better grouping by finding groups with longest common prefixes

app/helpers/models_helper.rb

@@ -1,11 +1,22 @@
 module ModelsHelper
  def group(files)
- groups = files.group_by { |i| i.filename.split(/[\ _\-:.]/)[0] }
- ungrouped = []
- groups.each_pair do |group, p|
- ungrouped << groups.delete(group)[0] if p.count == 1
+ sections = {}
+ min_section_size = 2
+ min_prefix_length = 3
+ names = files.map(&:basename)
+ slice = names.map(&:length).max
+ while slice > min_prefix_length
+ slice -= 1
+ candidates = names.map { |x| x.slice(0, slice) }
+ groups = candidates.group_by { |x| x }
+ ready = groups.select { |k, v| v.count >= min_section_size }.map(&:first)
+ ready.each do |r|
+ names.reject! { |x| x.starts_with? r }
+ sections[r], files = files.partition { |x| x.basename.starts_with? r }
+ end
  end
- groups.merge(nil => ungrouped)
+ # Sort and include empty set
+ { nil => files }.merge sections.sort_by {|k, v| k }.to_h
  end
 
  def status_badges(model)