Add TypeScript type declarations

- Add index.d.ts with comprehensive type definitions for all exported classes
- Include type declarations for Connection, NodeJSSerialConnection, and other connection types
- Add types for Constants, Advert, Packet, BufferUtils, and CayenneLpp
- Add type declarations for submodules (constants, buffer_reader, buffer_writer)
- Update package.json to reference the types file

This enables TypeScript users to have proper type checking and autocomplete when using the library.

index.d.ts

@@ -0,0 +1,187 @@
+/**
+ * TypeScript declarations for @liamcottle/meshcore.js
+ */
+
+declare module '@liamcottle/meshcore.js' {
+  import { EventEmitter } from 'events';
+
+  export class Connection extends EventEmitter {
+    connect(): Promise<void>;
+    close(): Promise<void>;
+
+    // High-level API methods
+    getSelfInfo(timeout?: number): Promise<SelfInfo>;
+    getWaitingMessages(): Promise<Message[]>;
+    getChannels(): Promise<Channel[]>;
+    getContacts(since?: number): Promise<Contact[]>;
+    syncNextMessage(): Promise<void>;
+
+    // Message sending
+    sendTextMessage(publicKey: Buffer, text: string): Promise<void>;
+    sendChannelTextMessage(channelIdx: number, text: string): Promise<void>;
+
+    // Contact lookup
+    findContactByPublicKeyPrefix(prefix: Buffer): Promise<Contact | null>;
+
+    // Frame handling (can be overridden in subclasses)
+    onFrameReceived(frame: Buffer): void;
+
+    // Events
+    on(event: 'connected', listener: () => void): this;
+    on(event: 'disconnected', listener: () => void): this;
+    on(event: number, listener: (data: any) => void): this;
+    on(event: string | number, listener: (...args: any[]) => void): this;
+
+    emit(event: string | number, ...args: any[]): boolean;
+  }
+
+  export class NodeJSSerialConnection extends Connection {
+    constructor(port: string);
+  }
+
+  export class WebSerialConnection extends Connection {
+    constructor();
+  }
+
+  export class TCPConnection extends Connection {
+    constructor(host: string, port: number);
+  }
+
+  export class WebBleConnection extends Connection {
+    constructor();
+  }
+
+  export class SerialConnection extends Connection {
+    constructor();
+  }
+
+  // Type definitions
+  export interface SelfInfo {
+    publicKey: Buffer;
+    name?: string;
+  }
+
+  export interface Message {
+    pubKeyPrefix: Buffer;
+    pathLen: number;
+    txtType: number;
+    senderTimestamp: number;
+    text: string;
+  }
+
+  export interface Channel {
+    channelIdx: number;
+    name: string;
+    secret: Buffer;
+  }
+
+  export interface Contact {
+    publicKey: Buffer;
+    name?: string;
+    lastSeen?: number;
+  }
+
+  // Constants
+  export class Constants {
+    static readonly SupportedCompanionProtocolVersion: number;
+
+    static readonly ResponseCodes: {
+      ContactMsgRecv: number;
+      ChannelMsgRecv: number;
+      [key: string]: number;
+    };
+
+    static readonly PushCodes: {
+      MsgWaiting: number;
+      NewAdvert: number;
+      [key: string]: number;
+    };
+
+    static readonly CommandCodes: {
+      AppStart: number;
+      SendTxtMsg: number;
+      SendChannelTxtMsg: number;
+      GetContacts: number;
+      GetDeviceTime: number;
+      SetDeviceTime: number;
+      SendSelfAdvert: number;
+      SetAdvertName: number;
+      [key: string]: number;
+    };
+  }
+
+  export class Advert {
+    constructor(data: Buffer);
+    publicKey: Buffer;
+    advName?: string;
+  }
+
+  export class Packet {
+    constructor(data: Buffer);
+    // Add packet methods as needed
+  }
+
+  export class BufferUtils {
+    static xor(a: Buffer, b: Buffer): Buffer;
+    static concat(...buffers: Buffer[]): Buffer;
+    // Add other utility methods as needed
+  }
+
+  export class CayenneLpp {
+    // Add CayenneLpp methods as needed
+  }
+}
+
+// Type declarations for submodules
+declare module '@liamcottle/meshcore.js/src/constants.js' {
+  const Constants: {
+    SupportedCompanionProtocolVersion: number;
+    ResponseCodes: {
+      ContactMsgRecv: number;
+      ChannelMsgRecv: number;
+      [key: string]: number;
+    };
+    PushCodes: {
+      MsgWaiting: number;
+      NewAdvert: number;
+      [key: string]: number;
+    };
+    CommandCodes: {
+      AppStart: number;
+      SendTxtMsg: number;
+      SendChannelTxtMsg: number;
+      GetContacts: number;
+      GetDeviceTime: number;
+      SetDeviceTime: number;
+      SendSelfAdvert: number;
+      SetAdvertName: number;
+      [key: string]: number;
+    };
+  };
+  export default Constants;
+}
+
+declare module '@liamcottle/meshcore.js/src/buffer_reader.js' {
+  export default class BufferReader {
+    constructor(buffer: Buffer);
+    readByte(): number;
+    readInt8(): number;
+    readUInt16LE(): number;
+    readUInt32LE(): number;
+    readBytes(length: number): Buffer;
+    readString(): string;
+  }
+}
+
+declare module '@liamcottle/meshcore.js/src/buffer_writer.js' {
+  export default class BufferWriter {
+    constructor();
+    writeByte(value: number): void;
+    writeInt8(value: number): void;
+    writeUInt16LE(value: number): void;
+    writeUInt32LE(value: number): void;
+    writeBytes(buffer: Buffer | Uint8Array): void;
+    writeString(str: string): void;
+    toBytes(): Buffer;
+  }
+}

package.json

@@ -3,6 +3,7 @@
   "version": "1.10.0",
   "description": "",
   "main": "src/index.js",
+  "types": "index.d.ts",
   "type": "module",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"