import { AfterShipErrorCodes, AftershipError } from "../error";

export interface Proxy {
  host: string;
  port: number;
  protocol?: string;
  auth?: {
    username: string;
    password: string;
  };
}

export function parseProxy(input?: string): Proxy | undefined {
  if (!input) {
    return undefined;
  }
  return { ...getAddress(input), ...getProtocol(input), ...getAuth(input) };
}

function getAddress(input: string): { host: string; port: number } {
  if (input.includes("@")) {
    input = input.substring(input.lastIndexOf("@") + 1);
  } else if (input.includes("://")) {
    input = input.split("://")[1];
  }
  if (!input.includes(":")) {
    throw new AftershipError(
      `Invalid option: proxy`,
      AfterShipErrorCodes.INVALID_OPTION,
    );
  }
  const host = input.split(":")[0];
  const port = parseInt(input.split(":")[1]);
  if (/^\w+$/.test(host)) {
    throw new AftershipError(
      `Invalid option: proxy`,
      AfterShipErrorCodes.INVALID_OPTION,
    );
  }
  if (isNaN(port)) {
    throw new AftershipError(
      `Invalid option: proxy`,
      AfterShipErrorCodes.INVALID_OPTION,
    );
  }
  return { host: host, port: port };
}

function getProtocol(input: string): { protocol: string } {
  if (!input.includes("://")) {
    return { protocol: "http" };
  }
  const protocol = input.split("://")[0];
  if (protocol.length < 3 || protocol.length > 6) {
    throw new AftershipError(
      `Invalid option: proxy`,
      AfterShipErrorCodes.INVALID_OPTION,
    );
  }
  return { protocol };
}

function getAuth(
  input: string,
): { auth: { username: string; password: string } } | undefined {
  if (!input.includes("@")) {
    return undefined;
  }
  if (input.includes("://")) {
    input = input.split("://")[1];
  }
  input = input.substring(0, input.lastIndexOf("@"));
  if (!input.includes(":")) {
    throw new AftershipError(
      `Invalid option: proxy`,
      AfterShipErrorCodes.INVALID_OPTION,
    );
  }
  const [username, password] = input.split(":");
  return { auth: { username, password } };
}