import { SitePagesContent } from '@/lib/site-pages'
import { FormData, PolicyDefaults, PrivacyPolicy } from '@/types/privacy-policy'

const API_BASE_URL = '/api'

/** Fehler einer API-Antwort inkl. der Feld-Validierungsmeldungen des Servers. */
export class ApiError extends Error {
  details: string[]

  constructor(message: string, details: string[] = []) {
    super(message)
    this.name = 'ApiError'
    this.details = details
  }
}

export class ApiClient {
  private async request(endpoint: string, options?: RequestInit) {
    const response = await fetch(`${API_BASE_URL}${endpoint}`, {
      headers: {
        'Content-Type': 'application/json',
        ...options?.headers,
      },
      ...options,
    })

    if (!response.ok) {
      const error = await response.json().catch(() => ({ error: 'Netzwerkfehler' }))
      throw new ApiError(
        error.error || 'Die Anfrage ist fehlgeschlagen',
        Array.isArray(error.details) ? error.details : []
      )
    }

    return response.json()
  }

  async getAllPolicies(admin = false): Promise<PrivacyPolicy[]> {
    const query = admin ? '?admin=true' : ''
    return this.request(`/privacy-policies${query}`)
  }

  async getPolicy(id: number): Promise<PrivacyPolicy> {
    return this.request(`/privacy-policies/${id}`)
  }

  async createPolicy(data: FormData): Promise<PrivacyPolicy> {
    return this.request('/privacy-policies', {
      method: 'POST',
      body: JSON.stringify(data),
    })
  }

  async updatePolicy(id: number, data: FormData): Promise<PrivacyPolicy> {
    return this.request(`/privacy-policies/${id}`, {
      method: 'PUT',
      body: JSON.stringify(data),
    })
  }

  async deletePolicy(id: number): Promise<{ message: string }> {
    return this.request(`/privacy-policies/${id}`, {
      method: 'DELETE',
    })
  }

  /** Liest die zentral gepflegten Standardtexte. */
  async getPolicyDefaults(): Promise<PolicyDefaults> {
    return this.request('/policy-defaults')
  }

  /** Speichert die zentral gepflegten Standardtexte (nur Admin). */
  async updatePolicyDefaults(data: Omit<PolicyDefaults, 'updatedAt'>): Promise<PolicyDefaults> {
    return this.request('/policy-defaults', {
      method: 'PUT',
      body: JSON.stringify(data),
    })
  }

  /** Liest die Inhalte von Impressum, Datenschutzerklärung und Barrierefreiheit. */
  async getSitePages(): Promise<SitePagesContent> {
    return this.request('/site-pages')
  }

  /** Speichert die Inhalte der rechtlichen Seiten (nur Admin). */
  async updateSitePages(data: SitePagesContent): Promise<SitePagesContent> {
    return this.request('/site-pages', {
      method: 'PUT',
      body: JSON.stringify(data),
    })
  }
}

export const apiClient = new ApiClient()