[Story] Verifiable Credentials can be issued via an action

[HexaField]

The issueCredential() function will live in a VerifiableCredentialSystem.ts file, in packages/client-core/src/systems. It will be triggered when an action query is met. (A system is a module with a default export of an async function that returns a regular (sync) function, that runs on every frame. Since triggering an 'issue & store a VC event' should happen only once, we'll need to use some kind of event to implement it.)

[speigg]

My suggested implementation:

In packages/engine/src/credentials/:

• CredentialAction.ts -- Isomorphic
• CrednetialSystem.ts -- Isomorphic
• CredentialVerificationSystem.ts -- Server-only

// in instancechannel channels.ts 
initSystems(world, [{
    type: SystemUpdateType.UPDATE,
    systemModulePromise: import('./credentials/CredentialVerificationSystem')
  }])
// in initializeEngine.ts
initSystems(world, [{
    type: SystemUpdateType.UPDATE,
    systemModulePromise: import('./credentials/CredentialSystem')
  }])

// in CredentialAction.ts
export class CredentialAction {
static requestVerify = defineAction({
    type: 'xre.credential.requestVerify',
    credential: matches.any,
    $cache: true,
    $topic: NetworkTopics.world
  })

  static didVerify = defineAction({
    $from: matchesHostId,
    type: 'xre.credential.didVerify',
    credential: matches.any,
    $cache: true,
    $topic: NetworkTopics.world
  })
  }

// in clientInputListener (for now, we can hook this to a trigger volume next)
addListener(window, 'keydown', () => {
// if c key is pressed, request credential from user
// requestCredential() => 
  dispatchAction(
    CredentialAction.requestVerifyCredential({
      credential: {} // credential object
    })
  )
})

// In CredentialVerificationSystem.ts
const requestVerifyCredential = (credential) => {
  // verify credential
  // if verified, dispatch action to set credential
  // if not verified, dispatch action to set error
  dispatchAction(
    CredentialAction.didVerifyCredential({credential})
  )
}

const CredentialVerifierSystem = () => {
  const requestVerifyCredentialActions = createActionQueue(CredentialAction.requestVerifyCredential.matches)
  return () => {
    for (action of requestVerifyCredentialActions()) requestVerifyCredential(action.credential)
  }
}

// In CredentialSystem.ts

function updateCredentialState(action:CredentialAction.didVerifyCredential.matches._TYPE) {
  if (action.$from !== Engine.instnace.currentWorld.hostId) return
  const credential = action.credential
  const credentialState = getState(CredentialState).userCredentials
  credentialState[userId].push(credential)
}

const CredentialSystem = () => {
  const didVerifyCredentialActions = createActionQueue(CredentialAction.didVerifyCredential.matches)
  return () => {
    for (action of didVerifyCredentialActions()) updateCredentialState(action)
  }
}

[dmitrizagidulin]

Implemented in PR #6871, closing.