// The OCR port over the platform's document reader: the one file of this module that knows the SDK's
// error type.
//
// `DocumentReader` (kit-platform) is `@conusai-sdk/ocr` wired to the deployment contract: `submit`
// returns when the platform has accepted the document and `wait` polls the job to its document. What
// this adapter adds is the one distinction core needs and the SDK only encodes in a string: "the
// platform says this job failed" (permanent, the document is marked failed) against everything else
// (a network error, a timeout, a 5xx: the job throws and the queue retries it). A page image the platform
// has none of is not a failure either: the page is read from its text.

import type { DocumentReader } from "@conusai-kit/platform"
import { OcrError } from "@conusai-sdk/ocr"
import { type DocumentOcr, OcrJobFailed } from "../core/ports.js"

export interface SdkOcrOptions {
  /** Poll interval of `wait`, in milliseconds. */
  readonly intervalMs?: number
  /** Give up on one job after this long; the document then retries from its stored job id. */
  readonly timeoutMs?: number
}

export function sdkDocumentOcr(
  reader: Pick<DocumentReader, "submit" | "wait" | "page">,
  options: SdkOcrOptions = {},
): DocumentOcr {
  return {
    async submit(bytes, { filename, idempotencyKey }) {
      const job = await reader.submit(bytes, { filename, idempotencyKey })
      return { jobId: job.id }
    },
    async wait(jobId, { signal } = {}) {
      try {
        return await reader.wait(jobId, {
          ...(options.intervalMs === undefined ? {} : { intervalMs: options.intervalMs }),
          ...(options.timeoutMs === undefined ? {} : { timeoutMs: options.timeoutMs }),
          ...(signal ? { signal } : {}),
        })
      } catch (error) {
        if (error instanceof OcrError && error.type === "job-failed") throw new OcrJobFailed()
        throw error
      }
    },
    async page(jobId, page, { signal } = {}) {
      try {
        const image = await reader.page(jobId, page, signal ? { signal } : {})
        return { bytes: image.bytes, mediaType: image.contentType }
      } catch (error) {
        // The platform keeps a job's input for a day and draws a page on demand: a job past that, or a
        // page it has none of, is a page read from its text. Anything else is transient and thrown.
        if (error instanceof OcrError && (error.status === 404 || error.status === 422)) return undefined
        throw error
      }
    },
  }
}