<?php
/**
 * Field Manager Class - UPDATED with Default Fields Support
 * Merges WooCommerce default fields with custom fields
 * 
 * @package Checkout_Field_Editor_Pro
 * @since 1.0.3
 */

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

class CFEP_Field_Manager {
    private static $instance = null;
    private $table_name;
    
    public static function instance() {
        if (is_null(self::$instance)) {
            self::$instance = new self();
        }
        return self::$instance;
    }
    
    private function __construct() {
        global $wpdb;
        $this->table_name = $wpdb->prefix . 'cfep_fields';
    }
    
    /**
     * Get all fields (default WooCommerce + custom)
     * This is the NEW main method that merges everything
     */
    public function get_all_fields($section = null, $enabled_only = false) {
        // Get WooCommerce default fields
        $wc_loader = CFEP_WC_Fields_Loader::instance();
        $default_fields = $wc_loader->get_default_fields();
        
        // Get custom fields from database
        $custom_fields = $this->get_custom_fields($section, $enabled_only);
        
        // Get user overrides for default fields
        $overrides = $this->get_field_overrides();
        
        $all_fields = array();
        
        // Process default fields with overrides
        foreach ($default_fields as $field) {
            $field_key = $field['field_key'];
            
            // Check if section filter applies
            if ($section && $field['section'] !== $section) {
                continue;
            }
            
            // Apply user overrides if they exist
            if (isset($overrides[$field_key])) {
                $field = array_merge($field, $overrides[$field_key]);
            }
            
            // Check enabled filter
            if ($enabled_only && !$field['enabled']) {
                continue;
            }
            
            $all_fields[] = $field;
        }
        
        // Add custom fields
        foreach ($custom_fields as $field) {
            $all_fields[] = $field;
        }
        
        // Sort by position
        usort($all_fields, function($a, $b) {
            return $a['position'] - $b['position'];
        });
        
        return $all_fields;
    }
    
    /**
     * Get only custom fields from database
     */
    public function get_custom_fields($section = null, $enabled_only = false) {
        global $wpdb;
        
        $where = array('is_default = 0');
        
        if ($section) {
            $where[] = $wpdb->prepare('section = %s', $section);
        }
        if ($enabled_only) {
            $where[] = 'enabled = 1';
        }
        
        $sql = "SELECT * FROM {$this->table_name} WHERE " . implode(' AND ', $where) . " ORDER BY position ASC";
        $cache_key = 'cfep_custom_fields_' . md5($sql);
        $results = wp_cache_get($cache_key, 'cfep');
        if ($results === false) {
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $results = $wpdb->get_results($sql, ARRAY_A);
            wp_cache_set($cache_key, $results, 'cfep', 300);
        }
        
        return array_map(array($this, 'parse_field_data'), $results);
    }
    
    /**
     * Get user overrides for default fields
     * Returns array with field_key as key
     */
    public function get_field_overrides() {
        global $wpdb;
        
        $sql = "SELECT * FROM {$this->table_name} WHERE is_default = 1";
        $cache_key = 'cfep_field_overrides';
        $results = wp_cache_get($cache_key, 'cfep');
        if ($results === false) {
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $results = $wpdb->get_results($sql, ARRAY_A);
            wp_cache_set($cache_key, $results, 'cfep', 300);
        }
        
        $overrides = array();
        foreach ($results as $row) {
            $overrides[$row['field_key']] = $this->parse_field_data($row);
        }
        
        return $overrides;
    }
    
    /**
     * Get a specific field (checks both default and custom)
     */
    public function get_field($field_key) {
        // Check if it's a default field with override
        $override = $this->get_field_override($field_key);
        if ($override) {
            return $override;
        }
        
        // Check if it's a custom field
        global $wpdb;
        $cache_key = 'cfep_field_' . $field_key;
        $result = wp_cache_get($cache_key, 'cfep');
        if ($result === false) {
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $result = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$this->table_name} WHERE field_key = %s AND is_default = 0", $field_key ), ARRAY_A );
            wp_cache_set($cache_key, $result, 'cfep', 300);
        }
        
        if ($result) {
            return $this->parse_field_data($result);
        }
        
        // Check if it's a default field without override
        $wc_loader = CFEP_WC_Fields_Loader::instance();
        $default_field = $wc_loader->get_default_field($field_key);
        
        return $default_field;
    }
    
    /**
     * Get override for a specific default field
     */
    public function get_field_override($field_key) {
        global $wpdb;
        
        $cache_key = 'cfep_field_override_' . $field_key;
        $result = wp_cache_get($cache_key, 'cfep');
        if ($result === false) {
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $result = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$this->table_name} WHERE field_key = %s AND is_default = 1", $field_key ), ARRAY_A );
            wp_cache_set($cache_key, $result, 'cfep', 300);
        }
        
        if (!$result) {
            return null;
        }
        
        // Merge with original default field
        $wc_loader = CFEP_WC_Fields_Loader::instance();
        $default_field = $wc_loader->get_default_field($field_key);
        
        if (!$default_field) {
            return null;
        }
        
        return array_merge($default_field, $this->parse_field_data($result));
    }
    
    /**
     * Save field (handles both custom and default field overrides)
     */
    public function save_field($data) {
        global $wpdb;
        

        
        $field_data = CFEP_Field_Types::sanitize_field_data($data);
        
        
        if (empty($field_data['field_key'])) {
            $field_data['field_key'] = 'cfep_' . uniqid();
        }
        
        // Check if this is a default field
        $wc_loader = CFEP_WC_Fields_Loader::instance();
        $is_default = $wc_loader->is_default_field($field_data['field_key']);
        
        $insert_data = array(
            'field_key' => $field_data['field_key'],
            'field_type' => $field_data['field_type'],
            'section' => $field_data['section'],
            'label' => $field_data['label'],
            'placeholder' => $field_data['placeholder'],
            'description' => $field_data['description'],
            'required' => absint($field_data['required']),
            'enabled' => absint($field_data['enabled']),
            'is_default' => $is_default ? 1 : 0,
            'can_delete' => $is_default ? 0 : 1,
            'position' => absint($field_data['position']),
            'field_class' => $field_data['field_class'],
            'options' => maybe_serialize($field_data['options']),
            'conditional_logic' => maybe_serialize($field_data['conditional_logic']),
            'validation_rules' => maybe_serialize($field_data['validation_rules']),
        );
        
        
        // Check if record exists
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
        $existing = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$this->table_name} WHERE field_key = %s", $field_data['field_key'] ), ARRAY_A );
        
        if ($existing) {
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $result = $wpdb->update(
                $this->table_name, 
                $insert_data, 
                array('field_key' => $field_data['field_key']),
                array('%s', '%s', '%s', '%s', '%s', '%s', '%d', '%d', '%d', '%d', '%d', '%s', '%s', '%s', '%s'),
                array('%s')
            );
            wp_cache_delete('cfep_field_' . $field_data['field_key'], 'cfep');
            wp_cache_delete('cfep_field_override_' . $field_data['field_key'], 'cfep');
            wp_cache_delete('cfep_field_overrides', 'cfep');
            
            if ($result === false) {
                return false;
            } else {
                return true;
            }
        } else {
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $result = $wpdb->insert(
                $this->table_name, 
                $insert_data,
                array('%s', '%s', '%s', '%s', '%s', '%s', '%d', '%d', '%d', '%d', '%d', '%s', '%s', '%s', '%s')
            );
            wp_cache_delete('cfep_field_overrides', 'cfep');
            
            if ($result === false) {
                return false;
            } else {
                return true;
            }
        }
    }
    
    /**
     * Delete field (only if can_delete = 1)
     */
    public function delete_field($field_key) {
        global $wpdb;
        
        // Get field to check if it can be deleted
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
        $field = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$this->table_name} WHERE field_key = %s", $field_key ), ARRAY_A );
        
        if (!$field) {
            // Check if it's a default field (not in DB yet)
            $wc_loader = CFEP_WC_Fields_Loader::instance();
            if ($wc_loader->is_default_field($field_key)) {
                return false; // Cannot delete default fields
            }
            return false; // Field doesn't exist
        }
        
        // Check can_delete flag
        if (isset($field['can_delete']) && $field['can_delete'] == 0) {
            return false;
        }
        
        // Delete the field
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
        $result = $wpdb->delete(
            $this->table_name,
            array('field_key' => $field_key),
            array('%s')
        );
        wp_cache_delete('cfep_field_' . $field_key, 'cfep');
        wp_cache_delete('cfep_field_override_' . $field_key, 'cfep');
        wp_cache_delete('cfep_field_overrides', 'cfep');
        
        return $result !== false;
    }
    
    /**
     * Reset default field to WooCommerce defaults
     */
    public function reset_default_field($field_key) {
        global $wpdb;
        
        // Check if it's a default field
        $wc_loader = CFEP_WC_Fields_Loader::instance();
        if (!$wc_loader->is_default_field($field_key)) {
            return false; // Not a default field
        }
        
        // Delete the override
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
        $wpdb->delete(
            $this->table_name,
            array(
                'field_key' => $field_key,
                'is_default' => 1
            ),
            array('%s', '%d')
        );
        wp_cache_delete('cfep_field_override_' . $field_key, 'cfep');
        wp_cache_delete('cfep_field_overrides', 'cfep');
        
        return true;
    }
    
    /**
     * Update field positions
     * Handles both custom fields (in DB) and default fields (creates override)
     */
    public function update_field_positions($positions) {
        global $wpdb;
        
        
        $success_count = 0;
        $error_count = 0;
        $wc_loader = CFEP_WC_Fields_Loader::instance();
        
        foreach ($positions as $field_key => $position) {
            // Check if field exists in database
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $exists = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM {$this->table_name} WHERE field_key = %s", $field_key ) );
            
            if ($exists) {
                // Field exists - just update position
                // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
                $result = $wpdb->update(
                    $this->table_name,
                    array('position' => absint($position)),
                    array('field_key' => sanitize_key($field_key)),
                    array('%d'),
                    array('%s')
                );
                wp_cache_delete('cfep_field_' . $field_key, 'cfep');
                wp_cache_delete('cfep_field_override_' . $field_key, 'cfep');
                
                if ($result === false) {
                    $error_count++;
                } else {
                    $success_count++;
                }
            } else {
                // Check if it's a default WooCommerce field
                if ($wc_loader->is_default_field($field_key)) {
                    // Create override record for default field (just to store position)
                    $default_field = $wc_loader->get_default_field($field_key);
                    
                    if ($default_field) {
                        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
                        $result = $wpdb->insert(
                            $this->table_name,
                            array(
                                'field_key' => $field_key,
                                'field_type' => $default_field['type'],
                                'section' => $default_field['section'],
                                'label' => $default_field['label'],
                                'placeholder' => $default_field['placeholder'] ?? '',
                                'description' => $default_field['description'] ?? '',
                                'required' => $default_field['required'],
                                'enabled' => 1,
                                'is_default' => 1,
                                'can_delete' => 0,
                                'position' => absint($position),
                                'field_class' => $default_field['field_class'],
                                'options' => maybe_serialize($default_field['options'] ?? array()),
                                'conditional_logic' => '',
                                'validation_rules' => ''
                            ),
                            array('%s', '%s', '%s', '%s', '%s', '%s', '%d', '%d', '%d', '%d', '%d', '%s', '%s', '%s', '%s')
                        );
                        
                        if ($result === false) {
                            $error_count++;
                        } else {
                            $success_count++;
                        }
                    }
                } else {
                    $error_count++;
                }
            }
        }
        
        
        return $error_count === 0;
    }
    
    /**
     * Parse field data (unserialize options)
     */
    private function parse_field_data($field) {
        if (!$field) {
            return null;
        }
        
        $field['options'] = maybe_unserialize($field['options']);
        $field['conditional_logic'] = maybe_unserialize($field['conditional_logic']);
        $field['validation_rules'] = maybe_unserialize($field['validation_rules']);
        
        if (!is_array($field['options'])) {
            $field['options'] = array();
        }
        
        return $field;
    }
}