<?php
/**
 * Callback management class for queue callbacks and outbound calling
 */
class TWP_Callback_Manager {
    
    /**
     * Request a callback from queue
     */
    public static function request_callback($phone_number, $queue_id = null, $call_sid = null) {
        global $wpdb;
        $table_name = $wpdb->prefix . 'twp_callbacks';
        
        $result = $wpdb->insert(
            $table_name,
            array(
                'phone_number' => sanitize_text_field($phone_number),
                'queue_id' => $queue_id ? intval($queue_id) : null,
                'original_call_sid' => $call_sid,
                'status' => 'pending'
            ),
            array('%s', '%d', '%s', '%s')
        );
        
        if ($result !== false) {
            // Send confirmation SMS if configured
            $sms_number = get_option('twp_sms_notification_number');
            if ($sms_number) {
                $message = "Callback requested for " . $phone_number . ". We'll call you back shortly.";
                self::send_sms($phone_number, $message);
            }
            
            return $wpdb->insert_id;
        }
        
        return false;
    }
    
    /**
     * Process pending callbacks
     */
    public static function process_callbacks() {
        global $wpdb;
        $table_name = $wpdb->prefix . 'twp_callbacks';
        
        // Get pending callbacks older than 2 minutes (to avoid immediate callback)
        $callbacks = $wpdb->get_results("
            SELECT * FROM $table_name 
            WHERE status = 'pending' 
            AND requested_at <= DATE_SUB(NOW(), INTERVAL 2 MINUTE)
            AND attempts < 3
            ORDER BY requested_at ASC
            LIMIT 10
        ");
        
        foreach ($callbacks as $callback) {
            self::initiate_callback($callback);
        }
    }
    
    /**
     * Initiate a callback
     */
    private static function initiate_callback($callback) {
        global $wpdb;
        $table_name = $wpdb->prefix . 'twp_callbacks';
        
        // Find an available agent
        $available_agent = TWP_Agent_Manager::get_available_agents();
        
        if (empty($available_agent)) {
            // No agents available, try again later
            $wpdb->update(
                $table_name,
                array('last_attempt' => current_time('mysql')),
                array('id' => $callback->id),
                array('%s'),
                array('%d')
            );
            return false;
        }
        
        $agent = $available_agent[0]; // Get first available agent
        
        // Create a conference call
        $twilio = new TWP_Twilio_API();
        
        // First call the agent
        $agent_call_result = $twilio->make_call(
            $agent->phone_number,
            home_url('/wp-json/twilio-webhook/v1/callback-agent'),
            array(
                'callback_id' => $callback->id,
                'customer_number' => $callback->phone_number
            )
        );
        
        if ($agent_call_result['success']) {
            // Update callback status
            $wpdb->update(
                $table_name,
                array(
                    'status' => 'calling',
                    'attempts' => $callback->attempts + 1,
                    'last_attempt' => current_time('mysql'),
                    'callback_call_sid' => $agent_call_result['call_sid']
                ),
                array('id' => $callback->id),
                array('%s', '%d', '%s', '%s'),
                array('%d')
            );
            
            // Set agent to busy
            TWP_Agent_Manager::set_agent_status($agent->user_id, 'busy', $agent_call_result['call_sid']);
            
            return true;
        }
        
        return false;
    }
    
    /**
     * Handle callback agent answered
     */
    public static function handle_agent_answered($callback_id, $agent_call_sid) {
        global $wpdb;
        $callbacks_table = $wpdb->prefix . 'twp_callbacks';
        
        $callback = $wpdb->get_row($wpdb->prepare(
            "SELECT * FROM $callbacks_table WHERE id = %d",
            $callback_id
        ));
        
        if (!$callback) {
            return false;
        }
        
        // Now call the customer and conference them in
        $twilio = new TWP_Twilio_API();
        
        $customer_call_result = $twilio->make_call(
            $callback->phone_number,
            home_url('/wp-json/twilio-webhook/v1/callback-customer'),
            array(
                'agent_call_sid' => $agent_call_sid,
                'callback_id' => $callback_id
            )
        );
        
        if ($customer_call_result['success']) {
            // Update callback status
            $wpdb->update(
                $callbacks_table,
                array('status' => 'connecting'),
                array('id' => $callback_id),
                array('%s'),
                array('%d')
            );
            
            return true;
        }
        
        return false;
    }
    
    /**
     * Complete callback
     */
    public static function complete_callback($callback_id) {
        global $wpdb;
        $table_name = $wpdb->prefix . 'twp_callbacks';
        
        $wpdb->update(
            $table_name,
            array(
                'status' => 'completed',
                'completed_at' => current_time('mysql')
            ),
            array('id' => $callback_id),
            array('%s', '%s'),
            array('%d')
        );
    }
    
    /**
     * Initiate outbound call (click-to-call)
     */
    public static function initiate_outbound_call($to_number, $agent_user_id) {
        $agent_phone = get_user_meta($agent_user_id, 'twp_phone_number', true);
        
        if (!$agent_phone) {
            return array('success' => false, 'error' => 'No phone number configured');
        }
        
        $twilio = new TWP_Twilio_API();
        
        // First call the agent
        $agent_call_result = $twilio->make_call(
            $agent_phone,
            home_url('/wp-json/twilio-webhook/v1/outbound-agent'),
            array(
                'target_number' => $to_number,
                'agent_user_id' => $agent_user_id
            )
        );
        
        if ($agent_call_result['success']) {
            // Set agent to busy
            TWP_Agent_Manager::set_agent_status($agent_user_id, 'busy', $agent_call_result['call_sid']);
            
            // Log the outbound call
            TWP_Call_Logger::log_call(array(
                'call_sid' => $agent_call_result['call_sid'],
                'from_number' => $agent_phone,
                'to_number' => $to_number,
                'status' => 'outbound_initiated',
                'workflow_name' => 'Outbound Call',
                'actions_taken' => json_encode(array(
                    'agent_id' => $agent_user_id,
                    'agent_name' => get_userdata($agent_user_id)->display_name,
                    'type' => 'click_to_call'
                ))
            ));
            
            return array('success' => true, 'call_sid' => $agent_call_result['call_sid']);
        }
        
        return array('success' => false, 'error' => $agent_call_result['error']);
    }
    
    /**
     * Handle outbound agent answered
     */
    public static function handle_outbound_agent_answered($target_number, $agent_call_sid) {
        $twilio = new TWP_Twilio_API();
        
        // Create TwiML to call the target number
        $twiml = new \Twilio\TwiML\VoiceResponse();
        $twiml->say('Connecting your call...', ['voice' => 'alice']);
        
        $dial = $twiml->dial([
            'callerId' => get_option('twp_caller_id_number', ''), // Use configured caller ID
            'timeout' => 30
        ]);
        $dial->number($target_number);
        
        // If no answer, leave a message
        $twiml->say('The number you called is not available. Please try again later.', ['voice' => 'alice']);
        
        return $twiml->asXML();
    }
    
    /**
     * Create callback option TwiML for queue
     */
    public static function create_callback_twiml($queue_id, $caller_number) {
        $twiml = new \Twilio\TwiML\VoiceResponse();
        
        $gather = $twiml->gather([
            'numDigits' => 1,
            'timeout' => 10,
            'action' => home_url('/wp-json/twilio-webhook/v1/callback-choice'),
            'method' => 'POST'
        ]);
        
        $gather->say(
            'You are currently in the queue. Press 1 to wait on the line, or press 2 to request a callback.',
            ['voice' => 'alice']
        );
        
        // Default to callback if no input
        $twiml->say('No input received. Requesting callback for you.', ['voice' => 'alice']);
        $twiml->redirect(home_url('/wp-json/twilio-webhook/v1/request-callback?' . http_build_query([
            'queue_id' => $queue_id,
            'phone_number' => $caller_number
        ])));
        
        return $twiml->asXML();
    }
    
    /**
     * Send SMS notification
     */
    private static function send_sms($to_number, $message) {
        $twilio = new TWP_Twilio_API();
        return $twilio->send_sms($to_number, $message);
    }
    
    /**
     * Get callback statistics
     */
    public static function get_callback_stats($days = 7) {
        global $wpdb;
        $table_name = $wpdb->prefix . 'twp_callbacks';
        
        $since_date = date('Y-m-d H:i:s', strtotime("-$days days"));
        
        $stats = array(
            'total_requests' => $wpdb->get_var($wpdb->prepare(
                "SELECT COUNT(*) FROM $table_name WHERE requested_at >= %s",
                $since_date
            )),
            'completed' => $wpdb->get_var($wpdb->prepare(
                "SELECT COUNT(*) FROM $table_name WHERE requested_at >= %s AND status = 'completed'",
                $since_date
            )),
            'pending' => $wpdb->get_var("SELECT COUNT(*) FROM $table_name WHERE status = 'pending'"),
            'avg_completion_time' => $wpdb->get_var($wpdb->prepare(
                "SELECT AVG(TIMESTAMPDIFF(MINUTE, requested_at, completed_at)) 
                 FROM $table_name 
                 WHERE requested_at >= %s AND status = 'completed'",
                $since_date
            ))
        );
        
        $stats['success_rate'] = $stats['total_requests'] > 0 ? 
            round(($stats['completed'] / $stats['total_requests']) * 100, 1) : 0;
        
        return $stats;
    }
    
    /**
     * Get pending callbacks for admin
     */
    public static function get_pending_callbacks() {
        global $wpdb;
        $table_name = $wpdb->prefix . 'twp_callbacks';
        $queues_table = $wpdb->prefix . 'twp_call_queues';
        
        return $wpdb->get_results("
            SELECT 
                c.*,
                q.queue_name,
                TIMESTAMPDIFF(MINUTE, c.requested_at, NOW()) as wait_minutes
            FROM $table_name c
            LEFT JOIN $queues_table q ON c.queue_id = q.id
            WHERE c.status IN ('pending', 'calling', 'connecting')
            ORDER BY c.requested_at ASC
        ");
    }
}