import {z} from 'zod'

export type ChatCompletionMessage = {role: 'user' | 'assistant' | 'system', content: string};

export type ChatCompletionRequest = {allow_clarification_query?: boolean | undefined, generate_related_questions?: number | undefined, inline_citations?: boolean | undefined, messages: Array<ChatCompletionMessage>, response_format?: string | undefined, stream?: boolean | undefined, verbosity?: string | undefined};

export type CreateApiAiV2ChatCompletionsArgs = {body: ChatCompletionRequest};

export type CreateApiAiV2ChatCompletionsOptions = {baseUrl?: string | undefined, apiKey?: string | undefined, fetch?: typeof fetch | undefined};

export const chatCompletionResponseMessage = z.record(z.string(), z.unknown());

export const chatCompletionResponse = z.object({messages: z.array(chatCompletionResponseMessage)});

export const chartSource = z.record(z.string(), z.unknown());

export const standardSource = z.record(z.string(), z.unknown());

export const chatCompletionResponseMetadataV2 = z.object({charts: z.array(chartSource).optional(), related_questions: z.array(z.string()).optional(), sources: z.array(standardSource).optional(), status: z.string(), trace_id: z.string()});

export const createApiAiV2ChatCompletionsResponse = z.object({data: chatCompletionResponse, error: z.string().optional(), metadata: chatCompletionResponseMetadataV2.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
};

/**
 * Generate chat completions with Messari AI
 * 
 * POST /ai/v2/chat/completions
 */
export const createApiAiV2ChatCompletions = async (args: CreateApiAiV2ChatCompletionsArgs, options?: CreateApiAiV2ChatCompletionsOptions) => {
const {baseUrl = "https://api.messari.io", fetch: fetchFn = fetch, apiKey} = options ?? {}

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

if (apiKey !== undefined) headers.set("X-Messari-API-Key", apiKey)

const url = `${baseUrl.replace(/\/+$/, '')}/ai/v2/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(createApiAiV2ChatCompletionsResponse, await res.json())
};