#!/usr/bin/env python

import os

from nose.tools import assert_raises
from nose.plugins.skip import SkipTest

import mapnik

from .utilities import execution_path, run_all

datadir = '../data/pngsuite'


def setup():
    # All of the paths used are relative, if we run the tests
    # from another directory we need to chdir()
    os.chdir(execution_path('.'))


def assert_broken_file(fname):
    assert_raises(RuntimeError, lambda: mapnik.Image.open(fname))


def assert_good_file(fname):
    assert mapnik.Image.open(fname)


def get_pngs(good):
    if not os.path.exists(datadir):
        raise SkipTest

    files = [x for x in os.listdir(datadir) if x.endswith('.png')]
    return [os.path.join(datadir, x)
            for x in files if good != x.startswith('x')]


def test_good_pngs():
    for x in get_pngs(True):
        yield assert_good_file, x


def test_broken_pngs():
    for x in get_pngs(False):
        yield assert_broken_file, x

if __name__ == "__main__":
    setup()
    exit(run_all(eval(x) for x in dir() if x.startswith("test_")))