<?php
/**
 * Eleven Labs API integration class
 */
class TWP_ElevenLabs_API {
    
    private $api_key;
    private $voice_id;
    private $model_id;
    private $api_base = 'https://api.elevenlabs.io/v1';
    
    /**
     * Constructor
     */
    public function __construct() {
        $this->api_key = get_option('twp_elevenlabs_api_key');
        $this->voice_id = get_option('twp_elevenlabs_voice_id');
        $this->model_id = get_option('twp_elevenlabs_model_id', 'eleven_multilingual_v2');
    }
    
    /**
     * Convert text to speech
     */
    public function text_to_speech($text, $voice_id = null) {
        // Handle both string voice_id and options array
        if (is_array($voice_id)) {
            $options = $voice_id;
            $voice_id = isset($options['voice_id']) ? $options['voice_id'] : null;
        }
        
        if (!$voice_id) {
            $voice_id = $this->voice_id;
        }
        
        $url = $this->api_base . '/text-to-speech/' . $voice_id;
        
        $data = array(
            'text' => $text,
            'model_id' => $this->model_id,
            'voice_settings' => array(
                'stability' => 0.5,
                'similarity_boost' => 0.5
            )
        );
        
        $response = $this->make_request('POST', $url, $data);
        
        if ($response['success']) {
            // Save audio file
            $upload_dir = wp_upload_dir();
            $filename = 'tts_' . uniqid() . '.mp3';
            $file_path = $upload_dir['path'] . '/' . $filename;
            $file_url = $upload_dir['url'] . '/' . $filename;
            
            file_put_contents($file_path, $response['data']);
            
            return array(
                'success' => true,
                'file_path' => $file_path,
                'file_url' => $file_url
            );
        }
        
        return $response;
    }
    
    /**
     * Get available voices
     */
    public function get_voices() {
        $url = $this->api_base . '/voices';
        $response = $this->make_request('GET', $url);
        
        if ($response['success'] && isset($response['data']['voices'])) {
            // Cache voices for 1 hour to reduce API calls
            set_transient('twp_elevenlabs_voices', $response['data']['voices'], HOUR_IN_SECONDS);
        }
        
        return $response;
    }
    
    /**
     * Get cached voices or fetch from API
     */
    public function get_cached_voices() {
        $cached_voices = get_transient('twp_elevenlabs_voices');
        
        if ($cached_voices !== false) {
            return array(
                'success' => true,
                'data' => array('voices' => $cached_voices)
            );
        }
        
        return $this->get_voices();
    }
    
    /**
     * Get voice details
     */
    public function get_voice($voice_id) {
        $url = $this->api_base . '/voices/' . $voice_id;
        return $this->make_request('GET', $url);
    }
    
    /**
     * Get user subscription info
     */
    public function get_subscription_info() {
        $url = $this->api_base . '/user/subscription';
        return $this->make_request('GET', $url);
    }
    
    /**
     * Get available models
     */
    public function get_models() {
        $url = $this->api_base . '/models';
        $response = $this->make_request('GET', $url);
        
        if ($response['success'] && isset($response['data'])) {
            // Filter models that support text-to-speech
            $tts_models = array();
            foreach ($response['data'] as $model) {
                if (isset($model['can_do_text_to_speech']) && $model['can_do_text_to_speech']) {
                    $tts_models[] = $model;
                }
            }
            
            // Cache models for 1 hour
            set_transient('twp_elevenlabs_models', $tts_models, HOUR_IN_SECONDS);
            
            return array(
                'success' => true,
                'data' => $tts_models
            );
        }
        
        return $response;
    }
    
    /**
     * Get cached models or fetch from API
     */
    public function get_cached_models() {
        $cached_models = get_transient('twp_elevenlabs_models');
        
        if ($cached_models !== false) {
            return array(
                'success' => true,
                'data' => $cached_models
            );
        }
        
        return $this->get_models();
    }
    
    /**
     * Generate speech for IVR menu
     */
    public function generate_ivr_prompt($text, $options = array()) {
        $default_options = array(
            'voice_id' => $this->voice_id,
            'stability' => 0.75,
            'similarity_boost' => 0.75,
            'style' => 0,
            'use_speaker_boost' => true
        );
        
        $options = wp_parse_args($options, $default_options);
        
        $url = $this->api_base . '/text-to-speech/' . $options['voice_id'];
        
        $data = array(
            'text' => $text,
            'model_id' => $this->model_id,
            'voice_settings' => array(
                'stability' => $options['stability'],
                'similarity_boost' => $options['similarity_boost'],
                'style' => $options['style'],
                'use_speaker_boost' => $options['use_speaker_boost']
            )
        );
        
        return $this->make_request('POST', $url, $data);
    }
    
    /**
     * Generate speech for queue messages
     */
    public function generate_queue_messages($messages) {
        $generated_files = array();
        
        foreach ($messages as $key => $message) {
            $result = $this->text_to_speech($message);
            
            if ($result['success']) {
                $generated_files[$key] = $result['file_url'];
            }
        }
        
        return $generated_files;
    }
    
    /**
     * Stream text to speech (for real-time applications)
     */
    public function stream_text_to_speech($text, $voice_id = null) {
        if (!$voice_id) {
            $voice_id = $this->voice_id;
        }
        
        $url = $this->api_base . '/text-to-speech/' . $voice_id . '/stream';
        
        $data = array(
            'text' => $text,
            'model_id' => $this->model_id,
            'voice_settings' => array(
                'stability' => 0.5,
                'similarity_boost' => 0.5
            ),
            'optimize_streaming_latency' => 3
        );
        
        return $this->make_request('POST', $url, $data, true);
    }
    
    /**
     * Make API request
     */
    private function make_request($method, $url, $data = array(), $stream = false) {
        $args = array(
            'method' => $method,
            'headers' => array(
                'xi-api-key' => $this->api_key,
                'Content-Type' => 'application/json',
                'Accept' => $stream ? 'audio/mpeg' : 'application/json'
            ),
            'timeout' => 60
        );
        
        if ($method === 'POST' && !empty($data)) {
            $args['body'] = json_encode($data);
        }
        
        if ($method === 'GET') {
            $response = wp_remote_get($url, $args);
        } else {
            $response = wp_remote_post($url, $args);
        }
        
        if (is_wp_error($response)) {
            return array(
                'success' => false,
                'error' => $response->get_error_message()
            );
        }
        
        $status_code = wp_remote_retrieve_response_code($response);
        $body = wp_remote_retrieve_body($response);
        
        if ($status_code >= 200 && $status_code < 300) {
            if ($stream || strpos(wp_remote_retrieve_header($response, 'content-type'), 'audio') !== false) {
                // Return raw audio data
                return array(
                    'success' => true,
                    'data' => $body
                );
            } else {
                $decoded = json_decode($body, true);
                return array(
                    'success' => true,
                    'data' => $decoded
                );
            }
        } else {
            $decoded = json_decode($body, true);
            return array(
                'success' => false,
                'error' => isset($decoded['detail']) ? $decoded['detail'] : 'API request failed',
                'code' => $status_code
            );
        }
    }
    
    /**
     * Cache generated audio
     */
    public function cache_audio($text, $audio_data) {
        $cache_key = 'twp_tts_' . md5($text . $this->voice_id);
        set_transient($cache_key, $audio_data, DAY_IN_SECONDS * 7);
        return $cache_key;
    }
    
    /**
     * Get cached audio
     */
    public function get_cached_audio($text) {
        $cache_key = 'twp_tts_' . md5($text . $this->voice_id);
        return get_transient($cache_key);
    }
}