import cv2
import numpy as np

from config import CAMERA_INDICES_TO_CHECK, FRAME_WIDTH, FRAME_HEIGHT

def _preview_camera(capture: cv2.VideoCapture, cameraID: int) -> str:
    """Show a live preview and return the user's choice: 'add', 'skip', or 'quit'."""
    window_name = f"Camera {cameraID}"
    cv2.namedWindow(window_name, cv2.WINDOW_NORMAL)
    print(f"[Camera {cameraID}] Press 'y' to add, 'n' to skip, 'q' to stop scanning.")

    try:
        while True:
            ok, frame = capture.read()
            if not ok:
                print(f"[Camera {cameraID}] Failed to read frame; skipping.")
                return "skip"

            cv2.imshow(window_name, frame)

            key = cv2.waitKey(1) & 0xFF

            if key == ord("y"):
                print(f"[Camera {cameraID}] Selected.")
                return "add"
            if key == ord("n"):
                print(f"[Camera {cameraID}] Skipped.")
                return "skip"
            if key == ord("q") or key == 27:  # 27 == ESC
                print(f"[Camera {cameraID}] Stopping camera scan.")
                return "quit"
    finally:
        cv2.destroyWindow(window_name)


def InitCameras():
    allCaptures = []

    setup_window = "Camera Setup"
    instructions = np.zeros((240, 560, 3), dtype=np.uint8)
    cv2.putText(instructions, "Camera Setup", (20, 40), cv2.FONT_HERSHEY_SIMPLEX, 1.0, (0, 200, 255), 2)
    cv2.putText(instructions, "Each camera will preview in its own window.", (20, 90), cv2.FONT_HERSHEY_SIMPLEX, 0.6, (200, 200, 200), 1)
    cv2.putText(instructions, "Use 'y' to add, 'n' to skip, 'q'/ESC to finish.", (20, 125), cv2.FONT_HERSHEY_SIMPLEX, 0.6, (200, 200, 200), 1)
    cv2.putText(instructions, "Close this window when you're done.", (20, 160), cv2.FONT_HERSHEY_SIMPLEX, 0.6, (200, 200, 200), 1)

    cv2.namedWindow(setup_window, cv2.WINDOW_AUTOSIZE)
    cv2.imshow(setup_window, instructions)
    cv2.waitKey(1)

    try:
        for cameraID in range(CAMERA_INDICES_TO_CHECK):
            capture = cv2.VideoCapture(cameraID)

            if not capture.isOpened():
                capture.release()
                continue

            capture.set(cv2.CAP_PROP_FRAME_WIDTH, FRAME_WIDTH)
            capture.set(cv2.CAP_PROP_FRAME_HEIGHT, FRAME_HEIGHT)

            decision = _preview_camera(capture, cameraID)

            if decision == "add":
                allCaptures.append(capture)
            else:
                capture.release()

            if decision == "quit":
                break

        if not all(capture.isOpened() for capture in allCaptures):
            print("Error: could not open all selected cameras.")
            return

        if not allCaptures:
            print("No cameras selected.")
            return

        return allCaptures
    finally:
        cv2.destroyWindow(setup_window)