import {z} from 'zod'

export type DocumentURLChunk = {document_name?: (string | null) | undefined, type?: string | undefined, document_url: string};

export type ImageURLChunk = {image_url: {detail?: (string | null) | undefined, url: string} | string, type?: 'image_url' | undefined};

export type OCRRequest = {pages?: (Array<number> | null) | undefined, image_min_size?: (number | null) | undefined, document: DocumentURLChunk | ImageURLChunk, include_image_base64?: (boolean | null) | undefined, image_limit?: (number | null) | undefined, model: string | null, id?: string | undefined};

export type CreateApiOcrArgs = {body: OCRRequest};

export type CreateApiOcrOptions = {baseUrl?: string | undefined, ApiKey?: string | undefined, fetch?: typeof fetch | undefined};

export const oCRImageObject = z.object({bottom_right_x: z.number().int().gte(0).nullable(), bottom_right_y: z.number().int().gte(0).nullable(), image_base64: z.string().nullable().optional(), top_left_y: z.number().int().gte(0).nullable(), id: z.string(), top_left_x: z.number().int().gte(0).nullable()});

export const oCRPageDimensions = z.object({width: z.number().int().gte(0), dpi: z.number().int().gte(0), height: z.number().int().gte(0)});

export const oCRPageObject = z.object({images: z.array(oCRImageObject), markdown: z.string(), index: z.number().int().gte(0), dimensions: oCRPageDimensions});

export const oCRUsageInfo = z.object({pages_processed: z.number().int().gte(0), doc_size_bytes: z.number().int().nullable().optional()});

export const oCRResponse = z.object({pages: z.array(oCRPageObject), model: z.string(), usage_info: oCRUsageInfo});

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
};

/**
 * OCR
 * 
 * POST /ocr
 */
export const createApiOcr = async (args: CreateApiOcrArgs, options?: CreateApiOcrOptions) => {
const {baseUrl = "https://api.mistral.ai/v1", fetch: fetchFn = fetch, ApiKey} = options ?? {}

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

if (ApiKey !== undefined) headers.set('authorization', `Bearer ${ApiKey}`)

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

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

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

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