"""Image/color matching helpers (OpenCV-based). Ported from scripts/detect_and_click.py."""
import os

import cv2
import numpy as np

from ba_auto import config, driver

SPARKLE_SHOT_PATH = os.path.join(config.SCRATCHPAD_DIR, "cafe_live.png")
SPARKLE_CLICK_OFFSET = (75, 47)
SPARKLE_THRESHOLD = 0.97

# The cafe camera's zoom level isn't reset before farming, and the sparkle
# icon's on-screen size scales with it (see screenshots/cafe/sparkle/
# 01_sparke_zoomed_centered.png vs 03_sparkle_zoomed_out.png) -- a single
# fixed-scale template match misses whenever the camera isn't at the exact
# zoom the template was captured at. Try a spread of scales instead.
SPARKLE_SCALES = (0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2)


def _masked_template(template):
    b, g, r = cv2.split(template.astype(np.int16))
    yellow_white = ((r > 180) & (g > 140) & (r - b > 60)) | ((r > 200) & (g > 200) & (b > 200))
    mask_plane = (yellow_white.astype(np.uint8)) * 255
    return cv2.merge([mask_plane, mask_plane, mask_plane])


def find_cafe_sparkle():
    driver.screenshot(SPARKLE_SHOT_PATH)
    template_full = cv2.imread(config.CAFE_SPARKLE_TEMPLATE)
    img = cv2.imread(SPARKLE_SHOT_PATH)
    th0, tw0 = template_full.shape[:2]

    best = None
    for scale in SPARKLE_SCALES:
        tw, th = max(1, round(tw0 * scale)), max(1, round(th0 * scale))
        template = cv2.resize(template_full, (tw, th))
        mask = _masked_template(template)

        result = cv2.matchTemplate(img, template, cv2.TM_CCORR_NORMED, mask=mask)
        _, max_val, _, max_loc = cv2.minMaxLoc(result)
        if max_val >= SPARKLE_THRESHOLD and (best is None or max_val > best[0]):
            best = (max_val, max_loc[0], max_loc[1], tw, th, scale)

    if best is None:
        return None

    score, x, y, tw, th, scale = best
    ox, oy = SPARKLE_CLICK_OFFSET
    return (x + tw // 2 + round(ox * scale), y + th // 2 + round(oy * scale), score)