import type { CollectionAfterChangeHook } from 'payload'
import { sendTenantEmail } from '../lib/email/tenant-email-service'

interface SubmissionData {
  field: string
  value: string
}

interface FormEmail {
  emailTo?: string | null
  cc?: string | null
  bcc?: string | null
  replyTo?: string | null
  emailFrom?: string | null
  subject?: string | null
  message?: string | null
}

interface FormDocument {
  id: number | string
  title: string
  emails?: FormEmail[]
  tenant?: { id: number | string } | number | string
}

/**
 * Hook: Sendet E-Mail-Benachrichtigungen bei neuen Formular-Einsendungen.
 * Verwendet den Tenant-spezifischen E-Mail-Service.
 */
export const sendFormNotification: CollectionAfterChangeHook = async ({
  doc,
  req,
  operation,
}) => {
  // Nur bei neuen Einsendungen
  if (operation !== 'create') return doc

  const { payload } = req

  try {
    // Form laden mit Details
    const form = (await payload.findByID({
      collection: 'forms',
      id: doc.form,
      depth: 1,
    })) as FormDocument | null

    if (!form) {
      console.warn('[Forms] Form not found for submission:', doc.form)
      return doc
    }

    // Prüfen ob E-Mail-Benachrichtigungen konfiguriert sind
    if (!form.emails || form.emails.length === 0) {
      return doc
    }

    // Tenant ermitteln
    const tenantId = typeof form.tenant === 'object' ? form.tenant?.id : form.tenant

    if (!tenantId) {
      console.warn('[Forms] No tenant found for form submission, skipping email')
      return doc
    }

    // Daten formatieren
    const submissionData = doc.submissionData as SubmissionData[] | undefined
    const dataHtml = submissionData
      ? submissionData
          .map(
            (item) =>
              `<tr><td style="padding: 8px; border: 1px solid #ddd;"><strong>${item.field}</strong></td><td style="padding: 8px; border: 1px solid #ddd;">${item.value || '-'}</td></tr>`,
          )
          .join('')
      : '<tr><td colspan="2">Keine Daten</td></tr>'

    const dataText = submissionData
      ? submissionData.map((item) => `${item.field}: ${item.value || '-'}`).join('\n')
      : 'Keine Daten'

    // E-Mails senden für jede konfigurierte E-Mail-Adresse
    for (const emailConfig of form.emails) {
      if (!emailConfig.emailTo) continue

      const subject = emailConfig.subject || `Neue Formular-Einsendung: ${form.title}`

      await sendTenantEmail(payload, tenantId, {
        to: emailConfig.emailTo,
        subject,
        replyTo: emailConfig.replyTo || undefined,
        source: 'form',
        metadata: {
          formId: form.id,
          formTitle: form.title,
          submissionId: doc.id,
        },
        html: `
          <div style="font-family: Arial, sans-serif; max-width: 600px; margin: 0 auto;">
            <h2 style="color: #333;">Neue Einsendung über "${form.title}"</h2>

            ${emailConfig.message ? `<p>${emailConfig.message}</p>` : ''}

            <table style="width: 100%; border-collapse: collapse; margin: 20px 0;">
              <thead>
                <tr style="background-color: #f5f5f5;">
                  <th style="padding: 8px; border: 1px solid #ddd; text-align: left;">Feld</th>
                  <th style="padding: 8px; border: 1px solid #ddd; text-align: left;">Wert</th>
                </tr>
              </thead>
              <tbody>
                ${dataHtml}
              </tbody>
            </table>

            <p style="color: #666; font-size: 12px;">
              Gesendet am ${new Date().toLocaleString('de-DE')}
            </p>
          </div>
        `,
        text: `Neue Einsendung über "${form.title}"\n\n${emailConfig.message || ''}\n\n${dataText}\n\nGesendet am ${new Date().toLocaleString('de-DE')}`,
      })

      console.log(`[Forms] Notification sent to ${emailConfig.emailTo} for form ${form.title}`)
    }
  } catch (error) {
    console.error('[Forms] Error sending notification:', error)
    // Fehler nicht weiterwerfen, damit die Einsendung trotzdem gespeichert wird
  }

  return doc
}