app.py

import logging
import os

from flask import Flask, render_template, request, session
from requests_oauthlib import OAuth2Session
from werkzeug.serving import WSGIRequestHandler


REQUIRED_ENVIRONMENT_VARIABLES = (
    "FITBIT_CLIENT_ID",
    "FITBIT_CLIENT_SECRET",
    "FITBIT_REDIRECT_URI",
    "FLASK_SECRET_KEY",
)

AUTHORIZATION_BASE_URL = "https://www.fitbit.com/oauth2/authorize"
TOKEN_URL = "https://api.fitbit.com/oauth2/token"


def load_required_configuration():
    missing = [
        name
        for name in REQUIRED_ENVIRONMENT_VARIABLES
        if not os.environ.get(name, "").strip()
    ]
    if missing:
        raise RuntimeError(
            "Missing required environment variables: " + ", ".join(missing)
        )
    return {name: os.environ[name] for name in REQUIRED_ENVIRONMENT_VARIABLES}


def development_insecure_transport_enabled():
    value = os.environ.get("FITBIT_ALLOW_INSECURE_TRANSPORT", "")
    return value.strip().lower() in {"1", "true", "yes", "on"}


configuration = load_required_configuration()

FITBIT_CLIENT_ID = configuration["FITBIT_CLIENT_ID"]
FITBIT_CLIENT_SECRET = configuration["FITBIT_CLIENT_SECRET"]
FITBIT_REDIRECT_URI = configuration["FITBIT_REDIRECT_URI"]

if development_insecure_transport_enabled():
    os.environ["OAUTHLIB_INSECURE_TRANSPORT"] = "1"
else:
    os.environ.pop("OAUTHLIB_INSECURE_TRANSPORT", None)

logging.basicConfig(level=logging.INFO)

app = Flask(__name__)
app.secret_key = configuration["FLASK_SECRET_KEY"]


class CredentialSafeRequestHandler(WSGIRequestHandler):
    """Avoid logging request paths or query strings that may contain OAuth data."""

    def log_request(self, code="-", size="-"):
        self.log(
            "info",
            '"%s [path redacted] %s" %s %s',
            self.command,
            self.request_version,
            code,
            size,
        )


@app.route("/")
def home():
    return render_template("index.html")


@app.route("/redirect")
def redirect_page():
    fitbit = OAuth2Session(FITBIT_CLIENT_ID, redirect_uri=FITBIT_REDIRECT_URI)
    token = fitbit.fetch_token(
        TOKEN_URL,
        client_secret=FITBIT_CLIENT_SECRET,
        authorization_response=request.url,
    )
    session["oauth_token"] = token
    return "You are successfully logged in with Fitbit!"


def authenticated_fitbit_session():
    return OAuth2Session(FITBIT_CLIENT_ID, token=session.get("oauth_token"))


@app.route("/fetch-steps")
def fetch_steps():
    response = authenticated_fitbit_session().get(
        "https://api.fitbit.com/1/user/-/activities/steps/date/today/1w.json"
    )
    return response.json()


@app.route("/fetch-heart-rate")
def fetch_heart_rate():
    response = authenticated_fitbit_session().get(
        "https://api.fitbit.com/1/user/-/activities/heart/date/today/1w.json"
    )
    return response.json()


@app.route("/fetch-sleep")
def fetch_sleep():
    response = authenticated_fitbit_session().get(
        "https://api.fitbit.com/1.2/user/-/sleep/date/today/1w.json"
    )
    return response.json()


if __name__ == "__main__":
    app.run(
        debug=False,
        port=int(os.environ.get("PORT", "8080")),
        request_handler=CredentialSafeRequestHandler,
    )