karate_halloween/watermark_processor.py

import io
import os
import sys
from PIL import Image, ImageDraw, ImageFont

def apply_watermark(input_img_path, output_img_path):
    base = Image.open(input_img_path).convert("RGBA")
    bw, bh = base.size

    base_dir = os.path.dirname(os.path.abspath(__file__))
    logo_path = os.path.join(base_dir, "public", "assets", "brand", "shanghai_karate_logo.webp")
    qr_path = os.path.join(base_dir, "public", "assets", "brand", "dojo_qr.png")

    margin = int(bw * 0.035)

    # 1. School Logo without background (Top-Left Corner)
    if os.path.exists(logo_path):
        logo = Image.open(logo_path).convert("RGBA")
        target_logo_w = int(bw * 0.28)
        target_logo_h = int(logo.height * (target_logo_w / logo.width))
        logo_resized = logo.resize((target_logo_w, target_logo_h), Image.Resampling.LANCZOS)
        base.paste(logo_resized, (margin, margin), logo_resized)

    # 2. WeChat-Scannable QR Code (Bottom-Right Corner)
    if os.path.exists(qr_path):
        qr = Image.open(qr_path).convert("RGBA")
        target_qr_w = int(bw * 0.17)
        qr_resized = qr.resize((target_qr_w, target_qr_w), Image.Resampling.LANCZOS)
        qr_pad = 5
        # Clean white backing ensures WeChat scans reliably even on dark or textured photos
        qr_bg = Image.new("RGBA", (target_qr_w + qr_pad * 2, target_qr_w + qr_pad * 2), (255, 255, 255, 250))
        qr_pos_x = bw - (target_qr_w + qr_pad * 2) - margin
        qr_pos_y = bh - (target_qr_w + qr_pad * 2) - int(margin * 1.5)

        base.paste(qr_bg, (qr_pos_x, qr_pos_y), qr_bg)
        base.paste(qr_resized, (qr_pos_x + qr_pad, qr_pos_y + qr_pad), qr_resized)

    # 3. Bottom Text: '上海健志空手道馆 · Shanghai Karate Club · Est. 2008'
    draw = ImageDraw.Draw(base)
    font_path = os.path.join(base_dir, "public", "fonts", "ZCOOLKuaiLe.ttf")
    font_size = max(14, int(bw * 0.026))
    try:
        font = ImageFont.truetype(font_path, font_size)
    except Exception:
        font = ImageFont.load_default()

    text = "上海健志空手道馆 · Shanghai Karate Club · Est. 2008"
    bbox = draw.textbbox((0, 0), text, font=font)
    th = bbox[3] - bbox[1]
    tx = margin
    ty = bh - int(margin * 1.2) - th

    # Subtle drop shadow + high-contrast text
    draw.text((tx + 1, ty + 1), text, font=font, fill=(0, 0, 0, 220))
    draw.text((tx, ty), text, font=font, fill=(255, 240, 200, 255))

    base.convert("RGB").save(output_img_path, format="JPEG", quality=94)

if __name__ == "__main__":
    if len(sys.argv) >= 3:
        apply_watermark(sys.argv[1], sys.argv[2])
    else:
        apply_watermark(
            r"public/test_style1_v2.jpg",
            r"public/test_watermarked_result.jpg"
        )