#!/usr/bin/env python

from __future__ import print_function

import sys, re, unittest as UT, xml.etree.ElementTree as ET
from os import path, getcwd
from errno import EISDIR, EINVAL, EACCES
from subprocess import Popen, PIPE
from traceback import format_exception

try:
    from io import StringIO
except:
    from StringIO import StringIO

try:
    from urllib2 import urlopen, HTTPError
    from urlparse import urljoin, urlunparse
except:
    from urllib.request import urlopen
    from urllib.error import HTTPError
    from urllib.parse import urljoin, urlunparse

debug = False

# program to run - None means we still need to search for it
zbarimg = None
# arguments to said program
zbarimg_args = [ '-q', '--xml', '--nodbus' ]


# namespace support
try:
    register_namespace = ET.register_namespace
except AttributeError:
    def register_namespace(prefix, uri):
        ET._namespace_map[uri] = prefix

# barcode results
BC = 'http://zbar.sourceforge.net/2008/barcode'
register_namespace('bc', BC)

# testcase extensions
TS = 'http://zbar.sourceforge.net/2009/test-spec'
register_namespace('test', TS)


# printing support
def fixtag(node):
    return str(node.tag).split('}', 1)[-1]

def toxml(node):
    s = StringIO()
    ET.ElementTree(node).write(s)
    return s.getvalue()

def hexdump(data):
    print(data)
    for i, c in enumerate(data):
        if i & 0x7 == 0:
            print('[%04x]' % i, end=' ')
        print(' %04x' % ord(c), end=' ')
        if i & 0x7 == 0x7:
            print()
    if len(c) & 0x7 != 0x7:
        print('\n')


# search for a file in the distribution
def distdir_search(subdir, base, suffixes=('',)):
    # start with current dir,
    # then try script invocation path
    rundir = path.dirname(sys.argv[0])
    search = [ '', rundir ]

    # finally, attempt to follow VPATH if present
    try:
        import re
        with open('Makefile', 'r') as makefile:
            for line in makefile:
                if re.match(r'^VPATH\s*=', line):
                    vpath = line.split('=', 1)[1].strip()
                    if vpath and vpath != rundir:
                        search.append(vpath)
                    break
    except:
        pass

    # poke around for subdir
    subdirs = tuple((subdir, path.join('..', subdir), '..', ''))

    for prefix in search:
        for subdir in subdirs:
            for suffix in suffixes:
                file = path.realpath(path.join(prefix, subdir, base + suffix))
                if path.isfile(file):
                    return(file)
    return None


def find_zbarimg():
    """search for zbarimg program to run.
    """
    global zbarimg
    # look in dist dir first
    zbarimg = distdir_search('zbarimg', 'zbarimg', ('', '.exe'))
    if not zbarimg:
        # fall back to PATH
        zbarimg = 'zbarimg'
        if debug:
            print('using zbarimg from PATH')
    elif debug:
        print('using:', zbarimg)


def run_zbarimg(images):
    """invoke zbarimg for the specified files.

    return results as an ET.Element
    """
    args = [ zbarimg ]
    args.extend(zbarimg_args)
    args.extend(images)
    if debug:
        print('running:', ' '.join(args))

    # FIXME should be able to pipe (feed) parser straight from output
    child = Popen(args, stdout = PIPE, stderr = PIPE)
    (xml, err) = child.communicate()

    rc = child.returncode
    if debug:
        print('zbarimg returned', rc)

    # FIXME trim usage from error msg
    assert rc in (0, 4), \
           'zbarimg returned error status (%d)\n' % rc + err

    assert not err, err

    result = ET.XML(xml)
    assert result.tag == ET.QName(BC, 'barcodes')
    return result


class TestCase(UT.TestCase):
    """single barcode source test.

    must have source attribute set to an ET.Element representation of a
    bc:source tag before test is run.
    """
    def shortDescription(self):
        return self.source.get('href')

    def setUp(self):
        if not zbarimg:
            find_zbarimg()

    def runTest(self):
        expect = self.source
        assert expect is not None
        assert expect.tag == ET.QName(BC, 'source')
        actual = run_zbarimg((expect.get('href'),))

        self.assertEqual(len(actual), 1)

        try:
            compare_sources(expect, actual[0])
        except AssertionError:
            if expect.get(str(ET.QName(TS, 'exception'))) != 'TODO':
                raise
            # ignore


class BuiltinTestCase(TestCase):
    def __init__(self, methodName='runTest'):
        TestCase.__init__(self, methodName)

        href = distdir_search('examples', 'ean-13.png')
        if not href:
            href = 'https://git.linuxtv.org/zbar.git/plain/examples/ean-13.png'

        self.source = src = ET.Element(ET.QName(BC, 'source'), href=href)
        sym = ET.SubElement(src, ET.QName(BC, 'symbol'), type='EAN-13',
                            orientation='UP')
        data = ET.SubElement(sym, ET.QName(BC, 'data'))
        data.text = '9789876543217'


def compare_maps(expect, actual, compare_func):
    errors = []
    notes = []
    for key, iact in actual.items():
        iexp = expect.pop(key, None)
        if iexp is None:
            errors.append('bonus unexpected result:\n' + toxml(iact))
            continue

        try:
            compare_func(iexp, iact)
        except:
            errors.append(''.join(format_exception(*sys.exc_info())))

        if iexp.get(str(ET.QName(TS, 'exception'))) == 'TODO':
            notes.append('TODO unexpected result:\n' + toxml(iact))

    for key, iexp in expect.items():

        exc = iexp.get(str(ET.QName(TS, 'exception')))

        if exc == 'TODO':
               notes.append('TODO missing expected result:\n' + toxml(iexp))
        elif exc is not None:
               errors.append('missing expected result:\n' + toxml(iexp))

    if len(notes) == 1:
        print('(TODO)', end=' ', file=sys.stderr)
    elif notes:
        print('(%d TODO)' % len(notes), end=' ', file=sys.stderr)
    assert not errors, '\n'.join(errors)


def compare_sources(expect, actual):
    assert actual.tag == ET.QName(BC, 'source')
    assert actual.get('href').endswith(expect.get('href')), \
           'source href mismatch: %s != %s' % (acthref, exphref)

    # FIXME process/trim test:* contents

    def map_source(src):
        if not len(src) or src[0].tag != ET.QName(BC, 'index'):
            # insert artificial hierarchy
            syms = src[:]
            del src[:]
            idx = ET.SubElement(src, ET.QName(BC, 'index'), num='0')
            idx[:] = syms
            exc = src.get(str(ET.QName(TS, 'exception')))
            if exc is not None:
                idx.set(str(ET.QName(TS, 'exception')), exc)
            return { '0': idx }
        elif len(src):
            assert src[0].tag != ET.QName(BC, 'symbol'), \
                   'invalid source element: ' + \
                   'expecting "index" or "symbol", got "%s"' % fixtag(src[0])

        srcmap = { }
        for idx in src:
            srcmap[idx.get('num')] = idx
        return srcmap

    compare_maps(map_source(expect), map_source(actual), compare_indices)


def compare_indices(expect, actual):
    assert actual.tag == ET.QName(BC, 'index')
    assert actual.get('num') == expect.get('num')

    # FIXME process/trim test:* contents

    def map_index(idx):
        idxmap = { }
        for sym in idx:
            assert sym.tag == ET.QName(BC, 'symbol')
            typ = sym.get('type')
            assert typ is not None
            data = sym.find(str(ET.QName(BC, 'data'))).text
            idxmap[typ, data] = sym

        return idxmap

    try:
        compare_maps(map_index(expect), map_index(actual), compare_symbols)
    except AssertionError:
        if expect.get(str(ET.QName(TS, 'exception'))) != 'TODO':
            raise


def compare_symbols(expect, actual):
    orient = expect.get('orientation')
    if orient:
        assert actual.get('orientation') == orient

# override unittest.TestLoader to populate tests from xml description
class TestLoader:
    suiteClass = UT.TestSuite

    def __init__(self):
        self.cwd = urlunparse(('file', '', getcwd() + '/', '', '', ''))
        if debug:
            print('cwd =', self.cwd)

    def loadTestsFromModule(self, module):
        return self.suiteClass([BuiltinTestCase()])

    def loadTestsFromNames(self, names, module=None):
        suites = [ self.loadTestsFromName(name, module) for name in names ]
        return self.suiteClass(suites)

    def loadTestsFromURL(self, url=None, file=None):
        if debug:
            print('loading url:', url)

        target = None
        if not file:
            if not url:
                return self.suiteClass([BuiltinTestCase()])

            content = None
            url = urljoin(self.cwd, url)
            # FIXME grok fragment

            try:
                if debug:
                    print('trying:', url)
                file = urlopen(url)
                content = file.info().get('Content-Type')
            except HTTPError as e:
                # possible remote directory
                pass
            except IOError as e:
                if e.errno not in (EISDIR, EINVAL, EACCES):
                    raise
                # could be local directory

            if (not file or
                content == 'text/html' or
                (isinstance(file, HTTPError) and file.code != 200)):
                # could be directory, try opening index
                try:
                    tmp = urljoin(url + '/', 'index.xml')
                    if debug:
                        print('trying index:', tmp)
                    file = urlopen(tmp)
                    content = file.info().get('Content-Type')
                    url = tmp
                except IOError:
                    raise IOError('no test index found at: %s' % url)

            if debug:
                print('\tContent-Type:', content)

            if content not in ('application/xml', 'text/xml'):
                # assume url is image to test, try containing index
                # FIXME should be able to keep searching up
                try:
                    target = url.rsplit('/', 1)[1]
                    index = urljoin(url, 'index.xml')
                    if debug:
                        print('trying index:', index)
                    file = urlopen(index)
                    content = file.info().get('Content-Type')
                    if debug:
                        print('\tContent-Type:', content)
                    assert content in ('application/xml', 'text/xml')
                    url = index
                except IOError:
                    raise IOError('no index found for: %s' % url)

        index = ET.ElementTree(file=file).getroot()
        assert index.tag == ET.QName(BC, 'barcodes')

        suite = self.suiteClass()
        for src in index:
            # FIXME trim any meta info
            href = src.get('href')
            if target and target != href:
                continue
            if src.tag == ET.QName(BC, 'source'):
                test = TestCase()
                # convert file URLs to filesystem paths
                href = urljoin(url, href)
                href = re.sub(r'^file://', '', href)
                src.set('href', href)
                test.source = src
                suite.addTest(test)
            elif src.tag == ET.QName(TS, 'index'):
                suite.addTest(self.loadTestsFromURL(urljoin(url, href)))
            else:
                raise AssertionError('malformed test index') # FIXME detail

        assert suite.countTestCases(), 'empty test index: %s' % url
        return suite

    def loadTestsFromName(self, name=None, module=None):
        return self.loadTestsFromURL(name)

    def unsupported(self, *args, **kwargs):
        raise TypeError("unsupported TestLoader API")

    # FAKE discover method needed for python3 to work
    def discover(self, start_dir, pattern, top_level_dir=None):
        return self.loadTestsFromURL()

    loadTestsFromTestCase = unsupported
    getTestCaseNames = unsupported


if __name__ == '__main__':
    if '-d' in sys.argv:
        debug = True
        sys.argv.remove('-d')

    UT.main(module=None, testLoader=TestLoader())