commit

#!/usr/bin/env ruby

logs = {}

diff = `git diff --cached --submodule`
diff.each_line do |line|
  if /^Submodule (?<submodule>.*) (?<old_hash>\w+)\.\.(?<non_ff>\.?)(?<new_hash>\w+)/ =~ line
    Dir.chdir(submodule) do
      if `git rev-parse HEAD` != `git rev-parse @{push}`
        puts "ERROR: #{submodule}: Some commits have not been pushed."
        exit 1
      end

      logs[submodule] =
        if non_ff != ''
          "#{submodule}: #{old_hash}...#{new_hash} (no fast-forward!)\n\n" +
            `git log #{old_hash}...#{new_hash} --no-merges --pretty="format:  * %m %h %s (%an)%n%n%w(76,4,4)%-b%n"`
        else
          "#{submodule}: #{old_hash}..#{new_hash}\n\n" +
            `git log #{old_hash}..#{new_hash} --no-merges --pretty="format:  * %h %s (%an)%n%n%w(76,4,4)%-b%n"`
        end
    end
  end
end

log = "Submodule updates: " + logs.keys.join(", ").gsub(".tmbundle", "") + "\n\n"
log << logs.values.join("\n")

IO.popen "git commit -e -F -", "w" do |f|
  f.puts log
end