AI-powered Voice Assistant Python, C++

```python
import speech_recognition as sr
import pyttsx3
import os
import datetime
import webbrowser
import wikipedia
import smtplib

# Initialize speech recognition and text-to-speech engine
recognizer = sr.Recognizer()
engine = pyttsx3.init()

# Set voice properties (optional)
voices = engine.getProperty('voices')
engine.setProperty('voice', voices[0].id)  # Use female voice (index 1 might work for some systems)

# Set speech rate (optional)
engine.setProperty('rate', 150)  # Adjust speed as needed


def speak(text):
    """Speak the given text using the text-to-speech engine."""
    engine.say(text)
    engine.runAndWait()


def take_command():
    """Listen for user input and return the recognized text."""
    with sr.Microphone() as source:
        print("Listening...")
        recognizer.pause_threshold = 1  # Adjust pause threshold as needed
        audio = recognizer.listen(source)

    try:
        print("Recognizing...")
        query = recognizer.recognize_google(audio, language='en-in')  # Specify language
        print(f"User said: {query}\n")

    except sr.UnknownValueError:
        print("Sorry, I did not understand. Please repeat.")
        return "None"
    except sr.RequestError as e:
        print(f"Could not request results from Google Speech Recognition service; {e}")
        return "None"

    return query.lower()


def wish_me():
    """Greet the user based on the time of day."""
    hour = int(datetime.datetime.now().hour)
    if 0 <= hour < 12:
        speak("Good Morning!")

    elif 12 <= hour < 18:
        speak("Good Afternoon!")

    else:
        speak("Good Evening!")

    speak("I am your AI Assistant. How may I help you?")


def send_email(to, content):
    """Sends an email.  You need to configure your email settings securely!"""
    # Replace with your actual email address and password/app password
    sender_email = "your_email@gmail.com"
    sender_password = "your_app_password" # Use an App Password for security

    try:
        server = smtplib.SMTP('smtp.gmail.com', 587)
        server.starttls()
        server.login(sender_email, sender_password)
        server.sendmail(sender_email, to, content)
        server.close()
        speak("Email has been sent!")

    except Exception as e:
        print(e)
        speak("Sorry, I was unable to send the email.")



if __name__ == "__main__":
    wish_me()

    while True:
        query = take_command()

        if query == "none":
            continue

        elif "wikipedia" in query:
            speak("Searching Wikipedia...")
            query = query.replace("wikipedia", "")
            try:
                results = wikipedia.summary(query, sentences=2)
                speak("According to Wikipedia:")
                print(results)
                speak(results)
            except wikipedia.exceptions.PageError:
                speak("Sorry, I couldn't find that on Wikipedia.")
            except wikipedia.exceptions.DisambiguationError as e:
                speak("There are multiple results for that query. Please be more specific.")
                print(e.options)  # Print the options

        elif "open youtube" in query:
            speak("Opening YouTube...")
            webbrowser.open("youtube.com")

        elif "open google" in query:
            speak("Opening Google...")
            webbrowser.open("google.com")

        elif "open stackoverflow" in query:
            speak("Opening Stack Overflow...")
            webbrowser.open("stackoverflow.com")

        elif "play music" in query:
            music_dir = 'C:\\path\\to\\your\\music\\directory'  # Replace with your music directory
            try:
                songs = os.listdir(music_dir)
                if songs:  # Check if the directory is not empty
                    os.startfile(os.path.join(music_dir, songs[0]))  # Plays the first song
                else:
                    speak("No music files found in the directory.")
            except FileNotFoundError:
                speak("The music directory was not found. Please update the path in the code.")

        elif "the time" in query:
            str_time = datetime.datetime.now().strftime("%H:%M:%S")
            speak(f"The time is {str_time}")

        elif "open code" in query:
            code_path = "C:\\path\\to\\your\\code.exe"  # Replace with your IDE or editor path
            try:
                os.startfile(code_path)
            except FileNotFoundError:
                speak("The code editor executable was not found. Please update the path in the code.")

        elif "send email" in query:
            try:
                speak("To whom should I send the email?")
                to = take_command()
                #Basic email validation - IMPROVE THIS!
                if "@" not in to or "." not in to:
                    speak("That doesn't seem like a valid email address.  Try again.")
                    continue #Go back to the beginning of the loop
                speak("What should I say?")
                content = take_command()
                send_email(to, content)
            except Exception as e:
                print(e)
                speak("Sorry, I am unable to send the email.")

        elif "exit" in query or "quit" in query or "stop" in query:
            speak("Okay, goodbye!")
            break

        else:
            speak("I am sorry, I don't understand that command. Please try again.")
```

```cpp
#include <iostream>
#include <string>
#include <vector>
#include <sstream>
#include <ctime>
#include <cstdlib> // For system()
#ifdef _WIN32
#include <windows.h>
#else
#include <unistd.h> // For sleep() on Linux/macOS
#endif


// Placeholder functions (replace with actual implementations)
// These are just stubs to simulate voice assistant functionality
// You would need to use a real TTS (Text-to-Speech) and STT (Speech-to-Text) library
// for actual voice interaction.  Examples of TTS libraries:  espeak, Festival, SAPI (Windows)
// Examples of STT Libraries:  Google Cloud Speech-to-Text API, CMU Sphinx

std::string recognizeSpeech() {
  // Simulate speech recognition (replace with actual STT)
  // For now, we'll just ask for input from the console
  std::string input;
  std::cout << "Listening... (Type your command): ";
  std::getline(std::cin, input);
  return input;
}


void speak(const std::string& text) {
  // Simulate speech output (replace with actual TTS)
  std::cout << "Assistant: " << text << std::endl;

  //Optional:  Use a system command to make some kind of sound.  Cross-platform is hard.
  //This is a very crude example that ONLY works on Linux.  Remove it for other platforms.
  #ifndef _WIN32
    //Beeping with aplay (Linux-only example. Needs 'aplay' command)
    std::string command = "aplay -q /usr/share/sounds/alsa/Front_Center.wav";  //Linux only, uses alsa-utils package
    system(command.c_str());
  #endif


}


std::string getCurrentTime() {
  time_t now = time(0);
  struct tm tstruct;
  char buf[80];
  tstruct = *localtime(&now);
  strftime(buf, sizeof(buf), "%X", &tstruct);  //HH:MM:SS
  return buf;
}



void openWebsite(const std::string& url) {
    std::string command;

    #ifdef _WIN32
        command = "start " + url;  // Windows
    #elif defined(__APPLE__)
        command = "open " + url;   // macOS
    #else
        command = "xdg-open " + url;  // Linux (using xdg-open)
    #endif

    int result = system(command.c_str());  // Execute the command
    if (result != 0) {
        speak("Sorry, I couldn't open the website.");
        std::cerr << "Error opening website. System command returned: " << result << std::endl;
    }
}


void wishMe() {
    time_t now = time(0);
    tm* ltm = localtime(&now);
    int hour = ltm->tm_hour;

    if (hour >= 0 && hour < 12) {
        speak("Good morning!");
    } else if (hour >= 12 && hour < 18) {
        speak("Good afternoon!");
    } else {
        speak("Good evening!");
    }

    speak("I am your AI Assistant. How may I help you?");
}


void playMusic() {
    //This is a VERY basic, platform-dependent example.  It just plays the first MP3 it finds.
    //You will need a proper music library integration for real functionality.

    #ifdef _WIN32
      //Find first MP3 in C:\Music (Windows)
      WIN32_FIND_DATA findFileData;
      HANDLE hFind = FindFirstFile("C:\\Music\\*.mp3", &findFileData); // Adjust path as needed

      if (hFind != INVALID_HANDLE_VALUE) {
          std::string musicPath = "C:\\Music\\" + std::string(findFileData.cFileName);  //Path to the music file
          FindClose(hFind);
          ShellExecute(NULL, "open", musicPath.c_str(), NULL, NULL, SW_SHOWNORMAL);
          speak("Playing music.");
      } else {
        speak("No music found in the specified directory.");
        std::cerr << "No music found, or error opening directory.\n";
      }

    #else
        speak("Music playing not implemented on this platform.  Requires OS-specific file searching and player control.");
    #endif


}



int main() {
  wishMe();

  while (true) {
    std::string query = recognizeSpeech();

    if (query.find("hello") != std::string::npos) {
      speak("Hello to you too!");
    }
    else if (query.find("time") != std::string::npos) {
        std::string time = getCurrentTime();
        speak("The time is " + time);
    }
    else if (query.find("open youtube") != std::string::npos) {
        speak("Opening YouTube.");
        openWebsite("https://www.youtube.com");
    }
     else if (query.find("open google") != std::string::npos) {
        speak("Opening Google.");
        openWebsite("https://www.google.com");
    }
    else if (query.find("play music") != std::string::npos) {
      playMusic();
    }
    else if (query.find("exit") != std::string::npos || query.find("quit") != std::string::npos) {
      speak("Goodbye!");
      break;
    }
    else {
      speak("I'm sorry, I didn't understand that.");
    }
  }

  return 0;
}
```