Create Base, Mainchain and Sidechain RecoveryClient classes

[ishantiw]

Description

• Create SidechainRecoveryClient class

abstract class BaseRecoveryClient {
	private _apiClient!: apiClient.APIClient;
	private _queryKeys!: Set<string>;

	public connect(_connectionObj: ConnectionObj) {
		// check for mode of connection and use connectionString to connect to the relevant client
	}
	public async getInclusionProof(_keys: string[]) {
		// Call RPC to get inclusionProof and return in appropriate format
		// await this._apiClient.invoke('state_prove', {});
	}
	public addQueryKeyForInclusionProof(queryKey: string) {
		this._queryKeys.add(queryKey);
	}

	public collectInclusionProofs() {
		// subscribe to chain_newBlock event and on every new block query the client with all the proofs
		this._apiClient.subscribe('chain_newBlock', _ => {
			this.getInclusionProof([...this._queryKeys.values()]);
			// save proof for each key in stateRecoveryDB with key { sidechainID+queryKey }
		});
	}

	public removeQueryKey(queryKey: string) {
		this._queryKeys.delete(queryKey);
	}

	// Based on finalized height and last certificate on the other chain delete irrelevant recovery data
	public cleanupStateRecoveryData() {}

	// Disconnect client and release resources
	public disconnectClient() {}
}

class MainchainRecoveryClient extends BaseRecoveryClient {
	// Collect new CCMs from the on-chain events
	// Collect inclusionProofs for the sidechain outbox for the CCMs: This part is done by calling addQueryKeyForInclusionProof from the manager class
	public collectCCMsAndProofs() {
		// collect CCMs on every newBlock and by calling getEvents for the block height and save them in messageRecoveryDB
	}

	// Based on finalized height and last certificate on the other chain delete irrelevant message recovery data
	public cleanupMessageRecoveryData() {}
}

class SidechainRecoveryClient extends BaseRecoveryClient {}

Acceptance Criteria

• Should have all the method definition
• Should have all the unit tests for the implemented methods