# The secure redirect I found in the snippets library did not satisfy me.
# Here is my version which satisfied my needs more. The next argument/
# referrer will only be used if your application knows how to route it.
# This won't work very well if you have multiple applications.
# Licensed under the Unlicense, go nuts.

## Create the base form ##
from flask import request, url_for, render_template
from flaskext.wtf import Form, HiddenField
from werkzeug.exceptions import NotFound, HTTPException

class RedirectForm(Form):
    next = HiddenField()

    def __init__(self, *args, **kwargs):
        super(RedirectForm, self).__init__(*args, **kwargs)

        if not self.next.data:
            self.next.data = request.args.get("next") or request.referrer

        try:
            # Will raise an exception if no endpoint exists for the url
            app.create_url_adapter(request).match(self.next.data)
        except NotFound:
            self.next.data = ""
        except HTTPException:
            # Any other exceptions are harmless (I think)
            pass

    @property
    def redirect_target(self):
        return self.next.data