import gdb
from teachos import format_size


class KapiBootModulesBootModulePrinter(gdb.ValuePrinter):
    class Iterator:
        def __init__(self, begin: gdb.Value, end: gdb.Value):
            self._item = begin
            self._end = end
            self._count = 0

        def __iter__(self):
            return self

        def __next__(self):
            count = self._count
            self._count = count + 1

            if self._item == self._end:
                raise StopIteration

            element = self._item.dereference()
            self._item += 1
            return (f"[{count}]", element)

    def __init__(self, val):
        self.__pointer_type = gdb.lookup_type("std::byte").pointer()

        self.__val = val
        self.__name = val["name"]
        self.__start = val["start_address"]
        self.__size = int(val["size"])
        self.__begin = val["start_address"]["m_value"].cast(self.__pointer_type)
        self.__end = self.__begin + self.__size
        self.__pretty_name = " " + str(self.__name) if str(self.__name) != '""' else ""

    def to_string(self):
        return f"boot module{self.__pretty_name} of size {format_size(self.__size)}, at {self.__start.cast(self.__pointer_type)}"

    def children(self):
        return self.Iterator(self.__begin, self.__end)

    def display_hint(self):
        return "array"