"""
OpenCV drawing layer. Pure image-in / image-out — no model logic here,
so it's easy to unit test and reuse (e.g. for a CCTV batch pipeline later).
"""

import cv2
import numpy as np

BOX_COLOR = (255, 140, 0)      # BGR - orange for detected objects
TEXT_COLOR = (255, 255, 255)   # white


def _hex_to_bgr(hex_color: str):
    hex_color = hex_color.lstrip("#")
    r, g, b = tuple(int(hex_color[i:i + 2], 16) for i in (0, 2, 4))
    return (b, g, r)


def draw_detections(image: np.ndarray, detections: list) -> np.ndarray:
    """Draw YOLO bounding boxes + class labels."""
    out = image.copy()
    for det in detections:
        x1, y1, x2, y2 = [int(v) for v in det["box"]]
        label = f'{det["class"]} {det["conf"]:.0%}'
        cv2.rectangle(out, (x1, y1), (x2, y2), BOX_COLOR, 2)
        (tw, th), _ = cv2.getTextSize(label, cv2.FONT_HERSHEY_SIMPLEX, 0.5, 1)
        cv2.rectangle(out, (x1, y1 - th - 8), (x1 + tw + 6, y1), BOX_COLOR, -1)
        cv2.putText(out, label, (x1 + 3, y1 - 5),
                    cv2.FONT_HERSHEY_SIMPLEX, 0.5, TEXT_COLOR, 1, cv2.LINE_AA)
    return out


def draw_risk_badge(image: np.ndarray, risk_score: int, risk_level: str, color_hex: str) -> np.ndarray:
    """Draw a top-left risk badge: e.g. 'RISK 92/100 - CRITICAL'."""
    out = image.copy()
    h, w = out.shape[:2]
    color_bgr = _hex_to_bgr(color_hex)

    text = f"RISK {risk_score}/100 - {risk_level}"
    font_scale = max(0.6, w / 1000)
    thickness = 2
    (tw, th), baseline = cv2.getTextSize(text, cv2.FONT_HERSHEY_SIMPLEX, font_scale, thickness)

    pad = 12
    overlay = out.copy()
    cv2.rectangle(overlay, (0, 0), (tw + pad * 2, th + baseline + pad * 2), color_bgr, -1)
    out = cv2.addWeighted(overlay, 0.85, out, 0.15, 0)

    cv2.putText(out, text, (pad, th + pad),
                cv2.FONT_HERSHEY_SIMPLEX, font_scale, TEXT_COLOR, thickness, cv2.LINE_AA)
    return out


def annotate(image_bgr: np.ndarray, detections: list, risk_score: int,
             risk_level: str, color_hex: str) -> np.ndarray:
    out = draw_detections(image_bgr, detections)
    out = draw_risk_badge(out, risk_score, risk_level, color_hex)
    return out