require 'puppet'
require 'puppet/util/tagging'
require 'puppet/util/pson'

# The simplest resource class.  Eventually it will function as the
# base class for all resource-like behaviour.
class Puppet::Resource
  include Puppet::Util::Tagging

  require 'puppet/resource/type_collection_helper'
  include Puppet::Resource::TypeCollectionHelper

  extend Puppet::Util::Pson
  include Enumerable
  attr_accessor :file, :line, :catalog, :exported, :virtual, :validate_parameters, :strict
  attr_reader :namespaces

  require 'puppet/indirector'
  extend Puppet::Indirector
  indirects :resource, :terminus_class => :ral

  ATTRIBUTES = [:file, :line, :exported]

  def self.from_pson(pson)
    raise ArgumentError, "No resource type provided in pson data" unless type = pson['type']
    raise ArgumentError, "No resource title provided in pson data" unless title = pson['title']

    resource = new(type, title)

    if params = pson['parameters']
      params.each { |param, value| resource[param] = value }
    end

    if tags = pson['tags']
      tags.each { |tag| resource.tag(tag) }
    end

    ATTRIBUTES.each do |a|
      if value = pson[a.to_s]
        resource.send(a.to_s + "=", value)
      end
    end

    resource.exported ||= false

    resource
  end

  def to_pson_data_hash
    data = ([:type, :title, :tags] + ATTRIBUTES).inject({}) do |hash, param|
      next hash unless value = self.send(param)
      hash[param.to_s] = value
      hash
    end

    data["exported"] ||= false

    params = self.to_hash.inject({}) do |hash, ary|
      param, value = ary

      # Don't duplicate the title as the namevar
      next hash if param == namevar and value == title

      hash[param] = Puppet::Resource.value_to_pson_data(value)
      hash
    end

    data["parameters"] = params unless params.empty?

    data
  end

  def self.value_to_pson_data(value)
    if value.is_a? Array
      value.map{|v| value_to_pson_data(v) }
    elsif value.is_a? Puppet::Resource
      value.to_s
    else
      value
    end
  end

  def to_pson(*args)
    to_pson_data_hash.to_pson(*args)
  end

  # Proxy these methods to the parameters hash.  It's likely they'll
  # be overridden at some point, but this works for now.
  %w{has_key? keys length delete empty? <<}.each do |method|
    define_method(method) do |*args|
      @parameters.send(method, *args)
    end
  end

  # Set a given parameter.  Converts all passed names
  # to lower-case symbols.
  def []=(param, value)
    validate_parameter(param) if validate_parameters
    @parameters[parameter_name(param)] = value
  end

  # Return a given parameter's value.  Converts all passed names
  # to lower-case symbols.
  def [](param)
    @parameters[parameter_name(param)]
  end

  def ==(other)
    return false unless other.respond_to?(:title) and self.type == other.type and self.title == other.title

    return false unless to_hash == other.to_hash
    true
  end

  # Compatibility method.
  def builtin?
    builtin_type?
  end

  # Is this a builtin resource type?
  def builtin_type?
    resource_type.is_a?(Class)
  end

  # Iterate over each param/value pair, as required for Enumerable.
  def each
    @parameters.each { |p,v| yield p, v }
  end

  def include?(parameter)
    super || @parameters.keys.include?( parameter_name(parameter) )
  end

  # These two methods are extracted into a Helper
  # module, but file load order prevents me
  # from including them in the class, and I had weird
  # behaviour (i.e., sometimes it didn't work) when
  # I directly extended each resource with the helper.
  def environment
    Puppet::Node::Environment.new(@environment)
  end

  def environment=(env)
    if env.is_a?(String) or env.is_a?(Symbol)
      @environment = env
    else
      @environment = env.name
    end
  end

  %w{exported virtual strict}.each do |m|
    define_method(m+"?") do
      self.send(m)
    end
  end

  # Create our resource.
  def initialize(type, title = nil, attributes = {})
    @parameters = {}
    @namespaces = [""]

    # Set things like namespaces and strictness first.
    attributes.each do |attr, value|
      next if attr == :parameters
      send(attr.to_s + "=", value)
    end

    # We do namespaces first, and use tmp variables, so our title
    # canonicalization works (i.e., namespaces are set and resource
    # types can be looked up)
    tmp_type, tmp_title = extract_type_and_title(type, title)
    self.type = tmp_type
    self.title = tmp_title

    if params = attributes[:parameters]
      extract_parameters(params)
    end

    resolve_type_and_title

    tag(self.type)
    tag(self.title) if valid_tag?(self.title)

    raise ArgumentError, "Invalid resource type #{type}" if strict? and ! resource_type
  end

  def ref
    to_s
  end

  # Find our resource.
  def resolve
    return(catalog ? catalog.resource(to_s) : nil)
  end

  def title=(value)
    @unresolved_title = value
    @title = nil
  end

  def resource_type
    @resource_type ||= case type
    when "Class"; find_hostclass(title)
    when "Node"; find_node(title)
    else
      find_resource_type(type)
    end
  end

  # Produce a simple hash of our parameters.
  def to_hash
    parse_title.merge @parameters
  end

  def to_s
    "#{type}[#{title}]"
  end

  def uniqueness_key
    # Temporary kludge to deal with inconsistant use patters
    h = self.to_hash
    h[namevar] ||= h[:name]
    h[:name]   ||= h[namevar]
    h.values_at(*key_attributes.sort_by { |k| k.to_s })
  end

  def key_attributes
    return(resource_type.respond_to? :key_attributes) ? resource_type.key_attributes : [:name]
  end

  # Convert our resource to Puppet code.
  def to_manifest
    "%s { '%s':\n%s\n}" % [self.type.to_s.downcase, self.title,
      @parameters.collect { |p, v|
        if v.is_a? Array
          "    #{p} => [\'#{v.join("','")}\']"
        else
          "    #{p} => \'#{v}\'"
        end
      }.join(",\n")
      ]
  end

  def to_ref
    ref
  end

  # Convert our resource to a RAL resource instance.  Creates component
  # instances for resource types that don't exist.
  def to_ral
    if typeklass = Puppet::Type.type(self.type)
      return typeklass.new(self)
    else
      return Puppet::Type::Component.new(self)
    end
  end

  # Translate our object to a backward-compatible transportable object.
  def to_trans
    if builtin_type? and type.downcase.to_s != "stage"
      result = to_transobject
    else
      result = to_transbucket
    end

    result.file = self.file
    result.line = self.line

    result
  end

  def to_trans_ref
    [type.to_s, title.to_s]
  end

  # Create an old-style TransObject instance, for builtin resource types.
  def to_transobject
    # Now convert to a transobject
    result = Puppet::TransObject.new(title, type)
    to_hash.each do |p, v|
      if v.is_a?(Puppet::Resource)
        v = v.to_trans_ref
      elsif v.is_a?(Array)
        v = v.collect { |av|
          av = av.to_trans_ref if av.is_a?(Puppet::Resource)
          av
        }
      end

      # If the value is an array with only one value, then
      # convert it to a single value.  This is largely so that
      # the database interaction doesn't have to worry about
      # whether it returns an array or a string.
      result[p.to_s] = if v.is_a?(Array) and v.length == 1
        v[0]
          else
            v
              end
    end

    result.tags = self.tags

    result
  end

  def name
    # this is potential namespace conflict
    # between the notion of an "indirector name"
    # and a "resource name"
    [ type, title ].join('/')
  end

  def to_resource
    self
  end

  # We have to lazy-evaluate this.
  def title=(value)
    @title = nil
    @unresolved_title = value
  end

  # We have to lazy-evaluate this.
  def type=(value)
    @type = nil
    @unresolved_type = value || "Class"
  end

  def title
    resolve_type_and_title unless @title
    @title
  end

  def type
    resolve_type_and_title unless @type
    @type
  end

  def valid_parameter?(name)
    resource_type.valid_parameter?(name)
  end

  def validate_parameter(name)
    raise ArgumentError, "Invalid parameter #{name}" unless valid_parameter?(name)
  end

  private

  def find_node(name)
    known_resource_types.node(name)
  end

  def find_hostclass(title)
    name = title == :main ? "" : title
    known_resource_types.find_hostclass(namespaces, name)
  end

  def find_resource_type(type)
    # It still works fine without the type == 'class' short-cut, but it is a lot slower.
    return nil if ["class", "node"].include? type.to_s.downcase
    find_builtin_resource_type(type) || find_defined_resource_type(type)
  end

  def find_builtin_resource_type(type)
    Puppet::Type.type(type.to_s.downcase.to_sym)
  end

  def find_defined_resource_type(type)
    known_resource_types.find_definition(namespaces, type.to_s.downcase)
  end

  # Produce a canonical method name.
  def parameter_name(param)
    param = param.to_s.downcase.to_sym
    if param == :name and n = namevar
      param = namevar
    end
    param
  end

  def namespaces=(ns)
    @namespaces = Array(ns)
  end

  # The namevar for our resource type. If the type doesn't exist,
  # always use :name.
  def namevar
    if builtin_type? and t = resource_type and t.key_attributes.length == 1
      t.key_attributes.first
    else
      :name
    end
  end

  # Create an old-style TransBucket instance, for non-builtin resource types.
  def to_transbucket
    bucket = Puppet::TransBucket.new([])

    bucket.type = self.type
    bucket.name = self.title

    # TransBuckets don't support parameters, which is why they're being deprecated.
    bucket
  end

  def extract_parameters(params)
    params.each do |param, value|
      validate_parameter(param) if strict?
      self[param] = value
    end
  end

  def extract_type_and_title(argtype, argtitle)
    if    (argtitle || argtype) =~ /^([^\[\]]+)\[(.+)\]$/m then [ $1,                 $2            ]
    elsif argtitle                                         then [ argtype,            argtitle      ]
    elsif argtype.is_a?(Puppet::Type)                      then [ argtype.class.name, argtype.title ]
    elsif argtype.is_a?(Hash)                              then
      raise ArgumentError, "Puppet::Resource.new does not take a hash as the first argument. "+
        "Did you mean (#{(argtype[:type] || argtype["type"]).inspect}, #{(argtype[:title] || argtype["title"]).inspect }) ?"
    else raise ArgumentError, "No title provided and #{argtype.inspect} is not a valid resource reference"
    end
  end

  def munge_type_name(value)
    return :main if value == :main
    return "Class" if value == "" or value.nil? or value.to_s.downcase == "component"

    value.to_s.split("::").collect { |s| s.capitalize }.join("::")
  end

  # This is an annoyingly complicated method for resolving qualified
  # types as necessary, and putting them in type or title attributes.
  def resolve_type_and_title
    if @unresolved_type
      @type = resolve_type
      @unresolved_type = nil
    end
    if @unresolved_title
      @title = resolve_title
      @unresolved_title = nil
    end
  end

  def resolve_type
    case type = munge_type_name(@unresolved_type)
    when "Class", "Node";
      type
    else
      # Otherwise, some kind of builtin or defined resource type
      munge_type_name( (r = find_resource_type(type)) ? r.name : type)
    end
  end

  # This method only works if resolve_type was called first
  def resolve_title
    case @type
    when "Node"; return @unresolved_title
    when "Class";
      resolve_title_for_class(@unresolved_title)
    else
      @unresolved_title
    end
  end

  def resolve_title_for_class(title)
    if title == "" or title == :main
      return :main
    end

    if klass = find_hostclass(title)
      result = klass.name
    end
    munge_type_name(result || title)
  end

  def parse_title
    h = {}
    type = find_resource_type(@type)
    if type.respond_to? :title_patterns
      type.title_patterns.each { |regexp, symbols_and_lambdas|
        if captures = regexp.match(title.to_s)
          symbols_and_lambdas.zip(captures[1..-1]).each { |symbol_and_lambda,capture|
            sym, lam = symbol_and_lambda
            #self[sym] = lam.call(capture)
            h[sym] = lam.call(capture)
          }
          return h
        end
      }
    else
      return { :name => title.to_s }
    end
  end
end