"""web/keeper 封面：1080x1920，孤岛灯塔主题——墨黑风暴海、孤塔双道光束、
雨丝与闪电微光，竖排标题《守塔人》。可复现脚本（固定 seed，无外部网络依赖）。

用法：python3 web/keeper/gen/gen_cover.py
      （或 .venv-tts/bin/python web/keeper/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(2114)  # 固定 seed：可复现
    img = Image.new("RGB", (W, H), (6, 10, 18))
    d = ImageDraw.Draw(img)

    # 背景竖向渐变：墨黑风暴 → 海面微光（灯塔下方最亮）
    for y in range(H):
        t = y / H
        glow = max(0.0, 1.0 - abs(t - 0.62) * 3.2) * 26
        d.line([(0, y), (W, y)],
               fill=(int(6 + 8 * t), int(10 + 12 * t), int(18 + 22 * t + glow)))

    # 雨丝（风暴签名）
    rain = Image.new("RGBA", (W, H), (0, 0, 0, 0))
    rd = ImageDraw.Draw(rain)
    for _ in range(340):
        x = rng.randint(-40, W + 40)
        y = rng.randint(0, H)
        ln = rng.randint(26, 64)
        rd.line([(x, y), (x - ln // 4, y + ln)],
                fill=(150, 175, 205, rng.randint(10, 30)), width=1)
    img.paste(rain, (0, 0), rain)
    d = ImageDraw.Draw(img)

    # 灯塔（中下偏左）：塔身条纹 + 灯室
    cx, base_y = W // 2 - 60, 1250
    top_y = 620
    for i in range(7):
        y0 = top_y + i * 90
        y1 = y0 + 90
        w0 = 46 + i * 7
        w1 = 46 + (i + 1) * 7
        col = (214, 218, 224) if i % 2 == 0 else (158, 42, 43)
        d.polygon([(cx - w0, y0), (cx + w0, y0), (cx + w1, y1), (cx - w1, y1)], fill=col)
    d.rectangle([cx - 40, top_y - 46, cx + 40, top_y], fill=(30, 34, 44))
    d.rectangle([cx - 26, top_y - 38, cx + 26, top_y - 8], fill=(255, 214, 120))
    d.polygon([(cx - 46, top_y - 46), (cx + 46, top_y - 46), (cx, top_y - 84)], fill=(24, 28, 38))

    # 双道光束（旋转灯扫过雨夜，暖黄、模糊压暗）
    beam = Image.new("RGBA", (W, H), (0, 0, 0, 0))
    bd = ImageDraw.Draw(beam)
    for ang, alpha in ((-18, 60), (162, 44)):
        a = math.radians(ang)
        bx, by = cx, top_y - 27
        L = 950
        ex, ey = bx + L * math.cos(a), by - L * math.sin(a) * 0.42
        spread = 90
        perp = (math.cos(a + math.pi / 2), -math.sin(a + math.pi / 2) * 0.42)
        bd.polygon([(bx, by),
                    (ex + perp[0] * spread, ey + perp[1] * spread),
                    (ex - perp[0] * spread, ey - perp[1] * spread)],
                   fill=(255, 206, 110, alpha))
    beam = beam.filter(ImageFilter.GaussianBlur(22))
    img.paste(beam, (0, 0), beam)
    d = ImageDraw.Draw(img)

    # 海面（塔基下）：暗色波纹横线
    sea = Image.new("RGBA", (W, H), (0, 0, 0, 0))
    sd = ImageDraw.Draw(sea)
    for i in range(60):
        y = base_y + rng.randint(-20, 330)
        x0 = rng.randint(-60, W - 200)
        ln = rng.randint(120, 400)
        sd.line([(x0, y), (x0 + ln, y)], fill=(90, 120, 150, rng.randint(16, 44)), width=2)
    img.paste(sea, (0, 0), sea)
    d = ImageDraw.Draw(img)

    # 标题与副题
    f_title = load_font(180)
    f_sub = load_font(52)
    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(1430, "守塔人", f_title, (238, 242, 250), spacing=16)
    ctext(1700, "风暴夜 · 一盏灯 · 一条频道", f_sub, (146, 162, 186))

    # 手势图例（极简两行）
    hints = ["单击 继续 / 跳句", "左右滑 抉择", "上滑 状态", "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, 1800 + row * 60), s, font=f_small, fill=(104, 124, 152))

    ctext(1180, "唱针落下是过去，风声回来是现在。", f_small, (96, 112, 140))

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


if __name__ == "__main__":
    main()