class Utils::LineBlamer

def self.blame(line)
  blamer = for_line(line)
  if blame = blamer.perform
    blame.sub!(/^[0-9a-f^]+/) { Term::ANSIColor.yellow($&) }
    blame.sub!(/\(([^)]+)\)/) { "(#{Term::ANSIColor.red($1)})" }
  end
end

def self.for_line(line)
  location = line.source_location and new *location
end

def initialize(file, lineno = 1)
  @file, @lineno = file, lineno
end

def perform(options = '')
  `git 2>/dev/null blame #{options} -L #@lineno,+1 "#@file"`.full?
end