require 'rubygems'
begin
  gem 'extlib'
  require 'extlib'
rescue 
  puts "CouchRest::Model requires extlib. This is left out of the gemspec on purpose."
  raise
end
require 'mime/types'
require File.join(File.dirname(__FILE__), "property")
require File.join(File.dirname(__FILE__), '..', 'mixins', 'extended_document_mixins')

module CouchRest
  
  # Same as CouchRest::Document but with properties and validations
  class ExtendedDocument < Document
    include CouchRest::Mixins::DocumentQueries
    include CouchRest::Mixins::DocumentProperties
    include CouchRest::Mixins::ExtendedViews
    include CouchRest::Mixins::DesignDoc

    
    # Automatically set <tt>updated_at</tt> and <tt>created_at</tt> fields
    # on the document whenever saving occurs. CouchRest uses a pretty
    # decent time format by default. See Time#to_json
    def self.timestamps!
      before(:save) do
        self['updated_at'] = Time.now
        self['created_at'] = self['updated_at'] if new_document?
      end
    end
  
    # Name a method that will be called before the document is first saved,
    # which returns a string to be used for the document's <tt>_id</tt>.
    # Because CouchDB enforces a constraint that each id must be unique,
    # this can be used to enforce eg: uniq usernames. Note that this id
    # must be globally unique across all document types which share a
    # database, so if you'd like to scope uniqueness to this class, you
    # should use the class name as part of the unique id.
    def self.unique_id method = nil, &block
      if method
        define_method :set_unique_id do
          self['_id'] ||= self.send(method)
        end
      elsif block
        define_method :set_unique_id do
          uniqid = block.call(self)
          raise ArgumentError, "unique_id block must not return nil" if uniqid.nil?
          self['_id'] ||= uniqid
        end
      end
    end
    
    ### instance methods
    
    # Returns the Class properties
    #
    # ==== Returns
    # Array:: the list of properties for the instance
    def properties
      self.class.properties
    end
    
    # Takes a hash as argument, and applies the values by using writer methods
    # for each key. It doesn't save the document at the end. Raises a NoMethodError if the corresponding methods are
    # missing. In case of error, no attributes are changed.    
    def update_attributes_without_saving(hash)
      hash.each do |k, v|
        raise NoMethodError, "#{k}= method not available, use key_accessor or key_writer :#{k}" unless self.respond_to?("#{k}=")
      end      
      hash.each do |k, v|
        self.send("#{k}=",v)
      end
    end

    # Takes a hash as argument, and applies the values by using writer methods
    # for each key. Raises a NoMethodError if the corresponding methods are
    # missing. In case of error, no attributes are changed.
    def update_attributes(hash)
      update_attributes_without_saving hash
      save
    end

    # for compatibility with old-school frameworks
    alias :new_record? :new_document?
    
    # Overridden to set the unique ID.
    # Returns a boolean value
    def save(bulk = false)
      set_unique_id if new_document? && self.respond_to?(:set_unique_id)
      result = database.save_doc(self, bulk)
      result["ok"] == true
    end
    
    # Saves the document to the db using create or update. Raises an exception
    # if the document is not saved properly.
    def save!
      raise "#{self.inspect} failed to save" unless self.save
    end

    # Deletes the document from the database. Runs the :destroy callbacks.
    # Removes the <tt>_id</tt> and <tt>_rev</tt> fields, preparing the
    # document to be saved to a new <tt>_id</tt>.
    def destroy
      result = database.delete_doc self
      if result['ok']
        self['_rev'] = nil
        self['_id'] = nil
      end
      result['ok']
    end
      
  end
end