import { prisma } from '@/lib/prisma'
import { sendSms } from '@/lib/semaphore'
import { formatPhone } from '@/lib/utils'

const MAX_ATTEMPTS = 3

export async function processQueue(): Promise<{ processed: number; failed: number }> {
  let processed = 0
  let failed = 0

  const jobs = await prisma.smsQueue.findMany({
    where: {
      status: { in: ['PENDING', 'RETRYING'] },
      attempts: { lt: MAX_ATTEMPTS },
      scheduledAt: { lte: new Date() },
    },
    include: { client: true },
    orderBy: { scheduledAt: 'asc' },
    take: 50,
  })

  for (const job of jobs) {
    await prisma.smsQueue.update({
      where: { id: job.id },
      data: { status: 'PROCESSING' },
    })

    const client = job.client
    if (!client.semaphoreKey || !client.isActive) {
      await prisma.smsQueue.update({
        where: { id: job.id },
        data: {
          status: 'FAILED',
          lastError: 'Client has no Semaphore API key configured',
          processedAt: new Date(),
        },
      })
      await createLog(job.id, client.id, job.parentPhone, job.message || '', 'FAILED', null, 'No Semaphore key')
      failed++
      continue
    }

    const message =
      job.message ||
      `${job.event === 'time_in' ? '✅ Time In' : '🔴 Time Out'}: ${job.studentName} (ID: ${job.studentId}) at ${new Date(job.timestamp).toLocaleString('en-PH', { timeZone: 'Asia/Manila' })}`

    const phone = formatPhone(job.parentPhone)
    const result = await sendSms(client.semaphoreKey, client.senderName || 'NFC-HUB', phone, message)

    const newAttempts = job.attempts + 1

    if (result.success) {
      await prisma.smsQueue.update({
        where: { id: job.id },
        data: { status: 'SENT', attempts: newAttempts, processedAt: new Date(), lastError: null },
      })
      await createLog(job.id, client.id, phone, message, 'SUCCESS', result.messageId, null)
      processed++
    } else {
      const nextStatus = newAttempts >= MAX_ATTEMPTS ? 'FAILED' : 'RETRYING'
      const retryDelay = Math.pow(2, newAttempts) * 60 * 1000
      const scheduledAt = nextStatus === 'RETRYING' ? new Date(Date.now() + retryDelay) : new Date()

      await prisma.smsQueue.update({
        where: { id: job.id },
        data: {
          status: nextStatus,
          attempts: newAttempts,
          lastError: result.error,
          scheduledAt,
          processedAt: nextStatus === 'FAILED' ? new Date() : undefined,
        },
      })

      if (nextStatus === 'FAILED') {
        await createLog(job.id, client.id, phone, message, 'FAILED', null, result.error || 'Max retries reached')
        failed++
      }
    }
  }

  return { processed, failed }
}

async function createLog(
  queueId: string,
  clientId: string,
  phone: string,
  message: string,
  status: 'SUCCESS' | 'FAILED',
  semaphoreId: string | null | undefined,
  errorReason: string | null | undefined
) {
  const existing = await prisma.smsLog.findUnique({ where: { queueId } })
  if (existing) return
  await prisma.smsLog.create({
    data: {
      queueId,
      clientId,
      phone,
      message,
      status,
      semaphoreId: semaphoreId ?? null,
      errorReason: errorReason ?? null,
    },
  })
}