import type { H3Event } from 'h3'

import type { PublicBooking, WhatsAppDeliveryResult } from '~~/shared/booking'

import {
  formatBookingCurrency
} from '~~/shared/booking'
import { normalizePhoneNumber } from '~~/shared/auth'

import { buildAppUrl } from './app-url'

type WhatsAppMessagesResponse = {
  messages?: Array<{
    id?: string
  }>
}

export function toWhatsAppPhoneNumber(phoneNumber: string) {
  return normalizePhoneNumber(phoneNumber).replace(/\D/g, '')
}

export function buildWhatsAppDeepLink(phoneNumber: string, message: string) {
  return `https://wa.me/${toWhatsAppPhoneNumber(phoneNumber)}?text=${encodeURIComponent(message)}`
}

export function buildBookingTicketReceiptMessage(event: H3Event, booking: PublicBooking) {
  const receiptUrl = buildAppUrl(event, `/receipt/${booking.receiptToken}`)

  return [
    booking.event.title,
    '',
    `Hi ${booking.customerName}, your ticket receipt has been confirmed.`,
    '',
    `Receipt: ${receiptUrl}`,
    `Seats: ${booking.seatCount}`,
    `Ticket Category: ${booking.ticketLabel || booking.ticketType.toUpperCase()}`,
    `Total Price: ${formatBookingCurrency(booking.totalPrice)}`,
    `Date: ${booking.event.dateLabel}`,
    `Time: ${booking.event.timeLabel}`,
    `Venue: ${booking.event.venue}`,
    '',
    'Please present the QR code from the receipt at the event.'
  ].join('\n')
}

export async function sendBookingTicketReceiptViaWhatsApp(
  event: H3Event,
  booking: PublicBooking
): Promise<WhatsAppDeliveryResult> {
  const recipientPhone = normalizePhoneNumber(booking.customerPhone)
  const to = toWhatsAppPhoneNumber(recipientPhone)
  const config = useRuntimeConfig()
  const accessToken = String(config.whatsappAccessToken || '')
  const phoneNumberId = String(config.whatsappPhoneNumberId || '')
  const apiVersion = String(config.whatsappApiVersion || 'v23.0')

  if (!accessToken || !phoneNumberId) {
    return {
      sent: false,
      skipped: true,
      recipientPhone,
      apiRecipientPhone: to,
      error: 'WhatsApp API credentials are not configured.'
    }
  }

  try {
    const response = await $fetch<WhatsAppMessagesResponse>(
      `https://graph.facebook.com/${apiVersion}/${phoneNumberId}/messages`,
      {
        method: 'POST',
        headers: {
          Authorization: `Bearer ${accessToken}`
        },
        body: {
          messaging_product: 'whatsapp',
          recipient_type: 'individual',
          to,
          type: 'text',
          text: {
            preview_url: true,
            body: buildBookingTicketReceiptMessage(event, booking)
          }
        }
      }
    )

    return {
      sent: true,
      skipped: false,
      recipientPhone,
      apiRecipientPhone: to,
      messageId: response.messages?.[0]?.id
    }
  } catch (error: any) {
    return {
      sent: false,
      skipped: false,
      recipientPhone,
      apiRecipientPhone: to,
      error: error?.data?.error?.message || error?.message || 'WhatsApp API request failed.'
    }
  }
}