#pylint: disable=too-many-public-methods,import-error,too-few-public-methods,missing-docstring,unused-variable
import os
import shutil
import tempfile
import unittest
from unittest.mock import patch
from gleetex import cachedconverter, image
from gleetex.caching import JsonParserException
from gleetex.image import  remove_all

def get_number_of_files(path):
    return len(os.listdir(path))

def mk_eqn(eqn, count=0, pos=(1,1)):
    """Create formula. Each formula must look like this:
    (eqn, pos, path, dsp, count) for self._convert_concurrently, this is a
    shorthand with mocking a few values."""
    return (pos, False, eqn)

def write(path, content='dummy'):
    with open(path, 'w', encoding='utf-8') as f:
        f.write(str(content))

class Tex2imgMock():
    """Could use a proper mock, but this one allows a bit more tricking."""
    def __init__(self, fmt):
        self.__format = fmt
        self.set_dpi = self.set_transparency = self.set_foreground_color \
                = self.set_background_color = lambda x: None # do nothing

    def create_dvi(self, dvi_fn):
        with open(dvi_fn, 'w') as f:
            f.write('dummy')

    def create_image(self, dvi_fn):
        if os.path.exists(dvi_fn):
            os.remove(dvi_fn)
        write(os.path.splitext(dvi_fn)[0] + '.' + self.__format.value)

    def convert(self, tx, basename):
        write(basename + '.tex', tx)
        dvi = basename + '.dvi'
        self.create_dvi(dvi)
        self.create_image(dvi)
        remove_all(dvi, basename + '.tex', basename + '.log', basename + '.aux')
        return {'depth': 9, 'height': 8, 'width': 7}

    def parse_log(self, _logdata):
        return {}


class TestCachedConverter(unittest.TestCase):
    #pylint: disable=protected-access
    def setUp(self):
        self.original_directory = os.getcwd()
        self.tmpdir = tempfile.mkdtemp()
        os.chdir(self.tmpdir)


    #pylint: disable=protected-access
    def tearDown(self):
        # restore static reference to converter
        cachedconverter.CachedConverter._converter = image.Tex2img
        os.chdir(self.original_directory)
        shutil.rmtree(self.tmpdir, ignore_errors=True)



    @patch('gleetex.image.Tex2img', Tex2imgMock)
    def test_that_subdirectory_is_created(self):
        c = cachedconverter.CachedConverter('subdirectory')
        formula = ({}, True, '\\textbf{FOO!}')
        c.convert_all([formula])
        # one directory exists
        self.assertEqual(get_number_of_files('.'), 1,
                "Found the following files, expected only 'subdirectory': " + \
                ', '.join(os.listdir('.')))
        # subdirectory contains 1 image and a cache
        self.assertEqual(get_number_of_files('subdirectory'), 2, "expected two"+\
            " files, found instead " + repr(os.listdir('subdirectory')))

    def test_that_unknown_options_trigger_exception(self):
        c = cachedconverter.CachedConverter('subdirectory')
        self.assertRaises(ValueError, c.set_option, 'cxzbiucxzbiuxzb', 'muh')

    def test_that_invalid_caches_trigger_error_by_default(self):
        with open('gladtex.cache', 'w') as f:
            f.write('invalid cache')
        with self.assertRaises(JsonParserException):
            c = cachedconverter.CachedConverter('')

    @patch('gleetex.image.Tex2img', Tex2imgMock)
    def test_that_invalid_caches_get_removed_if_specified(self):
        formulas = [mk_eqn('tau')]
        with open('gladtex.cache', 'w') as f:
            f.write('invalid cache')
        c = cachedconverter.CachedConverter('.', keep_old_cache=False)
        c.convert_all(formulas)
        # cache got overridden
        with open('gladtex.cache') as f:
            self.assertFalse('invalid' in f.read())

    @patch('gleetex.image.Tex2img', Tex2imgMock)
    def test_that_converted_formulas_are_cached(self):
        formulas = [mk_eqn('\\tau')]
        c = cachedconverter.CachedConverter('.')
        c.convert_all(formulas)
        self.assertTrue(c.get_data_for('\\tau', False))


    @patch('gleetex.image.Tex2img', Tex2imgMock)
    def test_that_file_names_are_correctly_picked(self):
        formulas = [mk_eqn('\\tau')]
        write('eqn000.svg')
        write('eqn001.svg')
        c = cachedconverter.CachedConverter('')
        to_convert = c._get_formulas_to_convert(formulas)
        self.assertTrue(len(to_convert), 1)
        self.assertEqual(to_convert[0][2], 'eqn002.svg')

    @patch('gleetex.image.Tex2img', Tex2imgMock)
    def test_that_all_converted_formulas_are_in_cache_and_meta_info_correct(self):
        formulas = [mk_eqn('a_{%d}' % i, pos=(i,i), count=i) for i in range(4)]
        c = cachedconverter.CachedConverter('.')
        c.convert_all(formulas)
        # expect all formulas and a gladtex cache to exist
        self.assertEqual(get_number_of_files('.'), len(formulas)+1,
                "present files:\n" + ', '.join(os.listdir('.')))
        for pos, dsp, formula in formulas:
            data = c.get_data_for(formula, False)
            self.assertEqual(data['pos'], {'depth': 9, 'height': 8, 'width': 7},
                    "expected the pos as defined in the dummy class")

    @patch('gleetex.image.Tex2img', Tex2imgMock)
    def test_that_inline_math_and_display_math_results_in_different_formulas(self):
        # two formulas, second is displaymath
        formula = r'\sum_{i=0}^n x_i'
        formulas = [((1,1), False, formula), ((3,1), True, formula)]
        c = cachedconverter.CachedConverter('.')
        c.convert_all(formulas)
        # expect all formulas and a gladtex cache to exist
        self.assertEqual(get_number_of_files('.'), len(formulas)+1,
                "present files:\n%s" % ', '.join(os.listdir('.')))