"""CSI 카메라 소스 (실장비 Pi5, picamera2). Implements SourcePort.

picamera2 is a SYSTEM package on Raspberry Pi OS (apt: python3-picamera2 + libcamera),
NOT a pip wheel — the venv sees it via --system-site-packages (see deploy/README).

COLOR NOTE: configured for "RGB888", which picamera2 delivers as a 3-channel array in
**BGR** byte order (documented picamera2 quirk). The downstream pose adapters
(MoveNet/Hailo) expect BGR (they do cv2.cvtColor(BGR2RGB)), same as cv2.VideoCapture,
so read() returns the array as-is. Validate the channel order on device during bringup
(a BGR<->RGB swap yields plausible-but-wrong keypoints).
"""


class PiCameraSource:
    def __init__(self, index: int = 0, size=(640, 480), picam2=None):
        self.index = index
        if picam2 is None:  # pragma: no cover (device-only: needs picamera2 + CSI camera)
            from picamera2 import Picamera2  # system apt package (python3-picamera2)
            picam2 = Picamera2(camera_num=index)
            picam2.configure(picam2.create_video_configuration(
                main={"size": tuple(size), "format": "RGB888"}))
            picam2.start()
        self.picam2 = picam2

    def read(self):
        frame = self.picam2.capture_array()
        if frame is None:
            return False, None
        return True, frame