# -*- coding: utf-8 -*-
"""原创离线合成样例；不连接模型、不读取账户。输出位于脚本旁。
已有输入保留，修改输入后可以重跑。失败边界由 --negative 单独演示。
"""
from pathlib import Path
import sys, json, csv, math, io, hashlib, html, base64, re
sys.stdout.reconfigure(encoding='utf-8')
sys.stderr.reconfigure(encoding='utf-8')
BASE = Path(__file__).resolve().parent
NEG = '--negative' in sys.argv
def write(name, value):
    p=BASE/name; p.parent.mkdir(parents=True,exist_ok=True)
    if isinstance(value,bytes): p.write_bytes(value)
    else: p.write_text(value,encoding='utf-8',newline='')
def seed(name,value):
    if not (BASE/name).exists(): write(name,value)
def jwrite(name,value): write(name,json.dumps(value,ensure_ascii=False,indent=2))
def jseed(name,value):
    if not (BASE/name).exists(): jwrite(name,value)
def load(name): return json.loads((BASE/name).read_text(encoding='utf-8'))
def table(name,heads,rows):
    f=io.StringIO(newline='');w=csv.writer(f);w.writerow(heads);w.writerows(rows);write(name,f.getvalue())
def page(name,title,body):
    write(name,'<!doctype html><html lang="zh-CN"><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"><title>'+html.escape(title)+'</title><style>body{max-width:1000px;margin:2rem auto;padding:0 1rem;font:17px/1.7 system-ui}table{border-collapse:collapse}td,th{border:1px solid #aaa;padding:.5rem}pre{white-space:pre-wrap;overflow-wrap:anywhere}img,svg{max-width:100%;height:auto}a{color:#125caa}</style><h1>'+html.escape(title)+'</h1>'+body+'</html>')
def emit(data): print(json.dumps(data,ensure_ascii=False))

jseed('colors.json',{'background':'#ffffff','candidates':['#777777','#767676','#111111'],'target':4.5});d=load('colors.json')
if NEG:d['background']='#ffffff80'
def luminance(hexcolor):
    if not re.fullmatch(r'#[0-9a-fA-F]{6}',hexcolor):raise ValueError('只支持不透明六位纯色，半透明须先合成')
    c=[int(hexcolor[i:i+2],16)/255 for i in (1,3,5)];v=[x/12.92 if x<=.04045 else ((x+.055)/1.055)**2.4 for x in c];return sum(x*w for x,w in zip(v,[.2126,.7152,.0722]))
bg=luminance(d['background']);rows=[]
for c in d['candidates']:
    fg=luminance(c);ratio=(max(bg,fg)+.05)/(min(bg,fg)+.05);rows.append([c,ratio,ratio>=d['target']])
table('contrast.csv',['foreground','ratio_unrounded','normal_text_AA'],rows);page('palette-preview.html','纯色文字对比度',''.join(f'<p style="background:{d["background"]};color:{c};padding:20px;border:1px solid #aaa">示例文字 {c}，比值 {ratio:.6f}，普通文本AA {passed}</p>' for c,ratio,passed in rows));emit({'ratios':rows,'selected':next((c for c,r,p in rows if p),None)})