import {z} from 'zod'

export type FineTuningJobCreate = {base_model_name: string, dataset_name: string, parameters: {batch_size?: number | undefined, num_epochs?: number | undefined, shuffle?: boolean | undefined, lr?: number | undefined, seed?: number | undefined} | {[key: string]: unknown}, name: string, type: 'LORA' | 'QLORA'};

export type CreateApiV1FineTuningArgs = {body: FineTuningJobCreate};

export type CreateApiV1FineTuningOptions = {baseUrl: string, ApiKeyAuth?: string | undefined, fetch?: typeof fetch | undefined};

export const fineTuningJobResponse = z.object({id: z.string().optional(), created_at: z.string().optional(), updated_at: z.string().optional(), status: z.enum(["NEW", "QUEUED", "RUNNING", "COMPLETED", "FAILED", "STOPPING", "STOPPED"]).optional(), base_model_name: z.string().optional(), dataset_name: z.string().optional(), name: z.string().optional(), type: z.enum(["LORA", "QLORA"]).optional(), current_step: z.number().int().optional(), total_steps: z.number().int().optional(), current_epoch: z.number().int().optional(), total_epochs: z.number().int().optional(), num_tokens: z.number().int().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
};

/**
 * Create a new fine-tuning job
 * 
 * POST /v1/fine-tuning
 */
export const createApiV1FineTuning = async (args: CreateApiV1FineTuningArgs, options: CreateApiV1FineTuningOptions) => {
const {baseUrl, fetch: fetchFn = fetch, ApiKeyAuth} = options ?? {}

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

if (ApiKeyAuth !== undefined) headers.set("x-api-key", ApiKeyAuth)

const url = `${baseUrl.replace(/\/+$/, '')}/v1/fine-tuning${query.size > 0 ? `?${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(fineTuningJobResponse, await res.json())
};