import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query"

import { apiClient } from "@/lib/api-client"

// --- Constants ---

const CLUB_ID = "00000000-0000-0000-0000-000000000001"

// --- Types ---

export type DocumentCategory =
  | "SATZUNG"
  | "PROTOKOLL"
  | "VERTRAG"
  | "VERSICHERUNG"
  | "GENEHMIGUNG"
  | "SONSTIGES"

export type DocumentAccessLevel = "ALL_MEMBERS" | "BOARD_ONLY"

export interface ClubDocument {
  id: string
  title: string
  category: DocumentCategory
  filename: string
  contentType: string
  fileSize: number
  accessLevel: DocumentAccessLevel
  description: string | null
  uploadedBy: string
  createdAt: string
  updatedAt: string | null
}

export interface StorageUsage {
  bytesUsed: number
}

export interface UploadDocumentRequest {
  title: string
  category: DocumentCategory
  accessLevel: DocumentAccessLevel
  description: string | null
  file: File
}

// --- Raw API functions ---

export async function uploadDocument(
  clubId: string,
  title: string,
  category: DocumentCategory,
  accessLevel: DocumentAccessLevel,
  description: string | null,
  file: File
): Promise<ClubDocument> {
  const formData = new FormData()
  formData.append("file", file)

  const params = new URLSearchParams({
    clubId,
    title,
    category,
    accessLevel,
  })
  if (description) params.append("description", description)

  // Multipart upload — use raw fetch since apiClient assumes JSON
  const res = await fetch(
    `/api/backend/documents/upload?${params.toString()}`,
    {
      method: "POST",
      body: formData,
    }
  )
  if (!res.ok) {
    if (res.status === 402) {
      const problem = await res.json()
      const error = new Error("Storage quota exceeded") as Error & {
        status: number
        problemDetail: unknown
      }
      error.status = 402
      error.problemDetail = problem
      throw error
    }
    throw new Error("Upload failed")
  }
  return res.json()
}

export function listDocuments(
  clubId: string,
  category?: DocumentCategory,
  accessLevel?: DocumentAccessLevel
): Promise<ClubDocument[]> {
  const params = new URLSearchParams({ clubId })
  if (category) params.append("category", category)
  if (accessLevel) params.append("accessLevel", accessLevel)
  return apiClient<ClubDocument[]>(`/documents?${params.toString()}`)
}

export async function downloadDocument(id: string): Promise<Blob> {
  const res = await fetch(`/api/backend/documents/${id}/download`)
  if (!res.ok) throw new Error("Download failed")
  return res.blob()
}

export function deleteDocument(id: string, clubId: string): Promise<void> {
  return apiClient<void>(`/documents/${id}?clubId=${clubId}`, {
    method: "DELETE",
  })
}

export function getStorageUsage(clubId: string): Promise<StorageUsage> {
  return apiClient<StorageUsage>(`/documents/usage?clubId=${clubId}`)
}

export function getPortalDocuments(clubId: string): Promise<ClubDocument[]> {
  return apiClient<ClubDocument[]>(`/portal/documents?clubId=${clubId}`)
}

// --- React Query Hooks ---

export function useDocumentsQuery(category?: DocumentCategory) {
  return useQuery({
    queryKey: ["documents", CLUB_ID, category],
    queryFn: () => listDocuments(CLUB_ID, category),
  })
}

export function useUploadDocumentMutation() {
  const queryClient = useQueryClient()
  return useMutation({
    mutationFn: (data: UploadDocumentRequest) =>
      uploadDocument(
        CLUB_ID,
        data.title,
        data.category,
        data.accessLevel,
        data.description,
        data.file
      ),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ["documents"] })
    },
  })
}

export function useDeleteDocumentMutation() {
  const queryClient = useQueryClient()
  return useMutation({
    mutationFn: (id: string) => deleteDocument(id, CLUB_ID),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ["documents"] })
    },
  })
}

// --- Helper: format file size ---

export function formatFileSize(bytes: number): string {
  if (bytes < 1024) return `${bytes} B`
  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`
  return `${(bytes / (1024 * 1024)).toFixed(1)} MB`
}

// --- Category labels ---

export const categoryLabels: Record<DocumentCategory, string> = {
  SATZUNG: "Satzung",
  PROTOKOLL: "Protokoll",
  VERTRAG: "Vertrag",
  VERSICHERUNG: "Versicherung",
  GENEHMIGUNG: "Genehmigung",
  SONSTIGES: "Sonstiges",
}