#!/usr/bin/env python3
"""复刻 PHPWind 9.x PwGDCode 渲染逻辑，生成代表性验证码。
依据 alibaba/phpwind: upload/src/library/utility/verifycode/PwGDCode.php + PwBaseCode.php
"""
import math
import random
import sys

import numpy as np
from PIL import Image, ImageDraw, ImageFont

W, H = 150, 60
CHARSET = "1234567890"  # PwBaseCode verifyType=1
FONT = "/System/Library/Fonts/Supplemental/Arial.ttf"


def rand_color():
    return (random.randint(0, 255), random.randint(0, 120), random.randint(0, 255))


def rand_noise_color():
    return (random.randint(50, 255), random.randint(50, 200), random.randint(25, 200))


def gen(out_path, code=None):
    if code is None:
        code = "".join(random.choice(CHARSET) for _ in range(4))

    # 背景：白底 (PwGDCode isRandBackground=false -> 255)
    img = Image.new("RGB", (W, H), (255, 255, 255))
    d = ImageDraw.Draw(img)

    # 逐字符绘制：随机字号14-20、随机角度-20~10、随机色
    codeX = (W - 20) / 4
    codeY = H // 2 + random.randint(5, 10)
    for i, ch in enumerate(code):
        size = random.randint(14, 20)
        angle = random.randint(-20, 10)
        font = ImageFont.truetype(FONT, size)
        # 在更大的画布上画字再旋转，避免裁剪
        tmp = Image.new("RGBA", (40, 40), (0, 0, 0, 0))
        td = ImageDraw.Draw(tmp)
        td.text((2, 2), ch, font=font, fill=rand_color() + (255,))
        tmp = tmp.rotate(angle, expand=True, fillcolor=(0, 0, 0, 0))
        x = int(codeX * i + 10)
        y = int(codeY - tmp.height / 2)
        img.paste(tmp.convert("RGB"), (x, y), tmp.split()[3])

    # 噪声：随机 线/点/弧 (PwGDCode _setRandGraph)
    d = ImageDraw.Draw(img)
    mode = random.randint(1, 3)
    if mode == 1:  # 30-40 条随机线
        for _ in range(random.randint(30, 40)):
            x1, y1 = random.randint(0, W), random.randint(0, H)
            d.line([(x1, y1), (random.randint(x1 - 10, x1 + 5), random.randint(y1 + 5, y1 + 20))], fill=rand_noise_color(), width=1)
    elif mode == 2:  # 600-800 随机点
        for _ in range(random.randint(600, 800)):
            d.point((random.randint(0, W - 1), random.randint(0, H - 1)), fill=rand_noise_color())
    else:  # 5-10 条弧
        for _ in range(random.randint(5, 10)):
            d.arc([random.randint(0, W), random.randint(10, H), random.randint(10, W), random.randint(H, H * 2)],
                  random.randint(0, 90), random.randint(0, 90), fill=rand_noise_color())

    # 正弦扭曲：x += sin(y/height*2π-0.6)*5
    arr = np.array(img)
    out = np.zeros_like(arr)
    for y in range(H):
        shift = int(math.sin(y / H * 2 * math.pi - 0.6) * 5)
        for x in range(W):
            sx = x + shift
            if 0 <= sx < W:
                out[y, x] = arr[y, sx]
    Image.fromarray(out).save(out_path)
    return code


if __name__ == "__main__":
    import os
    outdir = sys.argv[1] if len(sys.argv) > 1 else "/tmp/sp_pw9"
    os.makedirs(outdir, exist_ok=True)
    for i in range(6):
        code = gen(f"{outdir}/pw9_{i}.png")
        print(f"pw9_{i}.png  code={code}")