import { IIndicativeApi } from "./types";

// EXAMPLE OF INDICATIVE.COM SNIPPET TO USE WITH THIS LIBRARY
// DO NOT INITIALIZE IT BY API KEY JUST ADD ASYNC SCRIPT
//
// <script type="text/javascript">
//         (function() {
//                 var ind = document.createElement('script');
//                 ind.src = '//cdn.indicative.com/js/1.0.2/Indicative.min.js';
//                 ind.type = 'text/javascript';
//                 ind.async = 'true';
//
//                 var s = document.getElementsByTagName('script')[0];
//                 s.parentNode.insertBefore(ind, s);
//         })();
// </script>

function hasIndicativeSnippet(): boolean {
  return document.querySelectorAll('script[src*="//cdn.indicative.com"]').length > 0;
}

async function isIndicativeLoaded(): Promise<boolean> {
  const ts = Date.now();
  const timeout = 5 * 1000;

  return new Promise<boolean>(resolve => {
    const check = () => {
      if ("Indicative" in window) {
        resolve(true);
        return;
      }

      if (Date.now() - ts >= timeout) {
        resolve(false);
        return;
      }

      requestIdleCallback(check);
    };

    check();
  });
}

class IndicativeAPIWeb implements IIndicativeApi {
  private api: any;

  async initialize(apiKey: string): Promise<boolean> {
    const isLoaded = await isIndicativeLoaded();

    if (!isLoaded) {
      throw new Error("Error loading indicative.com snippet");
    }

    const api = (<any>window).Indicative;
    const { apiKey: initializedWithKey } = api;
    
    // workaround for typo in indicative library currently existing
    const initKey = 'initalized' in api ? 'initalized' : 'initialized';
    const initialized = api[initKey];

    if (initialized && initializedWithKey !== apiKey) {
      throw new Error("indicative.com already initialized with the different API key");
    }

    if (!initialized) {
      api.initialize(apiKey);
    }

    this.api = api;
    return api[initKey];
  }

  addProperties(props: object): void {
    this.api.addProperties(props);
  }

  setUniqueID(id: string): void {
    this.api.setUniqueID(id);
  }

  buildEvent(eventName: string, props?: object) {
    this.api.buildEvent(eventName, props);
  }
}

export const IndicativeAPIWebSdk = hasIndicativeSnippet() ? IndicativeAPIWeb : null;