# * George Moschovitis  <gm@navel.gr>
# (c) 2004-2005 Navel, all rights reserved.
# $Id$

module Og

module Enchant

	# Enchant a managed class. Add useful DB related methods 
	# to the class and its instances. 
	
	def enchant(klass)

		# Generate standard methods.
		
		klass.module_eval %{ 
			def self.create(*params, &block)
				obj = #{klass}.new(*params, &block)
				obj.save!
			end
				
			def self.save(obj)
				@@og_db << obj
			end
			
			def self.load(oid_or_name)
				@@og_db.load(oid_or_name, #{klass})
			end

			def self.get(oid_or_name)
				@@og_db.load(oid_or_name, #{klass})
			end
			
			def self.[](oid_or_name)
				@@og_db.load(oid_or_name, #{klass})
			end
			
			def self.load_all(extra_sql = nil)
				@@og_db.load_all(#{klass}, extra_sql)
			end
			
			def self.all(extra_sql = nil)
				@@og_db.load_all(#{klass}, extra_sql)
			end

			def self.update_all(set_sql, extra_sql = nil)
				@@og_db.exec("UPDATE #{klass::DBTABLE} SET \#\{set_sql\} \#\{extra_sql\}")
			end

			def self.update(set_sql, extra_sql = nil)
				@@og_db.exec("UPDATE #{klass::DBTABLE} SET \#\{set_sql\} \#\{extra_sql\}")
			end

			def self.count(sql = "SELECT COUNT(*) FROM #{klass::DBTABLE}")
				@@og_db.count(sql, #{klass})
			end

			def self.select(sql)
				@@og_db.select(sql, #{klass})
			end
			
			def self.find(sql)
				@@og_db.select(sql, #{klass})
			end

			def self.select_one(sql)
				@@og_db.select_one(sql, #{klass})
			end

			def self.find_one(sql)
				@@og_db.select_one(sql, #{klass})
			end

			def self.one(sql)
				@@og_db.select_one(sql, #{klass})
			end
			
			def self.delete(obj_or_oid)
				@@og_db.delete(obj_or_oid, #{klass})
			end

			def self.transaction(&block)
				@@og_db.transaction(&block)
			end

			def self.properties_and_relations
				@@__meta[:props_and_relations]
			end

			def self.each(&block)
				all.each(&block)
			end
			include Enumerable
			
			def save
				@@og_db << self
				return self
			end
			alias_method :save!, :save

			def reload
				raise 'Cannot reload unmanaged object' unless @oid
				res = @@og_db.query "SELECT * FROM #{klass::DBTABLE} WHERE oid=\#\{@oid\}"
				og_read(@@og_db.get_row(res))
			end
			alias_method :reload!, :reload

			def update_properties(updatesql)
				@@og_db.pupdate(updatesql, self.oid, #{klass})
			end
			alias_method :pupdate, :update_properties
			alias_method :update_property, :update_properties

			def set_property(prop, value)
				@@og_db.pupdate("\#\{prop\}=\#\{value\}", self.oid, #{klass})
			end
			
			def delete!
				@@og_db.delete(self, #{klass})
			end
		}

		# Generate finder methods.
	
		code = ''
		
		for p in klass.__props
			code << %{
				def self.find_by_#{p.name}(val, operator = '=', extra_sql = nil)
			}

			val = klass.og_db.adapter.typecast[p.klass].gsub(/\:s\:/, 'val')
			
			if p.meta[:unique]
				code <<	%{@@og_db.select_one("#{p.name}\#\{operator\}#{val} \#\{extra_sql\}", #{klass})}
			else
				code <<	%{@@og_db.select("#{p.name}\#\{operator\}#{val} \#\{extra_sql\}", #{klass})}
			end
			code << %{
				end; 
			}
		end
	
		klass.module_eval(code)
	end

end
	
end