export type Credential = { kind: 'password' | 'hash' | 'invite'; value: string }

function credentialHeaders(cred: Credential): Record<string, string> {
  if (cred.kind === 'password') return { 'X-Upload-Password': cred.value }
  if (cred.kind === 'hash') return { 'X-Upload-Password-Hash': cred.value }
  return { 'X-Upload-Invite': cred.value }
}

export async function checkCredential(cred: Credential): Promise<boolean> {
  const res = await fetch('/api/auth/check', {
    method: 'POST',
    headers: credentialHeaders(cred),
  })
  const body = (await res.json()) as { ok: boolean }
  return body.ok
}

export async function uploadDrop(
  ciphertext: Uint8Array,
  cred: Credential,
): Promise<{ id: string; ttl: number }> {
  const res = await fetch('/api/drops', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/octet-stream',
      ...credentialHeaders(cred),
    },
    body: ciphertext.slice().buffer,
  })
  if (!res.ok) {
    const body = (await res.json().catch(() => ({}))) as { error?: string }
    throw new Error(body.error ?? `upload failed: ${res.status}`)
  }
  return res.json()
}

export async function downloadDrop(
  id: string,
): Promise<{ ciphertext: Uint8Array; confirmToken: string }> {
  const res = await fetch(`/api/drops/${id}`)
  if (!res.ok) throw new Error(`download failed: ${res.status}`)
  const confirmToken = res.headers.get('X-Confirm-Token') ?? ''
  const ciphertext = new Uint8Array(await res.arrayBuffer())
  return { ciphertext, confirmToken }
}

export async function confirmDrop(id: string, confirmToken: string): Promise<void> {
  await fetch(`/api/drops/${id}/confirm`, {
    method: 'POST',
    headers: { Authorization: `Bearer ${confirmToken}` },
  })
}