding_lines)
+    used_lines = []
+    lined_content.each_with_index do |line, line_number|
+      used_lines.concat bounded_line_numbers(
+        line_number,
+        0,
+        lined_content.size,
+        surrounding_lines
+      ) if line.include?(query)
+    end
+
+    used_lines.uniq.sort
+  end
+
+  # 'Chunkify' entire snippet.  Splits the snippet data into matching lines +
+  # surrounding_lines() worth of unmatching lines.
+  #
+  # @returns a hash with {snippet_object, snippet_chunks:{data,start_line}}
+  def chunk_snippet(snippet, surrounding_lines = 3)
+    lined_content = snippet.content.split("\n")
+    used_lines = matching_lines(lined_content, surrounding_lines)
+
+    snippet_chunk = []
+    snippet_chunks = []
+    snippet_start_line = 0
+    last_line = -1
+
+    # Go through each used line, and add consecutive lines as a single chunk
+    # to the snippet chunk array.
+    used_lines.each do |line_number|
+      if last_line < 0
+        # Start a new chunk.
+        snippet_start_line = line_number
+        snippet_chunk << lined_content[line_number]
+      elsif last_line == line_number - 1
+        # Consecutive line, continue chunk.
+        snippet_chunk << lined_content[line_number]
+      else
+        # Non-consecutive line, add chunk to chunk array.
+        snippet_chunks << {
+          data: snippet_chunk.join("\n"),
+          start_line: snippet_start_line + 1
+        }
+
+        # Start a new chunk.
+        snippet_chunk = [lined_content[line_number]]
+        snippet_start_line = line_number
+      end
+      last_line = line_number
+    end
+    # Add final chunk to chunk array
+    snippet_chunks << {
+      data: snippet_chunk.join("\n"),
+      start_line: snippet_start_line + 1
+    }
+
+    # Return snippet with chunk array
+    { snippet_object: snippet, snippet_chunks: snippet_chunks }
+  end
 end