import useSWR, { mutate } from 'swr'
import { apiClient } from '@/lib/api'
import { FormData, PrivacyPolicy } from '@/types/privacy-policy'

const POLICIES_KEY = '/api/privacy-policies'

export function usePrivacyPolicies() {
  const ADMIN_POLICIES_KEY = '/api/privacy-policies?admin=true'
  
  const { data, error, isLoading } = useSWR<PrivacyPolicy[]>(
    ADMIN_POLICIES_KEY,
    () => apiClient.getAllPolicies(true),
    {
      refreshInterval: 5000, // Refresh every 5 seconds
      revalidateOnFocus: true,
      revalidateOnReconnect: true,
    }
  )

  return {
    policies: data || [],
    isLoading,
    error,
    mutate: () => mutate(ADMIN_POLICIES_KEY),
  }
}

/**
 * Öffentliche Erklärungen. `initial` sind die serverseitig gerenderten Daten:
 * Damit steht die Liste schon im ausgelieferten HTML und wird anschließend im
 * Hintergrund aktualisiert.
 */
export function usePublicPrivacyPolicies(initial?: PrivacyPolicy[]) {
  const { data, error, isLoading } = useSWR<PrivacyPolicy[]>(
    POLICIES_KEY,
    () => apiClient.getAllPolicies(),
    {
      fallbackData: initial,
      refreshInterval: 10000, // Refresh every 10 seconds for public view
      revalidateOnFocus: true,
      revalidateOnReconnect: true,
    }
  )

  const publicPolicies = data?.filter(policy => policy.isPublic) || []

  return {
    policies: publicPolicies,
    // Liegen Startdaten vom Server vor, gibt es nichts zu laden. SWR meldet
    // den ersten Hintergrund-Abgleich sonst als Ladezustand und die fertige
    // Liste würde durch Platzhalter ersetzt.
    isLoading: isLoading && !initial,
    error,
    mutate: () => mutate(POLICIES_KEY),
  }
}

export async function createPolicy(data: FormData) {
  try {
    const newPolicy = await apiClient.createPolicy(data)
    // Trigger revalidation of both admin and public policies lists
    mutate('/api/privacy-policies?admin=true')
    mutate(POLICIES_KEY)
    return newPolicy
  } catch (error) {
    throw error
  }
}

export async function updatePolicy(id: number, data: FormData) {
  try {
    const updatedPolicy = await apiClient.updatePolicy(id, data)
    // Trigger revalidation of both admin and public policies lists
    mutate('/api/privacy-policies?admin=true')
    mutate(POLICIES_KEY)
    return updatedPolicy
  } catch (error) {
    throw error
  }
}

export async function deletePolicy(id: number) {
  try {
    const result = await apiClient.deletePolicy(id)
    // Trigger revalidation of both admin and public policies lists
    mutate('/api/privacy-policies?admin=true')
    mutate(POLICIES_KEY)
    return result
  } catch (error) {
    throw error
  }
}