refactor: migrate WASignalGroup to TypeScript and remove deprecated files (#1320)

* refactor: migrate WASignalGroup to TypeScript and remove deprecated files

* chore: remove WASignalGroup JavaScript files from package.json

* refactor: update SenderKeyStore and SenderKeyStateStructure interfaces to export and add deserialize method. Fix types

* chore: lint issue

* refactor: improve constructor type checking and getSeed method in SenderChainKey

* refactor: update key handling to use Buffer for improved consistency

* signal: consistent naming and dir structure + add some missing types

* fix: lint issues

---------

Co-authored-by: Rajeh Taher <rajeh@reforward.dev>

src/Signal/Group/sender-key-state.ts

@@ -0,0 +1,145 @@
+import { SenderChainKey } from './sender-chain-key'
+import { SenderMessageKey } from './sender-message-key'
+
+interface SenderChainKeyStructure {
+	iteration: number
+	seed: Uint8Array
+}
+
+interface SenderSigningKeyStructure {
+	public: Uint8Array
+	private?: Uint8Array
+}
+
+interface SenderMessageKeyStructure {
+	iteration: number
+	seed: Uint8Array
+}
+
+interface SenderKeyStateStructure {
+	senderKeyId: number
+	senderChainKey: SenderChainKeyStructure
+	senderSigningKey: SenderSigningKeyStructure
+	senderMessageKeys: SenderMessageKeyStructure[]
+}
+
+export class SenderKeyState {
+	private readonly MAX_MESSAGE_KEYS = 2000
+	private readonly senderKeyStateStructure: SenderKeyStateStructure
+
+	constructor(
+		id?: number | null,
+		iteration?: number | null,
+		chainKey?: Uint8Array | null,
+		signatureKeyPair?: { public: Uint8Array; private: Uint8Array } | null,
+		signatureKeyPublic?: Uint8Array | null,
+		signatureKeyPrivate?: Uint8Array | null,
+		senderKeyStateStructure?: SenderKeyStateStructure | null
+	) {
+		if (senderKeyStateStructure) {
+			this.senderKeyStateStructure = senderKeyStateStructure
+		} else {
+			if (signatureKeyPair) {
+				signatureKeyPublic = signatureKeyPair.public
+				signatureKeyPrivate = signatureKeyPair.private
+			}
+
+			chainKey = typeof chainKey === 'string' ? Buffer.from(chainKey, 'base64') : chainKey
+
+			const senderChainKeyStructure: SenderChainKeyStructure = {
+				iteration: iteration || 0,
+				seed: chainKey || Buffer.alloc(0)
+			}
+
+			const signingKeyStructure: SenderSigningKeyStructure = {
+				public:
+					typeof signatureKeyPublic === 'string'
+						? Buffer.from(signatureKeyPublic, 'base64')
+						: signatureKeyPublic || Buffer.alloc(0)
+			}
+
+			if (signatureKeyPrivate) {
+				signingKeyStructure.private =
+					typeof signatureKeyPrivate === 'string' ? Buffer.from(signatureKeyPrivate, 'base64') : signatureKeyPrivate
+			}
+
+			this.senderKeyStateStructure = {
+				senderKeyId: id || 0,
+				senderChainKey: senderChainKeyStructure,
+				senderSigningKey: signingKeyStructure,
+				senderMessageKeys: []
+			}
+		}
+	}
+
+	public getKeyId(): number {
+		return this.senderKeyStateStructure.senderKeyId
+	}
+
+	public getSenderChainKey(): SenderChainKey {
+		return new SenderChainKey(
+			this.senderKeyStateStructure.senderChainKey.iteration,
+			this.senderKeyStateStructure.senderChainKey.seed
+		)
+	}
+
+	public setSenderChainKey(chainKey: SenderChainKey): void {
+		this.senderKeyStateStructure.senderChainKey = {
+			iteration: chainKey.getIteration(),
+			seed: chainKey.getSeed()
+		}
+	}
+
+	public getSigningKeyPublic(): Buffer {
+		const publicKey = this.senderKeyStateStructure.senderSigningKey.public
+		if (publicKey instanceof Buffer) {
+			return publicKey
+		}
+
+		return Buffer.from(publicKey || [])
+	}
+
+	public getSigningKeyPrivate(): Buffer | undefined {
+		const privateKey = this.senderKeyStateStructure.senderSigningKey.private
+		if (!privateKey) {
+			return undefined
+		}
+
+		if (privateKey instanceof Buffer) {
+			return privateKey
+		}
+
+		return Buffer.from(privateKey)
+	}
+
+	public hasSenderMessageKey(iteration: number): boolean {
+		return this.senderKeyStateStructure.senderMessageKeys.some(key => key.iteration === iteration)
+	}
+
+	public addSenderMessageKey(senderMessageKey: SenderMessageKey): void {
+		this.senderKeyStateStructure.senderMessageKeys.push({
+			iteration: senderMessageKey.getIteration(),
+			seed: senderMessageKey.getSeed()
+		})
+
+		if (this.senderKeyStateStructure.senderMessageKeys.length > this.MAX_MESSAGE_KEYS) {
+			this.senderKeyStateStructure.senderMessageKeys.shift()
+		}
+	}
+
+	public removeSenderMessageKey(iteration: number): SenderMessageKey | null {
+		const index = this.senderKeyStateStructure.senderMessageKeys.findIndex(key => key.iteration === iteration)
+
+		if (index !== -1) {
+			const messageKey = this.senderKeyStateStructure.senderMessageKeys[index]
+			this.senderKeyStateStructure.senderMessageKeys.splice(index, 1)
+			return new SenderMessageKey(messageKey.iteration, messageKey.seed)
+		}
+
+		return null
+	}
+
+	public getStructure(): SenderKeyStateStructure {
+		return this.senderKeyStateStructure
+	}
+}