# -*- coding: utf-8 -*-
"""画套餐底栏 PNG：盒子线稿 / 实心底，微信自定义栏必须用本地图。"""
import struct
import zlib
from pathlib import Path

SIZE = 81


def png(rgba_rows):
    def chunk(tag, data):
        return struct.pack('>I', len(data)) + tag + data + struct.pack('>I', zlib.crc32(tag + data) & 0xFFFFFFFF)

    raw = b''.join(b'\x00' + bytes(row) for row in rgba_rows)
    return (
        b'\x89PNG\r\n\x1a\n'
        + chunk(b'IHDR', struct.pack('>IIBBBBB', SIZE, SIZE, 8, 6, 0, 0, 0))
        + chunk(b'IDAT', zlib.compress(raw, 9))
        + chunk(b'IEND', b'')
    )


def blank():
    return [[0, 0, 0, 0] * SIZE for _ in range(SIZE)]


def set_px(rows, x, y, a=255):
    if 0 <= x < SIZE and 0 <= y < SIZE:
        i = x * 4
        rows[y][i:i + 4] = [28, 25, 23, a]


def line(rows, x0, y0, x1, y1, w=3):
    steps = max(abs(x1 - x0), abs(y1 - y0), 1)
    for i in range(steps + 1):
        t = i / steps
        x = int(round(x0 + (x1 - x0) * t))
        y = int(round(y0 + (y1 - y0) * t))
        for dx in range(-w // 2, w // 2 + 1):
            for dy in range(-w // 2, w // 2 + 1):
                set_px(rows, x + dx, y + dy)


def rect(rows, x, y, w, h, r=4, fill=False):
    if fill:
        for yy in range(y, y + h):
            for xx in range(x, x + w):
                set_px(rows, xx, yy)
        return
    line(rows, x + r, y, x + w - r, y)
    line(rows, x + w, y + r, x + w, y + h - r)
    line(rows, x + w - r, y + h, x + r, y + h)
    line(rows, x, y + h - r, x, y + r)


def write_icons(out_dir):
    out = Path(out_dir)
    outline = blank()
    # 盒身
    rect(outline, 16, 30, 49, 38, 5)
    line(outline, 16, 44, 65, 44)
    line(outline, 40, 30, 40, 68)
    line(outline, 24, 30, 40, 16)
    line(outline, 40, 16, 56, 30)
    (out / 'package.png').write_bytes(png(outline))

    filled = blank()
    rect(filled, 16, 26, 49, 42, 4, fill=True)
    line(filled, 24, 26, 40, 12)
    line(filled, 40, 12, 56, 26)
    (out / 'package-fill.png').write_bytes(png(filled))


if __name__ == '__main__':
    here = Path(__file__).resolve().parents[1] / 'static' / 'tabbar' / 'v2'
    write_icons(here)
    print('wrote', here)