"""web/abyss 封面：1080x1920，深潜救援主题——深海近黑蓝底、声呐同心圆、
单点脉冲光与竖排标题《深海回音》。可复现脚本（固定 seed，无外部网络依赖）。

用法（PIL 探测顺序：系统 python3 → .venv-tts → 装 pillow 后任一）：
  python3 web/abyss/gen/gen_cover.py
"""
import math
import os
import random

from PIL import Image, ImageDraw, ImageFilter, ImageFont

W, H = 1080, 1920
FONT_CANDIDATES = [
    "/home/xsl/SoundGame/web/rhythm/gen/NotoSansSC-Bold.ttf",
    "/home/xsl/SoundGame/app/src/reflex/gen/NotoSansSC-Bold.ttf",
]
OUT = os.path.join(os.path.dirname(os.path.abspath(__file__)), "..", "cover.png")


def load_font(size):
    for p in FONT_CANDIDATES:
        if os.path.exists(p):
            return ImageFont.truetype(p, size)
    raise SystemExit("未找到中文字体，请放一份 NotoSansSC-Bold.ttf 到 web/rhythm/gen/")


def main():
    rng = random.Random(922)  # 固定 seed：可复现
    img = Image.new("RGB", (W, H), (3, 8, 16))
    d = ImageDraw.Draw(img)

    # 背景竖向渐变：海面微光 -> 沟底近黑（下潜方向）
    for y in range(H):
        t = y / H
        d.line([(0, y), (W, y)],
               fill=(int(16 - 13 * t), int(34 - 26 * t), int(56 - 40 * t)))

    # 远景悬浮微粒（深海水雪 marine snow）
    dot = Image.new("RGBA", (W, H), (0, 0, 0, 0))
    dd = ImageDraw.Draw(dot)
    for _ in range(150):
        x, y = rng.randint(0, W - 1), rng.randint(0, H - 1)
        r = rng.choice([1, 1, 2])
        dd.ellipse([x - r, y - r, x + r, y + r],
                   fill=(180, 210, 230, rng.randint(14, 46)))
    img.paste(dot, (0, 0), dot)
    d = ImageDraw.Draw(img)

    # 中央：声呐同心圆（你发出的脉冲），青色环从光点向外扩散
    cx, cy = W // 2, 600
    for i, (r, alpha, wd) in enumerate([(348, 30, 3), (272, 48, 4), (196, 70, 5), (124, 96, 6)]):
        d.ellipse([cx - r, cy - r, cx + r, cy + r],
                  outline=(56, 189, 248, alpha) if i % 2 == 0 else (125, 211, 252, alpha),
                  width=wd)
    glow = Image.new("RGBA", (W, H), (0, 0, 0, 0))
    gd = ImageDraw.Draw(glow)
    gd.ellipse([cx - 44, cy - 44, cx + 44, cy + 44], fill=(186, 230, 253, 200))
    gd.ellipse([cx - 88, cy - 88, cx + 88, cy + 88], fill=(56, 189, 248, 60))
    glow = glow.filter(ImageFilter.GaussianBlur(10))
    img.paste(glow, (0, 0), glow)
    d = ImageDraw.Draw(img)
    d.ellipse([cx - 20, cy - 20, cx + 20, cy + 20], fill=(240, 249, 255))

    # 一记微弱回波：右下偏移的暗环（「深海回音」具象）
    rx, ry = cx + 250, cy + 170
    for r, alpha in [(150, 40), (104, 60), (64, 84)]:
        ring = Image.new("RGBA", (W, H), (0, 0, 0, 0))
        rd = ImageDraw.Draw(ring)
        rd.ellipse([rx - r, ry - r, rx + r, ry + r],
                   outline=(94, 234, 212, alpha), width=3)
        ring = ring.filter(ImageFilter.GaussianBlur(1.2))
        img.paste(ring, (0, 0), ring)
    d = ImageDraw.Draw(img)

    # 标题（居中）与副题
    f_title = load_font(172)
    f_sub = load_font(54)
    f_small = load_font(38)

    def ctext(y, s, font, fill, spacing=8):
        bbox = d.textbbox((0, 0), s, font=font)
        w = bbox[2] - bbox[0]
        x = (W - w) / 2
        for ch in s:
            d.text((x, y), ch, font=font, fill=fill)
            bb = d.textbbox((0, 0), ch, font=font)
            x += (bb[2] - bb[0]) + spacing

    ctext(1020, "深海回音", f_title, (224, 242, 254), spacing=16)
    ctext(1272, "声呐里，是被困潜艇的五个人", f_sub, (110, 134, 166))

    # 手势图例（极简两行）
    hints = ["单击 发声呐脉冲", "左右滑 抉择", "上滑 氧气与进度", "下滑 菜单", "双击 重听"]
    for i, s in enumerate(hints):
        col, row = i % 3, i // 3
        d.text((110 + col * 300, 1420 + row * 76), s, font=f_small, fill=(92, 112, 142))

    ctext(1700, "氧气在倒数。每次下潜，都是抉择。", f_small, (76, 94, 122))

    img.save(OUT)
    print(OUT, img.size)


if __name__ == "__main__":
    main()