Add an example for conversation with a bot using states.

examples/conversation/index.js

@@ -0,0 +1,87 @@
+const {TelegramClient} = require("telegram");
+const {StoreSession} = require("telegram/sessions");
+const input = require("input");
+const {NewMessage} = require("telegram/events"); // npm i input
+
+const API_ID = -1;// Fill your API ID
+const API_HASH = "";// Fill your API Hash
+const STATES = {
+    EMPTY: "no state (default)",
+    ASK_FOR_NAME: "asks the user for a name",
+    ASK_FOR_LAST_NAME: "asks the user for their last name",
+    ASK_FOR_AGE: "asks the user for their age"
+}; // different states
+const storage = {}; // holds the states; can be saved to a json file on disconnect for consistency
+function getState(event) {
+    // gets the state for a new message event using chatId+senderId;
+    return getData(event, "state") || STATES.EMPTY
+}
+
+function setState(event, state) {
+    // sets the state for a new message event
+    setData(event, "state", state);
+}
+
+function setData(event, name, value) {
+    // stores a value in storage
+    const key = event.chatId.toString() + ":" + (event.senderId || "Admin").toString();
+    if (!(key in storage)) {
+        storage[key] = {}
+    }
+    storage[key][name] = value;
+}
+
+function getData(event, name) {
+    const key = event.chatId.toString() + ":" +  (event.senderId || "Admin").toString();
+    if (!(key in storage)) {
+        return undefined;
+    }
+    return storage[key][name];
+
+}
+
+(async () => {
+    console.log("Loading interactive example...");
+    const client = new TelegramClient(new StoreSession("session_name"), API_ID, API_HASH, {
+        connectionRetries: 5,
+    });
+
+    await client.start({
+        botAuthToken: async () => await input.text("Please enter your bot token: "),
+        onError: (err) => console.log(err),
+    });
+    console.log("You should now be connected.");
+    client.addEventHandler(async (event) => {
+        const message = event.message;
+        const state = getState(message);
+        switch (state) {
+            case STATES.EMPTY:
+                await message.reply({message:"Heyy!. Please send your first name"});
+                setState(message, STATES.ASK_FOR_NAME)
+                break;
+            case STATES.ASK_FOR_NAME:
+                const name = message.text;
+                setData(message, "firstName", name);
+                await message.reply({message:"Please send your last name"});
+                setState(message, STATES.ASK_FOR_LAST_NAME);
+                break;
+            case STATES.ASK_FOR_LAST_NAME:
+                const lastName = message.text;
+                setData(message, "lastName", lastName);
+                await message.reply({message:"Please send your age as a number"});
+                setState(message, STATES.ASK_FOR_AGE);
+                break;
+            case STATES.ASK_FOR_AGE:
+                const age = message.text;
+                if (Number.isNaN(Number(age))) {
+                    await message.reply({message:"Wrong number; please try again"});
+                    break;
+                }
+                await message.reply({message:"Thank you!."});
+                await message.reply({message:"First Name: " + getData(message, "firstName")});
+                await message.reply({message:"Last Name: " + getData(message, "lastName")});
+                await message.reply({message:"Age: " + age});
+                setState(message, STATES.EMPTY);
+        }
+    }, new NewMessage());
+})();