// server/supabase/functions/_shared/payple.ts
// Payple 결제 API 래퍼 — 파트너 인증, 빌링 결제, 취소, 빌링키 해지

// ── 타입 ──────────────────────────────────────────────

export interface PaypleConfig {
  cstId: string
  custKey: string
  refundKey: string
  clientKey: string
  isTest: boolean
  baseUrl: string        // 'https://cpay.payple.kr' or 'https://democpay.payple.kr'
  siteUrl: string
}

export interface PaypleAuthResult {
  PCD_CST_ID: string     // 암호화된 상점 ID
  PCD_CUST_KEY: string   // 암호화된 고객 키
  PCD_AUTH_KEY: string    // 인증 토큰
  PCD_PAY_HOST: string   // 결제 요청 호스트
  PCD_PAY_URL: string    // 결제 요청 URL
}

export interface PaypleBillingResult {
  PCD_PAY_RST: 'success' | 'error'
  PCD_PAY_CODE: string
  PCD_PAY_MSG: string
  PCD_PAY_OID: string
  PCD_PAY_TYPE: string
  PCD_PAY_TOTAL: string
  PCD_PAY_CARDNAME?: string
  PCD_PAY_CARDNUM?: string
  PCD_PAY_CARDAUTHNO?: string
  PCD_PAY_CARDTRADENUM?: string
  PCD_PAY_CARDRECEIPT?: string
  PCD_PAYER_ID?: string
  PCD_PAY_TIME?: string
}

export interface PaypleCancelResult {
  PCD_PAY_RST: 'success' | 'error'
  PCD_PAY_CODE: string
  PCD_PAY_MSG: string
  PCD_PAY_OID: string
  PCD_REFUND_TOTAL: string
}

export interface PayplePaymentLookupResult {
  PCD_PAY_RST: 'success' | 'error'
  PCD_PAY_CODE: string
  PCD_PAY_MSG: string
  PCD_PAY_OID: string
  PCD_PAY_TYPE: 'card' | 'transfer'
  PCD_PAYER_ID?: string
  PCD_PAYER_NO?: string
  PCD_PAY_TOTAL?: string
  PCD_PAY_TIME?: string
  PCD_PAY_STATE?: string
}

export interface PaypleBillingKeyLookupResult {
  PCD_PAY_RST: 'success' | 'error'
  PCD_PAY_CODE: string
  PCD_PAY_MSG: string
  PCD_PAYER_ID?: string
  PCD_PAYER_NO?: string
}

export class PaypleConfigurationError extends Error {
  readonly code = 'payple_not_configured'

  constructor(message: string) {
    super(message)
    this.name = 'PaypleConfigurationError'
  }
}

export class PaypleVerificationError extends Error {
  readonly code: string

  constructor(code: string) {
    super(code)
    this.name = 'PaypleVerificationError'
    this.code = code
  }
}

export class PaypleBillingError extends Error {
  readonly code: string
  readonly definitive: boolean

  constructor(code: string, definitive: boolean) {
    super(code)
    this.name = 'PaypleBillingError'
    this.code = code
    this.definitive = definitive
  }
}

// ── 환경변수에서 설정 로드 ──────────────────────────────

export function buildPaypleConfig(values: Record<string, string | undefined>): PaypleConfig {
  const environment = values['PAYPLE_ENVIRONMENT']
  if (environment !== 'test' && environment !== 'live') {
    throw new PaypleConfigurationError('PAYPLE_ENVIRONMENT must be test or live')
  }

  const required = [
    'PAYPLE_CST_ID',
    'PAYPLE_CUST_KEY',
    'PAYPLE_REFUND_KEY',
    'PAYPLE_CLIENT_KEY',
    'PAYPLE_SITE_URL',
  ] as const
  for (const key of required) {
    if (!values[key]?.trim()) {
      throw new PaypleConfigurationError(`${key} is required`)
    }
  }

  const siteUrl = new URL(values['PAYPLE_SITE_URL']!.trim())
  if (siteUrl.protocol !== 'https:' && !(environment === 'test' && siteUrl.hostname === 'localhost')) {
    throw new PaypleConfigurationError('PAYPLE_SITE_URL must use HTTPS')
  }

  return {
    cstId: values['PAYPLE_CST_ID']!.trim(),
    custKey: values['PAYPLE_CUST_KEY']!.trim(),
    refundKey: values['PAYPLE_REFUND_KEY']!.trim(),
    clientKey: values['PAYPLE_CLIENT_KEY']!.trim(),
    siteUrl: siteUrl.origin,
    isTest: environment === 'test',
    baseUrl: environment === 'test'
      ? 'https://democpay.payple.kr'
      : 'https://cpay.payple.kr',
  }
}

export function getPaypleConfig(): PaypleConfig {
  return buildPaypleConfig({
    PAYPLE_ENVIRONMENT: Deno.env.get('PAYPLE_ENVIRONMENT'),
    PAYPLE_CST_ID: Deno.env.get('PAYPLE_CST_ID'),
    PAYPLE_CUST_KEY: Deno.env.get('PAYPLE_CUST_KEY'),
    PAYPLE_REFUND_KEY: Deno.env.get('PAYPLE_REFUND_KEY'),
    PAYPLE_CLIENT_KEY: Deno.env.get('PAYPLE_CLIENT_KEY'),
    PAYPLE_SITE_URL: Deno.env.get('PAYPLE_SITE_URL'),
  })
}

// ── Referer 헤더 ──────────────────────────────────────

function getReferer(config: PaypleConfig): string {
  return config.siteUrl
}

function getPaypleApiUrl(config: PaypleConfig, candidate: string | undefined, fallbackPath: string): string {
  const url = new URL(candidate || fallbackPath, config.baseUrl)
  const expected = new URL(config.baseUrl)
  if (url.protocol !== 'https:' || url.origin !== expected.origin) {
    throw new PaypleVerificationError('payple_untrusted_api_host')
  }
  return url.toString()
}

// ── 파트너 인증 ───────────────────────────────────────

export async function paypleAuth(
  config: PaypleConfig,
  options?: {
    cancelFlag?: boolean    // PCD_PAYCANCEL_FLAG
    simpleFlag?: boolean    // PCD_SIMPLE_FLAG (빌링 결제용)
    payWork?: string        // PCD_PAY_WORK (PUSERDEL 등)
    payCheckFlag?: boolean  // PCD_PAYCHK_FLAG (단건 결과조회)
  }
): Promise<PaypleAuthResult> {
  const body: Record<string, string> = {
    cst_id: config.cstId,
    custKey: config.custKey,
  }

  if (options?.cancelFlag) {
    body['PCD_PAYCANCEL_FLAG'] = 'Y'
  } else if (options?.payCheckFlag) {
    body['PCD_PAYCHK_FLAG'] = 'Y'
  } else if (options?.simpleFlag) {
    body['PCD_PAY_TYPE'] = 'card'
    body['PCD_SIMPLE_FLAG'] = 'Y'
  } else if (options?.payWork) {
    body['PCD_PAY_WORK'] = options.payWork
  }

  const resp = await fetch(`${config.baseUrl}/php/auth.php`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Cache-Control': 'no-cache',
      'Referer': getReferer(config),
    },
    body: JSON.stringify(body),
  })

  if (!resp.ok) {
    throw new Error(`Payple auth failed: HTTP ${resp.status}`)
  }

  const data = await resp.json() as Record<string, string>
  if (data['result'] !== 'success') {
    throw new Error(`Payple auth error: ${data['result_msg'] ?? data['cst_id'] ?? 'unknown'}`)
  }

  const result = {
    PCD_CST_ID: data['cst_id'] ?? '',
    PCD_CUST_KEY: data['custKey'] ?? '',
    PCD_AUTH_KEY: data['AuthKey'] ?? '',
    PCD_PAY_HOST: data['PCD_PAY_HOST'] ?? config.baseUrl,
    PCD_PAY_URL: data['PCD_PAY_URL'] ?? '',
  }
  if (!result.PCD_CST_ID || !result.PCD_CUST_KEY || !result.PCD_AUTH_KEY) {
    throw new PaypleVerificationError('payple_auth_response_incomplete')
  }
  getPaypleApiUrl(config, result.PCD_PAY_HOST, '/')
  return result
}

// ── 빌링키로 결제 ────────────────────────────────────

export async function paypleBilling(
  config: PaypleConfig,
  auth: PaypleAuthResult,
  params: {
    payerId: string           // PCD_PAYER_ID (빌링키)
    amount: number            // 결제 금액 (원)
    orderId: string           // 주문번호
    goodsName: string         // 상품명
  }
): Promise<PaypleBillingResult> {
  const url = getPaypleApiUrl(
    config,
    auth.PCD_PAY_HOST,
    '/php/SimplePayCardAct.php?ACT_=PAYM',
  )
  const billingUrl = new URL('/php/SimplePayCardAct.php?ACT_=PAYM', url).toString()

  let resp: Response
  try {
    resp = await fetch(billingUrl, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'Cache-Control': 'no-cache',
        'Referer': getReferer(config),
      },
      body: JSON.stringify({
        PCD_CST_ID: auth.PCD_CST_ID,
        PCD_CUST_KEY: auth.PCD_CUST_KEY,
        PCD_AUTH_KEY: auth.PCD_AUTH_KEY,
        PCD_PAY_TYPE: 'card',
        PCD_PAYER_ID: params.payerId,
        PCD_PAY_GOODS: params.goodsName,
        PCD_PAY_TOTAL: String(params.amount),
        PCD_PAY_OID: params.orderId,
        PCD_SIMPLE_FLAG: 'Y',
      }),
    })
  } catch {
    throw new PaypleBillingError('payple_billing_transport_unknown', false)
  }

  if (!resp.ok) {
    throw new PaypleBillingError('payple_billing_http_unknown', false)
  }

  let data: PaypleBillingResult
  try {
    data = await resp.json() as PaypleBillingResult
  } catch {
    throw new PaypleBillingError('payple_billing_response_unknown', false)
  }
  if (data.PCD_PAY_RST !== 'success') {
    throw new PaypleBillingError('payple_billing_declined', true)
  }

  return data
}

// ── 결제 취소/환불 ────────────────────────────────────

export async function paypleCancel(
  config: PaypleConfig,
  auth: PaypleAuthResult,
  params: {
    payOid: string           // 원거래 주문번호
    payDate: string          // 결제일자 (YYYYMMDD)
    refundTotal: number      // 환불 금액
  }
): Promise<PaypleCancelResult> {
  const resp = await fetch(`${config.baseUrl}/php/account/api/cPayCAct.php`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Cache-Control': 'no-cache',
      'Referer': getReferer(config),
    },
    body: JSON.stringify({
      PCD_CST_ID: auth.PCD_CST_ID,
      PCD_CUST_KEY: auth.PCD_CUST_KEY,
      PCD_AUTH_KEY: auth.PCD_AUTH_KEY,
      PCD_REFUND_KEY: config.refundKey,
      PCD_PAYCANCEL_FLAG: 'Y',
      PCD_PAY_OID: params.payOid,
      PCD_PAY_DATE: params.payDate,
      PCD_REFUND_TOTAL: String(params.refundTotal),
    }),
  })

  if (!resp.ok) {
    throw new Error(`Payple cancel failed: HTTP ${resp.status}`)
  }

  const data = await resp.json() as PaypleCancelResult
  if (data.PCD_PAY_RST !== 'success') {
    throw new Error(`Payple cancel error: ${data.PCD_PAY_MSG} (${data.PCD_PAY_CODE})`)
  }

  return data
}

// ── 빌링키 해지 ──────────────────────────────────────

export async function paypleDeleteBillingKey(
  config: PaypleConfig,
  auth: PaypleAuthResult,
  payerId: string
): Promise<void> {
  const host = getPaypleApiUrl(config, auth.PCD_PAY_HOST, '/')
  const url = new URL('/php/cPayUser/api/cPayUserAct.php?ACT_=PUSERDEL', host).toString()

  const resp = await fetch(url, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Cache-Control': 'no-cache',
      'Referer': getReferer(config),
    },
    body: JSON.stringify({
      PCD_CST_ID: auth.PCD_CST_ID,
      PCD_CUST_KEY: auth.PCD_CUST_KEY,
      PCD_AUTH_KEY: auth.PCD_AUTH_KEY,
      PCD_PAYER_ID: payerId,
    }),
  })

  if (!resp.ok) {
    throw new Error(`Payple delete billing key failed: HTTP ${resp.status}`)
  }

  const data = await resp.json() as { PCD_PAY_RST: string; PCD_PAY_MSG?: string }
  if (data.PCD_PAY_RST !== 'success') {
    throw new Error(`Payple delete billing key error: ${data.PCD_PAY_MSG ?? 'unknown'}`)
  }
}

// ── 서버 대 서버 결과조회 ──────────────────────────────

/**
 * Payple 국내 결제 웹훅에는 별도 서명 헤더 계약이 없다. 웹훅 payload를
 * 신뢰하지 않고 공식 단건 결과조회 API로 원거래를 다시 조회한 결과만
 * entitlement event로 사용할 수 있도록 한다.
 */
export async function paypleLookupPayment(
  config: PaypleConfig,
  auth: PaypleAuthResult,
  params: {
    orderId: string
    payType: 'card' | 'transfer'
    payDate: string
  },
): Promise<PayplePaymentLookupResult> {
  if (!/^[A-Za-z0-9._-]{8,64}$/.test(params.orderId)) {
    throw new PaypleVerificationError('payple_invalid_order_id')
  }
  if (!/^\d{8}$/.test(params.payDate)) {
    throw new PaypleVerificationError('payple_invalid_pay_date')
  }

  const lookupUrl = getPaypleApiUrl(
    config,
    auth.PCD_PAY_URL,
    '/php/PayChkAct.php',
  )
  const resp = await fetch(lookupUrl, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Cache-Control': 'no-cache',
      'Referer': getReferer(config),
    },
    body: JSON.stringify({
      PCD_CST_ID: auth.PCD_CST_ID,
      PCD_CUST_KEY: auth.PCD_CUST_KEY,
      PCD_AUTH_KEY: auth.PCD_AUTH_KEY,
      PCD_PAYCHK_FLAG: 'Y',
      PCD_PAY_TYPE: params.payType,
      PCD_PAY_OID: params.orderId,
      PCD_PAY_DATE: params.payDate,
    }),
  })

  if (!resp.ok) {
    throw new PaypleVerificationError(`payple_lookup_http_${resp.status}`)
  }
  const data = await resp.json() as PayplePaymentLookupResult
  if (
    data.PCD_PAY_RST !== 'success'
    || data.PCD_PAY_CODE !== 'PCHK0000'
    || data.PCD_PAY_OID !== params.orderId
    || data.PCD_PAY_TYPE !== params.payType
  ) {
    throw new PaypleVerificationError('payple_lookup_mismatch')
  }
  return data
}

export async function paypleLookupBillingKey(
  config: PaypleConfig,
  auth: PaypleAuthResult,
  payerId: string,
): Promise<PaypleBillingKeyLookupResult> {
  if (!payerId || payerId.length > 255) {
    throw new PaypleVerificationError('payple_invalid_payer_id')
  }
  const host = getPaypleApiUrl(config, auth.PCD_PAY_HOST, '/')
  const url = new URL('/php/cPayUser/api/cPayUserAct.php?ACT_=PUSERINFO', host).toString()
  const resp = await fetch(url, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Cache-Control': 'no-cache',
      'Referer': getReferer(config),
    },
    body: JSON.stringify({
      PCD_CST_ID: auth.PCD_CST_ID,
      PCD_CUST_KEY: auth.PCD_CUST_KEY,
      PCD_AUTH_KEY: auth.PCD_AUTH_KEY,
      PCD_PAYER_ID: payerId,
    }),
  })
  if (!resp.ok) {
    throw new PaypleVerificationError(`payple_billing_key_lookup_http_${resp.status}`)
  }
  return await resp.json() as PaypleBillingKeyLookupResult
}

export function parsePaypleTimestamp(value: string): Date {
  const compact = value.trim().replace(/[- :]/g, '')
  if (!/^\d{14}$/.test(compact)) {
    throw new PaypleVerificationError('payple_invalid_timestamp')
  }
  const iso = `${compact.slice(0, 4)}-${compact.slice(4, 6)}-${compact.slice(6, 8)}`
    + `T${compact.slice(8, 10)}:${compact.slice(10, 12)}:${compact.slice(12, 14)}+09:00`
  const parsed = new Date(iso)
  if (!Number.isFinite(parsed.getTime())) {
    throw new PaypleVerificationError('payple_invalid_timestamp')
  }
  return parsed
}

export function resolvePaypleOrderDate(orderId: string, payTime?: string): string {
  if (payTime) {
    const parsed = payTime.trim().replace(/[- :]/g, '')
    if (!/^\d{14}$/.test(parsed)) {
      throw new PaypleVerificationError('payple_invalid_pay_date')
    }
    return parsed.slice(0, 8)
  }
  const d3roMatch = /^D3RO-(\d{8})\d{6}-/.exec(orderId)
  if (d3roMatch) return d3roMatch[1]
  throw new PaypleVerificationError('payple_missing_pay_date')
}

export async function sha256Text(value: string): Promise<string> {
  const bytes = await crypto.subtle.digest('SHA-256', new TextEncoder().encode(value))
  return Array.from(new Uint8Array(bytes))
    .map((part) => part.toString(16).padStart(2, '0'))
    .join('')
}

export async function payplePayerNumber(userId: string): Promise<string> {
  const digest = await sha256Text(`d3ro-payple:${userId}`)
  return (BigInt(`0x${digest}`) % 1_000_000_000_000_000_000n)
    .toString()
    .padStart(18, '0')
}

export function payplePaymentEventId(orderId: string): string {
  if (!/^[A-Za-z0-9._-]{8,64}$/.test(orderId)) {
    throw new PaypleVerificationError('payple_invalid_order_id')
  }
  return `payment:${orderId}`
}

export async function payplePaymentEventDigest(params: {
  orderId: string
  payerId: string
  payType: 'card' | 'transfer'
  amount: number
}): Promise<string> {
  payplePaymentEventId(params.orderId)
  if (!params.payerId || params.payerId.length > 255) {
    throw new PaypleVerificationError('payple_invalid_payer_id')
  }
  if (!Number.isSafeInteger(params.amount) || params.amount <= 0) {
    throw new PaypleVerificationError('payple_invalid_amount')
  }
  return await sha256Text(JSON.stringify({
    amount: params.amount,
    order_id: params.orderId,
    payer_id: params.payerId,
    payment_type: params.payType,
  }))
}

// ── 주문번호 생성 유틸리티 ─────────────────────────────

export function generateOrderId(userId: string, nonce = crypto.randomUUID()): string {
  const koreaNow = new Date(Date.now() + 9 * 60 * 60 * 1000)
  const ts = koreaNow.toISOString().replace(/[-:T.Z]/g, '').substring(0, 14)
  const short = userId.substring(0, 8)
  const unique = nonce.replace(/-/g, '').substring(0, 8)
  return `D3RO-${ts}-${short}-${unique}`
}

// ── 구독 기간 계산 ────────────────────────────────────

export function calcSubscriptionPeriod(now = new Date()): { start: string; end: string } {
  const end = new Date(now)
  end.setMonth(end.getMonth() + 1)
  return {
    start: now.toISOString(),
    end: end.toISOString(),
  }
}

// ── 티어별 가격 ──────────────────────────────────────

export const TIER_PRICE: Record<string, number> = {
  pro: 9900,
  pro_plus: 29900,
}

export const TIER_GOODS_NAME: Record<string, string> = {
  pro: 'D3RO Voice Pro',
  pro_plus: 'D3RO Voice Pro+',
}