export async function sendWhatsAppMessage(
  phoneNumber: string,
  templateName: string,
  parameters: string[],
  phoneNumberId: string,
  accessToken: string,
): Promise<void> {
  const sanitized = phoneNumber.replace(/[^0-9]/g, '')
  if (!sanitized) return

  const body = {
    messaging_product: 'whatsapp',
    to: sanitized,
    type: 'template',
    template: {
      name: templateName,
      language: { code: 'en_US' },
      components: [
        {
          type: 'body',
          parameters: parameters.map(text => ({ type: 'text', text })),
        },
      ],
    },
  }

  const res = await fetch(
    `https://graph.facebook.com/v19.0/${phoneNumberId}/messages`,
    {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'Authorization': `Bearer ${accessToken}`,
      },
      body: JSON.stringify(body),
    }
  )

  if (!res.ok) {
    throw new Error(`WhatsApp API error: ${res.status}`)
  }
}