"""
DLD960 IoT MQTT 协议定义

基于《DLD960_IoT_MQTT协议.md》V1.03
双主题结构：{sn}/srv（服务器下发）、{sn}/dev（设备上报）
消息类型由 JSON `cmd` 字段区分。
"""

import json
import time
import struct
import zlib
from typing import Optional, Any
from dataclasses import dataclass, field, asdict


# ============================================================
# Topic 结构（V1.01 — 双主题）
# ============================================================

def topic_down(dev_serial: str) -> str:
    """服务器下发 — 设备订阅此主题接收所有命令"""
    return f"dld960/{dev_serial}/srv"


def topic_up(dev_serial: str) -> str:
    """设备上报 — 设备发布到此主题（数据、事件、心跳、响应）"""
    return f"dld960/{dev_serial}/dev"


# 保持向后兼容的别名（4.7 iot_topic_set 仍使用 topic_pub / topic_sub）
def topic_dev_pub(dev_serial: str) -> str:
    """设备发布主题（= topic_up）"""
    return topic_up(dev_serial)


def topic_dev_sub(dev_serial: str) -> str:
    """设备订阅主题（= topic_down）"""
    return topic_down(dev_serial)


# 服务器端通配符订阅（监听所有设备）
TOPIC_ALL_DEVICE_UP = "dld960/+/dev"


# ============================================================
# 命令枚举
# ============================================================

CMD_DEV_SERIAL_SET   = "dev_serial_set"
CMD_DEV_INFO_QUERY   = "dev_info_query"
CMD_SSC_NET_SET      = "ssc_net_set"
CMD_SSC_NET_QUERY    = "ssc_net_query"
CMD_IOT_NET_SET      = "iot_net_set"
CMD_IOT_NET_QUERY    = "iot_net_query"
CMD_IOT_TOPIC_SET    = "iot_topic_set"
CMD_IOT_TOPIC_QUERY  = "iot_topic_query"
CMD_PWD_VERIFY       = "pwd_verify"
CMD_PWD_SET          = "pwd_set"
CMD_FACTORY_RESET    = "factory_reset"
CMD_DEVICE_RESET     = "device_reset"
CMD_LOOP_PARAM_SET   = "loop_param_set"
CMD_LOOP_PARAM_QUERY = "loop_param_query"
CMD_REPORT_CONFIG    = "report_config"

# V1.06: 脱机事件日志
CMD_LOG_STAT   = "log_stat"
CMD_LOG_QUERY  = "log_query"
CMD_LOG_CLEAR  = "log_clear"

# 设备上报
CMD_LOOP_DATA    = "loop_data"
CMD_EVENT_REPORT = "event_report"
CMD_HEARTBEAT    = "heartbeat"
CMD_INITIALIZE   = "initialize"      # V1.03: 设备上电初始化

# 配置类命令 → topic
CONFIG_SET_COMMANDS = {CMD_DEV_SERIAL_SET, CMD_SSC_NET_SET, CMD_IOT_NET_SET, CMD_IOT_TOPIC_SET, CMD_LOOP_PARAM_SET}
CONFIG_QUERY_COMMANDS = {CMD_DEV_INFO_QUERY, CMD_SSC_NET_QUERY, CMD_IOT_NET_QUERY, CMD_IOT_TOPIC_QUERY, CMD_LOOP_PARAM_QUERY}
CTRL_COMMANDS = {CMD_PWD_VERIFY, CMD_PWD_SET, CMD_FACTORY_RESET, CMD_DEVICE_RESET, CMD_REPORT_CONFIG}
LOG_COMMANDS = {CMD_LOG_STAT, CMD_LOG_QUERY, CMD_LOG_CLEAR}   # V1.06 脱机日志

# V1.07: log_* 命令日志流 (与 BLE 0x28/0x2A 同语义)
STREAM_EVENT    = "event"
STREAM_SNAPSHOT = "snapshot"


# ============================================================
# 错误码
# ============================================================

ERR_SUCCESS        = 0
ERR_PARAM_ERROR    = 1
ERR_PWD_FAILED     = 2
ERR_DEVICE_BUSY    = 3
ERR_UNSUPPORTED    = 4
ERR_INTERNAL       = 5
ERR_DATA_TOO_LONG  = 6

ERROR_MSGS = {
    0: "成功",
    1: "参数错误",
    2: "密码验证失败",
    3: "设备忙",
    4: "不支持的命令",
    5: "内部错误",
    6: "数据超长",
}


# ============================================================
# 频率档位 / 输出模式 / 事件类型
# ============================================================

FREQ_LEVELS = ["high", "mid_high", "mid_low", "low"]
OUTPUT_MODES = ["exist", "enter_pulse", "leave_pulse", "direction"]
EVENT_TYPES = ["car_enter", "car_leave", "loop_cut", "loop_restore"]

# 脱机事件日志类型描述 (log_query 响应 records[].type, MQTT V1.06)
LOG_EVENT_TYPE_DESC = {
    "boot": "上电/复位",
    "iot_connect": "MQTT TCP 连接成功",
    "iot_ready": "MQTT 订阅完成→发 initialize",
    "iot_disconnect": "MQTT 断连",
    "iot_reconn": "重连退避",
    "evt_retry": "event ACK 超时重发",
    "evt_giveup": "event 重试耗尽挂起",
    "coil": "线圈事件",
    "time_anchor": "时钟同步锚点",
    "log_clear": "日志清除(审计)",
    "unknown": "未知类型",
}

# 传感快照 channels[].misc_type 描述 (log_query stream=snapshot, MQTT V1.07)
SNAP_MISC_TYPE_DESC = {
    "time": "时间量(50ms)",
    "cut_count": "线圈断开次数",
    "flow_count": "车流量",
    "relay_count": "继电器输出次数",
}


# ============================================================
# 消息构建
# ============================================================

_msg_id_counter = 0

def next_msg_id() -> int:
    global _msg_id_counter
    _msg_id_counter += 1
    return _msg_id_counter


def build_request(cmd: str, data: Optional[dict] = None) -> dict:
    """构建通用请求消息"""
    msg: dict[str, Any] = {
        "msg_id": next_msg_id(),
        "cmd": cmd,
        "ts": int(time.time()),
    }
    if data is not None:
        msg["data"] = data
    return msg


def build_response(cmd: str, msg_id: int, code: int = 0, msg_text: str = "success", data: Optional[dict] = None) -> dict:
    """构建响应消息"""
    resp: dict[str, Any] = {
        "msg_id": msg_id,
        "cmd": cmd,
        "ts": int(time.time()),
        "code": code,
        "msg": msg_text,
    }
    if data is not None:
        resp["data"] = data
    return resp


def get_topic_for_cmd(cmd: str, dev_serial: str) -> str:
    """获取命令对应的下发 topic。所有命令统一使用 topic_down"""
    return topic_down(dev_serial)


# ============================================================
# 特定命令的 data 构建器
# ============================================================

def data_dev_serial_set(dev_serial: str) -> dict:
    return {"dev_serial": dev_serial}


def data_ssc_net_set(dev_ip: str, subnet_mask: str, route_ip: str,
                     lssc_ip: str, dns: str, port: int) -> dict:
    return {
        "dev_ip": dev_ip,
        "subnet_mask": subnet_mask,
        "route_ip": route_ip,
        "lssc_ip": lssc_ip,
        "dns": dns,
        "port": port,
    }


def data_iot_net_set(host: str, port: int = 1883,
                     client_id: str = "", username: str = "", password: str = "") -> dict:
    return {
        "host": host,
        "port": port,
        "client_id": client_id,
        "username": username,
        "password": password,
    }


def data_iot_topic_set(client_id_enable: bool, topic_pub: str, topic_sub: str) -> dict:
    return {
        "client_id_enable": client_id_enable,
        "topic_pub": topic_pub,
        "topic_sub": topic_sub,
    }


def data_pwd_verify(password: str) -> dict:
    return {"password": password}


def data_pwd_set(old_password: str, new_password: str) -> dict:
    return {"old_password": old_password, "new_password": new_password}


def data_loop_param_set(channels: list[dict], auto_mode: bool = False) -> dict:
    return {"auto_mode": auto_mode, "channels": channels}


def data_report_config(sensor_type: int = 12, enable: bool = True,
                       once: bool = False, env_eval: bool = False,
                       interval: int = 5, ack_required: bool = False,
                       timeout: int = 0) -> dict:
    return {
        "sensor_type": sensor_type,
        "enable": enable,
        "once": once,
        "env_eval": env_eval,
        "interval": interval,
        "ack_required": ack_required,
        "timeout": timeout,
    }


def data_log_query(start_seq: int = 1, count: int = 4, stream: str = STREAM_EVENT) -> dict:
    """V1.07 log_query 分页拉取脱机日志
    stream=event:    事件流, count 上限 4 (设备侧超限按 4 处理)
    stream=snapshot: 快照流, count 上限 2 (hex 原始字节上报); 显式传 stream 字段
    """
    d: dict[str, Any] = {
        "start_seq": max(1, int(start_seq)),
        "count": min(4, max(1, int(count))),
    }
    if stream == STREAM_SNAPSHOT:
        d["stream"] = STREAM_SNAPSHOT
        d["count"] = min(2, max(1, int(count)))
    return d


def data_log_clear(stream: str = STREAM_EVENT) -> dict:
    """V1.07 log_clear 清除脱机日志 (审计留痕)
    stream=snapshot: 快照流清除 (~45ms, 审计写事件流)
    event 流省略 data (设备缺省 event, 兼容老固件)
    """
    if stream == STREAM_SNAPSHOT:
        return {"stream": STREAM_SNAPSHOT}
    return {}


# ============================================================
# OTA 远程升级 (V1.08: Loop MCU 先存后刷, ROADMAP P1.4 ①)
# 协议依据《DLD960_IoT_MQTT协议.md》§4.19~4.24 / §5.5
# ============================================================

CMD_OTA_BEGIN  = "ota_begin"
CMD_OTA_DATA   = "ota_data"
CMD_OTA_END    = "ota_end"
CMD_OTA_ABORT  = "ota_abort"
CMD_OTA_FLASH  = "ota_flash"
CMD_OTA_STATUS = "ota_status"
CMD_OTA_REPORT = "ota_report"   # dev→srv 主动上报

OTA_TARGET_LOOP = "loop"
OTA_CHUNK_SIZE  = 256            # 单片 256B（协议常量, 不接受协商）
OTA_MAX_SIZE    = 96 * 1024      # 镜像上限 96KB (Slot 100KB - 4KB 边界余量)
OTA_SLOT_A      = "a"
OTA_SLOT_B      = "b"

OTA_STATE_DESC = {
    "idle": "空闲(镜像保留,已刷写完成则 idle+size>0)",
    "downloading": "下载中",
    "ready": "校验通过(可刷写)",
    "flashing": "刷写中",
    "flash_failed": "刷写失败",
    "aborted": "已中止",
}

OTA_STAGE_DESC = {
    "begin": "会话开启",
    "downloading": "分片落盘",
    "ready": "校验通过",
    "flashing": "刷写中",
    "done": "刷写成功(Loop 已重启)",
    "failed": "刷写失败",
}

OTA_ERROR_DESC = {
    0x1001: "启动帧无响应",
    0x1002: "地址帧错误",
    0x1003: "数据块 ACK 超限",
    0x1004: "全镜像校验失败",
    0x1005: "安全窗口拒绝后强制失败",
}


def ota_crc32(data: bytes) -> int:
    """CRC-32/ISO-HDLC (协议 §4.19.1; zlib.crc32 即此算法, 设备查表法一致)"""
    return zlib.crc32(data) & 0xFFFFFFFF


def ota_split_bin(data: bytes, chunk_size: int = OTA_CHUNK_SIZE) -> list[tuple[int, int, str]]:
    """bin → 分片列表 [(offset, crc32, hex_str), ...] (单片 256B, hex 512 字符)"""
    if len(data) > OTA_MAX_SIZE:
        raise ValueError(f"镜像 {len(data)}B 超上限 {OTA_MAX_SIZE}B (96KB)")
    return [(off, ota_crc32(data[off:off + chunk_size]), data[off:off + chunk_size].hex())
            for off in range(0, len(data), chunk_size)]


def data_ota_begin(size: int, crc32: int, version: str = "",
                   target: str = OTA_TARGET_LOOP, force: bool = False) -> dict:
    """ota_begin 请求 data (开启会话 / 断点续传定位)"""
    return {"target": target, "size": size, "crc32": crc32,
            "version": version, "force": force}


def data_ota_data(offset: int, crc32: int, data_hex: str,
                  target: str = OTA_TARGET_LOOP) -> dict:
    """ota_data 请求 data (分片下发, offset 256 对齐)"""
    return {"target": target, "offset": offset, "crc32": crc32, "data": data_hex}


def data_ota_end(crc32: int, target: str = OTA_TARGET_LOOP) -> dict:
    """ota_end 请求 data (结束下载, 全镜像 CRC32 复核)"""
    return {"target": target, "crc32": crc32}


def data_ota_abort(target: str = OTA_TARGET_LOOP) -> dict:
    """ota_abort 请求 data (中止会话, 释放暂存)"""
    return {"target": target}


def data_ota_flash(slot: str = OTA_SLOT_A, force: bool = False,
                   target: str = OTA_TARGET_LOOP) -> dict:
    """ota_flash 请求 data (触发本地 ISP 刷写, 仅 ready 态)"""
    return {"target": target, "slot": slot, "force": force}


# ============================================================
# 解析设备上报
# ============================================================

def parse_topic_dev_serial(topic: str) -> Optional[str]:
    """从 topic 中提取设备序列码"""
    parts = topic.split("/")
    if len(parts) >= 2 and parts[0] == "dld960":
        return parts[1]
    return None


# ============================================================
# 脱机日志 hex 解析 (V1.07: log_query 响应 records[].hex 原始字节)
# 字段表与《DLD960 BLE 协议》§6.4 (SnapRec) / §7 (OfflogEvt) 一致
# ============================================================

# OfflogEvt 事件类型 (BLE 协议 §7 事件类型表)
OFFLOG_TYPE_NAMES = {
    0x01: "boot", 0x10: "iot_connect", 0x11: "iot_ready", 0x12: "iot_disconnect",
    0x13: "iot_reconn", 0x30: "evt_retry", 0x31: "evt_giveup", 0x40: "coil",
    0x50: "time_anchor", 0x70: "log_clear",
}
_OFFLOG_SUB_NAMES = {1: "car_enter", 2: "car_leave", 3: "loop_cut", 4: "loop_restore"}
_OFFLOG_DISC_REASONS = {1: "断开", 2: "超时", 3: "CONNACK拒绝", 4: "连接超时"}


def parse_offlog_hex(h: str) -> dict:
    """OfflogEvt 32B hex → dict (magic/type/seq/ts_ms/unix_ts/boot_seq/payload)"""
    b = bytes.fromhex(h)
    if len(b) != 32:
        return {"error": f"bad len {len(b)}"}
    magic, etype, elen, flags, seq, ts_ms, unix_ts, boot_seq, rsvd, payload = \
        struct.unpack('<BBBBIIIHH12s', b)
    return {"magic": magic, "type": etype, "len": elen, "flags": flags, "seq": seq,
            "ts_ms": ts_ms, "unix_ts": unix_ts, "boot_seq": boot_seq, "payload": payload}


def offlog_payload_desc(etype: int, payload: bytes) -> str:
    """事件 payload 人类可读描述 (BLE 协议 §7 payload 定义, 大端)"""
    if etype == 0x01:  # boot: 复位原因寄存器
        rst = int.from_bytes(payload[0:4], 'big') if len(payload) >= 4 else 0
        bits = [n for n, b in [("LPWR", 31), ("WWDG", 30), ("IWDG", 29),
                               ("SFT", 28), ("POR", 27), ("NRST", 26)] if rst & (1 << b)]
        return f"rst=0x{rst:08X} ({'+'.join(bits) if bits else 'none'})"
    if etype == 0x12:  # iot_disconnect
        r = payload[0] if payload else 0
        return f"reason={r} ({_OFFLOG_DISC_REASONS.get(r, '?')})"
    if etype == 0x13:  # iot_reconn
        return f"backoff_ms={int.from_bytes(payload[0:4], 'big')}" if len(payload) >= 4 else ""
    if etype == 0x30:  # evt_retry
        mid = int.from_bytes(payload[0:4], 'big') if len(payload) >= 4 else 0
        retry = payload[4] if len(payload) >= 5 else 0
        return f"msg_id={mid} retry={retry}"
    if etype == 0x31:  # evt_giveup
        mid = int.from_bytes(payload[0:4], 'big') if len(payload) >= 4 else 0
        return f"msg_id={mid}"
    if etype == 0x40:  # coil
        sub = _OFFLOG_SUB_NAMES.get(payload[0], payload[0]) if payload else "?"
        ch = payload[1] if len(payload) >= 2 else 0
        val = int.from_bytes(payload[2:6], 'big') if len(payload) >= 6 else 0
        return f"sub={sub} ch={ch} value={val}"
    if etype in (0x10, 0x11, 0x50, 0x70):  # 无 payload
        return ""
    return payload.hex() if payload else ""


def parse_snap_hex(h: str) -> dict:
    """SnapRec 64B hex → dict (seq/boot_seq/ts_ms/coil_count/channels[])"""
    b = bytes.fromhex(h)
    if len(b) != 64:
        return {"error": f"bad len {len(b)}"}
    magic, slen, flags, rsvd, seq, ts_ms, boot_seq, rsvd2, coils = \
        struct.unpack('<BBBBIIHH48s', b)
    coil_count = min(slen // 12, 4)
    channels = []
    for c in range(coil_count):
        p = coils[c * 12:(c + 1) * 12]
        cfg, cond = p[0], p[1]
        freq = p[2] | (p[3] << 8) | (p[4] << 16)
        var = p[5] | (p[6] << 8) | (p[7] << 16)
        if var & 0x800000:
            var -= 0x1000000
        misc = int.from_bytes(p[8:12], 'little')
        channels.append({
            "ch": c + 1,
            "freq_level": ("high", "mid_high", "mid_low", "low")[(cfg >> 6) & 3],
            "direction": (cfg >> 5) & 1,
            "freq_type": (cfg >> 4) & 1,
            "sensitivity": cfg & 0x0F,
            "condition": (cond >> 4) & 0x0F,
            "loop_ok": not ((cond >> 3) & 1),
            "has_car": bool((cond >> 2) & 1),
            "misc_type": ("time", "cut_count", "flow_count", "relay_count")[cond & 3],
            "freq": freq, "variation": var, "misc": misc,
        })
    return {"seq": seq, "boot_seq": boot_seq, "ts_ms": ts_ms,
            "coil_count": coil_count, "channels": channels}