"""Sonoff eWeLink Gateway Driver.

This driver represents an entire eWeLink account as a single "board".
Each discovered Sonoff device is stored as a SonoffDevice record linked
to the board.  Device control goes through the LAN (if device IP is known)
with automatic cloud fallback.

Key differences from hardware boards:
  - relay_num / input_num are NOT used (Sonoff devices are managed separately)
  - poll() syncs the SonoffDevice table from cloud
  - set_relay() / toggle_relay() are stubs (use set_device_channel() instead)
"""
from __future__ import annotations

import json
import logging
from typing import TYPE_CHECKING

from app.drivers.base import BoardDriver
from .ewelink_api import (
    EWeLinkAuthError,
    get_devices,
    login,
    parse_device,
    send_lan_command,
)

if TYPE_CHECKING:
    from app.models.board import Board

logger = logging.getLogger(__name__)


class SonoffEweLinkDriver(BoardDriver):
    DRIVER_ID = "sonoff_ewelink"
    DISPLAY_NAME = "Sonoff eWeLink Gateway"
    DESCRIPTION = (
        "Control all Sonoff devices in an eWeLink account over LAN and/or Cloud"
    )
    DEFAULT_NUM_RELAYS = 0
    DEFAULT_NUM_INPUTS = 0

    # ── Abstract method stubs (not used for gateway boards) ───────────────────

    def get_relay_status(self, board: "Board", relay_num: int):
        return None

    def set_relay(self, board: "Board", relay_num: int, state: bool) -> bool:
        return False

    def toggle_relay(self, board: "Board", relay_num: int):
        return None

    def register_webhook(self, board: "Board", callback_url: str) -> bool:
        return True  # No webhook concept for this driver

    def poll(self, board: "Board") -> dict:
        """Sync device list + states from eWeLink cloud.

        Returns a minimal dict so board_service doesn't break.
        Actual device states are stored in SonoffDevice records.
        """
        try:
            self.sync_devices(board)
            board.is_online = True
        except Exception as exc:
            logger.warning("Sonoff poll failed for board %d: %s", board.id, exc)
            board.is_online = False
        return {
            "relay_states": {},
            "input_states": {},
            "is_online": board.is_online,
        }

    # ── Gateway-specific public API ───────────────────────────────────────────

    def ensure_token(self, board: "Board") -> bool:
        """Authenticate with eWeLink if no valid token is stored.
        Updates board.config in-place (caller must commit).
        Returns True if token is available.
        """
        cfg = board.config
        at = cfg.get("ewelink_at")
        if at:
            return True

        username = cfg.get("ewelink_username", "")
        password = cfg.get("ewelink_password", "")
        country = cfg.get("ewelink_country_code", "+1")
        if not username or not password:
            logger.error("Board %d has no eWeLink credentials", board.id)
            return False

        try:
            auth = login(username, password, country)
            cfg["ewelink_at"] = auth["at"]
            cfg["ewelink_region"] = auth["region"]
            cfg["ewelink_apikey"] = auth["apikey"]
            board.config = cfg
            logger.info("eWeLink login OK for board %d (region=%s)", board.id, auth["region"])
            return True
        except EWeLinkAuthError as exc:
            logger.error("eWeLink auth error for board %d: %s", board.id, exc)
            cfg.pop("ewelink_at", None)
            board.config = cfg
            return False
        except Exception as exc:
            logger.error("eWeLink login failed for board %d: %s", board.id, exc)
            return False

    def sync_devices(self, board: "Board") -> int:
        """Fetch device list from cloud, upsert SonoffDevice records.
        Returns number of devices synced.
        """
        from app import db
        from app.models.sonoff_device import SonoffDevice
        from datetime import datetime

        if not self.ensure_token(board):
            return 0

        cfg = board.config
        at = cfg["ewelink_at"]
        region = cfg.get("ewelink_region", "eu")

        try:
            raw_devices = get_devices(at, region)
        except Exception as exc:
            # Token may have expired — clear it and retry once
            if "401" in str(exc) or "token" in str(exc).lower():
                cfg.pop("ewelink_at", None)
                board.config = cfg
                if not self.ensure_token(board):
                    return 0
                at = board.config["ewelink_at"]
                region = board.config.get("ewelink_region", "eu")
                raw_devices = get_devices(at, region)
            else:
                raise

        # Build lookup of existing records
        existing: dict[str, SonoffDevice] = {
            d.device_id: d
            for d in SonoffDevice.query.filter_by(board_id=board.id).all()
        }

        synced = 0
        seen_ids: set[str] = set()

        for raw in raw_devices:
            info = parse_device(raw)
            did = info["device_id"]
            if not did:
                continue
            seen_ids.add(did)

            dev = existing.get(did)
            if dev is None:
                from app.models.sonoff_device import _uiid_info
                dev = SonoffDevice(board_id=board.id, device_id=did)
                db.session.add(dev)

            # Always update these from cloud
            if not dev.name:
                dev.name = info["name"]
            dev.uiid = info["uiid"]
            dev.model = info["model"]
            dev.firmware = info["firmware"]
            dev.device_key = info["device_key"]
            dev.api_key = info["api_key"]
            dev.is_online = info["online"]

            from app.models.sonoff_device import _uiid_info
            dev.num_channels = _uiid_info(info["uiid"]).get("channels", 1)

            if info["params"]:
                dev.params = info["params"]

            if info["ip_address"]:
                dev.ip_address = info["ip_address"]
                dev.port = info["port"] or 8081

            if info["online"]:
                dev.last_seen = datetime.utcnow()

            synced += 1

        db.session.commit()
        logger.info("Board %d: synced %d Sonoff devices", board.id, synced)
        return synced

    def set_device_channel(
        self,
        board: "Board",
        device_id: str,
        channel: int,
        state: bool,
    ) -> bool:
        """Turn a Sonoff device channel ON or OFF.
        Tries LAN first, falls back to cloud.
        """
        from app.models.sonoff_device import SonoffDevice
        dev = SonoffDevice.query.filter_by(
            board_id=board.id, device_id=device_id
        ).first()
        if not dev:
            logger.error("Device %s not found on board %d", device_id, board.id)
            return False

        switch_val = "on" if state else "off"

        # Build params dict
        if dev.num_channels == 1:
            params = {"switch": switch_val}
            command = "switch"
        else:
            params = {"switches": [{"outlet": channel, "switch": switch_val}]}
            command = "switches"

        # ── Try LAN first ───────────────────────────────────────────────────
        if dev.ip_address:
            ok = send_lan_command(
                ip=dev.ip_address,
                port=dev.port or 8081,
                device_id=device_id,
                device_key=dev.device_key or "",
                params=params,
                command=command,
            )
            if ok:
                self._apply_state(dev, channel, state)
                from app import db
                db.session.commit()
                return True
            logger.debug("LAN failed for %s, trying cloud", device_id)

        # ── Cloud fallback ───────────────────────────────────────────────────
        if not self.ensure_token(board):
            return False

        cfg = board.config
        ok = self._cloud_set(
            at=cfg["ewelink_at"],
            region=cfg.get("ewelink_region", "eu"),
            device_id=device_id,
            api_key=dev.api_key or cfg.get("ewelink_apikey", ""),
            params=params,
        )
        if ok:
            self._apply_state(dev, channel, state)
            from app import db
            db.session.commit()
        return ok

    # ── Private helpers ───────────────────────────────────────────────────────

    @staticmethod
    def _apply_state(dev, channel: int, state: bool) -> None:
        """Update the SonoffDevice params in-memory after a successful command."""
        p = dev.params
        switch_val = "on" if state else "off"
        if dev.num_channels == 1:
            p["switch"] = switch_val
        else:
            switches = p.get("switches", [])
            updated = False
            for s in switches:
                if s.get("outlet") == channel:
                    s["switch"] = switch_val
                    updated = True
                    break
            if not updated:
                switches.append({"outlet": channel, "switch": switch_val})
            p["switches"] = switches
        dev.params = p

    @staticmethod
    def _cloud_set(at: str, region: str, device_id: str,
                   api_key: str, params: dict) -> bool:
        """Send a device update via the eWeLink cloud REST API (simple HTTP POST).

        This uses the v2 update-device endpoint rather than the WebSocket,
        which is simpler for synchronous Flask code.
        """
        import requests as req
        from .ewelink_api import API, APPID
        import time

        headers = {"Authorization": f"Bearer {at}", "X-CK-Appid": APPID}
        payload = {
            "deviceid": device_id,
            "params": params,
        }
        url = f"{API[region]}/v2/device/thing/status"
        try:
            r = req.post(url, json=payload, headers=headers, timeout=8)
            resp = r.json()
            ok = resp.get("error") == 0
            if ok:
                logger.debug("Cloud %s → %s OK", device_id, params)
            else:
                logger.warning("Cloud %s → %s ERR %s", device_id, params, resp)
            return ok
        except Exception as exc:
            logger.error("Cloud send failed for %s: %s", device_id, exc)
            return False