/**
 * WhatsApp Provider Abstraction Layer
 *
 * Supports multiple WhatsApp providers with a common interface:
 * - Meta WhatsApp Business Cloud API
 * - Twilio WhatsApp
 */

import { prisma } from '@/lib/prisma'
import { MetaWhatsAppProvider } from './meta-provider'
import { TwilioWhatsAppProvider } from './twilio-provider'

export interface WhatsAppResult {
  success: boolean
  messageId?: string
  error?: string
}

export interface WhatsAppProvider {
  sendText(to: string, body: string): Promise<WhatsAppResult>
  sendTemplate(
    to: string,
    template: string,
    params: Record<string, string>
  ): Promise<WhatsAppResult>
  testConnection(): Promise<{ success: boolean; error?: string }>
}

export type WhatsAppProviderType = 'META' | 'TWILIO'

/**
 * Get the configured WhatsApp provider
 * Returns null if WhatsApp is not enabled or not configured
 */
export async function getWhatsAppProvider(): Promise<WhatsAppProvider | null> {
  try {
    // Check if WhatsApp is enabled
    const enabledSetting = await prisma.systemSettings.findUnique({
      where: { key: 'whatsapp_enabled' },
    })

    if (enabledSetting?.value !== 'true') {
      return null
    }

    // Get provider type
    const providerSetting = await prisma.systemSettings.findUnique({
      where: { key: 'whatsapp_provider' },
    })

    const providerType = (providerSetting?.value || 'META') as WhatsAppProviderType

    if (providerType === 'META') {
      return await createMetaProvider()
    } else if (providerType === 'TWILIO') {
      return await createTwilioProvider()
    }

    return null
  } catch (error) {
    console.error('Failed to get WhatsApp provider:', error)
    return null
  }
}

/**
 * Create Meta WhatsApp provider from settings
 */
async function createMetaProvider(): Promise<WhatsAppProvider | null> {
  const [phoneNumberIdSetting, accessTokenSetting] = await Promise.all([
    prisma.systemSettings.findUnique({
      where: { key: 'whatsapp_meta_phone_number_id' },
    }),
    prisma.systemSettings.findUnique({
      where: { key: 'whatsapp_meta_access_token' },
    }),
  ])

  if (!phoneNumberIdSetting?.value || !accessTokenSetting?.value) {
    console.warn('Meta WhatsApp not fully configured')
    return null
  }

  return new MetaWhatsAppProvider(
    phoneNumberIdSetting.value,
    accessTokenSetting.value
  )
}

/**
 * Create Twilio WhatsApp provider from settings
 */
async function createTwilioProvider(): Promise<WhatsAppProvider | null> {
  const [accountSidSetting, authTokenSetting, phoneNumberSetting] = await Promise.all([
    prisma.systemSettings.findUnique({
      where: { key: 'whatsapp_twilio_account_sid' },
    }),
    prisma.systemSettings.findUnique({
      where: { key: 'whatsapp_twilio_auth_token' },
    }),
    prisma.systemSettings.findUnique({
      where: { key: 'whatsapp_twilio_phone_number' },
    }),
  ])

  if (
    !accountSidSetting?.value ||
    !authTokenSetting?.value ||
    !phoneNumberSetting?.value
  ) {
    console.warn('Twilio WhatsApp not fully configured')
    return null
  }

  return new TwilioWhatsAppProvider(
    accountSidSetting.value,
    authTokenSetting.value,
    phoneNumberSetting.value
  )
}

/**
 * Check if WhatsApp is configured and available
 */
export async function isWhatsAppEnabled(): Promise<boolean> {
  const provider = await getWhatsAppProvider()
  return provider !== null
}

/**
 * Get the current provider type
 */
export async function getWhatsAppProviderType(): Promise<WhatsAppProviderType | null> {
  try {
    const enabledSetting = await prisma.systemSettings.findUnique({
      where: { key: 'whatsapp_enabled' },
    })

    if (enabledSetting?.value !== 'true') {
      return null
    }

    const providerSetting = await prisma.systemSettings.findUnique({
      where: { key: 'whatsapp_provider' },
    })

    return (providerSetting?.value || 'META') as WhatsAppProviderType
  } catch {
    return null
  }
}