# -*- coding: utf-8 -*-
"""在图片上叠加文字标签：标题 + 副标题，带半透明背景条"""
from PIL import Image, ImageDraw, ImageFont
import sys
import os

def add_text_overlay(image_path, title, subtitle, output_path):
    img = Image.open(image_path).convert("RGBA")
    w, h = img.size

    # 创建文字图层
    txt_layer = Image.new("RGBA", (w, h), (0, 0, 0, 0))
    draw = ImageDraw.Draw(txt_layer)

    # 字体大小根据图片宽度自适应
    title_size = max(48, w // 18)
    sub_size = max(28, w // 30)

    # 尝试加载中文字体
    font_paths = [
        r"C:\Windows\Fonts\msyhbd.ttc",  # 微软雅黑粗体
        r"C:\Windows\Fonts\msyh.ttc",     # 微软雅黑
        r"C:\Windows\Fonts\simhei.ttf",   # 黑体
    ]
    title_font = None
    sub_font = None
    for fp in font_paths:
        if os.path.exists(fp):
            title_font = ImageFont.truetype(fp, title_size)
            sub_font = ImageFont.truetype(fp, sub_size)
            break

    if title_font is None:
        title_font = ImageFont.load_default()
        sub_font = ImageFont.load_default()

    # 文字位置：左上角，带边距
    margin_x = w // 15
    margin_y = h // 10

    # 绘制半透明背景条
    title_bbox = draw.textbbox((margin_x, margin_y), title, font=title_font)
    sub_bbox = draw.textbbox((margin_x, title_bbox[3] + 12), subtitle, font=sub_font)

    bar_top = margin_y - 16
    bar_bottom = sub_bbox[3] + 16
    bar_right = max(title_bbox[2], sub_bbox[2]) + 30

    draw.rectangle(
        [(margin_x - 16, bar_top), (bar_right, bar_bottom)],
        fill=(0, 0, 0, 140)
    )

    # 绘制标题（白色粗体）
    draw.text((margin_x, margin_y), title, font=title_font, fill=(255, 255, 255, 255))

    # 绘制副标题（浅白色）
    draw.text((margin_x, title_bbox[3] + 12), subtitle, font=sub_font, fill=(220, 230, 255, 230))

    # 合成
    result = Image.alpha_composite(img, txt_layer).convert("RGB")
    result.save(output_path, "PNG")
    print(f"Saved: {output_path}")


if __name__ == "__main__":
    if len(sys.argv) < 5:
        print("Usage: python add_text.py <image_path> <title> <subtitle> <output_path>")
        sys.exit(1)
    add_text_overlay(sys.argv[1], sys.argv[2], sys.argv[3], sys.argv[4])