# Cloud Foundry Java Buildpack
# Copyright 2013-2017 the original author or authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

require 'java_buildpack/component'
require 'java_buildpack/util/qualify_path'

module JavaBuildpack
  module Component

    # An abstraction encapsulating the +JAVA_OPTS+ of an application.
    #
    # A new instance of this type should be created once for the application.
    class JavaOpts < Array
      include JavaBuildpack::Util

      # Creates an instance of the +JAVA_OPTS+ abstraction.
      #
      # @param [Pathname] droplet_root the root directory of the droplet
      def initialize(droplet_root)
        @droplet_root = droplet_root
      end

      # Adds a +javaagent+ entry to the +JAVA_OPTS+. Prepends +$PWD+ to the path (relative to the droplet root) to
      # ensure that the path is always accurate.
      #
      # @param [Pathname] path the path to the +javaagent+ JAR
      # @return [JavaOpts]     +self+ for chaining
      def add_javaagent(path)
        add_preformatted_options "-javaagent:#{qualify_path path}"
      end

      # Adds a +agentpath+ entry to the +JAVA_OPTS+.  Prepends +$PWD+ to the path (relative to the droplet root) to
      # ensure that the path is always accurate.
      #
      # @param [Pathname] path the path to the +agentpath+ shared library
      # @param [Properties] props to append to the agentpath entry
      # @return [JavaOpts]     +self+ for chaining
      def add_agentpath_with_props(path, props)
        add_preformatted_options "-agentpath:#{qualify_path path}=" + props.map { |k, v| "#{k}=#{v}" }.join(',')
      end

      # Adds an +agentpath+ entry to the +JAVA_OPTS+. Prepends +$PWD+ to the path (relative to the droplet root) to
      # ensure that the path is always accurate.
      #
      # @param [Pathname] path the path to the +native+ +agent+
      # @return [JavaOpts]     +self+ for chaining
      def add_agentpath(path)
        add_preformatted_options "-agentpath:#{qualify_path path}"
      end

      # Adds a +bootclasspath/p+ entry to the +JAVA_OPTS+. Prepends +$PWD+ to the path (relative to the droplet root) to
      # ensure that the path is always accurate.
      #
      # @param [Pathname] path the path to the +javaagent+ JAR
      # @return [JavaOpts]     +self+ for chaining
      def add_bootclasspath_p(path)
        add_preformatted_options "-Xbootclasspath/p:#{qualify_path path}"
      end

      # Adds a system property to the +JAVA_OPTS+. Ensures that the key is prepended with +-D+.  If the value is a
      # +Pathname+, then prepends +$PWD+ to the path (relative to the droplet root) to ensure that the path is always
      # accurate.  Otherwise, uses the value as-is.
      #
      # @param [String] key             the key of the system property
      # @param [Pathname, String] value the value of the system property
      # @return [JavaOpts]              +self+ for chaining
      def add_system_property(key, value)
        add_preformatted_options "-D#{key}=#{qualify_value(value)}"
      end

      # Adds an option to the +JAVA_OPTS+. Nothing is prepended to the key.  If the value is a +Pathname+, then
      # prepends +$PWD+ to the path (relative to the droplet root) to ensure that the path is always accurate.
      # Otherwise, uses the value as-is.
      #
      # @param [String] key             the key of the option
      # @param [Pathname, String] value the value of the option
      # @return [JavaOpts]              +self+ for chaining
      def add_option(key, value)
        add_preformatted_options "#{key}=#{qualify_value(value)}"
      end

      # Adds a preformatted option to the +JAVA_OPTS+
      #
      # @param [String] value the value of options
      # @return [JavaOpts]    +self+ for chaining
      def add_preformatted_options(value)
        self << value
        self
      end

      # Returns the contents as an environment variable formatted as +JAVA_OPTS="<value1> <value2>"+
      #
      # @return [String] the contents as an environment variable
      def as_env_var
        "JAVA_OPTS=\"#{join(' ')}\""
      end

      private

      def qualify_value(value)
        value.respond_to?(:relative_path_from) ? qualify_path(value) : value
      end

    end

  end
end
