import {z} from 'zod'

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

export const floatStringNullable = z.string().nullable();

export const timestampNullable = z.string().nullable();

export const integerStringNullable = z.string().nullable();

export const floatString = z.string();

export const integerString = z.string();

export const statsResponse = z.object({average_block_time: z.number().optional(), coin_image: z.string().nullable().optional(), coin_price: floatStringNullable.optional(), coin_price_change_percentage: z.number().nullable().optional(), gas_price_updated_at: timestampNullable.optional(), gas_prices: z.object({}).nullable().optional(), gas_prices_update_in: z.number().int().nullable().optional(), gas_used_today: z.union([integerStringNullable, z.number().int()]).optional(), market_cap: floatString.optional(), network_utilization_percentage: z.number().nullable().optional(), secondary_coin_image: z.string().nullable().optional(), secondary_coin_price: floatStringNullable.optional(), static_gas_price: integerStringNullable.optional(), total_addresses: integerString.optional(), total_blocks: integerString.optional(), total_gas_used: integerString.optional(), total_transactions: integerString.optional(), transactions_today: integerString.optional(), tvl: integerStringNullable.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
};

/**
 * get stats counters
 * 
 * GET /stats
 * 
 * Also accepts auth: apiKeyAuth
 */
export const getApiStats = async (options?: GetApiStatsOptions) => {
const {baseUrl = "https://api.blockscout.com", fetch: fetchFn = fetch, bearerAuth} = options ?? {}

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

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

const url = `${baseUrl.replace(/\/+$/, '')}/stats${query.size > 0 ? `?${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(statsResponse, await res.json())
};