from .lib import TestBase, FileCreator

from smmap.util import (
    MapWindow,
    MapRegion,
    MapRegionList,
    ALLOCATIONGRANULARITY,
    is_64_bit,
    align_to_mmap
)

import os
import sys


class TestMMan(TestBase):

    def test_window(self):
        wl = MapWindow(0, 1)        # left
        wc = MapWindow(1, 1)        # center
        wc2 = MapWindow(10, 5)      # another center
        wr = MapWindow(8000, 50)    # right

        assert wl.ofs_end() == 1
        assert wc.ofs_end() == 2
        assert wr.ofs_end() == 8050

        # extension does nothing if already in place
        maxsize = 100
        wc.extend_left_to(wl, maxsize)
        assert wc.ofs == 1 and wc.size == 1
        wl.extend_right_to(wc, maxsize)
        wl.extend_right_to(wc, maxsize)
        assert wl.ofs == 0 and wl.size == 1

        # an actual left extension
        pofs_end = wc2.ofs_end()
        wc2.extend_left_to(wc, maxsize)
        assert wc2.ofs == wc.ofs_end() and pofs_end == wc2.ofs_end()

        # respects maxsize
        wc.extend_right_to(wr, maxsize)
        assert wc.ofs == 1 and wc.size == maxsize
        wc.extend_right_to(wr, maxsize)
        assert wc.ofs == 1 and wc.size == maxsize

        # without maxsize
        wc.extend_right_to(wr, sys.maxsize)
        assert wc.ofs_end() == wr.ofs and wc.ofs == 1

        # extend left
        wr.extend_left_to(wc2, maxsize)
        wr.extend_left_to(wc2, maxsize)
        assert wr.size == maxsize

        wr.extend_left_to(wc2, sys.maxsize)
        assert wr.ofs == wc2.ofs_end()

        wc.align()
        assert wc.ofs == 0 and wc.size == align_to_mmap(wc.size, True)

    def test_region(self):
        fc = FileCreator(self.k_window_test_size, "window_test")
        half_size = fc.size // 2
        rofs = align_to_mmap(4200, False)
        rfull = MapRegion(fc.path, 0, fc.size)
        rhalfofs = MapRegion(fc.path, rofs, fc.size)
        rhalfsize = MapRegion(fc.path, 0, half_size)

        # offsets
        assert rfull.ofs_begin() == 0 and rfull.size() == fc.size
        assert rfull.ofs_end() == fc.size   # if this method works, it works always

        assert rhalfofs.ofs_begin() == rofs and rhalfofs.size() == fc.size - rofs
        assert rhalfsize.ofs_begin() == 0 and rhalfsize.size() == half_size

        assert rfull.includes_ofs(0) and rfull.includes_ofs(fc.size - 1) and rfull.includes_ofs(half_size)
        assert not rfull.includes_ofs(-1) and not rfull.includes_ofs(sys.maxsize)
        # with the values we have, this test only works on windows where an alignment
        # size of 4096 is assumed.
        # We only test on linux as it is inconsitent between the python versions
        # as they use different mapping techniques to circumvent the missing offset
        # argument of mmap.
        if sys.platform != 'win32':
            assert rhalfofs.includes_ofs(rofs) and not rhalfofs.includes_ofs(0)
        # END handle platforms

        # auto-refcount
        assert rfull.client_count() == 1
        rfull2 = rfull
        assert rfull.client_count() == 1, "no auto-counting"

        # window constructor
        w = MapWindow.from_region(rfull)
        assert w.ofs == rfull.ofs_begin() and w.ofs_end() == rfull.ofs_end()

    def test_region_list(self):
        fc = FileCreator(100, "sample_file")

        fd = os.open(fc.path, os.O_RDONLY)
        for item in (fc.path, fd):
            ml = MapRegionList(item)

            assert len(ml) == 0
            assert ml.path_or_fd() == item
            assert ml.file_size() == fc.size
        # END handle input
        os.close(fd)

    def test_util(self):
        assert isinstance(is_64_bit(), bool)    # just call it
        assert align_to_mmap(1, False) == 0
        assert align_to_mmap(1, True) == ALLOCATIONGRANULARITY
