"""web/cipher 封面：1080x1920，1940 密战主题——墨绿电波底、摩尔斯点划
电文、耳机轮廓微光与竖排标题《暗码》。可复现脚本（固定 seed，无外部网络依赖）。

用法：python3 web/cipher/gen/gen_cover.py
      （或 .venv-tts/bin/python web/cipher/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(1940)  # 固定 seed：可复现
    img = Image.new("RGB", (W, H), (10, 16, 14))
    d = ImageDraw.Draw(img)

    # 背景竖向微渐变：军绿墨黑 → 电台暖绿（值机室的电子管夜光）
    for y in range(H):
        t = y / H
        d.line([(0, y), (W, y)],
               fill=(int(10 + 8 * t), int(16 + 18 * t), int(14 + 12 * t)))

    # 示波器绿光波纹（密电的频率具象，模糊压暗做背景）
    wave = Image.new("RGBA", (W, H), (0, 0, 0, 0))
    wd = ImageDraw.Draw(wave)
    for i in range(20):
        cy = rng.randint(0, H)
        amp = rng.randint(12, 60)
        phase = rng.uniform(0, math.pi * 2)
        freq = rng.uniform(0.004, 0.012)
        pts = [(x, cy + amp * math.sin(freq * x + phase)
                * math.exp(-((x - W / 2) / (W * 0.42)) ** 2))
               for x in range(0, W, 8)]
        wd.line(pts, fill=(96, 200, 140, rng.randint(10, 30)), width=3)
    wave = wave.filter(ImageFilter.GaussianBlur(1.8))
    img.paste(wave, (0, 0), wave)
    d = ImageDraw.Draw(img)

    # 中央：耳机轮廓 + 声波同心弧（「用耳朵当武器」的具象）
    cx, cy = W // 2, 660
    for i, (r, alpha) in enumerate([(310, 40), (236, 72), (168, 108), (110, 150)]):
        ring = Image.new("RGBA", (W, H), (0, 0, 0, 0))
        rd = ImageDraw.Draw(ring)
        rd.arc([cx - r, cy - r, cx + r, cy + r], start=200, end=340,
               fill=(140, 230, 170, alpha), width=9 - i * 2)
        img.paste(ring, (0, 0), ring)
    # 头梁 + 两侧耳罩
    d.arc([cx - 190, cy - 210, cx + 190, cy + 170], start=180, end=360,
          fill=(190, 235, 205, 210), width=26)
    for sx in (-1, 1):
        d.rounded_rectangle([cx + sx * 205 - 64, cy - 40, cx + sx * 205 + 64, cy + 190],
                            radius=64, fill=(24, 44, 34), outline=(170, 230, 190, 220), width=10)
    # 电键（手键）剪影：底座 + 黄铜杆
    ky = 1080
    d.rounded_rectangle([cx - 150, ky + 60, cx + 150, ky + 110], radius=18, fill=(28, 40, 32))
    d.line([cx - 30, ky + 62, cx + 96, ky - 46], fill=(212, 178, 106), width=22)
    d.ellipse([cx + 82, ky - 72, cx + 132, ky - 22], fill=(232, 200, 130))

    # 摩尔斯电文点划带：BAY ·− −··· / ·− / −·−− 的意象（不拼真码，做装饰带）
    band_y = 1290
    code = ([3, 1, 1, 1], [1, 3], [1, 3, 1, 3])  # −··· ·− −·−−（B A Y）
    x = cx - 330
    for letter in code:
        for u in letter:
            w = 34 if u == 3 else 14
            d.rounded_rectangle([x, band_y - 9, x + w, band_y + 9], radius=8,
                                fill=(150, 235, 180, 220))
            x += w + 22
        x += 34
    # 静电噪点
    for _ in range(700):
        x, y = rng.randint(0, W - 1), rng.randint(0, H - 1)
        a = rng.randint(6, 22)
        img.putpixel((x, y), (140, 220, 170))

    img = img.filter(ImageFilter.GaussianBlur(0.4))
    d = ImageDraw.Draw(img)

    # 竖排标题《暗码》（右下留白区，避免与遮罩文字重叠）
    f_title = load_font(236)
    f_sub = load_font(44)
    tx, ty = W - 330, 1420
    for i, ch in enumerate("暗码"):
        d.text((tx, ty + i * 260), ch, font=f_title, fill=(226, 242, 230),
               stroke_width=6, stroke_fill=(10, 22, 16))
    d.text((tx + 40, ty + 2 * 260 + 30), "1940 · 江城密电", font=f_sub,
           fill=(150, 210, 175))

    img.save(OUT)
    print("saved", OUT)


if __name__ == "__main__":
    main()