/**
 * Text-to-Speech Handler for AI Interactive Fiction
 * Uses Web Speech API for text-to-speech
 */
class TTSHandler {
  constructor() {
    this.enabled = false;
    this.speaking = false;
    this.queue = [];
    this.synthesis = window.speechSynthesis;
    this.utterance = null;
    
    // Check if browser supports speech synthesis
    if (this.synthesis) {
      console.log('Speech synthesis is supported in this browser');
      this.browserSupport = true;
    } else {
      console.warn('Speech synthesis is not supported in this browser');
      this.browserSupport = false;
    }
  }

  /**
   * Toggle TTS on/off
   */
  toggle() {
    this.enabled = !this.enabled;
    if (!this.enabled && this.speaking) {
      this.stop();
    }
    return this.enabled;
  }

  /**
   * Speak the given text
   */
  speak(text) {
    if (!this.enabled || !this.browserSupport) return;
    
    // Add to queue
    this.queue.push(text);
    
    // If not already speaking, start processing queue
    if (!this.speaking) {
      this.processQueue();
    }
  }

  /**
   * Process the speech queue
   */
  processQueue() {
    if (this.queue.length === 0 || this.speaking) return;
    
    this.speaking = true;
    const text = this.queue.shift();
    
    try {
      this.utterance = new SpeechSynthesisUtterance(text);
      
      // Configure speech options
      this.utterance.rate = 1.0;  // Speech rate (0.1 to 10)
      this.utterance.pitch = 1.0; // Speech pitch (0 to 2)
      
      // When speech ends, process the next item
      this.utterance.onend = () => {
        this.speaking = false;
        this.processQueue();
      };
      
      // If speech is interrupted or errors
      this.utterance.onerror = (event) => {
        console.error('TTS error:', event.error);
        this.speaking = false;
        this.processQueue();
      };
      
      this.synthesis.speak(this.utterance);
    } catch (error) {
      console.error('TTS error:', error);
      this.speaking = false;
      this.processQueue();
    }
  }

  /**
   * Stop current speech
   */
  stop() {
    if (this.synthesis && this.speaking) {
      this.synthesis.cancel();
    }
    this.queue = [];
    this.speaking = false;
  }

  /**
   * Check if TTS is ready
   */
  isReady() {
    return this.browserSupport;
  }
}

// Create a global instance
const tts = new TTSHandler();