/**
 * API TTS Handler Base Class
 * Base class for API-based TTS handlers
 */
import { TTSHandler } from './tts-handler.js';
import { moduleRegistry } from './module-registry.js';

export class ApiTTSHandlerBase extends TTSHandler {
    constructor(id, name) {
        super();
        this.id = id;
        this.name = name;
        
        // Base voice options
        this.voiceOptions = {
            speed: 1.0
        };
        
        // State
        this.available = false;
        this.isReady = false;
        this.currentAudio = null;
        
        // Common API settings
        this.apiKey = '';
        this.apiBaseUrl = '';
        
        // Dependencies
        this.dependencies = ['localization', 'persistence-manager'];
    }
    
    /**
     * Initialize the API TTS handler
     * @param {Function} progressCallback - Callback for progress updates
     * @returns {Promise<boolean>} - Resolves with success status
     */
    async initialize(progressCallback = null) {
        try {
            if (progressCallback) {
                progressCallback(10, `Initializing ${this.name}`);
            }
            
            this.changeState('LOADING');
            
            // Check for required dependencies
            const localization = this.getModule('localization');
            const persistenceManager = this.getModule('persistence-manager');
            
            if (!localization) {
                console.error(`${this.name}: Required dependency 'localization' not found`);
                this.changeState('ERROR');
                return false;
            }
            
            if (!persistenceManager) {
                console.error(`${this.name}: Required dependency 'persistence-manager' not found`);
                this.changeState('ERROR');
                return false;
            }
            
            if (progressCallback) {
                progressCallback(20, `${this.name} dependencies loaded`);
            }
            
            // Set up API key from preferences - should be empty by default
            this.apiKey = persistenceManager.getPreference('tts', `${this.id}_api_key`) || '';
            
            if (progressCallback) {
                progressCallback(30, `${this.name} API key loaded`);
            }
            
            // Get default API URL
            const defaultApiUrl = this.getDefaultApiBaseUrl();
            console.log(`${this.name}: Default API URL: ${defaultApiUrl}`);
            
            // Set up API base URL from preferences or use default
            const savedApiUrl = persistenceManager.getPreference('tts', `${this.id}_api_url`);
            this.apiBaseUrl = savedApiUrl || defaultApiUrl;
            
            // If no API URL was saved in preferences, save the default
            if (!savedApiUrl && defaultApiUrl) {
                console.log(`${this.name}: Saving default API URL to preferences: ${defaultApiUrl}`);
                persistenceManager.updatePreference('tts', `${this.id}_api_url`, defaultApiUrl);
            }
            
            if (progressCallback) {
                progressCallback(40, `${this.name} API URL set to: ${this.apiBaseUrl}`);
            }
            
            // Set up event listeners for API key and URL changes
            this.addEventListener('tts:api:keyChanged', this.handleApiKeyChanged);
            this.addEventListener('tts:api:urlChanged', this.handleApiUrlChanged);
            
            if (progressCallback) {
                progressCallback(50, `${this.name} event listeners registered`);
            }
            
            // Load available voices
            const voicesLoaded = await this.loadVoices();
            
            if (progressCallback) {
                progressCallback(70, `${this.name} voices loaded`);
            }
            
            // Set up voice based on preferences
            await this.setupVoiceFromPreferences();
            
            if (progressCallback) {
                progressCallback(90, `${this.name} voice preferences loaded`);
            }
            
            // Set availability based on API key presence
            this.available = true;
            this.isReady = true;
            
            if (progressCallback) {
                const statusMessage = this.available ? 
                    `${this.name} initialized successfully` : 
                    `${this.name} initialized but unavailable (API key missing)`;
                progressCallback(100, statusMessage);
            }
            
            this.changeState(this.available ? 'FINISHED' : 'WAITING');
            return true;
        } catch (error) {
            console.error(`${this.name}: Initialization error:`, error);
            if (progressCallback) {
                progressCallback(100, `${this.name} initialization failed - ${error.message}`);
            }
            this.changeState('ERROR');
            return false;
        }
    }
    
    /**
     * Get a module from the registry
     * @param {string} moduleId - ID of the module to get
     * @returns {Object|null} - The module or null if not found
     */
    getModule(moduleId) {
        return moduleRegistry.getModule(moduleId);
    }
    
    /**
     * Get the default API base URL for this provider
     * @returns {string} - Default API base URL
     */
    getDefaultApiBaseUrl() {
        // Should be implemented by subclasses
        return '';
    }
    
    /**
     * Set up voice based on preferences and locale
     * @returns {Promise<boolean>} - Resolves with success status
     */
    async setupVoiceFromPreferences() {
        const persistenceManager = this.getModule('persistence-manager');
        const localization = this.getModule('localization');
        
        if (!persistenceManager || !localization) {
            return false;
        }
        
        // Get current locale
        const locale = localization.getLocale();
        
        // Try to get voice preference for this specific provider
        const voiceId = persistenceManager.getPreference('tts', `${this.id}_voice`);
        
        if (voiceId) {
            // Set voice from preference
            this.voiceOptions.voice = voiceId;
            return true;
        }
        
        // If no specific voice preference, try to select a voice for the current locale
        return this.selectVoiceForLocale(locale);
    }
    
    /**
     * Load available voices from API
     * @returns {Promise<boolean>} - Resolves with success status
     */
    async loadVoices() {
        // Should be implemented by subclasses
        return false;
    }
    
    /**
     * Select a voice for the given locale
     * @param {string} locale - Locale code
     * @returns {boolean} - Success status
     */
    selectVoiceForLocale(locale) {
        // Should be implemented by subclasses
        return this.selectDefaultVoice();
    }
    
    /**
     * Select a default voice
     * @returns {boolean} - Success status
     */
    selectDefaultVoice() {
        // Should be implemented by subclasses
        return false;
    }
    
    /**
     * Preload speech for a text
     * @param {string} text - Text to preload
     * @returns {Promise<Object>} - Preloaded audio data
     */
    async preloadSpeech(text) {
        // Don't try to preload if handler isn't ready, available, or if no text or API key
        if (!this.isReady || !this.available || !text || !this.apiKey) {
            if (!this.apiKey) {
                console.log(`${this.name}: Skipping preload speech - no API key set`);
            }
            return null;
        }
        
        try {
            // Process text for TTS
            const processedText = this.preprocessText(text);
            
            // Generate speech audio data
            const audioData = await this.generateSpeechAudio(processedText);
            
            if (!audioData) {
                console.error(`${this.name}: Failed to generate audio data for preloading`);
                return null;
            }
            
            // Store in centralized TTSFactory cache
            const ttsFactory = this.getModule('tts-factory');
            if (ttsFactory) {
                ttsFactory.cacheSpeech(text, audioData);
            }
            
            // Return audio data
            return audioData;
        } catch (error) {
            console.error(`${this.name}: Preload speech error:`, error);
            return null;
        }
    }
    
    /**
     * Generate speech audio data
     * @param {string} text - Text to generate speech for
     * @returns {Promise<Object>} - Audio data (Blob)
     */
    async generateSpeechAudio(text) {
        // Should be implemented by subclasses
        return null;
    }
    
    /**
     * Speak text using preloaded audio
     * @param {Object} preloadData - Preloaded audio data
     * @param {Function} callback - Callback for when speech completes
     * @returns {boolean} - Success status
     */
    speakPreloaded(preloadData, callback = null) {
        if (!this.isReady || !this.available || !preloadData) {
            if (callback) {
                setTimeout(() => callback({ success: false, reason: 'not_available' }), 0);
            }
            return false;
        }
        
        try {
            // Stop any current audio
            this.stop();
            
            // Create Blob URL
            const audioUrl = URL.createObjectURL(preloadData);
            
            // Create new audio element
            const audio = new Audio(audioUrl);
            
            // Set up event handlers
            audio.addEventListener('ended', () => {
                // Clean up URL object
                URL.revokeObjectURL(audioUrl);
                
                // Clear current audio reference
                if (this.currentAudio === audio) {
                    this.currentAudio = null;
                }
                
                // Dispatch completion event
                this.dispatchEvent('tts:speak:complete', {});
                
                if (callback) {
                    callback({ success: true });
                }
            }, { once: true });
            
            audio.addEventListener('error', (error) => {
                console.error(`${this.name}: Playback error:`, error);
                
                // Clean up URL object
                URL.revokeObjectURL(audioUrl);
                
                // Dispatch error event
                this.dispatchEvent('tts:speak:error', { error: error.message || 'Unknown error' });
                
                if (callback) {
                    callback({ success: false, reason: 'playback_error', error });
                }
            }, { once: true });
            
            // Store reference to current audio
            this.currentAudio = audio;
            
            // Play the audio
            audio.play();
            
            return true;
        } catch (error) {
            console.error(`${this.name}: Error playing preloaded audio:`, error);
            
            // Dispatch error event
            this.dispatchEvent('tts:speak:error', {
                error: error.message || 'Unknown error'
            });
            
            if (callback) {
                setTimeout(() => callback({ success: false, reason: 'playback_error', error }), 0);
            }
            
            return false;
        }
    }
    
    /**
     * Speak text
     * @param {string} text - Text to speak
     * @param {Function} callback - Callback for when speech completes
     * @returns {boolean} - Success status
     */
    async speak(text, callback = null) {
        if (!this.isReady || !this.available || !text) {
            if (callback) {
                setTimeout(() => callback({ success: false, reason: 'not_available' }), 0);
            }
            return false;
        }
        
        try {
            // Process text for TTS
            const processedText = this.preprocessText(text);
            
            // Check if already preloaded
            const ttsFactory = this.getModule('tts-factory');
            if (ttsFactory && ttsFactory.isSpeechCached(text)) {
                return this.speakPreloaded(ttsFactory.getCachedSpeech(text), callback);
            }
            
            // Generate audio data
            const audioData = await this.generateSpeechAudio(processedText);
            
            if (!audioData) {
                if (callback) {
                    setTimeout(() => callback({ success: false, reason: 'generation_failed' }), 0);
                }
                return false;
            }
            
            // Store in centralized TTSFactory cache
            if (ttsFactory) {
                ttsFactory.cacheSpeech(text, audioData);
            }
            
            // Play the audio
            return this.speakPreloaded(audioData, callback);
        } catch (error) {
            console.error(`${this.name}: Error generating speech:`, error);
            
            // Dispatch error event
            this.dispatchEvent('tts:speak:error', { 
                text, 
                error: error.message || 'Unknown error' 
            });
            
            if (callback) {
                setTimeout(() => callback({ success: false, reason: 'generation_error', error }), 0);
            }
            
            return false;
        }
    }
    
    /**
     * Preprocess text for TTS
     * @param {string} text - Text to preprocess
     * @returns {string} - Processed text
     */
    preprocessText(text) {
        if (!text) return '';
        
        // Trim whitespace
        let processed = text.trim();
        
        // Replace multiple spaces with a single space
        processed = processed.replace(/\s+/g, ' ');
        
        // Add a period at the end if there's no punctuation
        if (!/[.!?]$/.test(processed)) {
            processed += '.';
        }
        
        return processed;
    }
    
    /**
     * Stop speaking
     */
    stop() {
        if (this.currentAudio) {
            try {
                this.currentAudio.pause();
                this.currentAudio = null;
            } catch (error) {
                console.error(`${this.name}: Error stopping speech:`, error);
            }
        }
    }
    
    /**
     * Check if TTS is available
     * @returns {boolean} - True if TTS is available
     */
    isAvailable() {
        return this.available;
    }
    
    /**
     * Get handler ID
     * @returns {string} - Handler ID
     */
    getId() {
        return this.id;
    }
    
    /**
     * Get available voices
     * @returns {Promise<Array>} - Resolves with array of voice objects
     */
    async getVoices() {
        // Should be implemented by subclasses
        return [];
    }
    
    /**
     * Set voice options
     * @param {Object} options - Voice options
     */
    setVoiceOptions(options = {}) {
        if (options.voice) {
            this.voiceOptions.voice = options.voice;
            
            // Save the voice preference
            const persistenceManager = this.getModule('persistence-manager');
            if (persistenceManager) {
                persistenceManager.updatePreference('tts', `${this.id}_voice`, options.voice);
            }
        }
        
        if (typeof options.speed === 'number') {
            // Clamp speed between 0.5 and 2.0
            this.voiceOptions.speed = Math.max(0.5, Math.min(2.0, options.speed));
        }
        
        // Additional provider-specific options should be handled by subclasses
    }
    
    /**
     * Handle API key change event
     * @param {Event} event - Event object
     */
    handleApiKeyChanged(event) {
        if (event && event.detail && event.detail.provider === this.id) {
            const newKey = event.detail.key || '';
            
            // Update API key
            this.apiKey = newKey;
            
            // Update functionality status but don't make it unavailable
            // We want it to stay in the dropdown for configuration
            const wasFullyFunctional = this.available;
            const isFullyFunctional = !!this.apiKey;
            
            // Only update internal state - don't change availability for UI purposes
            if (isFullyFunctional) {
                this.changeState('FINISHED');
            } else {
                // Not WAITING - we want it to stay in dropdown
                this.changeState('CONFIGURING'); 
            }
            
            // Log the key change but don't affect availability for UI
            console.log(`${this.name}: API key ${newKey ? 'set' : 'cleared'}. Fully functional: ${isFullyFunctional}`);
            
            // Always stay available in the UI dropdown
            this.available = true;
        }
    }
    
    /**
     * Handle API URL change event
     * @param {Event} event - Event object
     */
    handleApiUrlChanged(event) {
        if (event && event.detail && event.detail.provider === this.id) {
            const newUrl = event.detail.url || this.getDefaultApiBaseUrl();
            
            // Update API URL
            this.apiBaseUrl = newUrl;
            
            // Save to preferences
            const persistenceManager = this.getModule('persistence-manager');
            if (persistenceManager) {
                persistenceManager.updatePreference('tts', `${this.id}_api_url`, newUrl);
            }
            
            // Log the URL change but don't affect availability
            console.log(`${this.name}: API URL updated to ${newUrl}`);
            
            // Always stay available in the UI dropdown
            this.available = true;
        }
    }
}