#!/usr/bin/env python3
"""
按像素精确解析 PNG 平面图 —— 精确颜色分类 + 高分辨率网格化
颜色规则（依据实际采样校准）：
  W 黑色(0,0,0)             = 墙壁
  O 灰色(176,176,176)       = 办公室
  P 蓝色(64,176,240)        = 过道
  R 绿色(80,176,96)         = 休息厅
  Y 橙色(240,112,16)        = 共享工位区 / 楼道
  C 青绿(80,224,192)        = 玻璃顶
  . 白色(240,240,240)       = 空白/底
"""
import zlib, struct, sys, collections

def read_png(path):
    with open(path, 'rb') as f:
        data = f.read()
    assert data[:8] == b'\x89PNG\r\n\x1a\n', 'Not a PNG'
    pos = 8
    width = height = None
    bit_depth = color_type = None
    idat = b''
    while pos < len(data):
        ln = struct.unpack('>I', data[pos:pos+4])[0]
        typ = data[pos+4:pos+8]
        chunk = data[pos+8:pos+8+ln]
        pos += 12 + ln
        if typ == b'IHDR':
            width, height, bit_depth, color_type, _, _, _ = struct.unpack('>IIBBBBB', chunk)
        elif typ == b'IDAT':
            idat += chunk
        elif typ == b'IEND':
            break
    assert bit_depth == 8 and color_type in (2, 6) and width and height
    raw = zlib.decompress(idat)
    channels = 4 if color_type == 6 else 3
    bpp = channels
    stride = width * bpp
    rows = []
    off = 0
    prev = bytearray(stride)
    for y in range(height):
        ft = raw[off]; off += 1
        line = bytearray(raw[off:off+stride]); off += stride
        if ft == 1:
            for i in range(bpp, stride): line[i] = (line[i] + line[i-bpp]) & 0xFF
        elif ft == 2:
            for i in range(stride): line[i] = (line[i] + prev[i]) & 0xFF
        elif ft == 3:
            for i in range(stride):
                a = line[i-bpp] if i >= bpp else 0
                line[i] = (line[i] + ((a + prev[i]) >> 1)) & 0xFF
        elif ft == 4:
            for i in range(stride):
                a = line[i-bpp] if i >= bpp else 0
                b = prev[i]
                c = prev[i-bpp] if i >= bpp else 0
                p = a + b - c
                pa, pb, pc = abs(p-a), abs(p-b), abs(p-c)
                pr = a if (pa <= pb and pa <= pc) else (b if pb <= pc else c)
                line[i] = (line[i] + pr) & 0xFF
        rows.append(bytes(line))
        prev = line
    rgba = []
    for line in rows:
        if channels == 4:
            rgba.append([(line[i], line[i+1], line[i+2], line[i+3]) for i in range(0, stride, 4)])
        else:
            rgba.append([(line[i], line[i+1], line[i+2], 255) for i in range(0, stride, 3)])
    return width, height, rgba

# 精确色板（中心色 + 容差）
PALETTE = [
    ('W', (0, 0, 0), 70),          # 黑 = 墙壁
    ('O', (176, 176, 176), 40),    # 灰 = 办公室
    ('P', (64, 176, 240), 45),     # 蓝 = 过道
    ('R', (80, 176, 96), 40),      # 绿 = 休息厅
    ('Y', (240, 112, 16), 55),     # 橙 = 共享工位/楼道
    ('C', (80, 224, 192), 55),     # 青绿 = 玻璃顶
    ('.', (240, 240, 240), 40),    # 白 = 空白
]

def classify(rgb):
    r, g, b = rgb[:3]
    best, best_d = '?', 1e9
    for tag, (cr, cg, cb), tol in PALETTE:
        d = abs(r-cr) + abs(g-cg) + abs(b-cb)
        if d <= tol * 3 and d < best_d:
            best, best_d = tag, d
    return best

def main(path, grid_cols=48, grid_rows=28, sub=3):
    w, h, rgba = read_png(path)
    print(f'PNG: {w}x{h}  网格: {grid_cols}x{grid_rows}')
    cw, ch = w / grid_cols, h / grid_rows
    grid = []
    for gy in range(grid_rows):
        row = []
        for gx in range(grid_cols):
            cx = int((gx + 0.5) * cw)
            cy = int((gy + 0.5) * ch)
            votes = collections.Counter()
            rad_x, rad_y = max(2, int(cw*0.3)), max(2, int(ch*0.3))
            for dy in range(-rad_y, rad_y+1, sub):
                for dx in range(-rad_x, rad_x+1, sub):
                    yy, xx = cy+dy, cx+dx
                    if 0 <= yy < h and 0 <= xx < w:
                        votes[classify(rgba[yy][xx])] += 1
            row.append(votes.most_common(1)[0][0])
        grid.append(row)
    # 打印
    print('   ' + ''.join(str(c % 10) for c in range(grid_cols)))
    for gy, row in enumerate(grid):
        print(f'{gy:2d} ' + ''.join(row))
    return grid

if __name__ == '__main__':
    path = sys.argv[1] if len(sys.argv) > 1 else '详细的布局.png'
    main(path)