import {z} from 'zod'

export type ContentPart = {type: 'text' | 'image_url', text?: string | undefined, image_url?: ({url?: string | undefined}) | undefined};

export type ChatMessage = {role: 'system' | 'user' | 'assistant', content: string | Array<ContentPart>};

export type ChatRequest = {messages: Array<ChatMessage>, model?: string | undefined, stream?: boolean | undefined, temperature?: number | undefined, max_tokens?: number | undefined};

export type CreateApiV1ChatCompletionsArgs = {body: ChatRequest};

export type CreateApiV1ChatCompletionsOptions = {baseUrl?: string | undefined, BearerAuth?: string | undefined, fetch?: typeof fetch | undefined};

export const chatResponse = z.object({id: z.string().optional(), object: z.literal("chat.completion").optional(), created: z.number().int().optional(), model: z.string().optional(), choices: z.array(z.object({index: z.number().int().optional(), message: z.object({role: z.literal("assistant").optional(), content: z.string().optional()}).optional(), finish_reason: z.literal("stop").optional()})).optional(), usage: z.object({prompt_tokens: z.number().int().optional(), completion_tokens: z.number().int().optional(), total_tokens: z.number().int().optional()}).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
};

/**
 * Chat (POST)
 * 
 * POST /v1/chat/completions
 * 
 * Also accepts auth: ApiKeyHeader, ApiKeyQuery
 */
export const createApiV1ChatCompletions = async (args: CreateApiV1ChatCompletionsArgs, options?: CreateApiV1ChatCompletionsOptions) => {
const {baseUrl = "https://search.elixpo.com", fetch: fetchFn = fetch, BearerAuth} = options ?? {}

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

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

const url = `${baseUrl.replace(/\/+$/, '')}/v1/chat/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(chatResponse, await res.json())
};