import {
  // For using the browsers' Qworum features
  Qworum,

  // For creating Qworum scripts and session data
  QworumScript as qs,

  // For manipulating semantic RDF data in scripts and session data
  iri, irl, url, urn, IRI, IRL, URN,
  rdfTermFactory
} from 'https://esm.sh/gh/doga/qworum-for-web-pages@1.8.4/mod.mjs';

const
// Shortcuts for building Qworum scripts and session data
Json         = qs.Json.build,
SemanticData = qs.SemanticData.build,
Return       = qs.Return.build,
Sequence     = qs.Sequence.build,
Data         = qs.Data.build,
Try          = qs.Try.build,
Goto         = qs.Goto.build,
Call         = qs.Call.build,
Fault        = qs.Fault.build,
Script       = qs.Script.build;

try{
  await Qworum.checkAvailability();
}catch(error){
  console.error('Install the Qworum browser extension or enable it.');
}

await Qworum.eval(
  Script(
      Sequence(
        // Call a method of the current Qworum object
        Call('@', `../view-item`, { name: 'item id', value: Json(1) }),

        // Return to the current page in the current call
        Goto()
      ),
    )
  )
);

const
pathOfQworumObject = ['@', 'a qworum object'],
script = Script(
  Try(
    Sequence(
      // Initialise the Qworum object ? (May be required for Qworum classes that have instance properties)
      Try(
        // If the state of the Qworum object is readable, then the object exists.
        Data([...pathOfQworumObject, 'version']),
        {
          catch: '* reference',
          do: // the Qworum object does not exist; initialise it
          Call(
            pathOfQworumObject, 'https://a-qworum-service.example/a-qworum-class/new/',
            { name: 'initial state', value: Json({state: {xyz: '…'}}) }
          )
        }
      ),
      // Call the `edit` method of the Qworum object.
      Call(pathOfQworumObject, 'https://a-qworum-service.example/a-qworum-class/edit/'),

      // If the call to `edit` hasn't raised a fault, then the caller resumes its execution here.
      Goto('group-updated.html')
    ),
    { do:
      // If the call to `edit` has raised a fault, then go back to the current web page.
      Goto()
    }
  )
);

// Run the Qworum script in the web page. The end-user will experience this as a redirection.
await Qworum.eval(script);

let data = await Qworum.getData(['path', 'to', 'data']);

if(!data) {
  data = Json('some data');
  await Qworum.setData(['path', 'to', 'data'], data);
}

data.value === "some data"; // true