GpioCsvWriter

import csv
import time
from datetime import date, datetime
from pathlib import Path

HEADER = ("Date", "Time", "Sig_Name", "Pin_Status")


class GpioCsvWriter:
    def __init__(self, base_path, base_name, gpio_pins=None, header=HEADER):
        self.base_name = base_name
        self.base_path = base_path
        self.gpio_pins = gpio_pins or []
        self.header = header
        self._fd = None
        self._csv = None
        self._setup_gpio()

    @property
    def current_file(self):
        return Path(self.base_path, f"{date.today():%Y-%m-%d}_{self.base_name}.csv")

    @property
    def name(self):
        if self._fd is None:
            return ""

        return self._fd.name

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_obj, tb):
        self.close()

    def close(self):
        self._csv = None
        if self._fd is not None:
            self._fd.close()
        self._fd = None

    def _init_csv(self):
        if self._fd is not None:
            self._fd.close()

        if not self.current_file.exists():
            write_header = True
        else:
            write_header = False

        self._fd = self.current_file.open("at", encoding="utf8")
        self._csv = csv.writer(self._fd)

        if write_header:
            self._csv.writerow(self.header)

    def writerow(self, row):
        if self._fd is None or self._fd.name != self.current_file:
            self._init_csv()

        self._csv.writerow(row)
        self._fd.flush()

    def _signal(self, pin):
        now = datetime.now()
        self.writerow(
            [
                now.strptime("%Y-%m-%d"),
                now.strptime("%H:%M:%s"),
                str(gpio_pin),
                str(GPIO.input(gpio_pin)),
            ]
        )

    def _setup_gpio(self):
        if not self.gpio_pins:
            return

        GPIO.setmode(GPIO.BCM)
        for pin in self.gpio_pins:
            GPIO.setup(pin, GPIO.IN, GPIO.PUD_DOWN)
            GPIO.add_event_detect(pin, GPIO.BOTH, callback=self._signal)


if __name__ == "__main__":
    writer = GpioCsvWriter("/tmp", "foo_bar")
    # writer.writerow(["1970-01-01", "00:00", "1", "1"])