#!/bin/env python
"""Sets the monitor temperature based on the current time using Hyprsunset"""
from datetime import datetime
from os import environ
from pathlib import Path
from socket import AF_UNIX, SOCK_STREAM, socket


type Range = tuple[float, float]


def lerped_amount(x: float, edges: Range) -> float:
	"""How far `x` is between `values`"""
	return (x - edges[0]) / (edges[1] - edges[0])


def smoothstep(x: float, edges: Range) -> float:
	"""Smoothly interpolates between the `edges` based on `x`"""
	# Technically I should bounds check but whatever
	return (x * x * (3.0 - 2.0 * x)) * (edges[1] - edges[0]) + edges[0]


def day_elapsed(hours: int = 0, minutes: int = 0, seconds: int = 0) -> float:
	"""Converts (H, M, S) into [0, 1] representing how far through the day it is"""
	return ((((hours * 60) + minutes) * 60) + seconds) / 86400


def now_elapsed() -> float:
	"""How far through the day it is"""
	now = datetime.now()
	return day_elapsed(now.hour, now.minute, now.second)

def calculate_temperature(sunrise: Range, sunset: Range, temperature_range: Range) -> float:
	"""What temperature the monitor should be"""
	elapsed = now_elapsed()

	if elapsed <= sunrise[0]:
		return temperature_range[0]
	elif elapsed < sunrise[1]:
		return smoothstep(lerped_amount(elapsed, sunrise), temperature_range)
	elif elapsed <= sunset[0]:
		return temperature_range[1]
	elif elapsed < sunset[1]:
		return smoothstep(lerped_amount(elapsed, sunset), (temperature_range[1], temperature_range[0]))
	else:
		return temperature_range[0]


def setup_socket() -> socket:
	"""Connects to the Hyprsunset socket"""
	hyprsunset = socket(AF_UNIX, SOCK_STREAM)
	# In theory I should use $XDG_RUNTIME_DIR, but for me it's always `/run/user/1000/`
	hyprsunset.connect(f"{environ["XDG_RUNTIME_DIR"]}/hypr/{environ["HYPRLAND_INSTANCE_SIGNATURE"]}/.hyprsunset.sock")
	return hyprsunset


def get_temperature(hyprsunset: socket) -> int:
	"""Retrieves the current screen temperature"""
	# In theory the message might not send in one go, but in practice it does so I won't bother handling the error
	_ = hyprsunset.send(b"temperature")
	# 4 bytes should be enough but why not 8 for comfort
	# Just raise an error if it's not a number, nothing special to do here
	return int(hyprsunset.recv(8))


def set_temperature(hyprsunset: socket, temperature: float) -> None:
	# In theory the message might not send in one go, but in practice it does so I won't bother handling the error
	_ = hyprsunset.send(f"temperature {temperature:.1f}".encode())


def on_steam() -> bool:
	"""Whether the Steam PID is in use"""
	pid_file = Path("~/.steampid").expanduser().resolve(strict=True)
	pid = pid_file.read_text().strip()
	pid_dir = Path("/proc") / pid
	return pid_dir.is_dir()


def main(sunrise: Range, sunset: Range, temperature_range: Range) -> None:
	"""Adjusts the monitor temperature based on the current time"""
	hyprsunset = setup_socket()
	temperature = int(calculate_temperature(sunrise, sunset, temperature_range))
	if temperature != get_temperature(hyprsunset) and not on_steam():
		set_temperature(hyprsunset, temperature)


if __name__ == "__main__":
	main(
		(day_elapsed(5), day_elapsed(7)),
		(day_elapsed(21), day_elapsed(23)),
		(2500.0, 6000.0)
	)