import {z} from 'zod'

export type ServiceTier = 'auto' | 'default' | 'over-limit' | 'flex' | 'no-limit';

export type CompletionRequest = {model: string, prompt: string | Array<string> | Array<number>, stream?: (boolean | null) | undefined, stream_options?: ({[key: string]: boolean} | null) | undefined, max_tokens?: (number | null) | undefined, temperature?: (number | null) | undefined, top_p?: (number | null) | undefined, n?: (number | null) | undefined, logprobs?: (number | null) | undefined, echo?: (boolean | null) | undefined, stop?: (string | Array<string> | null) | undefined, presence_penalty?: (number | null) | undefined, frequency_penalty?: (number | null) | undefined, logit_bias?: ({[key: string]: number} | null) | undefined, user?: (string | null) | undefined, extra_body?: ({[key: string]: unknown} | null) | undefined, service_tier?: ServiceTier | undefined} | {[key: string]: unknown};

export type CreateApiV1CompletionsArgs = {ai_project_id?: (string | null) | undefined, body: CompletionRequest};

export type CreateApiV1CompletionsOptions = {baseUrl?: string | undefined, HTTPBearer?: string | undefined, fetch?: typeof fetch | undefined};

export const completionFinishReason = z.enum(["stop", "length", "content_filter"]);

export const completionChoice = z.object({index: z.number().int(), text: z.string(), finish_reason: completionFinishReason});

export const promptTokensDetails = z.object({cached_tokens: z.number().int().nullable().optional()});

export const completionTokensDetails = z.object({reasoning_tokens: z.number().int().nullable().optional()});

export const usage = z.object({completion_tokens: z.number().int(), prompt_tokens: z.number().int(), total_tokens: z.number().int(), prompt_tokens_details: promptTokensDetails.nullable().optional(), completion_tokens_details: completionTokensDetails.nullable().optional()});

export const serviceTier = z.enum(["auto", "default", "over-limit", "flex", "no-limit"]);

export const completionResponse = z.object({id: z.string(), object: z.string(), created: z.number().int(), model: z.string(), choices: z.array(completionChoice), usage: usage, service_tier: serviceTier});

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 completion
 * 
 * POST /v1/completions
 */
export const createApiV1Completions = async (args: CreateApiV1CompletionsArgs, options?: CreateApiV1CompletionsOptions) => {
const {baseUrl = "https://api.tokenfactory.nebius.com", fetch: fetchFn = fetch, HTTPBearer} = options ?? {}

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

if (args.ai_project_id != null) query.append("ai_project_id", String(args.ai_project_id))
if (HTTPBearer !== undefined) headers.set('authorization', `Bearer ${HTTPBearer}`)

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