import {z} from 'zod'

export type CreateApiOcrPdfToTextArgs = {recognitionMode?: string | undefined, language?: string | undefined, preprocessing?: string | undefined, body: BodyInit};

export type CreateApiOcrPdfToTextOptions = {baseUrl?: string | undefined, Apikey?: string | undefined, fetch?: typeof fetch | undefined};

export const ocrPageResult = z.object({PageNumber: z.number().int().optional(), MeanConfidenceLevel: z.number().optional(), TextResult: z.string().optional()});

export const pdfToTextResponse = z.object({Successful: z.boolean().optional(), OcrPages: z.array(ocrPageResult).optional(), AsyncJobID: z.string().optional(), AsyncJobStatus: z.string().optional()});

export const validateResponse = async <Output>(
  schema: {
    readonly '~standard': {
      readonly validate: (value: unknown) => ({ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }) | Promise<{ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }>
    }
  },
  value: unknown
): Promise<Output> => {
  const result = await schema['~standard'].validate(value)

  if (result.issues !== undefined) {
    const detail = result.issues
      .map(({ message, path }) =>
        path?.length
          ? `${path.map((segment) => String(typeof segment === 'object' ? segment.key : segment)).join('.')}: ${message}`
          : message
      )
      .join('; ')

    throw new Error(`Response does not match the schema: ${detail}`, { cause: { issues: result.issues } })
  }

  return result.value
};

/**
 * Converts an uploaded PDF file into text via Optical Character Recognition.
 * 
 * POST /ocr/pdf/toText
 */
export const createApiOcrPdfToText = async (args: CreateApiOcrPdfToTextArgs, options?: CreateApiOcrPdfToTextOptions) => {
const {baseUrl = "http://localhost", fetch: fetchFn = fetch, Apikey} = options ?? {}

const query = new URLSearchParams()
const headers = new Headers()
headers.set('accept', "application/json")

if (args.recognitionMode != null) headers.set("recognitionMode", String(args.recognitionMode))
if (args.language != null) headers.set("language", String(args.language))
if (args.preprocessing != null) headers.set("preprocessing", String(args.preprocessing))
if (Apikey !== undefined) headers.set("Apikey", Apikey)

const url = `${baseUrl.replace(/\/+$/, '')}/ocr/pdf/toText${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "POST", headers, body: args.body})

if (!res.ok) throw new Error(`Request failed with status ${res.status}`, {cause: {status: res.status, body: await res.text()}})

return validateResponse(pdfToTextResponse, await res.json())
};