"""
Demeter Server — CoAP-to-REST Bridge

Proxies HTTP requests to CoAP endpoints on ESP devices, allowing
the dashboard and external tools to query devices via standard HTTP.

Routes:
    GET  /api/devices/{device_id}/coap/{resource_path}  — proxy CoAP GET
    PUT  /api/devices/{device_id}/coap/{resource_path}  — proxy CoAP PUT
"""

from __future__ import annotations

from typing import Any

from fastapi import APIRouter, HTTPException, Request

router = APIRouter(prefix="/api", tags=["coap-bridge"])


def _get_store(request: Request):
    return request.app.state.store


def _get_observer(request: Request):
    return request.app.state.observer


@router.get("/devices/{device_id}/coap/{resource_path:path}")
async def coap_proxy_get(
    device_id: str,
    resource_path: str,
    request: Request,
) -> dict[str, Any]:
    """
    Proxy a CoAP GET request to an ESP device.

    Example: GET /api/devices/esp32-plant-01/coap/sensors/temperature
    → CoAP GET coap://192.168.1.100:5683/sensors/temperature
    """
    store = _get_store(request)
    observer = _get_observer(request)

    device = await store.get_device(device_id)
    if device is None:
        raise HTTPException(status_code=404, detail=f"Device {device_id!r} not found")

    try:
        result = await observer.coap_get(
            device.config.ip, device.config.port, resource_path
        )
        return {
            "device_id": device_id,
            "resource": resource_path,
            "method": "GET",
            "response": result,
        }
    except ConnectionError as e:
        raise HTTPException(status_code=504, detail=str(e))
    except ValueError as e:
        raise HTTPException(status_code=502, detail=str(e))


@router.put("/devices/{device_id}/coap/{resource_path:path}")
async def coap_proxy_put(
    device_id: str,
    resource_path: str,
    body: dict[str, Any],
    request: Request,
) -> dict[str, Any]:
    """
    Proxy a CoAP PUT request to an ESP device.

    Example: PUT /api/devices/esp32-plant-01/coap/config/interval
    Body: {"interval": 10}
    → CoAP PUT coap://192.168.1.100:5683/config/interval
    """
    store = _get_store(request)
    observer = _get_observer(request)

    device = await store.get_device(device_id)
    if device is None:
        raise HTTPException(status_code=404, detail=f"Device {device_id!r} not found")

    try:
        result = await observer.coap_put(
            device.config.ip, device.config.port, resource_path, body
        )
        return {
            "device_id": device_id,
            "resource": resource_path,
            "method": "PUT",
            "response": result,
        }
    except ConnectionError as e:
        raise HTTPException(status_code=504, detail=str(e))
    except ValueError as e:
        raise HTTPException(status_code=502, detail=str(e))