module Berkshelf::Chef::Cookbook
  # @author Jamie Winsor <reset@riotgames.com>
  #
  # Borrowed and modified from: {https://raw.github.com/opscode/chef/11.4.0/lib/chef/cookbook/metadata.rb}
  #
  # Copyright:: Copyright 2008-2010 Opscode, Inc.
  #
  # 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.
  #
  # == Chef::Cookbook::Metadata
  # Chef::Cookbook::Metadata provides a convenient DSL for declaring metadata
  # about Chef Cookbooks.
  class Metadata
    class << self
      def from_hash(hash)
        new.from_hash(hash)
      end
    end

    NAME              = 'name'.freeze
    DESCRIPTION       = 'description'.freeze
    LONG_DESCRIPTION  = 'long_description'.freeze
    MAINTAINER        = 'maintainer'.freeze
    MAINTAINER_EMAIL  = 'maintainer_email'.freeze
    LICENSE           = 'license'.freeze
    PLATFORMS         = 'platforms'.freeze
    DEPENDENCIES      = 'dependencies'.freeze
    RECOMMENDATIONS   = 'recommendations'.freeze
    SUGGESTIONS       = 'suggestions'.freeze
    CONFLICTING       = 'conflicting'.freeze
    PROVIDING         = 'providing'.freeze
    REPLACING         = 'replacing'.freeze
    ATTRIBUTES        = 'attributes'.freeze
    GROUPINGS         = 'groupings'.freeze
    RECIPES           = 'recipes'.freeze
    VERSION           = 'version'.freeze

    COMPARISON_FIELDS = [
      :name, :description, :long_description, :maintainer,
      :maintainer_email, :license, :platforms, :dependencies,
      :recommendations, :suggestions, :conflicting, :providing,
      :replacing, :attributes, :groupings, :recipes, :version
    ]

    include Berkshelf::Mixin::ParamsValidate
    include Chozo::Mixin::FromFile

    attr_reader :cookbook
    attr_reader :platforms
    attr_reader :dependencies
    attr_reader :recommendations
    attr_reader :suggestions
    attr_reader :conflicting
    attr_reader :providing
    attr_reader :replacing
    attr_reader :attributes
    attr_reader :groupings
    attr_reader :recipes
    attr_reader :version

    # Builds a new Chef::Cookbook::Metadata object.
    #
    # === Parameters
    # cookbook<String>:: An optional cookbook object
    # maintainer<String>:: An optional maintainer
    # maintainer_email<String>:: An optional maintainer email
    # license<String>::An optional license. Default is Apache v2.0
    #
    # === Returns
    # metadata<Chef::Cookbook::Metadata>
    def initialize(cookbook = nil, maintainer = 'YOUR_COMPANY_NAME', maintainer_email = 'YOUR_EMAIL', license = 'none')
      @cookbook = cookbook
      @name = cookbook ? cookbook.name : ""
      @long_description = ""
      self.maintainer(maintainer)
      self.maintainer_email(maintainer_email)
      self.license(license)
      self.description('A fabulous new cookbook')
      @platforms = Hashie::Mash.new
      @dependencies = Hashie::Mash.new
      @recommendations = Hashie::Mash.new
      @suggestions = Hashie::Mash.new
      @conflicting = Hashie::Mash.new
      @providing = Hashie::Mash.new
      @replacing = Hashie::Mash.new
      @attributes = Hashie::Mash.new
      @groupings = Hashie::Mash.new
      @recipes = Hashie::Mash.new
      @version = Solve::Version.new("0.0.0")
      if cookbook
        @recipes = cookbook.fully_qualified_recipe_names.inject({}) do |r, e|
          e = self.name if e =~ /::default$/
          r[e] = ""
          self.provides e
          r
        end
      end
    end

    def ==(other)
      COMPARISON_FIELDS.inject(true) do |equal_so_far, field|
        equal_so_far && other.respond_to?(field) && (other.send(field) == send(field))
      end
    end

    # Sets the cookbooks maintainer, or returns it.
    #
    # === Parameters
    # maintainer<String>:: The maintainers name
    #
    # === Returns
    # maintainer<String>:: Returns the current maintainer.
    def maintainer(arg = nil)
      set_or_return(
        :maintainer,
        arg,
        :kind_of => [ String ]
      )
    end

    # Sets the maintainers email address, or returns it.
    #
    # === Parameters
    # maintainer_email<String>:: The maintainers email address
    #
    # === Returns
    # maintainer_email<String>:: Returns the current maintainer email.
    def maintainer_email(arg = nil)
      set_or_return(
        :maintainer_email,
        arg,
        :kind_of => [ String ]
      )
    end

    # Sets the current license, or returns it.
    #
    # === Parameters
    # license<String>:: The current license.
    #
    # === Returns
    # license<String>:: Returns the current license
    def license(arg = nil)
      set_or_return(
        :license,
        arg,
        :kind_of => [ String ]
      )
    end

    # Sets the current description, or returns it. Should be short - one line only!
    #
    # === Parameters
    # description<String>:: The new description
    #
    # === Returns
    # description<String>:: Returns the description
    def description(arg = nil)
      set_or_return(
        :description,
        arg,
        :kind_of => [ String ]
      )
    end

    # Sets the current long description, or returns it. Might come from a README, say.
    #
    # === Parameters
    # long_description<String>:: The new long description
    #
    # === Returns
    # long_description<String>:: Returns the long description
    def long_description(arg = nil)
      set_or_return(
        :long_description,
        arg,
        :kind_of => [ String ]
      )
    end

    # Sets the current cookbook version, or returns it.  Can be two or three digits, seperated
    # by dots.  ie: '2.1', '1.5.4' or '0.9'.
    #
    # === Parameters
    # version<String>:: The curent version, as a string
    #
    # === Returns
    # version<String>:: Returns the current version
    def version(arg = nil)
      if arg
        @version = Solve::Version.new(arg)
      end

      @version.to_s
    end

    # Sets the name of the cookbook, or returns it.
    #
    # === Parameters
    # name<String>:: The curent cookbook name.
    #
    # === Returns
    # name<String>:: Returns the current cookbook name.
    def name(arg = nil)
      set_or_return(
        :name,
        arg,
        :kind_of => [ String ]
      )
    end

    # Adds a supported platform, with version checking strings.
    #
    # === Parameters
    # platform<String>,<Symbol>:: The platform (like :ubuntu or :mac_os_x)
    # version<String>:: A version constraint of the form "OP VERSION",
    # where OP is one of < <= = > >= ~> and VERSION has
    # the form x.y.z or x.y.
    #
    # === Returns
    # versions<Array>:: Returns the list of versions for the platform
    def supports(platform, *version_args)
      version = version_args.first
      @platforms[platform] = Solve::Constraint.new(version).to_s
      @platforms[platform]
    rescue Solve::Errors::InvalidConstraintFormat => ex
      raise InvalidVersionConstraint, ex.to_s
    end

    # Adds a dependency on another cookbook, with version checking strings.
    #
    # === Parameters
    # cookbook<String>:: The cookbook
    # version<String>:: A version constraint of the form "OP VERSION",
    # where OP is one of < <= = > >= ~> and VERSION has
    # the form x.y.z or x.y.
    #
    # === Returns
    # versions<Array>:: Returns the list of versions for the platform
    def depends(cookbook, *version_args)
      version = version_args.first
      @dependencies[cookbook] = Solve::Constraint.new(version).to_s
      @dependencies[cookbook]
    rescue Solve::Errors::InvalidConstraintFormat => ex
      raise InvalidVersionConstraint, ex.to_s
    end

    # Adds a recommendation for another cookbook, with version checking strings.
    #
    # === Parameters
    # cookbook<String>:: The cookbook
    # version<String>:: A version constraint of the form "OP VERSION",
    # where OP is one of < <= = > >= ~> and VERSION has
    # the form x.y.z or x.y.
    #
    # === Returns
    # versions<Array>:: Returns the list of versions for the platform
    def recommends(cookbook, *version_args)
      version = version_args.first
      @recommendations[cookbook] = Solve::Constraint.new(version).to_s
      @recommendations[cookbook]
    rescue Solve::Errors::InvalidConstraintFormat => ex
      raise InvalidVersionConstraint, ex.to_s
    end

    # Adds a suggestion for another cookbook, with version checking strings.
    #
    # === Parameters
    # cookbook<String>:: The cookbook
    # version<String>:: A version constraint of the form "OP VERSION",
    # where OP is one of < <= = > >= ~> and VERSION has the
    # formx.y.z or x.y.
    #
    # === Returns
    # versions<Array>:: Returns the list of versions for the platform
    def suggests(cookbook, *version_args)
      version = version_args.first
      @suggestions[cookbook] = Solve::Constraint.new(version).to_s
      @suggestions[cookbook]
    rescue Solve::Errors::InvalidConstraintFormat => ex
      raise InvalidVersionConstraint, ex.to_s
    end

    # Adds a conflict for another cookbook, with version checking strings.
    #
    # === Parameters
    # cookbook<String>:: The cookbook
    # version<String>:: A version constraint of the form "OP VERSION",
    # where OP is one of < <= = > >= ~> and VERSION has
    # the form x.y.z or x.y.
    #
    # === Returns
    # versions<Array>:: Returns the list of versions for the platform
    def conflicts(cookbook, *version_args)
      version = version_args.first
      @conflicting[cookbook] = Solve::Constraint.new(version).to_s
      @conflicting[cookbook]
    rescue Solve::Errors::InvalidConstraintFormat => ex
      raise InvalidVersionConstraint, ex.to_s
    end

    # Adds a recipe, definition, or resource provided by this cookbook.
    #
    # Recipes are specified as normal
    # Definitions are followed by (), and can include :params for prototyping
    # Resources are the stringified version (service[apache2])
    #
    # === Parameters
    # recipe, definition, resource<String>:: The thing we provide
    # version<String>:: A version constraint of the form "OP VERSION",
    # where OP is one of < <= = > >= ~> and VERSION has
    # the form x.y.z or x.y.
    #
    # === Returns
    # versions<Array>:: Returns the list of versions for the platform
    def provides(cookbook, *version_args)
      version = version_args.first
      @providing[cookbook] = Solve::Constraint.new(version).to_s
      @providing[cookbook]
    rescue Solve::Errors::InvalidConstraintFormat => ex
      raise InvalidVersionConstraint, ex.to_s
    end

    # Adds a cookbook that is replaced by this one, with version checking strings.
    #
    # === Parameters
    # cookbook<String>:: The cookbook we replace
    # version<String>:: A version constraint of the form "OP VERSION",
    # where OP is one of < <= = > >= ~> and VERSION has the form x.y.z or x.y.
    #
    # === Returns
    # versions<Array>:: Returns the list of versions for the platform
    def replaces(cookbook, *version_args)
      version = version_args.first
      @replacing[cookbook] = Solve::Constraint.new(version).to_s
      @replacing[cookbook]
    rescue Solve::Errors::InvalidConstraintFormat => ex
      raise InvalidVersionConstraint, ex.to_s
    end

    # Adds a description for a recipe.
    #
    # === Parameters
    # recipe<String>:: The recipe
    # description<String>:: The description of the recipe
    #
    # === Returns
    # description<String>:: Returns the current description
    def recipe(name, description)
      @recipes[name] = description
    end

    # Adds an attribute )hat a user needs to configure for this cookbook. Takes
    # a name (with the / notation for a nested attribute), followed by any of
    # these options
    #
    #   display_name<String>:: What a UI should show for this attribute
    #   description<String>:: A hint as to what this attr is for
    #   choice<Array>:: An array of choices to present to the user.
    #   calculated<Boolean>:: If true, the default value is calculated by the recipe and cannot be displayed.
    #   type<String>:: "string" or "array" - default is "string"  ("hash" is supported for backwards compatibility)
    #   required<String>:: Whether this attr is 'required', 'recommended' or 'optional' - default 'optional' (true/false values also supported for backwards compatibility)
    #   recipes<Array>:: An array of recipes which need this attr set.
    #   default<String>,<Array>,<Hash>:: The default value
    #
    # === Parameters
    # name<String>:: The name of the attribute ('foo', or 'apache2/log_dir')
    # options<Hash>:: The description of the options
    #
    # === Returns
    # options<Hash>:: Returns the current options hash
    def attribute(name, options)
      validate(
        options,
        {
          :display_name => { :kind_of => String },
          :description => { :kind_of => String },
          :choice => { :kind_of => [ Array ], :default => [] },
          :calculated => { :equal_to => [ true, false ], :default => false },
          :type => { :equal_to => [ "string", "array", "hash", "symbol" ], :default => "string" },
          :required => { :equal_to => [ "required", "recommended", "optional", true, false ], :default => "optional" },
          :recipes => { :kind_of => [ Array ], :default => [] },
          :default => { :kind_of => [ String, Array, Hash ] }
        }
      )
      options[:required] = remap_required_attribute(options[:required]) unless options[:required].nil?
      validate_string_array(options[:choice])
      validate_calculated_default_rule(options)
      validate_choice_default_rule(options)

      @attributes[name] = options
      @attributes[name]
    end

    def grouping(name, options)
      validate(
        options,
        {
          :title => { :kind_of => String },
          :description => { :kind_of => String }
        }
      )
      @groupings[name] = options
      @groupings[name]
    end

    def to_hash
      {
        NAME             => self.name,
        DESCRIPTION      => self.description,
        LONG_DESCRIPTION => self.long_description,
        MAINTAINER       => self.maintainer,
        MAINTAINER_EMAIL => self.maintainer_email,
        LICENSE          => self.license,
        PLATFORMS        => self.platforms,
        DEPENDENCIES     => self.dependencies,
        RECOMMENDATIONS  => self.recommendations,
        SUGGESTIONS      => self.suggestions,
        CONFLICTING      => self.conflicting,
        PROVIDING        => self.providing,
        REPLACING        => self.replacing,
        ATTRIBUTES       => self.attributes,
        GROUPINGS        => self.groupings,
        RECIPES          => self.recipes,
        VERSION          => self.version
      }
    end

    def from_hash(o)
      @name             = o[NAME] if o.has_key?(NAME)
      @description      = o[DESCRIPTION] if o.has_key?(DESCRIPTION)
      @long_description = o[LONG_DESCRIPTION] if o.has_key?(LONG_DESCRIPTION)
      @maintainer       = o[MAINTAINER] if o.has_key?(MAINTAINER)
      @maintainer_email = o[MAINTAINER_EMAIL] if o.has_key?(MAINTAINER_EMAIL)
      @license          = o[LICENSE] if o.has_key?(LICENSE)
      @platforms        = o[PLATFORMS] if o.has_key?(PLATFORMS)
      @dependencies     = handle_deprecated_constraints(o[DEPENDENCIES]) if o.has_key?(DEPENDENCIES)
      @recommendations  = handle_deprecated_constraints(o[RECOMMENDATIONS]) if o.has_key?(RECOMMENDATIONS)
      @suggestions      = handle_deprecated_constraints(o[SUGGESTIONS]) if o.has_key?(SUGGESTIONS)
      @conflicting      = handle_deprecated_constraints(o[CONFLICTING]) if o.has_key?(CONFLICTING)
      @providing        = o[PROVIDING] if o.has_key?(PROVIDING)
      @replacing        = handle_deprecated_constraints(o[REPLACING]) if o.has_key?(REPLACING)
      @attributes       = o[ATTRIBUTES] if o.has_key?(ATTRIBUTES)
      @groupings        = o[GROUPINGS] if o.has_key?(GROUPINGS)
      @recipes          = o[RECIPES] if o.has_key?(RECIPES)
      @version          = o[VERSION] if o.has_key?(VERSION)
      self
    end

    def from_file(filepath)
      super
    rescue IOError => ex
      raise Berkshelf::CookbookNotFound, ex.to_s
    end

    private

      # Verify that the given array is an array of strings
      #
      # Raise an exception if the members of the array are not Strings
      #
      # === Parameters
      # arry<Array>:: An array to be validated
      def validate_string_array(arry)
        if arry.kind_of?(Array)
          arry.each do |choice|
            validate( {:choice => choice}, {:choice => {:kind_of => String}} )
          end
        end
      end

      # For backwards compatibility, remap Boolean values to String
      #   true is mapped to "required"
      #   false is mapped to "optional"
      #
      # === Parameters
      # required_attr<String><Boolean>:: The value of options[:required]
      #
      # === Returns
      # required_attr<String>:: "required", "recommended", or "optional"
      def remap_required_attribute(value)
        case value
        when true
          value = "required"
        when false
          value = "optional"
        end
        value
      end

      def validate_calculated_default_rule(options)
        calculated_conflict = ((options[:default].is_a?(Array) && !options[:default].empty?) ||
                               (options[:default].is_a?(String) && !options[:default] != "")) &&
                              options[:calculated] == true
        raise ArgumentError, "Default cannot be specified if calculated is true!" if calculated_conflict
      end

      def validate_choice_default_rule(options)
        return if !options[:choice].is_a?(Array) || options[:choice].empty?

        if options[:default].is_a?(String) && options[:default] != ""
          raise ArgumentError, "Default must be one of your choice values!" if options[:choice].index(options[:default]) == nil
        end

        if options[:default].is_a?(Array) && !options[:default].empty?
          options[:default].each do |val|
            raise ArgumentError, "Default values must be a subset of your choice values!" if options[:choice].index(val) == nil
          end
        end
      end

      # This method translates version constraint strings from
      # cookbooks with the old format.
      #
      # Before we began respecting version constraints, we allowed
      # multiple constraints to be placed on cookbooks, as well as the
      # << and >> operators, which are now just < and >. For
      # specifications with more than one constraint, we return an
      # empty array (otherwise, we're silently abiding only part of
      # the contract they have specified to us). If there is only one
      # constraint, we are replacing the old << and >> with the new <
      # and >.
      def handle_deprecated_constraints(specification)
        specification.inject(Hashie::Mash.new) do |acc, (cb, constraints)|
          constraints = Array(constraints)
          acc[cb] = (constraints.empty? || constraints.size > 1) ? [] : constraints.first.gsub(/>>/, '>').gsub(/<</, '<')
          acc
        end
      end
  end

  #== Chef::Cookbook::MinimalMetadata
  # MinimalMetadata is a duck type of Cookbook::Metadata, used
  # internally by Chef Server when determining the optimal set of
  # cookbooks for a node.
  #
  # MinimalMetadata objects typically contain only enough information
  # to solve the cookbook collection for a run list, but not enough to
  # generate the proper response
  class MinimalMetadata < Metadata
    def initialize(name, params)
      @name = name
      from_hash(params)
    end
  end
end