import {z} from 'zod'

export type WidgetAmountCurrency = 'local' | 'crypto';

export type OffRampPaymentChannel = 'bank' | 'airtime' | 'mobile_money' | 'paybill';

export type OffRampNetwork = 'AVALANCHE' | 'POLYGON' | 'CELO' | 'ETHEREUM';

export type OffRampAsset = 'USDC' | 'USDT' | 'CUSD' | 'CKES' | 'CGHS';

export type GetApiApiOfframpBestOfferArgs = {amount: number, currency: WidgetAmountCurrency, countryIsoCode: string, paymentChannel: OffRampPaymentChannel, network: OffRampNetwork, asset: OffRampAsset};

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

export const offRampPaymentChannel = z.enum(["bank", "airtime", "mobile_money", "paybill"]);

export const requiredFieldType = z.enum(["number", "string", "date", "boolean", "email", "enum"]);

export const offrampBestOfferResponse = z.object({quoteId: z.string().optional(), offer: z.object({paymentChannel: offRampPaymentChannel.optional(), countryIsoCode: z.string().optional(), currencyIsoCode: z.string().optional(), exchangeRate: z.number().optional(), cryptoExchangeRate: z.number().optional(), requiredFields: z.record(z.string(), z.object({type: requiredFieldType.optional(), label: z.string().optional(), required: z.boolean().optional(), options: z.array(z.object({value: z.string().optional(), label: z.string().optional()})).optional()})).optional()}).optional(), cashout: z.object({localCurrencyAmount: z.number().optional(), usdAmount: z.number().optional(), feeAmountUsd: z.number().optional(), feeAmountUsdFonbnk: z.number().optional(), feeAmountUsdPartner: z.number().optional(), feeAmountLocalCurrency: z.number().optional(), feeAmountLocalCurrencyFonbnk: z.number().optional(), feeAmountLocalCurrencyPartner: z.number().optional(), cryptoAmount: z.number().optional(), feeAmountCrypto: z.number().optional(), feeAmountCryptoFonbnk: z.number().optional(), feeAmountCryptoPartner: z.number().optional()}).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 best offer
 * 
 * GET /api/offramp/best-offer
 * 
 * Also accepts auth: TimestampHeader, SignatureHeader
 */
export const getApiApiOfframpBestOffer = async (args: GetApiApiOfframpBestOfferArgs, options?: GetApiApiOfframpBestOfferOptions) => {
const {baseUrl = "https://sandbox-api.fonbnk.com", fetch: fetchFn = fetch, ClientIdHeader} = options ?? {}

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

if (args.amount != null) query.append("amount", String(args.amount))
if (args.currency != null) query.append("currency", String(args.currency))
if (args.countryIsoCode != null) query.append("countryIsoCode", String(args.countryIsoCode))
if (args.paymentChannel != null) query.append("paymentChannel", String(args.paymentChannel))
if (args.network != null) query.append("network", String(args.network))
if (args.asset != null) query.append("asset", String(args.asset))
if (ClientIdHeader !== undefined) headers.set("x-client-id", ClientIdHeader)

const url = `${baseUrl.replace(/\/+$/, '')}/api/offramp/best-offer${query.size > 0 ? `?${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(offrampBestOfferResponse, await res.json())
};