import {z} from 'zod'

export type GetApiV1FlowTickerMomentumArgs = {ticker: string, as_of?: string | undefined, lookback_days?: number | undefined, min_dte?: number | undefined, max_dte?: number | undefined};

export type GetApiV1FlowTickerMomentumOptions = {baseUrl?: string | undefined, bearerApiKey?: string | undefined, fetch?: typeof fetch | undefined};

export const momentumWindowMetrics = z.object({tradeCount: z.number().int().gte(0), premium: z.number(), bullishPremium: z.number(), bearishPremium: z.number(), netPremium: z.number(), fir: z.number()});

export const momentumBaselineRef = z.object({timeOfDay: z.string(), lookbackDays: z.number().int(), daysInBaseline: z.number().int().gte(0), avg5mPremium: z.number(), stddev5mPremium: z.number(), avg5mFir: z.number(), stddev5mFir: z.number()});

export const momentumSignals = z.object({firZscore5m: z.number(), premiumZscore5m: z.number(), trend: z.enum(["accelerating", "steady", "fading", "neutral"]), interpretation: z.string()});

export const momentumResponse = z.object({ticker: z.string(), asOf: z.string(), current5m: momentumWindowMetrics, current30m: momentumWindowMetrics, current1h: momentumWindowMetrics, baseline: momentumBaselineRef.nullable().optional(), signals: momentumSignals, queryTimeMs: z.number().int().gte(0)});

export const meta = z.object({timestamp: z.string(), requestId: z.string()});

export const momentumSuccess = z.object({data: momentumResponse, meta: meta});

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
};

/**
 * Live momentum signal vs baseline (5m / 30m / 1h windows)
 * 
 * GET /v1/flow/{ticker}/momentum
 */
export const getApiV1FlowTickerMomentum = async (args: GetApiV1FlowTickerMomentumArgs, options?: GetApiV1FlowTickerMomentumOptions) => {
const {baseUrl = "https://flow-api.skylit.ai", fetch: fetchFn = fetch, bearerApiKey} = options ?? {}

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

if (args.as_of != null) query.append("as_of", String(args.as_of))
if (args.lookback_days != null) query.append("lookback_days", String(args.lookback_days))
if (args.min_dte != null) query.append("min_dte", String(args.min_dte))
if (args.max_dte != null) query.append("max_dte", String(args.max_dte))
if (bearerApiKey !== undefined) headers.set('authorization', `Bearer ${bearerApiKey}`)

const url = `${baseUrl.replace(/\/+$/, '')}/v1/flow/${encodeURIComponent(String(args.ticker))}/momentum${query.size > 0 ? `?${query}` : ''}`

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

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

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