"""Olimex ESP32-C6-EVB board driver.

Hardware
--------
- 4 relays  (outputs)
- 4 digital inputs
- HTTP REST API served directly by the board on port 80

API endpoints
-------------
POST /relay/on?relay=<n>          → {"state": true}
POST /relay/off?relay=<n>         → {"state": false}
POST /relay/toggle?relay=<n>      → {"state": <new>}
GET  /relay/status?relay=<n>      → {"state": <bool>}
GET  /input/status?input=<n>      → {"state": <bool>}
POST /register?callback_url=<url> → {"status": "ok"}

Webhook (board → server)
------------------------
The board POSTs to the registered callback_url whenever an input changes:
    POST <callback_url>
    {"input": <n>, "state": <bool>}
"""
from __future__ import annotations

import logging
import requests
from typing import TYPE_CHECKING

from app.drivers.base import BoardDriver

if TYPE_CHECKING:
    from app.models.board import Board

logger = logging.getLogger(__name__)
_TIMEOUT = 3


def _get(url: str) -> dict | None:
    try:
        r = requests.get(url, timeout=_TIMEOUT)
        r.raise_for_status()
        return r.json()
    except Exception as exc:
        logger.debug("GET %s → %s", url, exc)
        return None


def _post(url: str) -> dict | None:
    try:
        r = requests.post(url, timeout=_TIMEOUT)
        r.raise_for_status()
        return r.json()
    except Exception as exc:
        logger.debug("POST %s → %s", url, exc)
        return None


class OlimexESP32C6EVBDriver(BoardDriver):
    """Driver for the Olimex ESP32-C6-EVB board."""

    DRIVER_ID = "olimex_esp32_c6_evb"
    DISPLAY_NAME = "Olimex ESP32-C6-EVB"
    DESCRIPTION = "4 relays · 4 digital inputs · HTTP REST + webhook callbacks"
    DEFAULT_NUM_RELAYS = 4
    DEFAULT_NUM_INPUTS = 4
    FIRMWARE_URL = "https://github.com/OLIMEX/ESP32-C6-EVB"

    # ── relay control ─────────────────────────────────────────────────────────

    def get_relay_status(self, board: "Board", relay_num: int) -> bool | None:
        data = _get(f"{board.base_url}/relay/status?relay={relay_num}")
        return bool(data["state"]) if data is not None else None

    def set_relay(self, board: "Board", relay_num: int, state: bool) -> bool:
        action = "on" if state else "off"
        return _post(f"{board.base_url}/relay/{action}?relay={relay_num}") is not None

    def toggle_relay(self, board: "Board", relay_num: int) -> bool | None:
        data = _post(f"{board.base_url}/relay/toggle?relay={relay_num}")
        return bool(data["state"]) if data is not None else None

    # ── poll ──────────────────────────────────────────────────────────────────

    def poll(self, board: "Board") -> dict:
        _offline = {"relay_states": {}, "input_states": {}, "is_online": False}

        # ── Connectivity probe ─────────────────────────────────────────────
        # Try the very first endpoint.  If the board doesn't reply we know
        # it's offline and skip all remaining requests (saving N × 3 s worth
        # of connect timeouts on every recheck cycle).
        relay_states: dict = {}
        input_states: dict = {}

        if board.num_relays > 0:
            probe = _get(f"{board.base_url}/relay/status?relay=1")
            if probe is None:
                return _offline
            relay_states["relay_1"] = bool(probe.get("state", False))
        elif board.num_inputs > 0:
            probe = _get(f"{board.base_url}/input/status?input=1")
            if probe is None:
                return _offline
            input_states["input_1"] = bool(probe.get("state", False))
        else:
            return _offline

        # Board is reachable — collect remaining endpoints
        for n in range(2, board.num_relays + 1):
            data = _get(f"{board.base_url}/relay/status?relay={n}")
            if data is not None:
                relay_states[f"relay_{n}"] = bool(data.get("state", False))

        input_start = 2 if (board.num_relays == 0 and board.num_inputs > 0) else 1
        for n in range(input_start, board.num_inputs + 1):
            data = _get(f"{board.base_url}/input/status?input={n}")
            if data is not None:
                input_states[f"input_{n}"] = bool(data.get("state", True))

        return {
            "relay_states": relay_states,
            "input_states": input_states,
            "is_online": True,
        }

    # ── webhook registration ──────────────────────────────────────────────────

    def register_webhook(self, board: "Board", callback_url: str) -> bool:
        url = f"{board.base_url}/register?callback_url={callback_url}"
        ok = _post(url) is not None
        if ok:
            logger.info("Webhook registered on board '%s' → %s", board.name, callback_url)
        else:
            logger.warning("Webhook registration failed for board '%s'", board.name)
        return ok