from fields import Field

class Model(object):    
    record_identifier = '  '

    def __init__(self):
        for (key, value) in self.__class__.__dict__.items():
            if isinstance(value, Field):
                field = getattr(self, key)
                if not field.name:
                    setattr(field, 'name', key)

    def __setattr__(self, key, value):
        if hasattr(self, key) and isinstance(getattr(self, key), Field):
            getattr(self, key).value = value
        else:
            self.__dict__[key] = value

    def get_fields(self):
        fields = []
        for key in self.__class__.__dict__.keys():
            attr = getattr(self, key)
            if isinstance(attr, Field):
                fields.append(attr)  
        return fields

    def get_sorted_fields(self):
        fields = self.get_fields()
        fields.sort(key=lambda x:x.creation_counter)
        return fields

    def validate(self):
        for f in self.get_fields():
            f.validate()

            try:
                custom_validator = getattr(self, 'validate_' + f.name)
            except AttributeError, e:
                continue
            if callable(custom_validator):
                 custom_validator(f)

    def output(self):
        return ''.join([self.record_identifier] + [field.get_data() for field in self.get_sorted_fields()])
    
    def read(self, fp):
        for field in self.get_sorted_fields():
            field.read(fp)