# Copyright 2015 Google LLC.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# [START gae_flex_analytics_track_event]
import logging
import os

from flask import Flask
import requests


app = Flask(__name__)


# Environment variables are defined in app.yaml.
GA_TRACKING_ID = os.environ["GA_TRACKING_ID"]


def track_event(category, action, label=None, value=0):
    data = {
        "v": "1",  # API Version.
        "tid": GA_TRACKING_ID,  # Tracking ID / Property ID.
        # Anonymous Client Identifier. Ideally, this should be a UUID that
        # is associated with particular user, device, or browser instance.
        "cid": "555",
        "t": "event",  # Event hit type.
        "ec": category,  # Event category.
        "ea": action,  # Event action.
        "el": label,  # Event label.
        "ev": value,  # Event value, must be an integer
        "ua": "Opera/9.80 (Windows NT 6.0) Presto/2.12.388 Version/12.14",
    }

    response = requests.post("https://www.google-analytics.com/collect", data=data)

    # If the request fails, this will raise a RequestException. Depending
    # on your application's needs, this may be a non-error and can be caught
    # by the caller.
    response.raise_for_status()


@app.route("/")
def track_example():
    track_event(category="Example", action="test action")
    return "Event tracked."


@app.errorhandler(500)
def server_error(e):
    logging.exception("An error occurred during a request.")
    return (
        """
    An internal error occurred: <pre>{}</pre>
    See logs for full stacktrace.
    """.format(
            e
        ),
        500,
    )


if __name__ == "__main__":
    # This is used when running locally. Gunicorn is used to run the
    # application on Google App Engine. See entrypoint in app.yaml.
    app.run(host="127.0.0.1", port=8080, debug=True)
# [END gae_flex_analytics_track_event]