<?php
/**
 * HVAC AJAX Handlers
 * 
 * Implements missing AJAX endpoints with comprehensive security
 *
 * @package HVAC_Community_Events
 * @since 2.0.0
 */

if (!defined('ABSPATH')) {
    exit;
}

/**
 * Class HVAC_Ajax_Handlers
 * 
 * Handles AJAX requests for trainer stats and announcement management
 */
class HVAC_Ajax_Handlers {
    
    /**
     * Instance of this class
     *
     * @var HVAC_Ajax_Handlers
     */
    private static $instance = null;
    
    /**
     * Get instance of this class
     *
     * @return HVAC_Ajax_Handlers
     */
    public static function get_instance() {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }
    
    /**
     * Constructor
     */
    private function __construct() {
        $this->init_hooks();
    }
    
    /**
     * Initialize AJAX hooks
     */
    private function init_hooks() {
        // Trainer stats endpoint
        add_action('wp_ajax_hvac_get_trainer_stats', array($this, 'get_trainer_stats'));
        add_action('wp_ajax_nopriv_hvac_get_trainer_stats', array($this, 'unauthorized_access'));
        
        // Announcement management endpoint
        add_action('wp_ajax_hvac_manage_announcement', array($this, 'manage_announcement'));
        add_action('wp_ajax_nopriv_hvac_manage_announcement', array($this, 'unauthorized_access'));
        
        // Enhanced approval endpoint (wrapper for existing)
        add_action('wp_ajax_hvac_approve_trainer_v2', array($this, 'approve_trainer_secure'));
        add_action('wp_ajax_nopriv_hvac_approve_trainer_v2', array($this, 'unauthorized_access'));
    }
    
    /**
     * Get trainer statistics
     * 
     * Provides statistics for trainers with proper security validation
     */
    public function get_trainer_stats() {
        // Security verification
        $security_check = HVAC_Ajax_Security::verify_ajax_request(
            'get_trainer_stats',
            HVAC_Ajax_Security::NONCE_GENERAL,
            array('hvac_master_trainer', 'view_master_dashboard', 'manage_options'),
            false
        );
        
        if (is_wp_error($security_check)) {
            wp_send_json_error(
                array(
                    'message' => $security_check->get_error_message(),
                    'code' => $security_check->get_error_code()
                ),
                $security_check->get_error_data() ? $security_check->get_error_data()['status'] : 403
            );
            return;
        }
        
        // Input validation
        $input_rules = array(
            'trainer_id' => array(
                'type' => 'int',
                'required' => false,
                'min' => 1
            ),
            'date_from' => array(
                'type' => 'text',
                'required' => false,
                'validate' => function($value) {
                    if (!empty($value) && !strtotime($value)) {
                        return new WP_Error('invalid_date', 'Invalid date format');
                    }
                    return true;
                }
            ),
            'date_to' => array(
                'type' => 'text',
                'required' => false,
                'validate' => function($value) {
                    if (!empty($value) && !strtotime($value)) {
                        return new WP_Error('invalid_date', 'Invalid date format');
                    }
                    return true;
                }
            ),
            'stat_type' => array(
                'type' => 'text',
                'required' => false,
                'validate' => function($value) {
                    $valid_types = array('events', 'attendees', 'revenue', 'ratings', 'all');
                    if (!empty($value) && !in_array($value, $valid_types)) {
                        return new WP_Error('invalid_type', 'Invalid statistics type');
                    }
                    return true;
                }
            )
        );
        
        $params = HVAC_Ajax_Security::sanitize_input($_POST, $input_rules);
        
        if (is_wp_error($params)) {
            wp_send_json_error(
                array(
                    'message' => $params->get_error_message(),
                    'errors' => $params->get_error_data()
                ),
                400
            );
            return;
        }
        
        // Set defaults
        $trainer_id = isset($params['trainer_id']) ? $params['trainer_id'] : null;
        $date_from = isset($params['date_from']) ? $params['date_from'] : date('Y-m-d', strtotime('-30 days'));
        $date_to = isset($params['date_to']) ? $params['date_to'] : date('Y-m-d');
        $stat_type = isset($params['stat_type']) ? $params['stat_type'] : 'all';
        
        // Get statistics
        $stats = $this->compile_trainer_stats($trainer_id, $date_from, $date_to, $stat_type);
        
        if (is_wp_error($stats)) {
            wp_send_json_error(
                array(
                    'message' => $stats->get_error_message()
                ),
                500
            );
            return;
        }
        
        // Log successful stats retrieval
        if (class_exists('HVAC_Logger')) {
            HVAC_Logger::info('Trainer stats retrieved', 'AJAX', array(
                'user_id' => get_current_user_id(),
                'trainer_id' => $trainer_id,
                'date_range' => $date_from . ' to ' . $date_to
            ));
        }
        
        wp_send_json_success(array(
            'stats' => $stats,
            'parameters' => array(
                'trainer_id' => $trainer_id,
                'date_from' => $date_from,
                'date_to' => $date_to,
                'stat_type' => $stat_type
            ),
            'generated_at' => current_time('mysql')
        ));
    }
    
    /**
     * Compile trainer statistics
     * 
     * @param int|null $trainer_id Specific trainer or all
     * @param string $date_from Start date
     * @param string $date_to End date
     * @param string $stat_type Type of statistics
     * @return array|WP_Error
     */
    private function compile_trainer_stats($trainer_id, $date_from, $date_to, $stat_type) {
        global $wpdb;
        
        $stats = array();
        
        try {
            // Base query conditions
            $where_conditions = array("1=1");
            $query_params = array();
            
            if ($trainer_id) {
                $where_conditions[] = "trainer_id = %d";
                $query_params[] = $trainer_id;
            }
            
            // Events statistics
            if (in_array($stat_type, array('events', 'all'))) {
                $events_query = "
                    SELECT 
                        COUNT(DISTINCT p.ID) as total_events,
                        SUM(CASE WHEN p.post_status = 'publish' THEN 1 ELSE 0 END) as published_events,
                        SUM(CASE WHEN p.post_status = 'draft' THEN 1 ELSE 0 END) as draft_events
                    FROM {$wpdb->posts} p
                    INNER JOIN {$wpdb->postmeta} pm ON p.ID = pm.post_id
                    WHERE p.post_type = 'tribe_events'
                    AND pm.meta_key = '_EventStartDate'
                    AND pm.meta_value BETWEEN %s AND %s
                ";
                
                if ($trainer_id) {
                    $events_query .= " AND p.post_author = %d";
                    $events_result = $wpdb->get_row($wpdb->prepare($events_query, $date_from, $date_to, $trainer_id));
                } else {
                    $events_result = $wpdb->get_row($wpdb->prepare($events_query, $date_from, $date_to));
                }
                
                $stats['events'] = array(
                    'total' => intval($events_result->total_events),
                    'published' => intval($events_result->published_events),
                    'draft' => intval($events_result->draft_events)
                );
            }
            
            // Attendees statistics
            if (in_array($stat_type, array('attendees', 'all'))) {
                // This would integrate with your attendee tracking system
                $stats['attendees'] = array(
                    'total' => 0,
                    'unique' => 0,
                    'average_per_event' => 0
                );
                
                // If you have attendee data, query it here
                // Example: Query from custom attendee table or meta
            }
            
            // Trainer summary
            if (!$trainer_id) {
                $trainer_stats = $wpdb->get_row("
                    SELECT 
                        COUNT(DISTINCT u.ID) as total_trainers,
                        SUM(CASE WHEN um.meta_value = 'approved' THEN 1 ELSE 0 END) as approved_trainers,
                        SUM(CASE WHEN um.meta_value = 'pending' THEN 1 ELSE 0 END) as pending_trainers
                    FROM {$wpdb->users} u
                    INNER JOIN {$wpdb->usermeta} um ON u.ID = um.user_id
                    WHERE um.meta_key = 'hvac_trainer_status'
                ");
                
                $stats['trainers'] = array(
                    'total' => intval($trainer_stats->total_trainers),
                    'approved' => intval($trainer_stats->approved_trainers),
                    'pending' => intval($trainer_stats->pending_trainers)
                );
            }
            
            // Add metadata
            $stats['meta'] = array(
                'date_from' => $date_from,
                'date_to' => $date_to,
                'generated' => current_time('mysql')
            );
            
            return $stats;
            
        } catch (Exception $e) {
            return new WP_Error('stats_error', 'Failed to compile statistics: ' . $e->getMessage());
        }
    }
    
    /**
     * Manage announcements
     * 
     * Unified endpoint for announcement CRUD operations
     */
    public function manage_announcement() {
        // Determine action
        $action = isset($_POST['announcement_action']) ? sanitize_text_field($_POST['announcement_action']) : '';
        
        if (empty($action)) {
            wp_send_json_error(
                array('message' => 'No action specified'),
                400
            );
            return;
        }
        
        // Map actions to required capabilities
        $action_capabilities = array(
            'create' => array('hvac_master_trainer', 'edit_posts', 'manage_options'),
            'update' => array('hvac_master_trainer', 'edit_posts', 'manage_options'),
            'delete' => array('hvac_master_trainer', 'delete_posts', 'manage_options'),
            'read' => array('hvac_trainer', 'hvac_master_trainer', 'read')
        );
        
        $required_caps = isset($action_capabilities[$action]) ? $action_capabilities[$action] : array('manage_options');
        $is_sensitive = in_array($action, array('delete'));
        
        // Security verification
        $security_check = HVAC_Ajax_Security::verify_ajax_request(
            'manage_announcement_' . $action,
            HVAC_Ajax_Security::NONCE_ANNOUNCEMENT,
            $required_caps,
            $is_sensitive
        );
        
        if (is_wp_error($security_check)) {
            wp_send_json_error(
                array(
                    'message' => $security_check->get_error_message(),
                    'code' => $security_check->get_error_code()
                ),
                $security_check->get_error_data() ? $security_check->get_error_data()['status'] : 403
            );
            return;
        }
        
        // Route to appropriate handler
        switch ($action) {
            case 'create':
                $this->create_announcement();
                break;
            case 'update':
                $this->update_announcement();
                break;
            case 'delete':
                $this->delete_announcement();
                break;
            case 'read':
                $this->read_announcement();
                break;
            default:
                wp_send_json_error(
                    array('message' => 'Invalid action'),
                    400
                );
        }
    }
    
    /**
     * Create announcement
     */
    private function create_announcement() {
        // Input validation rules
        $input_rules = array(
            'title' => array(
                'type' => 'text',
                'required' => true,
                'max_length' => 200
            ),
            'content' => array(
                'type' => 'html',
                'required' => true,
                'allowed_html' => wp_kses_allowed_html('post')
            ),
            'excerpt' => array(
                'type' => 'textarea',
                'required' => false,
                'max_length' => 500
            ),
            'status' => array(
                'type' => 'text',
                'required' => false,
                'validate' => function($value) {
                    $valid_statuses = array('publish', 'draft', 'private');
                    if (!empty($value) && !in_array($value, $valid_statuses)) {
                        return new WP_Error('invalid_status', 'Invalid announcement status');
                    }
                    return true;
                }
            ),
            'categories' => array(
                'type' => 'array',
                'required' => false
            ),
            'tags' => array(
                'type' => 'text',
                'required' => false,
                'max_length' => 500
            )
        );
        
        $data = HVAC_Ajax_Security::sanitize_input($_POST, $input_rules);
        
        if (is_wp_error($data)) {
            wp_send_json_error(
                array(
                    'message' => $data->get_error_message(),
                    'errors' => $data->get_error_data()
                ),
                400
            );
            return;
        }
        
        // Create announcement post
        $post_data = array(
            'post_title' => $data['title'],
            'post_content' => $data['content'],
            'post_excerpt' => isset($data['excerpt']) ? $data['excerpt'] : '',
            'post_status' => isset($data['status']) ? $data['status'] : 'draft',
            'post_type' => 'hvac_announcement',
            'post_author' => get_current_user_id()
        );
        
        $post_id = wp_insert_post($post_data, true);
        
        if (is_wp_error($post_id)) {
            wp_send_json_error(
                array('message' => 'Failed to create announcement: ' . $post_id->get_error_message()),
                500
            );
            return;
        }
        
        // Set categories and tags if provided
        if (!empty($data['categories'])) {
            wp_set_object_terms($post_id, $data['categories'], 'hvac_announcement_category');
        }
        
        if (!empty($data['tags'])) {
            $tags = array_map('trim', explode(',', $data['tags']));
            wp_set_object_terms($post_id, $tags, 'hvac_announcement_tag');
        }
        
        // Log creation
        if (class_exists('HVAC_Logger')) {
            HVAC_Logger::info('Announcement created', 'AJAX', array(
                'post_id' => $post_id,
                'user_id' => get_current_user_id(),
                'title' => $data['title']
            ));
        }
        
        wp_send_json_success(array(
            'message' => 'Announcement created successfully',
            'post_id' => $post_id,
            'redirect' => get_permalink($post_id)
        ));
    }
    
    /**
     * Update announcement
     */
    private function update_announcement() {
        // Input validation rules
        $input_rules = array(
            'post_id' => array(
                'type' => 'int',
                'required' => true,
                'min' => 1
            ),
            'title' => array(
                'type' => 'text',
                'required' => false,
                'max_length' => 200
            ),
            'content' => array(
                'type' => 'html',
                'required' => false,
                'allowed_html' => wp_kses_allowed_html('post')
            ),
            'excerpt' => array(
                'type' => 'textarea',
                'required' => false,
                'max_length' => 500
            ),
            'status' => array(
                'type' => 'text',
                'required' => false,
                'validate' => function($value) {
                    $valid_statuses = array('publish', 'draft', 'private', 'trash');
                    if (!empty($value) && !in_array($value, $valid_statuses)) {
                        return new WP_Error('invalid_status', 'Invalid announcement status');
                    }
                    return true;
                }
            )
        );
        
        $data = HVAC_Ajax_Security::sanitize_input($_POST, $input_rules);
        
        if (is_wp_error($data)) {
            wp_send_json_error(
                array(
                    'message' => $data->get_error_message(),
                    'errors' => $data->get_error_data()
                ),
                400
            );
            return;
        }
        
        // Verify post exists and user can edit
        $post = get_post($data['post_id']);
        if (!$post || $post->post_type !== 'hvac_announcement') {
            wp_send_json_error(
                array('message' => 'Announcement not found'),
                404
            );
            return;
        }
        
        if (!current_user_can('edit_post', $data['post_id'])) {
            wp_send_json_error(
                array('message' => 'You do not have permission to edit this announcement'),
                403
            );
            return;
        }
        
        // Update post data
        $update_data = array(
            'ID' => $data['post_id']
        );
        
        if (isset($data['title'])) {
            $update_data['post_title'] = $data['title'];
        }
        if (isset($data['content'])) {
            $update_data['post_content'] = $data['content'];
        }
        if (isset($data['excerpt'])) {
            $update_data['post_excerpt'] = $data['excerpt'];
        }
        if (isset($data['status'])) {
            $update_data['post_status'] = $data['status'];
        }
        
        $result = wp_update_post($update_data, true);
        
        if (is_wp_error($result)) {
            wp_send_json_error(
                array('message' => 'Failed to update announcement: ' . $result->get_error_message()),
                500
            );
            return;
        }
        
        // Log update
        if (class_exists('HVAC_Logger')) {
            HVAC_Logger::info('Announcement updated', 'AJAX', array(
                'post_id' => $data['post_id'],
                'user_id' => get_current_user_id(),
                'changes' => array_keys($update_data)
            ));
        }
        
        wp_send_json_success(array(
            'message' => 'Announcement updated successfully',
            'post_id' => $data['post_id']
        ));
    }
    
    /**
     * Delete announcement
     */
    private function delete_announcement() {
        // Input validation
        $input_rules = array(
            'post_id' => array(
                'type' => 'int',
                'required' => true,
                'min' => 1
            ),
            'permanent' => array(
                'type' => 'boolean',
                'required' => false
            )
        );
        
        $data = HVAC_Ajax_Security::sanitize_input($_POST, $input_rules);
        
        if (is_wp_error($data)) {
            wp_send_json_error(
                array(
                    'message' => $data->get_error_message(),
                    'errors' => $data->get_error_data()
                ),
                400
            );
            return;
        }
        
        // Verify post exists and user can delete
        $post = get_post($data['post_id']);
        if (!$post || $post->post_type !== 'hvac_announcement') {
            wp_send_json_error(
                array('message' => 'Announcement not found'),
                404
            );
            return;
        }
        
        if (!current_user_can('delete_post', $data['post_id'])) {
            wp_send_json_error(
                array('message' => 'You do not have permission to delete this announcement'),
                403
            );
            return;
        }
        
        // Delete or trash post
        $permanent = isset($data['permanent']) ? $data['permanent'] : false;
        
        if ($permanent) {
            $result = wp_delete_post($data['post_id'], true);
        } else {
            $result = wp_trash_post($data['post_id']);
        }
        
        if (!$result) {
            wp_send_json_error(
                array('message' => 'Failed to delete announcement'),
                500
            );
            return;
        }
        
        // Log deletion
        if (class_exists('HVAC_Logger')) {
            HVAC_Logger::warning('Announcement deleted', 'AJAX', array(
                'post_id' => $data['post_id'],
                'user_id' => get_current_user_id(),
                'permanent' => $permanent
            ));
        }
        
        wp_send_json_success(array(
            'message' => 'Announcement deleted successfully',
            'post_id' => $data['post_id']
        ));
    }
    
    /**
     * Read announcement
     */
    private function read_announcement() {
        // Input validation
        $input_rules = array(
            'post_id' => array(
                'type' => 'int',
                'required' => true,
                'min' => 1
            )
        );
        
        $data = HVAC_Ajax_Security::sanitize_input($_POST, $input_rules);
        
        if (is_wp_error($data)) {
            wp_send_json_error(
                array(
                    'message' => $data->get_error_message(),
                    'errors' => $data->get_error_data()
                ),
                400
            );
            return;
        }
        
        // Get announcement
        $post = get_post($data['post_id']);
        if (!$post || $post->post_type !== 'hvac_announcement') {
            wp_send_json_error(
                array('message' => 'Announcement not found'),
                404
            );
            return;
        }
        
        // Check if user can read
        if ($post->post_status === 'private' && !current_user_can('read_private_posts')) {
            wp_send_json_error(
                array('message' => 'You do not have permission to view this announcement'),
                403
            );
            return;
        }
        
        // Prepare response
        $response = array(
            'id' => $post->ID,
            'title' => $post->post_title,
            'content' => apply_filters('the_content', $post->post_content),
            'excerpt' => $post->post_excerpt,
            'status' => $post->post_status,
            'author' => get_the_author_meta('display_name', $post->post_author),
            'date' => $post->post_date,
            'modified' => $post->post_modified,
            'categories' => wp_get_object_terms($post->ID, 'hvac_announcement_category', array('fields' => 'names')),
            'tags' => wp_get_object_terms($post->ID, 'hvac_announcement_tag', array('fields' => 'names')),
            'can_edit' => current_user_can('edit_post', $post->ID),
            'can_delete' => current_user_can('delete_post', $post->ID)
        );
        
        wp_send_json_success($response);
    }
    
    /**
     * Enhanced secure trainer approval
     * 
     * Wrapper for existing approval with enhanced security
     */
    public function approve_trainer_secure() {
        // Enhanced security verification
        $security_check = HVAC_Ajax_Security::verify_ajax_request(
            'approve_trainer',
            HVAC_Ajax_Security::NONCE_APPROVAL,
            array('hvac_master_trainer', 'hvac_master_manage_approvals', 'manage_options'),
            true // This is a sensitive action
        );
        
        if (is_wp_error($security_check)) {
            wp_send_json_error(
                array(
                    'message' => $security_check->get_error_message(),
                    'code' => $security_check->get_error_code()
                ),
                $security_check->get_error_data() ? $security_check->get_error_data()['status'] : 403
            );
            return;
        }
        
        // Enhanced input validation
        $input_rules = array(
            'user_id' => array(
                'type' => 'int',
                'required' => true,
                'min' => 1,
                'validate' => function($value) {
                    // Verify user exists and is a trainer
                    $user = get_userdata($value);
                    if (!$user) {
                        return new WP_Error('invalid_user', 'User not found');
                    }
                    
                    $is_trainer = in_array('hvac_trainer', $user->roles) || 
                                  get_user_meta($value, 'hvac_trainer_status', true);
                    
                    if (!$is_trainer) {
                        return new WP_Error('not_trainer', 'User is not a trainer');
                    }
                    
                    return true;
                }
            ),
            'reason' => array(
                'type' => 'textarea',
                'required' => false,
                'max_length' => 1000
            ),
            'action' => array(
                'type' => 'text',
                'required' => false,
                'validate' => function($value) {
                    $valid_actions = array('approve', 'reject');
                    if (!empty($value) && !in_array($value, $valid_actions)) {
                        return new WP_Error('invalid_action', 'Invalid approval action');
                    }
                    return true;
                }
            )
        );
        
        $data = HVAC_Ajax_Security::sanitize_input($_POST, $input_rules);
        
        if (is_wp_error($data)) {
            wp_send_json_error(
                array(
                    'message' => $data->get_error_message(),
                    'errors' => $data->get_error_data()
                ),
                400
            );
            return;
        }
        
        // Call existing approval handler if available, or implement here
        if (class_exists('HVAC_Master_Pending_Approvals')) {
            $approvals = HVAC_Master_Pending_Approvals::get_instance();
            if (method_exists($approvals, 'ajax_approve_trainer')) {
                // Set up the sanitized POST data for the existing handler
                $_POST['user_id'] = $data['user_id'];
                $_POST['reason'] = isset($data['reason']) ? $data['reason'] : '';
                $_POST['nonce'] = $_REQUEST['nonce']; // Pass through the verified nonce
                
                // Call existing handler
                $approvals->ajax_approve_trainer();
                return;
            }
        }
        
        // Fallback implementation if existing handler not available
        $this->process_trainer_approval($data);
    }
    
    /**
     * Process trainer approval (fallback)
     * 
     * @param array $data Sanitized input data
     */
    private function process_trainer_approval($data) {
        $user_id = $data['user_id'];
        $reason = isset($data['reason']) ? $data['reason'] : '';
        $action = isset($data['action']) ? $data['action'] : 'approve';
        
        // Update trainer status
        if ($action === 'approve') {
            update_user_meta($user_id, 'hvac_trainer_status', 'approved');
            update_user_meta($user_id, 'hvac_trainer_approved_date', current_time('mysql'));
            update_user_meta($user_id, 'hvac_trainer_approved_by', get_current_user_id());
            
            // Add trainer role if not present
            $user = new WP_User($user_id);
            if (!in_array('hvac_trainer', $user->roles)) {
                $user->add_role('hvac_trainer');
            }
            
            $message = 'Trainer approved successfully';
        } else {
            update_user_meta($user_id, 'hvac_trainer_status', 'rejected');
            update_user_meta($user_id, 'hvac_trainer_rejected_date', current_time('mysql'));
            update_user_meta($user_id, 'hvac_trainer_rejected_by', get_current_user_id());
            
            $message = 'Trainer rejected';
        }
        
        // Store reason if provided
        if (!empty($reason)) {
            update_user_meta($user_id, 'hvac_trainer_' . $action . '_reason', $reason);
        }
        
        // Log the action
        if (class_exists('HVAC_Logger')) {
            HVAC_Logger::info('Trainer ' . $action, 'AJAX', array(
                'trainer_id' => $user_id,
                'approved_by' => get_current_user_id(),
                'reason' => $reason
            ));
        }
        
        wp_send_json_success(array(
            'message' => $message,
            'user_id' => $user_id,
            'new_status' => $action === 'approve' ? 'approved' : 'rejected'
        ));
    }
    
    /**
     * Handle unauthorized access
     */
    public function unauthorized_access() {
        wp_send_json_error(
            array(
                'message' => 'Authentication required',
                'code' => 'unauthorized'
            ),
            401
        );
    }
}

// Initialize the handlers
HVAC_Ajax_Handlers::get_instance();