from random import uniform
import datetime
import time
import configparser
import os
from flask import Flask, render_template, jsonify, request
import flask.json
from sqlalchemy import create_engine


class JSONEncoder(flask.json.JSONEncoder):
    def default(self, object):
        if isinstance(object, datetime.datetime):
            return object.isoformat()
        return super().default(object)


def parse_datetime(date_str):
    return datetime.datetime.strptime(date_str, '%Y-%m-%dT%H:%M:%S')


app = Flask(__name__)
app.json_encoder = JSONEncoder
config = configparser.ConfigParser()
config.read(os.environ['SEEPARKINI'])
apikey = config.get('openweathermap', 'apikey')


def open_engine(config):
    user = config.get('database', 'user')
    pwd = config.get('database', 'password')
    host = config.get('database', 'hostname')
    db = config.get('database', 'database')
    engine = create_engine('mysql+mysqldb://{}:{}@{}/{}'.format(user, pwd, host, db), echo=False)
    return engine


@app.route('/api/<version>/sensors/')
def sensors(version):
    """List all sensors found in the database"""
    engine = open_engine(config)
    with engine.connect() as conn:
        cursor = conn.execute('select distinct sensor_id, sensor_name, value_type from sensors')
        result = [dict(row) for row in cursor]
        return jsonify(result)


@app.route('/api/<version>/sensor/<sensor_id>')
def sensor(version, sensor_id):
    """Return all sensor data

    URL parameters:
    begin=<datetime>, optional, format like "2018-05-19T21:07:53"
    end=<datetime>, optional, format like "2018-05-19T21:07:53"
    """
    engine = open_engine(config)
    with engine.connect() as conn:
        where = ['sensor_id=%s']
        sql_args = [sensor_id]
        if 'begin' in request.args:
            where.append('timestamp>=%s')
            sql_args.append(request.args.get('begin', None, parse_datetime))
        if 'end' in request.args:
            where.append('timestamp<=%s')
            sql_args.append(request.args.get('end', None, parse_datetime))
        sql = 'select * from sensors where {} order by id'.format(' and '.join(where))
        cursor = conn.execute(sql, *sql_args)
        result = [dict(row) for row in cursor]
        return jsonify(result)


@app.route('/data/', defaults={'timespan': 1})
@app.route("/data/<int:timespan>", methods=['GET'])
def data(timespan):
    granularity = 5 * timespan               # (every) minute(s) per day
    samples = 60/granularity * 24 * timespan # per hour over whole timespan
    s4m   = []
    s4m_x = []
    s5m   = []
    s5m_x = []
    end   = time.time()
    start = end - samples * granularity * 60

    for i in range(int(samples)):
        s4m.append(uniform(-10,30))
        s5m.append(uniform(-10,30))
        s4mt = uniform(start, end)
        s5mt = uniform(start, end)
        s4m_x.append(time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(s4mt)))
        s5m_x.append(time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(s5mt)))

    data = {
        '0316a2193bff':   s4m,
        '0316a2193bff_x': s4m_x,
        '0316a21383ff':   s5m,
        '0316a21383ff_x': s5m_x,
        }

    return jsonify(data)


@app.route("/")
def index():
    return render_template('seepark_web.html', apikey=apikey)