#!/usr/bin/env python3
"""Waybar widget for the cooling-pad fan controller.

Talks to fan_controller over its Unix socket (/tmp/fan_controller.sock).

Usage:
  fan.py               print status as Waybar JSON (return-type: "json")
  fan.py cycle         auto -> 25% -> 50% -> 75% -> 100% -> auto (on-click)
  fan.py auto          switch back to auto mode (on-right-click)
  fan.py duty 75       set manual duty, 0-100
  fan.py setpoint 55   set auto-mode setpoint, 35-85

Connection: the daemon's command socket lives on the Pi. This script uses the
local Unix socket if present, otherwise a TCP tunnel to it (default
127.0.0.1:10250, provided by the fan-tunnel systemd service:
  ssh -N -L 10250:/tmp/fan_controller.sock root@10.55.0.1).
Override with FAN_CONTROLLER_ENDPOINT: "unix:/path" or "host:port".
"""
import json
import os
import socket
import sys

UNIX_PATH = "/tmp/fan_controller.sock"
TUNNEL_HOST, TUNNEL_PORT = "127.0.0.1", 10250
STEPS = [25, 50, 75, 100]


def make_socket():
    endpoint = os.environ.get("FAN_CONTROLLER_ENDPOINT")
    if endpoint is None:
        if os.path.exists(UNIX_PATH):
            endpoint = f"unix:{UNIX_PATH}"
        else:
            endpoint = f"{TUNNEL_HOST}:{TUNNEL_PORT}"
    if endpoint.startswith("unix:"):
        s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
        s.connect(endpoint[len("unix:"):])
    else:
        host, port = endpoint.rsplit(":", 1)
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect((host, int(port)))
    return s


def cmd(command: str) -> str:
    with make_socket() as s:
        s.settimeout(2)
        s.sendall(command.encode() + b"\n")
        chunks = []
        while True:
            data = s.recv(1024)
            if not data:
                break
            chunks.append(data)
    return b"".join(chunks).decode().strip()


def status():
    return json.loads(cmd("STATUS"))


def emit(text, tooltip=None, cls=None, alt=None):
    out = {"text": text}
    if tooltip:
        out["tooltip"] = tooltip
    if cls:
        out["class"] = " ".join(cls)
    if alt:
        out["alt"] = alt
    print(json.dumps(out))


def main():
    arg = sys.argv[1] if len(sys.argv) > 1 else None
    try:
        if arg is None:
            st = status()
            mode = st.get("mode", "?")
            if mode == "auto":
                label = f"auto {st['setpoint']:.0f}°"
            else:
                label = f"{st['duty']:.0f}%"
            text = f"{st['temp']:.1f}°  {label}"
            tooltip = (
                f"Temp: {st['temp']:.1f}°C\n"
                f"Fan: {st['duty']:.0f}%  /  {st['rpm']} rpm\n"
                f"Mode: {mode}"
            )
            if mode == "auto":
                tooltip += f"  (setpoint {st['setpoint']:.0f}°C)"
            if st.get("safe"):
                tooltip += "\nSafe mode: ON"
            cls = ["fan"]
            if st.get("safe"):
                cls.append("safe")
            emit(text, tooltip, cls, alt=f"{st['rpm']} rpm")

        elif arg == "cycle":
            st = status()
            if st["mode"] == "manual":
                d = float(st["duty"])
                nxt = next((x for x in STEPS if x > d + 0.5), None)
                if nxt is None:
                    cmd("SET_MODE auto")
                else:
                    cmd(f"SET_DUTY {nxt}")
            else:
                cmd("SET_MODE manual")
                cmd(f"SET_DUTY {STEPS[0]}")

        elif arg == "auto":
            cmd("SET_MODE auto")

        elif arg == "duty":
            d = float(sys.argv[2])
            if not 0 <= d <= 100:
                sys.exit("duty must be 0-100")
            cmd("SET_MODE manual")
            cmd(f"SET_DUTY {d:.0f}")

        elif arg == "setpoint":
            sp = float(sys.argv[2])
            if not 35 <= sp <= 85:
                sys.exit("setpoint must be 35-85")
            cmd(f"SET_SETPOINT {sp:.1f}")

        else:
            sys.exit(__doc__)

    except (OSError, ValueError) as e:
        if arg is None:
            emit("fan: offline", "fan_controller not reachable", ["fan", "offline"])
        else:
            sys.exit(f"error: {e}")


if __name__ == "__main__":
    main()