import sys

from django.template import Context, Engine, TemplateDoesNotExist, TemplateSyntaxError
from django.template.base import UNKNOWN_SOURCE
from django.test import SimpleTestCase, override_settings
from django.urls import NoReverseMatch
from django.utils import translation
from django.utils.html import escape


class TemplateTestMixin:
    def _engine(self, **kwargs):
        return Engine(debug=self.debug_engine, **kwargs)

    def test_string_origin(self):
        template = self._engine().from_string("string template")
        self.assertEqual(template.origin.name, UNKNOWN_SOURCE)
        self.assertIsNone(template.origin.loader_name)
        self.assertEqual(template.source, "string template")

    @override_settings(SETTINGS_MODULE=None)
    def test_url_reverse_no_settings_module(self):
        """
        #9005 -- url tag shouldn't require settings.SETTINGS_MODULE to
        be set.
        """
        t = self._engine().from_string("{% url will_not_match %}")
        c = Context()
        with self.assertRaises(NoReverseMatch):
            t.render(c)

    def test_url_reverse_view_name(self):
        """
        #19827 -- url tag should keep original strack trace when reraising
        exception.
        """
        t = self._engine().from_string("{% url will_not_match %}")
        c = Context()
        try:
            t.render(c)
        except NoReverseMatch:
            tb = sys.exc_info()[2]
            depth = 0
            while tb.tb_next is not None:
                tb = tb.tb_next
                depth += 1
            self.assertGreater(
                depth, 5, "The traceback context was lost when reraising the traceback."
            )

    def test_no_wrapped_exception(self):
        """
        # 16770 -- The template system doesn't wrap exceptions, but annotates
        them.
        """
        engine = self._engine()
        c = Context({"coconuts": lambda: 42 / 0})
        t = engine.from_string("{{ coconuts }}")

        with self.assertRaises(ZeroDivisionError) as e:
            t.render(c)

        if self.debug_engine:
            debug = e.exception.template_debug
            self.assertEqual(debug["start"], 0)
            self.assertEqual(debug["end"], 14)

    def test_invalid_block_suggestion(self):
        """
        Error messages should include the unexpected block name and be in all
        English.
        """
        engine = self._engine()
        msg = (
            "Invalid block tag on line 1: 'endblock', expected 'elif', 'else' "
            "or 'endif'. Did you forget to register or load this tag?"
        )
        with self.settings(USE_I18N=True), translation.override("de"):
            with self.assertRaisesMessage(TemplateSyntaxError, msg):
                engine.from_string("{% if 1 %}lala{% endblock %}{% endif %}")

    def test_unknown_block_tag(self):
        engine = self._engine()
        msg = (
            "Invalid block tag on line 1: 'foobar'. Did you forget to "
            "register or load this tag?"
        )
        with self.assertRaisesMessage(TemplateSyntaxError, msg):
            engine.from_string("lala{% foobar %}")

    def test_compile_filter_expression_error(self):
        """
        19819 -- Make sure the correct token is highlighted for
        FilterExpression errors.
        """
        engine = self._engine()
        msg = "Could not parse the remainder: '@bar' from 'foo@bar'"

        with self.assertRaisesMessage(TemplateSyntaxError, msg) as e:
            engine.from_string("{% if 1 %}{{ foo@bar }}{% endif %}")

        if self.debug_engine:
            debug = e.exception.template_debug
            self.assertEqual((debug["start"], debug["end"]), (10, 23))
            self.assertEqual((debug["during"]), "{{ foo@bar }}")

    def test_compile_tag_error(self):
        """
        Errors raised while compiling nodes should include the token
        information.
        """
        engine = self._engine(
            libraries={"bad_tag": "template_tests.templatetags.bad_tag"},
        )
        with self.assertRaises(RuntimeError) as e:
            engine.from_string("{% load bad_tag %}{% badtag %}")
        if self.debug_engine:
            self.assertEqual(e.exception.template_debug["during"], "{% badtag %}")

    def test_compile_tag_error_27584(self):
        engine = self._engine(
            app_dirs=True,
            libraries={"tag_27584": "template_tests.templatetags.tag_27584"},
        )
        t = engine.get_template("27584_parent.html")
        with self.assertRaises(TemplateSyntaxError) as e:
            t.render(Context())
        if self.debug_engine:
            self.assertEqual(e.exception.template_debug["during"], "{% badtag %}")

    def test_compile_tag_error_27956(self):
        """Errors in a child of {% extends %} are displayed correctly."""
        engine = self._engine(
            app_dirs=True,
            libraries={"tag_27584": "template_tests.templatetags.tag_27584"},
        )
        t = engine.get_template("27956_child.html")
        with self.assertRaises(TemplateSyntaxError) as e:
            t.render(Context())
        if self.debug_engine:
            self.assertEqual(e.exception.template_debug["during"], "{% badtag %}")

    def test_render_tag_error_in_extended_block(self):
        """Errors in extended block are displayed correctly."""
        e = self._engine(app_dirs=True)
        template = e.get_template("test_extends_block_error.html")
        context = Context()
        with self.assertRaises(TemplateDoesNotExist) as cm:
            template.render(context)
        if self.debug_engine:
            self.assertEqual(
                cm.exception.template_debug["during"],
                escape('{% include "missing.html" %}'),
            )

    def test_super_errors(self):
        """
        #18169 -- NoReverseMatch should not be silence in block.super.
        """
        engine = self._engine(app_dirs=True)
        t = engine.get_template("included_content.html")
        with self.assertRaises(NoReverseMatch):
            t.render(Context())

    def test_extends_generic_template(self):
        """
        #24338 -- Allow extending django.template.backends.django.Template
        objects.
        """
        engine = self._engine()
        parent = engine.from_string("{% block content %}parent{% endblock %}")
        child = engine.from_string(
            "{% extends parent %}{% block content %}child{% endblock %}"
        )
        self.assertEqual(child.render(Context({"parent": parent})), "child")

    def test_node_origin(self):
        """
        #25848 -- Set origin on Node so debugging tools can determine which
        template the node came from even if extending or including templates.
        """
        template = self._engine().from_string("content")
        for node in template.nodelist:
            self.assertEqual(node.origin, template.origin)

    def test_render_built_in_type_method(self):
        """
        Templates should not crash when rendering methods for built-in types
        without required arguments.
        """
        template = self._engine().from_string("{{ description.count }}")
        self.assertEqual(template.render(Context({"description": "test"})), "")


class TemplateTests(TemplateTestMixin, SimpleTestCase):
    debug_engine = False


class DebugTemplateTests(TemplateTestMixin, SimpleTestCase):
    debug_engine = True
