#!/usr/bin/env python3

""" Converts CSV exports from https://www.madavi.de/sensor/csvfiles.php to InfluxDB LineProtocol

    Note: timestamps are in seconds, therefore precision "s" needs to be set
    when writing, see https://docs.influxdata.com/influxdb/v1.2/tools/api/#write

Settings:

    Please set
    * SENSOR_ID
    * INFLUXDB_DATABASE
    in your environment

CSV file spec:

    Semiconlos are used as delimiters. First line are the header columns.
    Generally the column name is used as a DB field name, but there are some legacy
    exceptions like "time" instead of "Time" as listed in the following table.

    | DB Field           | DB field | CSV Column         | CSV Format
    |--------------------|----------|--------------------|--------------------------
    | time               | time     | Time               | 2017/05/19 00:00:11 (UTC)
    | ?                  | ?        | durP1              |
    | ?                  | ?        | ratioP1            |
    | ?                  | ?        | P1                 |
    | ?                  | ?        | durP2              |
    | ?                  | ?        | ratioP2            |
    | ?                  | ?        | P2                 |
    | SDS_P1             | field    | SDS_P1             | 10.36
    | SDS_P2             | field    | SDS_P2             | 9.50
    | PMS_P1             | field    | PMS_P1             |
    | PMS_P2             | field    | PMS_P2             |
    | temperature        | field    | Temp               | 16.00
    | humidity           | field    | Humidity           | 79.00
    | BMP_temperature    | field    | BMP_temperature    |
    | BMP_pressure       | field    | BMP_pressure       |
    | BME280_temperature | field    | BME280_temperature |
    | BME280_humidity    | field    | BME280_humidity    |
    | BME280_pressure    | field    | BME280_pressure    |
    | samples            | field    | Samples            | 828799
    | min_micro          | field    | Min_cycle          | 172
    | max_micro          | field    | Max_cycle          | 25198
    | signal             | field    | Signal             | -91
    | node               | tag      | N/A filename?      | e.g. esp8266-16229960

"""

import os
import sys
import csv
from datetime import datetime, timedelta

def get_timestamp(timestr):
    """Converts CSV time value to a UTC timestamp in seconds"""
    naive_dt = datetime.strptime(timestr, '%Y/%m/%d %H:%M:%S')
    utc = (naive_dt - datetime(1970, 1, 1)) / timedelta(seconds=1)
    return int(utc)

SENSOR_ID = os.environ.get('SENSOR_ID', '16229960')
DATABASE = os.environ.get('INFLUXDB_DATABASE', 'sensors')

NODE = 'esp8266-' + SENSOR_ID

NAME_MAP = {
    'Humidity':
    'humidity',
    'Max_cycle': 'max_micro',
    'Samples': 'samples',
    'Min_cycle': 'min_micro',
    'Signal': 'signal',
    'Temp': 'temperature'
}

READER = csv.DictReader(sys.stdin, delimiter=';')
for row in READER:
    measurements = []
    for header, value in row.items():
        if header == 'Time' or not value:
            continue
        measurements.append('{0}={1}'.format(NAME_MAP.get(header, header), value))

    values = {
        'database': DATABASE,
        'node': NODE,
        'measurements': ','.join(measurements),
        'time': get_timestamp(row['Time'])
    }

    print('{database},node={node} {measurements} {time}'.format(**values))