class Bundler::GemHelper

def already_tagged?
  if sh('git tag').split(/\n/).include?(version_tag)
    Bundler.ui.confirm "Tag #{version_tag} has already been created."
    true
  end
end

def build_gem
  file_name = nil
  sh("gem build -V '#{spec_path}'") { |out, code|
    file_name = File.basename(built_gem_path)
    FileUtils.mkdir_p(File.join(base, 'pkg'))
    FileUtils.mv(built_gem_path, 'pkg')
    Bundler.ui.confirm "#{name} #{version} built to pkg/#{file_name}."
  }
  File.join(base, 'pkg', file_name)
end

def built_gem_path
  Dir[File.join(base, "#{name}-*.gem")].sort_by{|f| File.mtime(f)}.last
end

def clean?
  sh_with_code("git diff --exit-code")[1] == 0
end

def committed?
  sh_with_code("git diff-index --quiet --cached HEAD")[1] == 0
end

def gem_push?
  ! %w{n no nil false off 0}.include?(ENV['gem_push'].to_s.downcase)
end

def gemspec(&block)
  gemspec = instance.gemspec
  block.call(gemspec) if block
  gemspec
end

def git_push
  perform_git_push
  perform_git_push ' --tags'
  Bundler.ui.confirm "Pushed git commits and tags."
end

def guard_clean
  clean? && committed? or raise("There are files that need to be committed first.")
end

def initialize(base = nil, name = nil)
  Bundler.ui = UI::Shell.new
  @base = (base ||= SharedHelpers.pwd)
  gemspecs = name ? [File.join(base, "#{name}.gemspec")] : Dir[File.join(base, "{,*}.gemspec")]
  raise "Unable to determine name from existing gemspec. Use :name => 'gemname' in #install_tasks to manually set it." unless gemspecs.size == 1
  @spec_path = gemspecs.first
  @gemspec = Bundler.load_gemspec(@spec_path)
end

def install
  built_gem_path = nil
  desc "Build #{name}-#{version}.gem into the pkg directory."
  task 'build' do
    built_gem_path = build_gem
  end
  desc "Build and install #{name}-#{version}.gem into system gems."
  task 'install' => 'build' do
    install_gem(built_gem_path)
  end
  desc "Build and install #{name}-#{version}.gem into system gems without network access."
  task 'install:local' => 'build' do
    install_gem(built_gem_path, :local)
  end
  desc "Create tag #{version_tag} and build and push #{name}-#{version}.gem to Rubygems\n" \
       "To prevent publishing in Rubygems use `gem_push=no rake release`"
  task 'release' => ['build', 'release:guard_clean',
                     'release:source_control_push', 'release:rubygem_push'] do
  end
  task 'release:guard_clean' do
    guard_clean
  end
  task 'release:source_control_push' do
    tag_version { git_push } unless already_tagged?
  end
  task 'release:rubygem_push' do
    rubygem_push(built_gem_path) if gem_push?
  end
  GemHelper.instance = self
end

def install_gem(built_gem_path = nil, local = false)
  built_gem_path ||= build_gem
  out, _ = sh_with_code("gem install '#{built_gem_path}'#{' --local' if local}")
  raise "Couldn't install gem, run `gem install #{built_gem_path}' for more detailed output" unless out[/Successfully installed/]
  Bundler.ui.confirm "#{name} (#{version}) installed."
end

def install_tasks(opts = {})
  new(opts[:dir], opts[:name]).install
end

def name
  gemspec.name
end

def perform_git_push(options = '')
  cmd = "git push #{options}"
  out, code = sh_with_code(cmd)
  raise "Couldn't git push. `#{cmd}' failed with the following output:\n\n#{out}\n" unless code == 0
end

def rubygem_push(path)
  if Pathname.new("~/.gem/credentials").expand_path.exist?
    sh("gem push '#{path}'")
    Bundler.ui.confirm "Pushed #{name} #{version} to rubygems.org."
  else
    raise "Your rubygems.org credentials aren't set. Run `gem push` to set them."
  end
end

def sh(cmd, &block)
  out, code = sh_with_code(cmd, &block)
  code == 0 ? out : raise(out.empty? ? "Running `#{cmd}' failed. Run this command directly for more detailed output." : out)
end

def sh_with_code(cmd, &block)
  cmd << " 2>&1"
  outbuf = ''
  Bundler.ui.debug(cmd)
  SharedHelpers.chdir(base) {
    outbuf = `#{cmd}`
    if $? == 0
      block.call(outbuf) if block
    end
  }
  [outbuf, $?]
end

def tag_version
  sh "git tag -a -m \"Version #{version}\" #{version_tag}"
  Bundler.ui.confirm "Tagged #{version_tag}."
  yield if block_given?
rescue
  Bundler.ui.error "Untagging #{version_tag} due to error."
  sh_with_code "git tag -d #{version_tag}"
  raise
end

def version
  gemspec.version
end

def version_tag
  "v#{version}"
end