module Bones::Plugins::Git

def define_tasks
  return unless have? :git
  config = ::Bones.config
  namespace :git do
    # A prerequisites task that all other tasks depend upon
    task :prereqs
    desc 'Show tags from the git repository'
    task :tags => 'git:prereqs' do |t|
      puts Git.open('.').tags.map {|t| t.name}.reverse
    end
    desc 'Show all log messages since the last release'
    task :changes => 'git:prereqs' do |t|
      tag = Git.open('.').tags.map {|t| t.name}.last
      range = tag ? "#{tag}..HEAD" : ''
      system "git log --oneline #{range}"
    end
    desc 'Create a new tag in the git repository'
    task :create_tag => 'git:prereqs' do |t|
      v = ENV['VERSION'] or abort 'Must supply VERSION=x.y.z'
      abort "Versions don't match #{v} vs #{config.version}" if v != config.version
      git = Git.open '.'
      tag = "%s-%s" % [config.name, config.version]
      puts "Creating git tag '#{tag}'."
      begin
        git.add_tag tag
      rescue Git::GitExecuteError
        abort "Tag creation failed: tag '#{tag}' already exists."
      end
      if git.remotes.map {|r| r.name}.include? 'origin'
        unless system "git push origin #{tag}"
          abort "Could not push tag to remote git repository."
        end
      end
    end  # task
    desc 'Delete a tag from the git repository'
    task :delete_tag => 'git:prereqs' do |t|
      v = ENV['VERSION'] or abort 'Must supply VERSION=x.y.z'
      git = Git.open '.'
      tag = "%s-%s" % [config.name, v]
      unless git.tags.map {|t| t.name}.include? tag
        puts "Tag '#{tag}' does not exist."
        break
      end
      puts "Deleting git tag '#{tag}'."
      abort 'Tag deletion failed.' unless system "git tag -d '#{tag}'"
      if git.remotes.map {|r| r.name}.include? 'origin'
        unless system "git push origin ':refs/tags/#{tag}'"
          abort "Could not delete tag from remote git repository."
        end
      end
    end  # task
  end  # namespace :git
  task 'gem:release' => 'git:create_tag'
end