import flask
import sys
from flask import request, jsonify, g
from flask_apscheduler import APScheduler
from datetime import datetime,timedelta,timezone
import sqlite3
import smtplib

# testing:
# start dummy web server for dev with root: python3 -m smtpd -c DebuggingServer -n localhost:25

# Request:
# curl -X POST "http://localhost:5000/api/v1?topic=abc.def&secs=60&email=j.tretter@gmail.com"
DATABASE='deadswitch.sqlite3'

class Config(object):
    JOBS = [
        {
            'id': 'job1',
            'func': 'api1:expiryCheck',
            'trigger': 'interval',
            'seconds': 10
        }
    ]

    SCHEDULER_API_ENABLED = True

def sendMail(topic,toAddr):
    print(f"sending mail to {toAddr} for topic {topic}")
    port = 25
    server=smtplib.SMTP("localhost", port)
    sender_email = "deadswitch@kawomi.com"
    receiver_email = toAddr
    message = f"""Subject: deadSwitch not pushed on topic {topic}\n\nNotification of deadSwitch not pushed on topic {topic}."""
    server.sendmail(sender_email, receiver_email, message)


def expiryCheck():
    print('.',end='')
    db=sqlite3.connect(DATABASE,detect_types=sqlite3.PARSE_DECLTYPES)
    cursor = db.cursor()
    for theRow in cursor.execute("select expiry,topic,email from entries where active=True and isNotified=False and expiry < datetime()"):
        print(theRow)
        sendMail(theRow[1],theRow[2])
        db.execute("update entries set isNotified=True where topic=?",[theRow[1]])
        db.commit()
    db.close()

if __name__ == '__main__':
    app = flask.Flask(__name__)
    app.config["DEBUG"] = False

    app.config.from_object(Config())
    scheduler = APScheduler()
    # it is also possible to enable the API directly
    # scheduler.api_enabled = True
    scheduler.init_app(app)
    scheduler.start()

    def get_db():
        db = getattr(g, '_database', None)
        if db is None:
            db = g._database = sqlite3.connect(DATABASE,detect_types=sqlite3.PARSE_DECLTYPES)
        return db

    @app.teardown_appcontext
    def close_connection(exception):
        db = getattr(g, '_database', None)
        if db is not None:
            db.commit()
            db.close()

    @app.route('/', methods=['GET'])
    def home():
        return """<h1>Dead-Switch web service</h1>
        <hr>
        <h2>2020-10-29 - j.tretter@gmail.com</h2>
        <hr>
        Examples:
        <ul>
        <li>curl "https://deadswitch.kawomi.com/api/v1?topic=sys.demo"</li>
        <li>curl -d "" -X POST "https://deadswitch.kawomi.com/api/v1?topic=sys.demo&secs=60&email=demo@demo.com"</li>
        </ul>"""


    @app.route('/api/v1', methods=['GET'])
    def api_getByTopic():
        if 'topic' in request.args:
            topic=request.args['topic']
        else:
            return jsonify({'success':False, 'error':"No topic given"})

        cursor = get_db().cursor()
        cursor.execute("select active,expiry,email,isNotified,expiry<datetime('now') \"isExpired\",lastSeen from entries where topic=?",[topic])
        theRow=cursor.fetchone()
        if theRow is None:
            return jsonify({'success':False, 'error':f"No entry found for topic _{topic}_"})

        return jsonify({'success':True, 'topic':topic, 'active':bool(theRow[0]), 'expiry':theRow[1].strftime("%Y-%m-%d %H:%M:%S"), 'lastSeen':theRow[5].strftime("%Y-%m-%d %H:%M:%S"),'isExpired':bool(theRow[4]),'email':theRow[2], 'isNotified':bool(theRow[3])})

    @app.route('/api/v1', methods=['PUT','POST'])
    def api_setRecord():
        if 'topic' in request.args:
            topic = request.args['topic']
        else:
            return jsonify({'success':False, 'error':"No topic given"})

        if 'email' in request.args:
            email = request.args['email']
        else:
            return jsonify({'success':False, 'error':"No email given"})

        if 'secs' in request.args:
            secs = int(request.args['secs'])
        else:
            return jsonify({'success':False, 'error':"No secs given"})

        expiryDateTime=datetime.now(tz=timezone.utc) + timedelta(seconds=secs)
        
        try:
            cursor = get_db().cursor()
            cursor.execute("update entries set active=True,isNotified=False,email=?,expiry=?,lastSeen=datetime('now') where topic=?",[email,expiryDateTime,topic])
            if cursor.rowcount == 0:
                cursor.execute("Insert into entries (active,topic,expiry,email,isNotified,lastSeen) values (True,?,?,?,False,datetime('now'))",[topic,expiryDateTime,email])
        except Exception as e:
            return jsonify({'success':False, 'error':str(e)})

        return jsonify({'success':True, 'expiry':expiryDateTime.strftime("%Y-%m-%d %H:%M:%S"), 'email':email})

    app.run(use_reloader=False,port=5123)