import {z} from 'zod'

export type ApiTokenVerification = 'whitelisted' | 'blacklisted' | 'community' | 'unknown';

export type GetApiV2TokensArgs = {verification?: ApiTokenVerification | undefined};

export type GetApiV2TokensOptions = {baseUrl?: string | undefined, ApiKey?: string | undefined, fetch?: typeof fetch | undefined};

export const apiTokenAddress = z.object({blockchain: z.string(), address: z.string()});

export const apiTokenVerification = z.enum(["whitelisted", "blacklisted", "community", "unknown"]);

export const apiTokenMetadata = z.object({name: z.string(), symbol: z.string(), decimals: z.number().int(), image_url: z.string().optional(), listed: z.boolean(), verification: apiTokenVerification});

export const apiToken = z.object({address: apiTokenAddress, metadata: apiTokenMetadata});

export const getApiV2TokensResponse = z.array(apiToken);

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
};

/**
 * Returns list of tokens supported by the service
 * 
 * GET /v2/tokens
 */
export const getApiV2Tokens = async (args: GetApiV2TokensArgs, options?: GetApiV2TokensOptions) => {
const {baseUrl = "https://backend.swap.coffee", fetch: fetchFn = fetch, ApiKey} = options ?? {}

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

if (args.verification != null) query.append("verification", String(args.verification))
if (ApiKey !== undefined) headers.set("X-Api-Key", ApiKey)

const url = `${baseUrl.replace(/\/+$/, '')}/v2/tokens${query.size > 0 ? `?${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(getApiV2TokensResponse, await res.json())
};