import type { AxiosRequestConfig } from 'axios'
import axios from 'axios'
import { ResultAsync, errAsync, okAsync } from 'neverthrow'
import { PRICE_REPORTER_ROUTE } from '../../constants.js'
import { getDefaultQuoteToken } from '../../types/token.js'
import { HttpError, PriceReporterError } from './error.js'

const ERR_NO_PRICE_REPORTER_URL =
  'PRICE_REPORTER_URL environment variable is not set'
const ERR_INVALID_URL =
  'PRICE_REPORTER_URL must be a valid URL including protocol and port'

export class PriceReporterClient {
  constructor(private readonly baseUrl: string) {}

  /**
   * Creates a new PriceReporterClient instance
   * @returns A Result containing either a PriceReporterClient or a PriceReporterError
   */
  static new(): ResultAsync<PriceReporterClient, PriceReporterError> {
    if (!process.env.PRICE_REPORTER_URL) {
      return errAsync(new PriceReporterError(ERR_NO_PRICE_REPORTER_URL))
    }

    try {
      const baseUrl = new URL(`https://${process.env.PRICE_REPORTER_URL}:3000`)
      return ResultAsync.fromPromise(
        Promise.resolve(new PriceReporterClient(baseUrl.toString())),
        (err: unknown) =>
          new PriceReporterError(
            err instanceof Error ? err.message : String(err),
          ),
      )
    } catch {
      return errAsync(new PriceReporterError(ERR_INVALID_URL))
    }
  }

  static getBinancePrice(
    address: `0x${string}`,
  ): ResultAsync<number, PriceReporterError> {
    const exchange = 'binance'
    const quote = getDefaultQuoteToken(exchange).address

    return PriceReporterClient.new().andThen((client) =>
      client.getPrice(exchange, address, quote),
    )
  }

  public getPrice(
    exchange: string,
    address: `0x${string}`,
    quote: `0x${string}`,
  ): ResultAsync<number, PriceReporterError> {
    const route = PRICE_REPORTER_ROUTE(exchange, address, quote)
    return this.get<string>(route).andThen((textPrice) => {
      const price = Number(textPrice)
      return okAsync(price)
    })
  }

  private get<T>(route: string): ResultAsync<T, PriceReporterError> {
    const url = new URL(route, this.baseUrl)
    const endpointUrl = url.toString()

    const config: AxiosRequestConfig = {
      method: 'GET',
      url: endpointUrl,
    }

    const safeRequest = ResultAsync.fromThrowable(
      () => axios.request<T>(config),
      (error) => new HttpError(error, endpointUrl, config.method || 'GET'),
    )

    return safeRequest().map((response) => response.data)
  }
}