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Conversation Broker Service

This service is responsible for managing interaction between UI components and other services related to chat (and voice) functionality.

Isolation of business logic

All interaction with voice and chat MUST come through this service. Logic related to all global interaction has been encapsulated into this service, so that UI components can focus on UI states and only UI related logic that responds to changes reflected in this service.

This service should reflect the global state of events necessary for UI components.

service ConvoBrokerService

Attributes

private attr recorder

AudioRecorder is the object responsible for recording user audio.

private attr activeProfile

Profile | undefined tracks the currently active profile. This is updated by a subscription instantiated by the constructor.

attr $micState

BehaviorSubject<MicState> is the global controller for the mic state, used to control the UI state of the main mic button on the voice page.

attr $sendTimeout

BehaviorSubject<boolean> is a boolean flag used to signal if a timeout should be invoked.

attr $isWaitingForVoiceApi

BehaviorSubject<boolean> to track if a response has been made from the backend API regarding voice chat.

private meth Initialise Voice Chat

private async initVoiceChat(): Promise<void>
Description
Method to initialise voice activity detection, and initialise AudioRecorder. It is called in the constructor of the service.
This method instantiates the subscription for VAD detection, and contains side effects.

VAD is only active in voice mode

To prevent undesired VAD, the initialised subscribtion to handle VAD will only trigger side effects when the user is in ChatMode.Voice.

private meth Start Recording

private handleStarteRecording(): void
Description
Method to trigger the start of audio recording.

private meth Stop Recording

private handleStopRecording(): void
Description
Handle the stopping of recording, and post process the recorded audio. The recorded audio will be sent to the backend as a voice message.

private meth Stop Audio Playback

private handleStopPlaying(): void
Description
Method to stop the current audio playback and reset the mic state. Also unsubscribes from the voice stream to prevent further audio from playing.

private meth Unsubscribe from Voice Stream

private unsubscribeVoiceStream(): void
Description
Method to unsubscribe from the voice stream and reset any active voice subscriptions. This method ensures that any ongoing or pending voice stream is canceled properly to avoid memory leaks.

private meth Play Base64 Encoded Audio

private async playAudioBase64(val:string): Promise<void>
Description
Method to play a base 64 encoded audio. This induces side effects in AudioPlayerService.
Parameters
val (string): Base 64 encoded audio file.

private meth Send Voice

private async sendVoice(audio: Blob, profile: Profile): Promise<void>
Description
Sends audio blob to the backend for LLM and voice chat functionality; it will handle the responses and updating of states related to voice chat. Side effects include audio player and chat message service.
Parameters
audio (Blob): Blob of audio recording file.
profile (Profile): Profile used in the conversation

meth Mic Button Click

handleMicButtonClick(): void
Description
Method used in callbacks when the mic button to trigger audio recording actions has been clicked.

Text Chat Related Methods

meth Send Chat

async sendChat(message: string, profile: Profile): Promise<void>
Description
Method to send a chat message. This will handle the persistence of messages into IndexedDB, and interacting with the backend via the EndpointService.
Parameters
message (string): User input message
profile (Profile): Active profile used in the conversation.

meth Send Feedback

async sendFeedback(feedback: Feedback)
Description
Method to send a feedback object. This will handle the persistence of messages into IndexedDB, and interacting with the backend via the EndpointService.
Parameters
feedback (feedback): Feedback object
Updated 22 Oct 2024
Contributor Ong Tsien Jin