import { XMLParser } from 'fast-xml-parser'

export const CWMP_VERSIONS: Record<string, string> = {
  'urn:dslforum-org:cwmp-1-0': '1.0',
  'urn:dslforum-org:cwmp-1-1': '1.1',
  'urn:dslforum-org:cwmp-1-2': '1.2',
  'urn:dslforum-org:cwmp-1-3': '1.3',
  'urn:dslforum-org:cwmp-1-4': '1.4',
}

const xmlParser = new XMLParser({
  ignoreAttributes: false,
  attributeNamePrefix: '$',
  textNodeName: '_',
  numberParseOptions: { leadingZeros: false, hex: false },
  isArray: (name) => {
    const arrayTags = ['ParameterValueStruct', 'ParameterInfoStruct', 'EventStruct', 'string']
    return arrayTags.includes(name)
  },
})

export interface SoapEnvelope {
  header: SoapHeader
  body: any
  cwmpVersion: string
}

export interface SoapHeader {
  id?: string
  holdRequests?: boolean
  noMoreRequests?: boolean
}

export interface CwmpMessage {
  type: string
  data: any
}

export function parseSoapXml(xml: string): SoapEnvelope {
  const parsed = xmlParser.parse(xml)
  const envelope = parsed['soap-env:Envelope'] || parsed['SOAP-ENV:Envelope'] || parsed['soapenv:Envelope'] || {}
  const header = envelope['soap-env:Header'] || envelope['SOAP-ENV:Header'] || envelope['soapenv:Header'] || {}
  const body = envelope['soap-env:Body'] || envelope['SOAP-ENV:Body'] || envelope['soapenv:Body'] || {}

  // Detect CWMP version from namespace
  let cwmpVersion = '1.0'
  for (const [, value] of Object.entries(envelope)) {
    if (typeof value === 'string' && value.startsWith('urn:dslforum-org:cwmp-')) {
      cwmpVersion = CWMP_VERSIONS[value] || '1.0'
      break
    }
  }

  const soapHeader: SoapHeader = {}
  const idNode = header['cwmp:ID'] || header['cwmp:Id']
  if (idNode) {
    soapHeader.id = typeof idNode === 'string' ? idNode : idNode._ || idNode
  }

  return { header: soapHeader, body, cwmpVersion }
}

export function extractCwmpMessage(body: any): CwmpMessage | null {
  for (const key of Object.keys(body)) {
    if (key.startsWith('cwmp:')) {
      const type = key.replace('cwmp:', '')
      return { type, data: body[key] }
    }
  }

  // Detect SOAP Fault (CPE sends soap-env:Fault / SOAP-ENV:Fault when it cannot process a request)
  const faultKey = Object.keys(body).find(
    (k) => k.toLowerCase().endsWith(':fault') || k === 'Fault'
  )
  if (faultKey) {
    return { type: 'Fault', data: body[faultKey] }
  }

  return null
}

export function buildSoapEnvelope(cwmpId: string | undefined, bodyContent: string): string {
  const id = cwmpId || Math.random().toString(36).substring(2, 10)
  return `<?xml version="1.0" encoding="UTF-8"?>
<soap-env:Envelope
  xmlns:soap-env="http://schemas.xmlsoap.org/soap/envelope/"
  xmlns:soap-enc="http://schemas.xmlsoap.org/soap/encoding/"
  xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:cwmp="urn:dslforum-org:cwmp-1-0">
  <soap-env:Header>
    <cwmp:ID soap-env:mustUnderstand="1">${id}</cwmp:ID>
  </soap-env:Header>
  <soap-env:Body>
    ${bodyContent}
  </soap-env:Body>
</soap-env:Envelope>`
}