#!/usr/bin/env ruby
#
# Git commit-msg hook. Prepend branch name to commit tasks.
# If your branch name is in the numeric form "12345", also prepend "(Task 123)" to commit messages,
# unless #notask is included in the message (#notask will be stripped).
#
# Based on git://gist.github.com/750755.git
# 
# Place code into .git/hooks/prepare-commit-msg
# chmod 755 .git/hooks/prepare-commit-msg

branchname = `git branch --no-color 2> /dev/null`[/^\* (.+)/, 1].strip

message_file = ARGV[0]
message = File.read(message_file).strip

prepend = "[#{branchname}] "

# When task branch name is numeric and not a merge, use it for task number
if branchname =~ /\d+/ && (message =~ /Merge branch.*into #{branchname}/).nil?
  task_number = branchname.gsub(/[^\d]/, '')
  prepend += "(Task #{task_number}) "
end

# When message is blank and starts with comments, add a line break
prepend += "\n" if message.chars.first == "#"

if message.include?("#notask")
  message.sub!(/^\s*#notask\s*|\s*#notask/, '')
else
  message = prepend + message
end

File.open(message_file, 'w') {|f| f.write message }