import {bytesToHex, bytesToMac} from '../utils/hex'
import {joinLowHigh, readUint16LE, toUint8Array} from '../utils/bytes'
import {DEVICE_PROFILE} from '../protocols/profiles'

/**
 * 解析 UUID_STATE 的状态字节，转为有符号 8bit。
 */
export function parseStateCode(payload) {
  const bytes = toUint8Array(payload)
  if (!bytes.length) {
    return null
  }

  return bytes[0] > 127 ? bytes[0] - 256 : bytes[0]
}

/**
 * ED713 MSG 解析。
 * 文档布局：MAC(6) + bindStatus(1) + 其它(3) + productId_H(1) + productId_L(1)
 *           + baseBoard(1) + coreBoard(1) + 其它(2) + deviceType(1)
 *           + wifiStatus(1) + cellularStatus(1) + 其它(1)
 */
function parseEd713DeviceInfo(bytes) {
  if (!bytes.length) {
    return {
      raw: bytes, mac: '', bindStatus: null, productId: null,
      deviceType: null, wifiStatus: null, cellularStatus: null
    }
  }

  return {
    raw: bytes,
    mac: bytesToMac(bytes.slice(0, 6)),
    bindStatus: bytes.length > 6 ? bytes[6] : null,
    productId: bytes.length > 11 ? joinLowHigh(bytes[11], bytes[10]) : null,
    baseBoardVersion: bytes.length > 12 ? bytes[12] : null,
    coreBoardVersion: bytes.length > 13 ? bytes[13] : null,
    deviceType: bytes.length > 16 ? bytes[16] : null,
    wifiStatus: bytes.length > 17 ? bytes[17] : null,
    cellularStatus: bytes.length > 18 ? bytes[18] : null
  }
}

/**
 * ED719 MSG 解析。
 * 实际偏移与 ED713 一致（文档省略了 bindStatus/productId 但底板数据布局相同）：
 * MAC(6) + bindStatus(1) + 其它(3) + productId_H(1) + productId_L(1)
 * + baseBoard(1) + coreBoard(1) + 其它(2) + deviceType(1)
 * + wifiStatus(1) + cellularStatus(1) + 其它(1)
 */
function parseEd719DeviceInfo(bytes) {
  return parseEd713DeviceInfo(bytes)
}

/**
 * 解析 UUID_MSG 设备信息（按 profile 区分 ED713/ED719）。
 */
export function parseDeviceInfo(payload, profileId = DEVICE_PROFILE.UNKNOWN) {
  const bytes = toUint8Array(payload)

  if (!bytes.length) {
    return {
      raw: bytes, mac: '', bindStatus: null, productId: null,
      deviceType: null, wifiStatus: null, cellularStatus: null
    }
  }

  if (profileId === DEVICE_PROFILE.ED713) return parseEd713DeviceInfo(bytes)
  if (profileId === DEVICE_PROFILE.ED719) return parseEd719DeviceInfo(bytes)

  // UNKNOWN：按 ED713 布局兼容
  return parseEd713DeviceInfo(bytes)
}

/**
 * ED713 雷达数据解析。
 * 协议帧长度不足时返回 valid:false，交由上层决定是否忽略。
 */
export function parseEd713Radar(payload) {
  const bytes = toUint8Array(payload)

  if (bytes.length < 60) {
    return {
      type: 'ED713',
      valid: false,
      reason: 'LENGTH_LT_60',
      raw: bytes
    }
  }

  return {
    type: 'ED713',
    valid: true,
    raw: bytes,
    peopleCount: bytes[24],
    peopleLocalDecimeter: bytes[25],
    peopleState: bytes[26],
    heartRate: bytes[28],
    respRate: bytes[29],
    activityState: bytes[30],
    moveIndex: bytes[35],
    waveNum: bytes[37],
    respWave: Array.from(bytes.slice(38, 58)),
    narrowFlag: bytes[59]
  }
}

/**
 * ED719 雷达数据解析。
 * 按文档结构体定义：
 * header[4] + event(1) + people(1) + num(1) + nodata(1)
 * + height(2) + mode(1) + beeper(1) + left(2) + right(2) + front(2) + back(2)
 * + sensitive(1) + nodata1(1) + stateDelay(2) = 24 bytes
 * shield_num 在 offset 24，屏蔽区在 offset 25
 * 屏蔽区之后：wallOption + peopleHaveSwitch + peopleActivitySwitch
 */
export function parseEd719Radar(payload) {
  const bytes = toUint8Array(payload)

  if (bytes.length < 24) {
    return {
      type: 'ED719',
      valid: false,
      reason: 'LENGTH_LT_24',
      raw: bytes
    }
  }

  const shieldNum = bytes[24] || 0
  const shieldStart = 25
  const shieldBlockLength = Math.min(Math.max(shieldNum, 0), 4) * 9

  const wallOffset = shieldStart + shieldBlockLength

  return {
    type: 'ED719',
    valid: true,
    raw: bytes,
    eventState: bytes[4],
    peopleState: bytes[5],
    peopleNum: bytes[6],
    installHeight: readUint16LE(bytes, 8),
    installMode: bytes[10],
    beeperOn: bytes[11],
    leftDist: readUint16LE(bytes, 12),
    rightDist: readUint16LE(bytes, 14),
    frontDist: readUint16LE(bytes, 16),
    backDist: readUint16LE(bytes, 18),
    sensitive: bytes[20],
    stateDelay: readUint16LE(bytes, 22),
    shieldNum,
    shieldZoneRaw: Array.from(bytes.slice(shieldStart, shieldStart + shieldBlockLength)),
    wallOption: bytes[wallOffset] ?? null,
    peopleHaveSwitch: bytes[wallOffset + 1] ?? null,
    peopleActivitySwitch: bytes[wallOffset + 2] ?? null
  }
}