#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""生成 qt_mainwindow_showcase 所需的极简 PNG 图标。

仅用 Python 标准库（zlib + struct）手写最小 PNG 编码器，无第三方依赖。
幂等：重复运行覆盖生成相同文件。

  python gen_icons.py        # *nix / 已配置 py 启动器的 Windows
  py gen_icons.py            # Windows 官方 py 启动器
"""
import os
import struct
import zlib

HERE = os.path.dirname(os.path.abspath(__file__))
ICONS_DIR = os.path.join(HERE, "icons")

# 5×7 点阵字模（"1" = 前景白色像素）
GLYPHS = {
    "M": ["10001", "11011", "10101", "10001", "10001", "10001", "10001"],
    "N": ["10001", "11001", "10101", "10011", "10001", "10001", "10001"],
    "Q": ["01110", "10001", "10001", "10001", "10101", "10011", "01111"],
    "A": ["01110", "10001", "10001", "11111", "10001", "10001", "10001"],
    "D": ["11110", "10001", "10001", "10001", "10001", "10001", "11110"],
}


def write_png(path, width, height, rgb_rows):
    """写一张 8 位、颜色类型 2（RGB）的 PNG。rgb_rows: 每行 width*3 个 0-255 整数。"""
    def chunk(tag, data):
        body = tag + data
        return (struct.pack(">I", len(data)) + body +
                struct.pack(">I", zlib.crc32(body) & 0xffffffff))

    sig = b"\x89PNG\r\n\x1a\n"
    ihdr = struct.pack(">IIBBBBB", width, height, 8, 2, 0, 0, 0)
    raw = b"".join(b"\x00" + bytes(row) for row in rgb_rows)  # 每行前加 filter byte(0)
    idat = zlib.compress(raw, 9)
    with open(path, "wb") as f:
        f.write(sig + chunk(b"IHDR", ihdr) + chunk(b"IDAT", idat) + chunk(b"IEND", b""))


def make_icon(size, bg, letter):
    """生成 size×size 的像素矩阵：纯色背景 + 居中白色字母。"""
    glyph = GLYPHS[letter]
    bw, bh = 5, 7
    pix = 1 if size <= 16 else 2          # 16px 用 1:1 字模，32px 放大 2 倍
    gw, gh = bw * pix, bh * pix
    ox = (size - gw) // 2
    oy = (size - gh) // 2
    rows = []
    for y in range(size):
        row = []
        for x in range(size):
            gx, gy = (x - ox) // pix, (y - oy) // pix
            if 0 <= gx < bw and 0 <= gy < bh and glyph[gy][gx] == "1":
                row.extend((255, 255, 255))
            else:
                row.extend(bg)
        rows.append(row)
    return rows


# (文件名, 尺寸, 背景色 RGB, 字母)
SPECS = [
    ("app.png",   32, (30, 80, 180),  "M"),
    ("new.png",   16, (40, 150, 70),  "N"),
    ("quit.png",  16, (200, 50, 50),  "Q"),
    ("about.png", 16, (220, 140, 30), "A"),
    ("dock.png",  16, (130, 60, 180), "D"),
]


def main():
    os.makedirs(ICONS_DIR, exist_ok=True)
    for name, size, bg, letter in SPECS:
        write_png(os.path.join(ICONS_DIR, name), size, size, make_icon(size, bg, letter))
        print(f"wrote {name} ({size}x{size})")
    print(f"done -> {ICONS_DIR}")


if __name__ == "__main__":
    main()