import re
import gdb

class CoordPrinter(object):
    def __init__(self, title, val):
        self.title = title
        self.val = val

    def to_string(self):
        return self.title

    def display_hint(self):
        return 'array'

    class _iterator(object):
        def __init__(self, data):
            self.data = data

        def __iter__(self):
            indices = self.data.type.range()
            for i in range(indices[0], indices[1] + 1):
                res = (str(i), self.data[i])
                yield res
            raise StopIteration()


    def children(self):
        return self._iterator(self.val['data'])


class ViewPrinter(object):
    def __init__(self, title, val):
        self.title = title
        self.val = val

    def to_string(self):
        return self.title

    def display_hint(self):
        return 'array'

    class _iterator(object):
        def __init__(self, first, last):
            self.cursor = first
            self.last = last
            self.index = 0

        def __iter__(self):
            return self

        def __next__(self):
            if self.cursor == self.last:
                raise StopIteration

            val = self.cursor.dereference()
            res = ("[%d]" % self.index, val)

            self.cursor = self.cursor + 1
            self.index = self.index + 1

            return res

    def children(self):
        return self._iterator(
            self.val["m_begin"],
            self.val["m_end"]
        )

def build_cruft_dict():
    pretty_printers_dict[re.compile('^cruft::point.*$') ] = lambda title, val: CoordPrinter(title, val)
    pretty_printers_dict[re.compile('^cruft::vector.*$')] = lambda title, val: CoordPrinter(title, val)
    pretty_printers_dict[re.compile('^cruft::extent.*$')] = lambda title, val: CoordPrinter(title, val)
    pretty_printers_dict[re.compile('^cruft::colour.*$')] = lambda title, val: CoordPrinter(title, val)

    pretty_printers_dict[re.compile('^cruft::view')] = lambda title, val: ViewPrinter(title, val)


def lookup(val):
    type = val.type

    if type.code == gdb.TYPE_CODE_REF:
        type = type.target()

    type = type.unqualified().strip_typedefs()

    typename = type.tag
    if typename == None:
        return None

    for function in pretty_printers_dict:
        if function.search(typename):
            return pretty_printers_dict[function](typename, val)

    return None


def register_cruft_printers():
    gdb.pretty_printers.append(lookup)


pretty_printers_dict = {}
build_cruft_dict ()