import base64
import json
import logging

from nats.aio.client import Client
from src.backend.nats_client.subjects import Subjects

logger = logging.getLogger(__name__)

_camera = None


def set_camera(camera):
    global _camera
    _camera = camera


def _nats_response(success: bool, data=None, error=None) -> bytes:
    return json.dumps({
        "success": success,
        "data": data,
        "error": error,
    }).encode()


async def register_all(nc: Client):
    async def handle_snapshot(msg):
        try:
            if not _camera or not _camera.is_open():
                await msg.respond(_nats_response(
                    False, error={"code": "NO_CAMERA", "message": "Camera not open"}
                ))
                return

            import cv2
            frame = _camera.capture()
            if frame is None:
                await msg.respond(_nats_response(
                    False, error={"code": "TIMEOUT", "message": "Frame capture timeout"}
                ))
                return

            _, rgb_buf = cv2.imencode(".jpg", frame.rgb, [cv2.IMWRITE_JPEG_QUALITY, 85])
            _, depth_buf = cv2.imencode(".png", frame.depth)

            await msg.respond(_nats_response(True, data={
                "rgb_jpeg_b64": base64.b64encode(rgb_buf.tobytes()).decode(),
                "depth_png_b64": base64.b64encode(depth_buf.tobytes()).decode(),
                "timestamp": frame.timestamp,
                "width": frame.rgb.shape[1],
                "height": frame.rgb.shape[0],
            }))
        except Exception as e:
            logger.error(f"Snapshot handler error: {e}")
            await msg.respond(_nats_response(
                False, error={"code": "PROCESSING_ERROR", "message": str(e)}
            ))

    async def handle_status(msg):
        await msg.respond(_nats_response(True, data={
            "camera_open": _camera.is_open() if _camera else False,
            "sdk_initialized": _camera.is_initialized() if _camera else False,
        }))

    await nc.subscribe(Subjects.action("snapshot"), cb=handle_snapshot)
    await nc.subscribe(Subjects.action("status"), cb=handle_status)