import gdb


class KstdUniquePtrPrinter:

    def __init__(self, val):
        self.val = val
        self.type = val.type.template_argument(0)

    def to_string(self):
        pointer = self.val["pointer"]
        if int(pointer) == 0:
            return f"kstd::unique_ptr<{self.type}> (empty)"
        return f"kstd::unique_ptr<{self.type}>"

    def children(self):
        pointer = self.val["m_ptr"]
        if int(pointer) != 0:
            yield ("get()", pointer)
            yield ("*get()", pointer.dereference())


class KstdSharedPtrPrinter:

    def __init__(self, val):
        self.val = val
        self.type = val.type.template_argument(0)

    def to_string(self):
        pointer = self.val["pointer"]
        cb = self.val["control_block"]

        if int(pointer) == 0 or int(cb) == 0:
            return f"kstd::shared_ptr<{self.type}> (empty)"

        strong_refs = int(cb["m_strong_refs"])
        weak_refs = int(cb["m_weak_refs"])

        return f"kstd::shared_ptr<{self.type}> (use_count={strong_refs}, weak_count={weak_refs})"

    def children(self):
        pointer = self.val["pointer"]
        control_block = self.val["control"]

        if int(pointer) != 0:
            yield ("get()", pointer)
            yield ("*get()", pointer.dereference())

        if int(control_block) != 0:
            yield ("[control_block]", control_block.dereference())