add commit combiner

platform/vcs-impl/src/com/intellij/ide/starter/commit_combiner.rb

+require 'date'
+require 'pp'
+require 'json'
+
+CommitInfo = Struct.new(:hash, :time, :author, :repo_name, :grouping_id)
+
+GIT_ROOTS = %w[/ /contrib /community /community/android /community/android/tools-base /CIDR].freeze
+
+def distance(mina, maxa, minb, maxb)
+  if minb <= mina && mina <= maxb || minb <= maxa && maxa <= maxb
+    0
+  elsif mina >= maxb
+    mina - maxb
+  else
+    minb - maxa
+  end
+end
+
+def parse_git_log(dir)
+  pwd = Dir.pwd
+  Dir.chdir(pwd + dir)
+  result = `git log --format="%H|%cd|%an" rubymine/191.1564^..HEAD`.split("\n").map do |commit|
+    commit_split = commit.split('|')
+    CommitInfo.new(commit_split[0], DateTime.parse(commit_split[1]).to_time, commit_split[2], dir)
+  end
+  Dir.chdir(pwd)
+  result
+end
+
+
+repos = GIT_ROOTS.map(&method(:parse_git_log))
+
+grouping_id = 0
+repos.each do |repo|
+  repo.each_index do |index|
+    repo[index].grouping_id = if index > 0 && repo[index].author == repo[index - 1].author
+                                repo[index - 1].grouping_id
+                              else
+                                grouping_id += 1
+                              end
+  end
+end
+
+grouping = repos.map { |repo| repo.group_by(&:grouping_id) }
+
+flatten = grouping.map(&:values).flatten(1).sort_by { |it| it.last.time.to_i }
+
+flatten.each_with_index do |group, index|
+  (0..index - 1).each do |prev|
+    prev_group = flatten[prev]
+    next unless prev_group.first.author == group.first.author
+    prev_min = prev_group.map { |commit| commit.time.to_i }.min
+    prev_max = prev_group.map { |commit| commit.time.to_i }.max
+
+    group_min = group.map { |commit| commit.time.to_i }.min
+    group_max = group.map { |commit| commit.time.to_i }.max
+
+    next if distance(prev_min, prev_max, group_min, group_max) > 300
+
+    group_id = prev_group.first.grouping_id
+    group.each { |commit| commit.grouping_id = group_id }
+    break
+  end
+end
+
+commit_groups = repos.flatten.group_by(&:grouping_id)
+
+File.open("changes.json", "w") do |f|
+  f.write(JSON.pretty_generate(commit_groups.each { |key, value| commit_groups[key] = value.map(&:to_h) }))
+end
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