"""板侧协议在服务器这一侧的镜像（需求文档 §10.8「A12 / A14 定稿」）。

改这里之前先看固件：
  · 命令与错误码 —— firmware/main/cmd.h（数字冻结，只许追加）
  · 事件类型     —— firmware/main/evlog.h 的 log_ev_t（数字就是 flash 格式，冻结）
  · topic        —— firmware/main/mlink.h
两边对不上时**不会报错**：事件会被显示成别的类型、命令会被板子回 unknown_cmd。
"""
import re
import time
from typing import Dict, Optional, Tuple

TOPIC_ROOT = "phonerail"
TOPIC_RE = re.compile(r"^phonerail/([0-9a-f]{12})/(cmd|rsp|tele|state)$")

RAILS = 5

# log_ev_t（firmware/main/evlog.h）。⚠️ 数字冻结。
EVENT_TYPES: Dict[int, Tuple[str, str]] = {
    0: ("NONE", "（空槽位）"),
    1: ("BOOT", "板子上电"),
    2: ("LOST", "事件丢失"),
    3: ("OVER_VOLT", "过压关路"),
    4: ("UNDER_VOLT", "欠压关路"),
    5: ("REVERSE", "反灌断 VBUS"),
    6: ("PUSHED_UP", "顶高断 VBUS"),
    7: ("EFUSE_FAULT", "eFuse 故障"),
    8: ("PG_CHANGE", "PG 变化"),
    9: ("I2C_LOST", "I²C 失联"),
    10: ("THERMAL_DERATE", "过温降载"),
    11: ("FAN_STALL", "风扇停转"),
    12: ("REBOOT", "重启序列"),
    13: ("CMD_REJECT", "命令被拒"),
    14: ("MUX_LOST", "mux 失联全断"),
    15: ("SLOT_EMPTY", "刀片不在位"),
    16: ("PD_LIMIT", "PD 限功率"),
}

# 严重程度：界面上标红的那些（会断电 / 断 VBUS / 硬件故障）。
EVENT_SEVERE = {3, 4, 5, 6, 7, 9, 11, 14}

# cmd_id_t（firmware/main/cmd.h），CMD_REJECT 事件的 arg 就是它。
CMD_NAMES = {1: "status", 2: "set_voltage", 3: "power_cycle", 4: "key", 5: "edl", 6: "vbus",
             7: "fan", 8: "events", 9: "power", 10: "wifi", 11: "mqtt", 12: "net"}

KEYS = ("pwr", "vup", "vdn")
KEY_MAX_MS = 15000
MV_MIN, MV_MAX = 3524, 4010


class CmdError(ValueError):
    """请求在发出去之前就被服务器拒了（参数不对）。"""


def _rail(v) -> int:
    if not isinstance(v, int) or isinstance(v, bool) or not 1 <= v <= RAILS:
        raise CmdError("rail 必须是 1~%d" % RAILS)
    return v


def _bool(v, name: str) -> bool:
    if not isinstance(v, bool):
        raise CmdError("%s 必须是 true/false" % name)
    return v


def build_command(req: dict) -> dict:
    """网页 / 自动恢复发来的请求 → 发给板子的命令（不含 seq）。

    **白名单**：只放行管理界面该有的命令。`wifi` / `mqtt` 板子本来就只收 USB，
    这里再拦一道，免得界面上出现一个永远失败的按钮；`events` 由服务器自己同步。
    服务器这一侧先校验一遍，是为了让操作者立刻看到中文的错误，而不是等板子回 `range`；
    **板子的校验仍然是唯一的权威**（SR-13 在固件里）。
    """
    cmd = req.get("cmd")
    if cmd == "status" or cmd == "net":
        return {"cmd": cmd}
    if cmd == "set_voltage":
        mv = req.get("mv")
        if not isinstance(mv, int) or isinstance(mv, bool) or not MV_MIN <= mv <= MV_MAX:
            raise CmdError("电压必须是 %d~%d mV" % (MV_MIN, MV_MAX))
        return {"cmd": cmd, "rail": _rail(req.get("rail")), "mv": mv}
    if cmd in ("power_cycle", "edl"):
        return {"cmd": cmd, "rail": _rail(req.get("rail"))}
    if cmd == "key":
        keys = req.get("keys")
        if not isinstance(keys, str) or not keys or any(k not in KEYS for k in keys.split("+")):
            raise CmdError("keys 只能是 pwr / vup / vdn 用 + 连起来")
        ms = req.get("ms")
        if not isinstance(ms, int) or isinstance(ms, bool) or not 1 <= ms <= KEY_MAX_MS:
            raise CmdError("按键时长必须是 1~%d ms" % KEY_MAX_MS)
        return {"cmd": cmd, "rail": _rail(req.get("rail")), "keys": keys, "ms": ms}
    if cmd in ("vbus", "power"):
        return {"cmd": cmd, "rail": _rail(req.get("rail")), "on": _bool(req.get("on"), "on")}
    if cmd == "fan":
        duty = req.get("duty")
        if not isinstance(duty, int) or isinstance(duty, bool) or not 0 <= duty <= 1000:
            raise CmdError("风扇下限必须是 0~1000‰（0 = 自动）")
        return {"cmd": cmd, "duty": duty}
    raise CmdError("不支持的命令：%r" % (cmd,))


def is_mutating(cmd: str) -> bool:
    return cmd not in ("status", "events", "net")


class SeqGen:
    """seq 生成器：以毫秒时间戳为底、进程内严格递增，落在 1~2^32−1。

    板子的判重窗口按「值相等」判（cmd.h），不要求单调，只要求**不撞**：
    服务重启之后从当前时间重新起步，不会撞上重启前刚用过的那几十个号。
    """

    def __init__(self, clock=time.time):
        self._clock = clock
        self._last = 0

    def next(self) -> int:
        now = int(self._clock() * 1000)
        v = max(self._last + 1, now)
        self._last = v
        return (v - 1) % 0xFFFFFFFF + 1


def parse_topic(topic: str) -> Optional[Tuple[str, str]]:
    m = TOPIC_RE.match(topic)
    return (m.group(1), m.group(2)) if m else None


def topic(board: str, kind: str) -> str:
    return "%s/%s/%s" % (TOPIC_ROOT, board, kind)