require 'uri'

module Astrovan
  module Deploy
    # Deploy an application to the remote servers.
    #
    # Options:
    # * +application+ - a name for the application. If not provided, the application name is taken from the last component of the path to the source repository.
    # * +deploy_to+ - the path of the directory for application deployment. Defaults to '/u/apps/:application'
    #
    # If a block is provided, the block is run to deploy the application in the specified environment.
    #
    # If no block is provided, a default deployment recipe is applied. The default recipe is:
    # * create the deployment, release and shared directories
    # * update the application from the repository into the release directory
    # * symlink to the current application
    #
    # Due to differences in application environments, no provision is made to restart the application in the default
    # recipe.
    def deploy(repository, options = {})
      original_environment = self.environment.dup

      self.environment.merge!(options)

      self.repository = repository
      self.application ||= File.basename(parse_repository_uri(repository).path.split('/').last,".git")
      self.deploy_to ||= "/u/apps/#{application}"
      self.shared_path = File.join(deploy_to, 'shared')
      self.shared_repository = File.join(shared_path, "#{application}.git")
      self.release_name = Time.now.utc.strftime("%Y%m%d%H%M%S")
      self.releases_path = File.join(deploy_to, 'releases')
      self.release_path = File.join(releases_path, release_name)
      self.current_path = File.join(deploy_to, 'current')

      if block_given?
        yield
      else
        mkdir deploy_to, releases_path, shared_path, options
        update options
      end
    rescue => e
      # TODO: rollback
      # rollback
      raise
    ensure
      self.environment.replace original_environment
    end

    # Create a symlink from a file or directory in the shared folder into the current release.
    #
    # Options:
    # * +shared_path+ - specify the parent directory of the file or directory to be shared
    # * +release_path+ - specify the parent directory to contain the shared file or directory
    def share(path, options = {})
      shared_path = options[:shared_path] || self.shared_path
      release_path = options[:release_path] || self.release_path
      symlink "#{shared_path}/#{path}", options.merge(:to => "#{release_path}/#{path}")
    end

  private
    #:stopdoc:
    GIT_URI_REGEXP = %r'^(?:(\w+)@)?((?:\w+.)*\w+):([/~]?[^/].+)$'
    #:startdoc:

    def parse_repository_uri(uri)
      # [user@]host.xz:/path/to/repo.git/
      # [user@]host.xz:~user/path/to/repo.git/
      # [user@]host.xz:path/to/repo.git

      if uri =~ GIT_URI_REGEXP
        URI::Generic.new(nil, $1, $2, nil, nil, $3, nil, nil, nil)
      else
        URI.parse(uri)
      end
    end
  end
end