#
# Copyright (c), 2016-2021, SISSA (International School for Advanced Studies).
# All rights reserved.
# This file is distributed under the terms of the MIT License.
# See the file 'LICENSE' in the root directory of the present
# distribution, or http://opensource.org/licenses/MIT.
#
# @author Davide Brunato <brunato@sissa.it>
#
# mypy: ignore-errors
"""
Tests subpackage module: common definitions for unittest scripts of the 'xmlschema' package.
"""
import unittest
import re
import os
from textwrap import dedent
from xml.etree.ElementTree import Element, iselement

from xmlschema.exceptions import XMLSchemaValueError
from xmlschema.names import XSD_NAMESPACE, XSI_NAMESPACE, XSD_SCHEMA
from xmlschema.helpers import get_namespace
from xmlschema.resources import fetch_namespaces
from xmlschema.validators import XMLSchema10
from ._helpers import etree_elements_assert_equal


PROTECTED_PREFIX_PATTERN = re.compile(r'\bns\d:')
SCHEMA_TEMPLATE = """<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" version="{0}">
    {1}
</xs:schema>"""


class XsdValidatorTestCase(unittest.TestCase):
    """
    Base class for testing XSD validators.
    """
    TEST_CASES_DIR = None
    schema_class = XMLSchema10

    vh_xsd_file: str
    vh_xml_file: str
    col_xsd_file: str
    col_xml_file: str
    st_xsd_file: str
    models_xsd_file: str

    @classmethod
    def setUpClass(cls):
        cls.errors = []
        cls.xsd_types = cls.schema_class.builtin_types()
        cls.content_pattern = re.compile(r'(<|<xs:)(sequence|choice|all)')

        cls.default_namespaces = {
            'xsi': 'http://www.w3.org/2001/XMLSchema-instance',
            'tns': 'http://xmlschema.test/ns',
            'ns': 'ns',
        }

        if os.path.isfile(cls.casepath('testfiles')):
            cls.vh_dir = cls.casepath('examples/vehicles')
            cls.vh_xsd_file = cls.casepath('examples/vehicles/vehicles.xsd')
            cls.vh_xml_file = cls.casepath('examples/vehicles/vehicles.xml')
            cls.vh_json_file = cls.casepath('examples/vehicles/vehicles.json')
            cls.vh_schema = cls.schema_class(cls.vh_xsd_file)
            cls.vh_namespaces = fetch_namespaces(cls.vh_xml_file)

            cls.col_dir = cls.casepath('examples/collection')
            cls.col_xsd_file = cls.casepath('examples/collection/collection.xsd')
            cls.col_xml_file = cls.casepath('examples/collection/collection.xml')
            cls.col_json_file = cls.casepath('examples/collection/collection.json')
            cls.col_schema = cls.schema_class(cls.col_xsd_file)
            cls.col_namespaces = fetch_namespaces(cls.col_xml_file)

            cls.st_xsd_file = cls.casepath('features/decoder/simple-types.xsd')
            cls.st_schema = cls.schema_class(cls.st_xsd_file)

            cls.models_xsd_file = cls.casepath('features/models/models.xsd')
            cls.models_schema = cls.schema_class(cls.models_xsd_file)

    @classmethod
    def casepath(cls, relative_path):
        """
        Returns the absolute path from a relative path specified from the referenced TEST_CASES_DIR.
        """
        return os.path.join(cls.TEST_CASES_DIR or '', relative_path)

    def get_schema_source(self, source):
        """
        Returns a schema source that can be used to create an XMLSchema instance.

        :param source: A string or an ElementTree's Element.
        :return: An schema source string, an ElementTree's Element or a full pathname.
        """
        if iselement(source):
            if source.tag in (XSD_SCHEMA, 'schema'):
                return source
            elif get_namespace(source.tag):
                raise XMLSchemaValueError("source %r namespace has to be empty." % source)
            elif source.tag not in {'element', 'attribute', 'simpleType', 'complexType',
                                    'group', 'attributeGroup', 'notation'}:
                raise XMLSchemaValueError("% is not an XSD global definition/declaration." % source)

            root = Element('schema', attrib={
                'xmlns:xs': XSD_NAMESPACE,
                'xmlns:xsi': XSI_NAMESPACE,
                'elementFormDefault': "qualified",
                'version': self.schema_class.XSD_VERSION,
            })
            root.append(source)
            return root
        else:
            source = dedent(source.strip())
            if not source.startswith('<'):
                return self.casepath(source)
            elif source.startswith('<?xml ') or source.startswith('<xs:schema '):
                return source
            else:
                return SCHEMA_TEMPLATE.format(self.schema_class.XSD_VERSION, source)

    def get_schema(self, source, **kwargs):
        return self.schema_class(self.get_schema_source(source), **kwargs)

    def get_element(self, name, **attrib):
        source = '<xs:element name="{}" {}/>'.format(
            name, ' '.join(f'{k}="{v}"' for k, v in attrib.items())
        )
        schema = self.schema_class(self.get_schema_source(source))
        return schema.elements[name]

    def check_etree_elements(self, elem, other):
        """Checks if two ElementTree elements are equal."""
        try:
            self.assertIsNone(
                etree_elements_assert_equal(elem, other, strict=False, skip_comments=True)
            )
        except AssertionError as err:
            self.assertIsNone(err, None)

    def check_namespace_prefixes(self, s):
        """Checks that a string doesn't contain protected prefixes (ns0, ns1 ...)."""
        match = PROTECTED_PREFIX_PATTERN.search(s)
        if match:
            msg = f"Protected prefix {match.group(0)!r} found:\n {s}"
            self.assertIsNone(match, msg)

    def check_schema(self, source, expected=None, **kwargs):
        """
        Create a schema for a test case.

        :param source: A relative path or a root Element or a portion of schema for a template.
        :param expected: If it's an Exception class test the schema for raise an error. \
        Otherwise build the schema and test a condition if expected is a callable, or make \
        a substring test if it's not `None` (maybe a string). Then returns the schema instance.
        """
        if isinstance(expected, type) and issubclass(expected, Exception):
            with self.assertRaises(expected):
                self.schema_class(self.get_schema_source(source), **kwargs)
        else:
            schema = self.schema_class(self.get_schema_source(source), **kwargs)
            if callable(expected):
                self.assertTrue(expected(schema))
            return schema

    def check_errors(self, path, expected):
        """
        Checks schema or validation errors, checking information completeness of the
        instances and those number against expected.

        :param path: the path of the test case.
        :param expected: the number of expected errors.
        """
        for e in self.errors:
            error_string = str(e)
            self.assertTrue(e.path, "Missing path for: %s" % error_string)
            if e.namespaces:
                self.check_namespace_prefixes(error_string)

        if not self.errors and expected:
            raise ValueError(f"{path!r}: found no errors when {expected} expected.")
        elif len(self.errors) != expected:
            num_errors = len(self.errors)
            if num_errors == 1:
                msg = "{!r}: n.{} errors expected, found {}:\n\n{}"
            elif num_errors <= 5:
                msg = "{!r}: n.{} errors expected, found {}. Errors follow:\n\n{}"
            else:
                msg = "{!r}: n.{} errors expected, found {}. First five errors follow:\n\n{}"

            error_string = '\n++++++++++\n\n'.join([str(e) for e in self.errors[:5]])
            raise ValueError(msg.format(path, expected, len(self.errors), error_string))
