<?php
/**
 * Mobile App REST API Endpoints
 *
 * Provides REST API endpoints for mobile app functionality
 */
class TWP_Mobile_API {

    private $auth;

    /**
     * Constructor
     */
    public function __construct() {
        // Initialize auth handler
        require_once plugin_dir_path(__FILE__) . 'class-twp-mobile-auth.php';
        $this->auth = new TWP_Mobile_Auth();
    }

    /**
     * Register REST API endpoints
     */
    public function register_endpoints() {
        add_action('rest_api_init', function() {
            // Agent status endpoints
            register_rest_route('twilio-mobile/v1', '/agent/status', array(
                'methods' => 'GET',
                'callback' => array($this, 'get_agent_status'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            register_rest_route('twilio-mobile/v1', '/agent/status', array(
                'methods' => 'POST',
                'callback' => array($this, 'update_agent_status'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            // Queue state endpoint
            register_rest_route('twilio-mobile/v1', '/queues/state', array(
                'methods' => 'GET',
                'callback' => array($this, 'get_queue_state'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            // Queue calls (specific queue)
            register_rest_route('twilio-mobile/v1', '/queues/(?P<id>\d+)/calls', array(
                'methods' => 'GET',
                'callback' => array($this, 'get_queue_calls'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            // Call control endpoints
            register_rest_route('twilio-mobile/v1', '/calls/(?P<call_sid>[^/]+)/accept', array(
                'methods' => 'POST',
                'callback' => array($this, 'accept_call'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            register_rest_route('twilio-mobile/v1', '/calls/(?P<call_sid>[^/]+)/reject', array(
                'methods' => 'POST',
                'callback' => array($this, 'reject_call'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            register_rest_route('twilio-mobile/v1', '/calls/(?P<call_sid>[^/]+)/hold', array(
                'methods' => 'POST',
                'callback' => array($this, 'hold_call'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            register_rest_route('twilio-mobile/v1', '/calls/(?P<call_sid>[^/]+)/unhold', array(
                'methods' => 'POST',
                'callback' => array($this, 'unhold_call'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            register_rest_route('twilio-mobile/v1', '/calls/(?P<call_sid>[^/]+)/transfer', array(
                'methods' => 'POST',
                'callback' => array($this, 'transfer_call'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            // FCM token registration
            register_rest_route('twilio-mobile/v1', '/fcm/register', array(
                'methods' => 'POST',
                'callback' => array($this, 'register_fcm_token'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            // Agent phone number
            register_rest_route('twilio-mobile/v1', '/agent/phone', array(
                'methods' => 'GET',
                'callback' => array($this, 'get_agent_phone'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));

            register_rest_route('twilio-mobile/v1', '/agent/phone', array(
                'methods' => 'POST',
                'callback' => array($this, 'update_agent_phone'),
                'permission_callback' => array($this->auth, 'verify_token')
            ));
        });
    }

    /**
     * Get agent status
     */
    public function get_agent_status($request) {
        $user_id = $this->auth->get_current_user_id();

        global $wpdb;
        $table = $wpdb->prefix . 'twp_agent_status';

        $status = $wpdb->get_row($wpdb->prepare(
            "SELECT status, is_logged_in, current_call_sid, last_activity, available_for_queues FROM $table WHERE user_id = %d",
            $user_id
        ));

        if (!$status) {
            // Create default status
            $wpdb->insert(
                $table,
                array('user_id' => $user_id, 'status' => 'offline', 'is_logged_in' => 0),
                array('%d', '%s', '%d')
            );

            $status = (object) array(
                'status' => 'offline',
                'is_logged_in' => 0,
                'current_call_sid' => null,
                'last_activity' => current_time('mysql'),
                'available_for_queues' => 1
            );
        }

        return new WP_REST_Response(array(
            'success' => true,
            'status' => $status->status,
            'is_logged_in' => (bool)$status->is_logged_in,
            'current_call_sid' => $status->current_call_sid,
            'last_activity' => $status->last_activity,
            'available_for_queues' => (bool)$status->available_for_queues
        ), 200);
    }

    /**
     * Update agent status
     */
    public function update_agent_status($request) {
        $user_id = $this->auth->get_current_user_id();
        $new_status = $request->get_param('status');
        $is_logged_in = $request->get_param('is_logged_in');

        if (!in_array($new_status, array('available', 'busy', 'offline'))) {
            return new WP_Error('invalid_status', 'Status must be available, busy, or offline', array('status' => 400));
        }

        global $wpdb;
        $table = $wpdb->prefix . 'twp_agent_status';

        // Check if status exists
        $exists = $wpdb->get_var($wpdb->prepare(
            "SELECT COUNT(*) FROM $table WHERE user_id = %d",
            $user_id
        ));

        $data = array(
            'status' => $new_status,
            'last_activity' => current_time('mysql')
        );

        if ($is_logged_in !== null) {
            $data['is_logged_in'] = $is_logged_in ? 1 : 0;
            if ($is_logged_in) {
                $data['logged_in_at'] = current_time('mysql');
            }
        }

        if ($exists) {
            $wpdb->update(
                $table,
                $data,
                array('user_id' => $user_id),
                array('%s', '%s'),
                array('%d')
            );
        } else {
            $data['user_id'] = $user_id;
            $wpdb->insert($table, $data);
        }

        return new WP_REST_Response(array(
            'success' => true,
            'message' => 'Status updated successfully'
        ), 200);
    }

    /**
     * Get queue state (all queues user has access to)
     */
    public function get_queue_state($request) {
        $user_id = $this->auth->get_current_user_id();

        global $wpdb;
        $queues_table = $wpdb->prefix . 'twp_call_queues';
        $calls_table = $wpdb->prefix . 'twp_queued_calls';
        $assignments_table = $wpdb->prefix . 'twp_queue_assignments';

        // Get queues assigned to this user
        $queue_ids = $wpdb->get_col($wpdb->prepare(
            "SELECT queue_id FROM $assignments_table WHERE user_id = %d",
            $user_id
        ));

        // Also include personal queues
        $personal_queue_ids = $wpdb->get_col($wpdb->prepare(
            "SELECT id FROM $queues_table WHERE user_id = %d",
            $user_id
        ));

        $all_queue_ids = array_unique(array_merge($queue_ids, $personal_queue_ids));

        if (empty($all_queue_ids)) {
            return new WP_REST_Response(array(
                'success' => true,
                'queues' => array()
            ), 200);
        }

        $queue_ids_str = implode(',', array_map('intval', $all_queue_ids));

        // Get queue information with call counts
        $queues = $wpdb->get_results("
            SELECT
                q.id,
                q.queue_name,
                q.queue_type,
                q.extension,
                COUNT(c.id) as waiting_count
            FROM $queues_table q
            LEFT JOIN $calls_table c ON q.id = c.queue_id AND c.status = 'waiting'
            WHERE q.id IN ($queue_ids_str)
            GROUP BY q.id
        ");

        $result = array();
        foreach ($queues as $queue) {
            $result[] = array(
                'id' => (int)$queue->id,
                'name' => $queue->queue_name,
                'type' => $queue->queue_type,
                'extension' => $queue->extension,
                'waiting_count' => (int)$queue->waiting_count
            );
        }

        return new WP_REST_Response(array(
            'success' => true,
            'queues' => $result
        ), 200);
    }

    /**
     * Get calls in a specific queue
     */
    public function get_queue_calls($request) {
        $user_id = $this->auth->get_current_user_id();
        $queue_id = (int)$request['id'];

        // Verify user has access to this queue
        if (!$this->user_has_queue_access($user_id, $queue_id)) {
            return new WP_Error('forbidden', 'You do not have access to this queue', array('status' => 403));
        }

        global $wpdb;
        $table = $wpdb->prefix . 'twp_queued_calls';

        $calls = $wpdb->get_results($wpdb->prepare(
            "SELECT call_sid, from_number, to_number, position, status, joined_at, enqueued_at
             FROM $table
             WHERE queue_id = %d AND status = 'waiting'
             ORDER BY position ASC",
            $queue_id
        ));

        $result = array();
        foreach ($calls as $call) {
            $result[] = array(
                'call_sid' => $call->call_sid,
                'from_number' => $call->from_number,
                'to_number' => $call->to_number,
                'position' => (int)$call->position,
                'status' => $call->status,
                'wait_time' => $this->calculate_wait_time($call->enqueued_at ?: $call->joined_at)
            );
        }

        return new WP_REST_Response(array(
            'success' => true,
            'calls' => $result
        ), 200);
    }

    /**
     * Accept a call (dequeue and connect to agent)
     */
    public function accept_call($request) {
        $user_id = $this->auth->get_current_user_id();
        $call_sid = $request['call_sid'];

        // Get agent phone number
        $agent_number = get_user_meta($user_id, 'twp_agent_phone', true);

        if (empty($agent_number)) {
            return new WP_Error('no_phone', 'No phone number configured for agent', array('status' => 400));
        }

        // Initialize Twilio API
        require_once plugin_dir_path(dirname(__FILE__)) . 'includes/class-twp-twilio-api.php';
        $twilio = new TWP_Twilio_API();

        // Get call info from queue
        global $wpdb;
        $calls_table = $wpdb->prefix . 'twp_queued_calls';

        $call = $wpdb->get_row($wpdb->prepare(
            "SELECT * FROM $calls_table WHERE call_sid = %s AND status = 'waiting'",
            $call_sid
        ));

        if (!$call) {
            return new WP_Error('call_not_found', 'Call not found or no longer waiting', array('status' => 404));
        }

        // Verify user has access to this queue
        if (!$this->user_has_queue_access($user_id, $call->queue_id)) {
            return new WP_Error('forbidden', 'You do not have access to this queue', array('status' => 403));
        }

        try {
            // Connect agent to call
            $agent_call = $twilio->create_call(
                $agent_number,
                $call->to_number,
                array(
                    'url' => site_url('/wp-json/twilio-webhook/v1/connect-agent'),
                    'statusCallback' => site_url('/wp-json/twilio-webhook/v1/agent-call-status'),
                    'statusCallbackEvent' => array('completed', 'no-answer', 'busy', 'failed'),
                    'timeout' => 30
                )
            );

            // Update call record
            $wpdb->update(
                $calls_table,
                array(
                    'status' => 'connecting',
                    'agent_phone' => $agent_number,
                    'agent_call_sid' => $agent_call->sid
                ),
                array('call_sid' => $call_sid),
                array('%s', '%s', '%s'),
                array('%s')
            );

            // Update agent status
            $status_table = $wpdb->prefix . 'twp_agent_status';
            $wpdb->update(
                $status_table,
                array('status' => 'busy', 'current_call_sid' => $call_sid),
                array('user_id' => $user_id),
                array('%s', '%s'),
                array('%d')
            );

            return new WP_REST_Response(array(
                'success' => true,
                'message' => 'Call accepted, connecting to agent',
                'agent_call_sid' => $agent_call->sid
            ), 200);

        } catch (Exception $e) {
            return new WP_Error('twilio_error', $e->getMessage(), array('status' => 500));
        }
    }

    /**
     * Reject a call (send to voicemail)
     */
    public function reject_call($request) {
        $user_id = $this->auth->get_current_user_id();
        $call_sid = $request['call_sid'];

        global $wpdb;
        $calls_table = $wpdb->prefix . 'twp_queued_calls';

        $call = $wpdb->get_row($wpdb->prepare(
            "SELECT * FROM $calls_table WHERE call_sid = %s AND status = 'waiting'",
            $call_sid
        ));

        if (!$call) {
            return new WP_Error('call_not_found', 'Call not found or no longer waiting', array('status' => 404));
        }

        // Verify user has access to this queue
        if (!$this->user_has_queue_access($user_id, $call->queue_id)) {
            return new WP_Error('forbidden', 'You do not have access to this queue', array('status' => 403));
        }

        try {
            // Initialize Twilio API
            require_once plugin_dir_path(dirname(__FILE__)) . 'includes/class-twp-twilio-api.php';
            $twilio = new TWP_Twilio_API();

            // Redirect call to voicemail
            $twiml = new \Twilio\TwiML\VoiceResponse();
            $twiml->say('The agent is unavailable. Please leave a message after the tone.');
            $twiml->record(array(
                'action' => site_url('/wp-json/twilio-webhook/v1/voicemail-complete'),
                'maxLength' => 120,
                'transcribe' => true
            ));
            $twiml->say('We did not receive a recording. Goodbye.');

            $twilio->update_call($call_sid, array('twiml' => $twiml->asXML()));

            // Update call status
            $wpdb->update(
                $calls_table,
                array('status' => 'voicemail', 'ended_at' => current_time('mysql')),
                array('call_sid' => $call_sid),
                array('%s', '%s'),
                array('%s')
            );

            return new WP_REST_Response(array(
                'success' => true,
                'message' => 'Call sent to voicemail'
            ), 200);

        } catch (Exception $e) {
            return new WP_Error('twilio_error', $e->getMessage(), array('status' => 500));
        }
    }

    /**
     * Hold a call
     */
    public function hold_call($request) {
        $user_id = $this->auth->get_current_user_id();
        $call_sid = $request['call_sid'];

        try {
            require_once plugin_dir_path(dirname(__FILE__)) . 'includes/class-twp-admin.php';
            require_once plugin_dir_path(dirname(__FILE__)) . 'includes/class-twp-twilio-api.php';

            $admin = new TWP_Admin('twilio-wp-plugin', TWP_VERSION);
            $twilio = new TWP_Twilio_API();

            // Find customer call leg
            $customer_call_sid = $admin->find_customer_call_leg($call_sid, $twilio);

            if (!$customer_call_sid) {
                return new WP_Error('call_not_found', 'Could not find customer call leg', array('status' => 404));
            }

            // Get user's hold queue
            global $wpdb;
            $ext_table = $wpdb->prefix . 'twp_user_extensions';
            $queues_table = $wpdb->prefix . 'twp_call_queues';

            $extension = $wpdb->get_row($wpdb->prepare(
                "SELECT hold_queue_id FROM $ext_table WHERE user_id = %d",
                $user_id
            ));

            if (!$extension || !$extension->hold_queue_id) {
                return new WP_Error('no_hold_queue', 'No hold queue configured', array('status' => 400));
            }

            $hold_queue = $wpdb->get_row($wpdb->prepare(
                "SELECT queue_name, wait_music_url FROM $queues_table WHERE id = %d",
                $extension->hold_queue_id
            ));

            // Put call on hold
            $twiml = new \Twilio\TwiML\VoiceResponse();
            $twiml->say('Please hold while we transfer your call.');
            $enqueue = $twiml->enqueue($hold_queue->queue_name, array(
                'waitUrl' => $hold_queue->wait_music_url ?: site_url('/wp-json/twilio-webhook/v1/queue-wait')
            ));

            $twilio->update_call($customer_call_sid, array('twiml' => $twiml->asXML()));

            return new WP_REST_Response(array(
                'success' => true,
                'message' => 'Call placed on hold'
            ), 200);

        } catch (Exception $e) {
            return new WP_Error('hold_error', $e->getMessage(), array('status' => 500));
        }
    }

    /**
     * Unhold a call (resume from hold queue)
     */
    public function unhold_call($request) {
        // Implementation would retrieve from hold queue and reconnect
        return new WP_REST_Response(array(
            'success' => true,
            'message' => 'Unhold functionality - to be implemented with queue retrieval'
        ), 501);
    }

    /**
     * Transfer a call to another extension/queue
     */
    public function transfer_call($request) {
        $user_id = $this->auth->get_current_user_id();
        $call_sid = $request['call_sid'];
        $target = $request->get_param('target'); // Extension number or queue ID

        if (empty($target)) {
            return new WP_Error('missing_target', 'Transfer target is required', array('status' => 400));
        }

        try {
            require_once plugin_dir_path(dirname(__FILE__)) . 'includes/class-twp-admin.php';
            require_once plugin_dir_path(dirname(__FILE__)) . 'includes/class-twp-twilio-api.php';

            $admin = new TWP_Admin('twilio-wp-plugin', TWP_VERSION);
            $twilio = new TWP_Twilio_API();

            // Find customer call leg
            $customer_call_sid = $admin->find_customer_call_leg($call_sid, $twilio);

            if (!$customer_call_sid) {
                return new WP_Error('call_not_found', 'Could not find customer call leg', array('status' => 404));
            }

            // Look up target (extension or queue)
            global $wpdb;
            $ext_table = $wpdb->prefix . 'twp_user_extensions';
            $queues_table = $wpdb->prefix . 'twp_call_queues';

            // Try as extension first
            $target_queue = $wpdb->get_row($wpdb->prepare(
                "SELECT q.* FROM $queues_table q
                 JOIN $ext_table e ON q.id = e.personal_queue_id
                 WHERE e.extension = %s",
                $target
            ));

            // If not extension, try as queue ID
            if (!$target_queue && is_numeric($target)) {
                $target_queue = $wpdb->get_row($wpdb->prepare(
                    "SELECT * FROM $queues_table WHERE id = %d",
                    $target
                ));
            }

            if (!$target_queue) {
                return new WP_Error('invalid_target', 'Transfer target not found', array('status' => 404));
            }

            // Transfer to queue
            $twiml = new \Twilio\TwiML\VoiceResponse();
            $twiml->say('Transferring your call.');
            $twiml->enqueue($target_queue->queue_name, array(
                'waitUrl' => $target_queue->wait_music_url ?: site_url('/wp-json/twilio-webhook/v1/queue-wait')
            ));

            $twilio->update_call($customer_call_sid, array('twiml' => $twiml->asXML()));

            return new WP_REST_Response(array(
                'success' => true,
                'message' => 'Call transferred successfully'
            ), 200);

        } catch (Exception $e) {
            return new WP_Error('transfer_error', $e->getMessage(), array('status' => 500));
        }
    }

    /**
     * Register FCM token for push notifications
     */
    public function register_fcm_token($request) {
        $user_id = $this->auth->get_current_user_id();
        $fcm_token = $request->get_param('fcm_token');
        $refresh_token = $request->get_param('refresh_token');

        if (empty($fcm_token)) {
            return new WP_Error('missing_token', 'FCM token is required', array('status' => 400));
        }

        $this->auth->update_fcm_token($user_id, $refresh_token, $fcm_token);

        return new WP_REST_Response(array(
            'success' => true,
            'message' => 'FCM token registered successfully'
        ), 200);
    }

    /**
     * Get agent phone number
     */
    public function get_agent_phone($request) {
        $user_id = $this->auth->get_current_user_id();
        $agent_number = get_user_meta($user_id, 'twp_agent_phone', true);

        return new WP_REST_Response(array(
            'success' => true,
            'phone_number' => $agent_number ?: null
        ), 200);
    }

    /**
     * Update agent phone number
     */
    public function update_agent_phone($request) {
        $user_id = $this->auth->get_current_user_id();
        $phone_number = $request->get_param('phone_number');

        if (empty($phone_number)) {
            return new WP_Error('missing_phone', 'Phone number is required', array('status' => 400));
        }

        // Validate E.164 format
        if (!preg_match('/^\+[1-9]\d{1,14}$/', $phone_number)) {
            return new WP_Error('invalid_phone', 'Phone number must be in E.164 format (+1XXXXXXXXXX)', array('status' => 400));
        }

        update_user_meta($user_id, 'twp_agent_phone', $phone_number);

        return new WP_REST_Response(array(
            'success' => true,
            'message' => 'Phone number updated successfully'
        ), 200);
    }

    /**
     * Check if user has access to a queue
     */
    private function user_has_queue_access($user_id, $queue_id) {
        global $wpdb;
        $queues_table = $wpdb->prefix . 'twp_call_queues';
        $assignments_table = $wpdb->prefix . 'twp_queue_assignments';

        // Check if it's user's personal queue
        $is_personal = $wpdb->get_var($wpdb->prepare(
            "SELECT COUNT(*) FROM $queues_table WHERE id = %d AND user_id = %d",
            $queue_id, $user_id
        ));

        if ($is_personal) {
            return true;
        }

        // Check if user is assigned to this queue
        $is_assigned = $wpdb->get_var($wpdb->prepare(
            "SELECT COUNT(*) FROM $assignments_table WHERE queue_id = %d AND user_id = %d",
            $queue_id, $user_id
        ));

        return (bool)$is_assigned;
    }

    /**
     * Calculate wait time in seconds
     */
    private function calculate_wait_time($start_time) {
        if (!$start_time) {
            return 0;
        }

        $start = strtotime($start_time);
        $now = current_time('timestamp');

        return max(0, $now - $start);
    }
}