module Sprout
  class RemoteFileTargetError < StandardError #:nodoc:
  end

  class RemoteFileTarget # :nodoc:

    attr_writer   :archive_path
    
    # The user path where this gem will download and install files
    # This value is set by the Sprout::Builder that creates this RemoteFileTarget
    attr_accessor :install_path

    # Optional md5 hash, usually set in the sprout.spec for each RemoteFileTarget
    # If this value is set, the downloaded archive will be hashed, the hashes will
    # be compared and if they differ, the installation process will break.
    attr_accessor :md5

    # Used for dmg archives. Absolute path to the mounted dmg (essentially it's name)
    attr_accessor :mount_path

    # Which platform will this RemoteFileTarget support.
    # Supported options are:
    #  * universal
    #  * macosx
    #  * win32
    #  * linux
    attr_accessor :platform

    # URL where Sprouts can go to download the RemoteFileTarget archive
    attr_accessor :url

    # Relative path within the archive to the executable or binary of interest
    def archive_path
      @archive_path ||= ''
    end

    # Resolve this RemoteFileTarget now. This method is called by the Sprout::Builder
    # and will download, install and unpack the described archive
    def resolve(update=false)
      if(url)
        @loader = RemoteFileLoader.new
        if(url && (update || !File.exists?(downloaded_path)))
          download(url, downloaded_path, update)
        end

        if(!File.exists?(installed_path) || !File.exists?(File.join(installed_path, archive_path) ))
          archive_root = File.join(install_path, 'archive')
          install(downloaded_path, archive_root)
        end
      end
    end
    
    # Return the basename of the executable that this RemoteFileTarget refers to
    def executable
      return File.basename(archive_path)
    end
    
    # The root path to the unpacked archive files. This is the base path that will be added to any
    # +archive_path+ relative paths
    def installed_path
      @installed_path ||= File.join(install_path, 'archive')
      return @installed_path
    end
    
    # Parent directory where archives are downloaded
    # can be something like: ~/Library/Sprouts/cache/0.7/sprout-somesprout-tool.x.x.x/
    def downloaded_path
      @downloaded_path ||= File.join(install_path, file_name)
      return @downloaded_path
    end
    
    # Base file name represented by the provided +url+
    # Will strip off any ? arguments and trailing slashes. May not play nice with Rails URLS,
    # We expect archive file name suffixes like, zip, gzip, tar.gz, dmg, etc.
    def file_name
      if(url.split('').last == '/')
        return name
      end
      file = url.split('/').pop
      file = file.split('?').shift
      return file
    end
    
    private
    def download(url, path, update=false)
      @loader = RemoteFileLoader.new
      @loader.get_remote_file(url, path, update, md5)
    end
    
    def install(from, to)
      @loader.unpack_downloaded_file(from, to)
    end
    
  end
end