#!/usr/bin/env ruby

require 'optparse'

options = {:all => false, :sha => ARGV.shift}

optparser = OptionParser.new  do |parser|
  parser.banner = "Usage: git-meta [sha|ref] [ --get | --get-all ]"
  
  parser.on('-a', '--get-all',
            "Retrieves all the keys as YAML data.") do |all|
    options[:all] = all
  end

  parser.on('-g', '--get KEY',
            "Retrives a certain KEY from the git commit object") do |key|
    options[:keys] = key.split(".")
  end
  
  parser.on('-h', '--help',
            "Returns Usage Notes") do 
    puts parser
    exit
  end
  
end

if !options[:sha]
  puts optparser
  exit
end

optparser.parse(ARGV)

git_commit_info, data, output = nil, nil, nil

IO.popen("git-cat-file -p #{options[:sha]}", 'r') do |git_cat_file|
  git_commit_info = git_cat_file.read
end

if git_commit_info =~ /^(---git-meta---\s*\n)(.*\n)(^---git-meta---.*\n)/m
  if options[:keys]
    data = YAML.load($2)
    options[:keys].each do |key|
      data = data.fetch(key, Hash.new(""))
    end
    puts data.to_yaml.gsub(/^--- \n?/, '')
  elsif options[:all]
    puts $2
  end
end