#! /usr/bin/python3

import argparse
import logging
import datetime
import re
import sys
import csv
import os
import configparser
from sqlalchemy import create_engine
import warnings
import MySQLdb.cursors

#May 27 21:32 /sys/bus/w1/devices/28-0416a1bab9ff
#May 27 21:33 /sys/bus/w1/devices/28-0416a1ac66ff
#May 27 21:35 /sys/bus/w1/devices/28-0516a207a4ff
#May 27 21:38 /sys/bus/w1/devices/28-0316a2193bff
#May 27 21:38 /sys/bus/w1/devices/28-0316a21383ff

# Eine Funktion:
# einen Sensor auslesen
#/sys/bus/w1/devices/

class ReadsensorError(RuntimeError):
    pass
    
    
def readsensor(sensor_id):
    sensorfile = "/sys/bus/w1/devices/28-{}/w1_slave".format(sensor_id)
    file = open(sensorfile)

    # Inhalt des Sensors:
    # 64 01 4b 46 7f ff 0c 10 01 : crc=01 YES
    # 64 01 4b 46 7f ff 0c 10 01 t=22250

    # Suche nach YES
    linecrc = file.readline()
    match = re.search(": crc=[0-9a-f]{2} (YES|NO)",linecrc)

    yesno = match.group(1)
    if yesno != "YES":
        raise ReadsensorError('Could not evaluate sensorfile "{}"'.format(sensorfile))
        
    # Temperatur raus
    linetemp = file.readline()
    match = re.search(" t=([-0-9]+)",linetemp)

    temp_raw = match.group(1)
    temp = float(temp_raw)/1000

    file.close()
    jetzt = datetime.datetime.now()

    return jetzt, temp_raw, temp


def writesensordatacsv(config, sensor_id, sensor_name, timestamp, value_type, value_raw, value):
    # Schreiben des csv-files
    with open(os.path.expanduser(config.get("csv", "filename")), "a", newline = "") as file:
        writer = csv.writer(file, dialect = "excel")
        writer.writerow([timestamp.strftime("%Y-%m-%d %H:%M"), sensor_id, sensor_name, "{:.1f}".format(value)])


def readcsvfile(csvfile):
    with open(csvfile, "r", newline="") as file:
        yield from csv.DictReader(file, dialect = "excel", fieldnames=("timestamp", "sensor_id", "sensor_name", "value"))


def writesensordatadb(config, sensor_id, sensor_name, timestamp, value_type, value_raw, value):
    # Schreiben des db-files
    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)
    conn = engine.connect()
    with warnings.catch_warnings():
        # ignore _mysql_exceptions.Warning: Duplicate entry '0316a2193bff-2018-08-29 14:30:00' for key 'sensorid_timestamp'
        warnings.simplefilter("ignore", category=MySQLdb.cursors.Warning)
        conn.execute("insert ignore into sensors (sensor_id, sensor_name, value_type, value_raw, value, timestamp) values (%s,%s,%s,%s,%s,%s)", sensor_id, sensor_name, value_type, value_raw, value, timestamp)
    conn.close()


def process_csv_file(config, fromcsvfile, value_type, sensors):
    # "timestamp", "sensor_id", "sensor_name", "value"
    sensors_ids = [sensor_id for sensor_id, sensor_name in sensors]
    for record in readcsvfile(fromcsvfile):
        timestamp, sensor_id, sensor_name, value = (record["timestamp"], record["sensor_id"], record["sensor_name"], float(record["value"]))
        if sensor_id in sensors_ids:
            value_raw = None
            writesensordatadb(config, sensor_id, sensor_name, timestamp, value_type, value_raw, value)


def main(configfile, fromcsvfile):
    config = configparser.ConfigParser()
    config.read(configfile)
    sensors = config.items('temperature')
    value_type = "Wassertemperatur"

    if fromcsvfile:
        process_csv_file(config, fromcsvfile, value_type, sensors)
        return

    for sensor_id, sensor_name in sensors:
        timestamp, value_raw, value = readsensor(sensor_id)
        writesensordatacsv(config, sensor_id, sensor_name, timestamp, value_type, value_raw, value)
        writesensordatadb(config, sensor_id, sensor_name, timestamp, value_type, value_raw, value)
        logging.info('Sensor {}: {:.1f}°C'.format(sensor_id, value))


if __name__ == '__main__':
    default_config_file = os.path.expanduser('~/seewasser.ini')
    parser = argparse.ArgumentParser(description='Read sensor data')
    parser.add_argument('--config', default=default_config_file, help='configuration file')
    parser.add_argument('--fromcsvfile', help='write values from csv file to database')
    args = parser.parse_args()
    main(args.config, args.fromcsvfile)