import {z} from 'zod'

export type CreateApiCygnalV1MessagesOptions = {baseUrl?: string | undefined, fetch?: typeof fetch | undefined};

export const contentBlockOutput = z.object({type: z.literal("text"), text: z.string()});

export const jSONPrimitive = z.union([z.string(), z.number().int(), z.number(), z.boolean()]).nullable();

export const jSONValueOutput: z.ZodType<JSONValueOutput> = z.union([jSONPrimitive, z.array(z.lazy(() => jSONValueOutput)), z.record(z.string(), z.lazy(() => jSONValueOutput))]);

export const toolUseBlock = z.object({type: z.literal("tool_use"), id: z.string(), name: z.string(), input: z.record(z.string(), jSONValueOutput)});

export const anthropicUsage = z.object({input_tokens: z.number().int(), output_tokens: z.number().int()});

export const apiTypesResponsesAnthropicResponseCreateChatCompletionResponse = z.object({id: z.string(), type: z.literal("message"), role: z.literal("assistant"), content: z.array(z.union([contentBlockOutput, toolUseBlock])), model: z.string(), stop_reason: z.enum(["end_turn", "max_tokens", "stop_sequence", "tool_use", "content_filter"]).nullable().optional(), usage: anthropicUsage.nullable().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
};

/**
 * Cygnal Anthropic Messages
 * 
 * POST /cygnal/v1/messages
 */
export const createApiCygnalV1Messages = async (options?: CreateApiCygnalV1MessagesOptions) => {
const {baseUrl = "https://api.grayswan.ai", fetch: fetchFn = fetch} = options ?? {}

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

const url = `${baseUrl.replace(/\/+$/, '')}/cygnal/v1/messages${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "POST", headers})

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

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