battery-monitor

#!/bin/env python

from __future__ import annotations

import dataclasses
import pathlib
import enum
import subprocess
import time

POWER_SUPPLY_PATH = pathlib.Path("/sys/class/power_supply")
BATTERY_TYPE = pathlib.Path("type")
BATTERY_CAPACITY = pathlib.Path("capacity")
BATTERY_STATUS = pathlib.Path("status")


class Message(enum.Enum):
    FullyCharged = enum.auto()
    TwentyPercentRemaining = enum.auto()
    TenPercentRemaining = enum.auto()
    FivePercentRemaining = enum.auto()

    @staticmethod
    def send(message_type: Message):
        message: str
        urgency: str
        match message_type:
            case Message.FullyCharged:
                message = "Fully charged"
                urgency = "normal"
            case Message.TwentyPercentRemaining:
                message = "20% Remaining"
                urgency = "normal"
            case Message.TenPercentRemaining:
                message = "10% Remaining"
                urgency = "normal"
            case Message.FivePercentRemaining:
                message = "5% Remaining"
                urgency = "critical"

        subprocess.run(["notify-send", message, "--urgency", urgency])

@dataclasses.dataclass
class Battery:
    path: pathlib.Path
    percent: int = 100
    charging: bool = False

    sent_messages: list[Message] = dataclasses.field(default_factory=list)

    def __post_init__(self):
        self.sent_messages = [
            Message.FullyCharged,
            Message.TwentyPercentRemaining,
            Message.TenPercentRemaining,
            Message.FivePercentRemaining,
        ]

    @classmethod
    def from_path(cls, path: pathlib.Path) -> Battery | None:
        battery = cls(path)

        if (path / BATTERY_TYPE).open().readline().strip() != "Battery":
            return None

        battery.update()

        return battery

    def update(self):
        self.percent = int((self.path / BATTERY_CAPACITY).open().readline().strip())
        self.charging = (
            self.path / BATTERY_STATUS
        ).open().readline().strip() == "Charging"

    def check(self):
        # First reset messages
        if self.percent <= 99 and Message.FullyCharged in self.sent_messages:
            self.sent_messages.remove(Message.FullyCharged)

        if self.percent >= 21 and Message.TwentyPercentRemaining in self.sent_messages:
            self.sent_messages.remove(Message.TwentyPercentRemaining)
        if self.percent >= 11 and Message.TenPercentRemaining in self.sent_messages:
            self.sent_messages.remove(Message.TenPercentRemaining)
        if self.percent >= 6 and Message.FivePercentRemaining in self.sent_messages:
            self.sent_messages.remove(Message.FivePercentRemaining)

        if self.percent == 100 and Message.FullyCharged not in self.sent_messages:
            Message.send(Message.FullyCharged)
            self.sent_messages.append(Message.FullyCharged)
        if (
            self.percent == 20
            and Message.TwentyPercentRemaining not in self.sent_messages
        ):
            Message.send(Message.TwentyPercentRemaining)
            self.sent_messages.append(Message.TwentyPercentRemaining)
        if self.percent == 10 and Message.TenPercentRemaining not in self.sent_messages:
            Message.send(Message.TenPercentRemaining)
            self.sent_messages.append(Message.TenPercentRemaining)
        if self.percent == 5 and Message.FivePercentRemaining not in self.sent_messages:
            Message.send(Message.FivePercentRemaining)
            self.sent_messages.append(Message.FivePercentRemaining)


def open_batteries() -> list[Battery]:
    batteries = []

    for path in POWER_SUPPLY_PATH.iterdir():
        if (bat := Battery.from_path(path)) != None:
            batteries.append(bat)

    return batteries


def main():
    batteries = open_batteries()
    while True:
        for bat in batteries:
            bat.update()
            bat.check()
        time.sleep(10)

if __name__ == "__main__":
    main()