import gc
import platform
import threading

import pytest
from werkzeug.exceptions import NotFound

import flask

_gc_lock = threading.Lock()


class assert_no_leak:
    def __enter__(self):
        gc.disable()
        _gc_lock.acquire()
        loc = flask._request_ctx_stack._local

        # Force Python to track this dictionary at all times.
        # This is necessary since Python only starts tracking
        # dicts if they contain mutable objects.  It's a horrible,
        # horrible hack but makes this kinda testable.
        loc.__storage__["FOOO"] = [1, 2, 3]

        gc.collect()
        self.old_objects = len(gc.get_objects())

    def __exit__(self, exc_type, exc_value, tb):
        gc.collect()
        new_objects = len(gc.get_objects())
        if new_objects > self.old_objects:
            pytest.fail("Example code leaked")
        _gc_lock.release()
        gc.enable()


@pytest.mark.skipif(platform.python_implementation() == "PyPy", reason="CPython only")
def test_memory_consumption():
    app = flask.Flask(__name__)

    @app.route("/")
    def index():
        return flask.render_template("simple_template.html", whiskey=42)

    def fire():
        with app.test_client() as c:
            rv = c.get("/")
            assert rv.status_code == 200
            assert rv.data == b"<h1>42</h1>"

    # Trigger caches
    fire()

    with assert_no_leak():
        for _x in range(10):
            fire()


def test_safe_join_toplevel_pardir():
    from flask.helpers import safe_join

    with pytest.raises(NotFound):
        safe_join("/foo", "..")


def test_aborting(app):
    class Foo(Exception):
        whatever = 42

    @app.errorhandler(Foo)
    def handle_foo(e):
        return str(e.whatever)

    @app.route("/")
    def index():
        raise flask.abort(flask.redirect(flask.url_for("test")))

    @app.route("/test")
    def test():
        raise Foo()

    with app.test_client() as c:
        rv = c.get("/")
        assert rv.headers["Location"] == "http://localhost/test"
        rv = c.get("/test")
        assert rv.data == b"42"