import type { BrokerLedgerLike } from '../economy/auto-topup'

/**
 * A listed inference service from a provider catalog (0G serving-broker
 * `listService()` for Direct; the public `/v1/models` list for Router).
 */
export interface ListedService {
  provider: string
  url?: string
  endpoint?: string
  model: string
  serviceType?: string
  inputPrice?: bigint
  outputPrice?: bigint
  verifiability?: string
  [k: string]: unknown
}

/**
 * Provider-specific seam for the OpenAI-compatible completion call.
 *
 * {@link OGComputeBrain} owns everything provider-agnostic: the tool loop, the
 * `<think>`/dash sanitizers, compaction, channel history + persistence, and
 * the actual `fetch` + request-body build + response parse. A
 * `CompletionTransport` owns ONLY the three things that differ per provider:
 *
 *   1. endpoint + model resolution ({@link init} → {@link baseUrl}/{@link modelId})
 *   2. per-request auth headers ({@link authHeaders})
 *   3. HTTP-error mapping ({@link mapHttpError})
 *
 * Direct (0G serving-broker, EIP-712 per-request vouchers) is the default impl
 * (`DirectTransport`) and is what every existing caller gets when no transport
 * is injected. The 0G Router (OpenAI-compatible gateway, `Bearer sk-`) is the
 * opt-in second impl (`RouterTransport`). Keeping the fetch + parse shared is
 * what makes the Direct path bit-identical after extraction.
 */
export interface CompletionTransport {
  /** Idempotent. Resolve {@link baseUrl} + {@link modelId} + any auth/session setup. */
  init(): Promise<void>
  /** Base URL for the OpenAI-compatible endpoint (no trailing slash). Valid after {@link init}. */
  readonly baseUrl: string
  /** Model id to send in the request body. Valid after {@link init}. */
  readonly modelId: string
  /**
   * Provider-specific auth headers for ONE completion POST. `lastContent` is
   * the last message's content; Direct binds it into the per-request EIP-712
   * voucher, Router ignores it (Bearer auth is content-independent).
   */
  authHeaders(lastContent: string): Promise<Record<string, string>>
  /**
   * Map a non-OK HTTP completion response into a typed Error, or `null` to let
   * the caller throw a generic `Brain HTTP <status>` error.
   */
  mapHttpError(status: number, body: string): Error | null
  /**
   * Whether the brain should strip inline `<think>...</think>` blocks from
   * `content`. True for Router (MiniMax-M3 emits CoT inline); false/undefined
   * for Direct so the Direct path stays byte-identical (qwen routes CoT into
   * `reasoning_content`, not `content`).
   */
  readonly stripInlineThink?: boolean
  /**
   * Called by the brain on an HTTP 401/403 (auth) from a completion. Re-establish
   * credentials (e.g. Router re-mints its sk- via SIWE) and return `true` if the
   * request should be retried once. Absent/`false` → no retry (Direct's
   * per-request voucher never expires, so it has none).
   */
  reprovision?(): Promise<boolean>
  /**
   * The prepaid-credit ledger object the auto-topup manager consumes, or
   * `null` when N/A. Direct returns `broker.ledger`; Router returns `null`
   * (it has no serving-broker ledger, the Payment Layer is funded separately).
   */
  getLedger(): BrokerLedgerLike | null
  /** Live prepaid balance in 0G, or `null` on failure / when N/A. */
  getLedgerBalance(): Promise<number | null>
  /** Live model/service catalog. */
  listServices(): Promise<ListedService[]>
}