import hmac

import bson
import flask

from . import common
from . import locations
from . import types


def build_app(root_directory: str) -> flask.Flask:
    locs = locations.Locations(root_directory)
    app = flask.Flask(__name__)

    @app.route('/favicon.ico')
    def favicon():
        return flask.send_file('static/favicon.ico')

    @app.route('/')
    def home():
        return 'Weather server'

    @app.route('/_submit', methods=['POST'])
    def submit():
        req = flask.request
        reader = bson.decode_file_iter(
            req.stream, codec_options=common.BSON_OPTIONS)
        try:
            preamble = next(reader)
            loc_name = preamble['location']
            password = str(preamble['password'])
            loc, logger = locs.get(loc_name)
            if not hmac.compare_digest(password, loc.password):
                flask.abort(400)
            entries = [
                types.Reading.from_now(
                    sample_time=item['sample_time'],
                    temp_c=item['temp_c'],
                    rh_pct=item['rh_pct'],
                )
                for item in reader
            ]
        except (KeyError, bson.InvalidBSON):
            flask.abort(400)
        logger.write_rows(entries)
        return flask.jsonify({'status': 'OK'})

    @app.route('/<location>')
    def show(location):
        try:
            loc, logger = locs.get(location)
        except KeyError:
            flask.abort(404)
        data = logger.data
        if data:
            last_reading = data[-1]
            tz = loc.timezone()
            date = tz.normalize(last_reading.sample_time.astimezone(tz))
        else:
            last_reading = None
            date = None
        return flask.render_template(
            'location.html',
            location=loc,
            last_reading=last_reading,
            date=date)

    return app


def main(argv):
    """Main function for a simple local demo."""
    app = server.build_app(argv[0])
    app.run(host='0.0.0.0')


if __name__ == '__main__':
    main(sys.argv[1:])