Translation memory models

@classmethod
def _get_data_hash(cls, data):
    """
    Generates a UUID from the given string.

    Args:
        data (string): The string to generate a hash of.

    Returns:
        UUID: The UUID hash.
    """
    return uuid.uuid5(cls.UUID_NAMESPACE, data)

def as_value(self):
    """
    Creates a StringValue object from the contents of this string.

    Returns:
        StringValue: A StringValue instance with the content of this String.
    """
    return StringValue(self.data)

@classmethod
def from_value(cls, locale, stringvalue):
    """
    Gets or creates a String instance from a StringValue object.

    Args:
        locale (ForeignKey to Locale) The locale of the string.
        stringvalue (StringValue): The value of the string.

    Returns:
        String: The String instance that corresponds with the given stringvalue and locale.
    """
    string, created = cls.objects.get_or_create(
        locale_id=pk(locale),
        data_hash=cls._get_data_hash(stringvalue.data),
        defaults={"data": stringvalue.data},
    )

    return string

@classmethod
def from_text(cls, translation_of, locale, context, data):
    """
    Gets or creates a StringTranslation instance from the given parameters.

    Args:
        translation_of (ForeignKey to String): The String that this is a translation of.
        locale (ForeignKey to Locale): The Locale of this translation.
        context (ForeignKey to TranslationContext): The context that this translation was made in. This allows different
            fields/pages to have different translations of the same source string.
        data (TextField): The translation.

    Returns:
        String: The String instance that corresponds with the given stringvalue and locale.
    """
    segment, created = cls.objects.get_or_create(
        translation_of=translation_of,
        locale_id=pk(locale),
        context_id=pk(context),
        defaults={"data": data},
    )

    return segment

def get_comment(self):
    """
    Returns a comment to display to the user containing info on how and when the string was translated.

    Returns:
        str: A comment to display to the user.
    """
    if self.tool_name:
        return _("Translated with {tool_name} on {date}").format(tool_name=self.tool_name, date=self.updated_at.strftime(DATE_FORMAT))

    elif self.translation_type == self.TRANSLATION_TYPE_MANUAL:
        return _("Translated manually on {date}").format(date=self.updated_at.strftime(DATE_FORMAT))

    elif self.translation_type == self.TRANSLATION_TYPE_MACHINE:
        return _("Machine translated on {date}").format(date=self.updated_at.strftime(DATE_FORMAT))

def get_error(self):
    """
    Returns a string containing any validation errors on the saved value.

    Returns:
        str: The validation error if there is one.
        None: If there isn't an error.
    """
    if not self.has_error:
        return

    # Check for HTML validation errors
    try:
        StringValue.from_translated_html(self.data)
        validate_translation_links(self.translation_of.data, self.data)
    except ValueError as e:
        return e.args[0]

    # Check if a database error was raised when we last attempted to publish
    if self.context is not None and self.field_error:
        return self.field_error

def set_field_error(self, error):
    """
    This sets the `has_error`/`field_error` fields to the value of the given ValidationError instance.

    Note: If the given ValidationError contains multiple errors, only the first one is stored.

    Note: This updates the database instance as well.

    Args:
        error (ValidationError): The validation error to store.
    """
    self.has_error = True
    # TODO (someday): We currently only support one error at a time
    self.field_error = error[0].messages[0]
    self.save(update_fields=['has_error', 'field_error'])

@classmethod
def from_value(cls, template_value):
    """
    Gets or creates a Template instance from a TemplateValue object.

    Args:
        template_value (TemplateValue): The value of the template.

    Returns:
        Template: The Template instance that corresponds with the given template_value.
    """
    uuid_namespace = uuid.uuid5(cls.BASE_UUID_NAMESPACE, template_value.format)

    template, created = cls.objects.get_or_create(
        uuid=uuid.uuid5(uuid_namespace, template_value.template),
        defaults={
            "template": template_value.template,
            "template_format": template_value.format,
            "string_count": template_value.string_count,
        },
    )

    return template

@classmethod
def _get_path_id(cls, path):
    """
    Generates a UUID from the given content path.

    Args:
        path (string): The content path to generate a hash of.

    Returns:
        UUID: The UUID hash.
    """
    return uuid.uuid5(uuid.UUID("fcab004a-2b50-11ea-978f-2e728ce88125"), path)

def get_field_path(self, instance):
    """
    Gets the field path for this context

    Field path's were introduced in version 1.0, any contexts that were created before that release won't have one.
    """
    if not self.field_path:
        def get_field_path_from_field(instance, path_components):
            field_name = path_components[0]
            field = instance._meta.get_field(field_name)

            if isinstance(field, StreamField):
                def get_field_path_from_stream_block(stream_value, path_components):
                    stream_blocks_by_id = {
                        block.id: block
                        for block in stream_value
                    }
                    block_id = path_components[0]
                    block = stream_blocks_by_id[block_id]
                    block_def = stream_value.stream_block.child_blocks[block.block_type]

                    if isinstance(block_def, blocks.StructBlock):
                        return [block.block_type, path_components[1]]

                    elif isinstance(block_def, blocks.StreamBlock):
                        return [block.block_type] + get_field_path_from_stream_block(block.value, path_components[1:])

                    else:
                        return [block.block_type]

                return [field_name] + get_field_path_from_stream_block(field.value_from_object(instance), path_components[1:])

            elif (
                isinstance(field, (models.ManyToOneRel))
                and isinstance(field.remote_field, ParentalKey)
                and issubclass(field.related_model, TranslatableMixin)
            ):
                manager = getattr(instance, field_name)
                child_instance = manager.get(translation_key=path_components[1])
                return [field_name] + get_field_path_from_field(child_instance, path_components[2:])

            else:
                return [field_name]

        self.field_path = '.'.join(get_field_path_from_field(instance, self.path.split('.')))
        self.save(update_fields=['field_path'])

    return self.field_path