import { apiClient } from "@/lib/api/client"
import type { ContactImportInput } from "@/lib/contacts/import-parsers"

/** Backend bulk-import item (user derived from token; never in the body). */
export type BulkImportContact = {
  full_name?: string
  email?: string
  phone?: string
  org?: string
  uid?: string
  raw_vcard?: string
}

export type BulkImportResult = {
  created: number
  failed: { index: number; error: string }[]
}

/** Backend caps: 5000 contacts / request, 8 MiB body. */
const MAX_PER_REQUEST = 5000

export function importInputToBulk(c: ContactImportInput): BulkImportContact {
  const fullName = `${c.firstName} ${c.lastName}`.trim()
  return {
    full_name: fullName || c.emails[0]?.value || undefined,
    email: c.emails[0]?.value,
    phone: c.phones[0]?.value,
    org: c.company,
  }
}

/**
 * Bulk import contacts into a book via POST /contacts/books/{bookID}/import,
 * chunked to respect the backend per-request cap. Replaces the previous
 * N-times-POST loop.
 */
export async function bulkImportContacts(
  bookId: string,
  contacts: (BulkImportContact | string)[]
): Promise<BulkImportResult> {
  let created = 0
  const failed: { index: number; error: string }[] = []

  for (let offset = 0; offset < contacts.length; offset += MAX_PER_REQUEST) {
    const chunk = contacts.slice(offset, offset + MAX_PER_REQUEST)
    const res = await apiClient.post<BulkImportResult>(
      `/contacts/books/${encodeURIComponent(bookId)}/import`,
      { contacts: chunk }
    )
    created += res?.created ?? 0
    for (const f of res?.failed ?? []) {
      failed.push({ index: f.index + offset, error: f.error })
    }
  }

  return { created, failed }
}