"""会话态模型:web_new_encrypt 离线生成所需的会话级输入。

F-2049/F-2051(E3):encrypt_msg 与当前会话绑定——
  - xMidasOps: goods.shtml 页面内嵌伪随机表(59640 值,服务端每次生成,页面级)
  - key16:     goodsBiz VM 加载期 Math.random 前 16 次调用(页面级恒定)
  - key1:      诱饵密钥(点击级,捕获即可)
服务端能验证 key 派生状态(随机 key 变体 ret:1099),因此新订单必须先捕获会话态。
"""
from __future__ import annotations

import json
from dataclasses import dataclass, field
from pathlib import Path

DEFAULT_XMIDAS_TOKEN = "DE46DBA4754D42A6B66ADD4319FF80C144D9ED22ED73384C271793D9A9AA2FFBD6C104BE8D4A7F4ED2A8688FCB6F7540"


@dataclass
class SessionState:
    """一次 goods 页加载捕获的会话态。

    xmidas_ops: list[int] 59640 项(页面级)
    key16: list[int] 16 字节(VM 加载期 Math.random 前 16 次)
    key1: list[int] 16 字节(诱饵)
    xmidas_token: str
    cookies: dict[str, str](提交 web_save 用,可选)
    openid/openkey: str(提交 web_save 用,可选)
    """

    xmidas_ops: list[int] = field(default_factory=list)
    key16: list[int] = field(default_factory=list)
    key1: list[int] = field(default_factory=list)
    xmidas_token: str = DEFAULT_XMIDAS_TOKEN
    args_template_d: str = ""  # webSave 18 参深拷贝(deepcap PC 85091 的 C[2] 原始 D 编码,会话绑定)
    cookies: dict[str, str] = field(default_factory=dict)
    openid: str = ""
    openkey: str = ""
    source: str = ""  # 捕获来源说明

    def validate(self) -> list[str]:
        errs: list[str] = []
        if len(self.xmidas_ops) != 59640:
            errs.append(f"xmidas_ops 长度 {len(self.xmidas_ops)} != 59640")
        if len(self.key16) != 16:
            errs.append(f"key16 长度 {len(self.key16)} != 16")
        if len(self.key1) != 16:
            errs.append(f"key1 长度 {len(self.key1)} != 16")
        if not self.xmidas_token:
            errs.append("xmidas_token 为空")
        if not self.args_template_d:
            errs.append("args_template_d 为空(需 deepcap PC 85091 的 C[2] 原始 D 编码)")
        return errs

    def to_json(self) -> dict:
        return {
            "xmidas_ops": self.xmidas_ops,
            "key16": self.key16,
            "key1": self.key1,
            "xmidas_token": self.xmidas_token,
            "args_template_d": self.args_template_d,
            "cookies": self.cookies,
            "openid": self.openid,
            "openkey": self.openkey,
            "source": self.source,
        }

    @classmethod
    def from_json(cls, d: dict) -> "SessionState":
        return cls(
            xmidas_ops=list(d.get("xmidas_ops", [])),
            key16=list(d.get("key16", [])),
            key1=list(d.get("key1", [])),
            xmidas_token=d.get("xmidas_token", DEFAULT_XMIDAS_TOKEN),
            args_template_d=d.get("args_template_d", ""),
            cookies=dict(d.get("cookies", {})),
            openid=d.get("openid", ""),
            openkey=d.get("openkey", ""),
            source=d.get("source", ""),
        )


def load_session(path: str | Path) -> SessionState:
    """从 JSON 加载会话态并校验。"""
    p = Path(path)
    if not p.exists():
        raise FileNotFoundError(f"会话态文件不存在: {p}")
    st = SessionState.from_json(json.loads(p.read_text(encoding="utf-8")))
    errs = st.validate()
    if errs:
        raise ValueError("会话态校验失败:\n  " + "\n  ".join(errs))
    return st