import {z} from 'zod'

export type ChatCompletionRequest = {model: string, messages: Array<{role: 'system' | 'user' | 'assistant' | 'tool', content: unknown, name?: string | undefined, tool_calls?: Array<Record<string, never>> | undefined, tool_call_id?: string | undefined}>, temperature?: number | undefined, top_p?: number | undefined, max_tokens?: number | undefined, max_completion_tokens?: number | undefined, stream?: boolean | undefined, stop: unknown, presence_penalty?: number | undefined, frequency_penalty?: number | undefined, user?: string | undefined, response_format?: Record<string, never> | undefined, seed?: number | undefined, tools?: Array<Record<string, never>> | undefined, tool_choice: unknown};

export type CreateApiV1ChatCompletionsArgs = {'X-Provider-Key': string, traceparent?: string | undefined, body: ChatCompletionRequest};

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

export const chatCompletionResponse = z.object({id: z.string(), object: z.literal("chat.completion"), created: z.number().int(), model: z.string(), choices: z.array(z.object({index: z.number().int().optional(), message: z.object({role: z.string().optional(), content: z.string().nullable().optional(), tool_calls: z.array(z.object({})).optional()}).optional(), finish_reason: z.enum(["stop", "length", "tool_calls", "content_filter", "null"]).nullable().optional()})), usage: z.object({prompt_tokens: z.number().int().optional(), completion_tokens: z.number().int().optional(), total_tokens: z.number().int().optional()}).optional(), system_fingerprint: 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
};

/**
 * OpenAI-compatible chat completions with policy enforcement
 * 
 * POST /v1/chat/completions
 */
export const createApiV1ChatCompletions = async (args: CreateApiV1ChatCompletionsArgs, options?: CreateApiV1ChatCompletionsOptions) => {
const {baseUrl = "https://agent.getaxonflow.com", fetch: fetchFn = fetch} = options ?? {}

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

if (args['X-Provider-Key'] != null) headers.set("X-Provider-Key", String(args['X-Provider-Key']))
if (args.traceparent != null) headers.set("traceparent", String(args.traceparent))

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(chatCompletionResponse, await res.json())
};