<?php
/**
 * Data Migration Script for Trainer Profile Custom Post Types
 * 
 * This script migrates existing user meta data to the new trainer_profile custom post type system.
 * It should be run once after the new system is deployed.
 */

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

class HVAC_Trainer_Profile_Migration {
    
    private static $migration_log = [];
    private static $migration_stats = [
        'total_users' => 0,
        'profiles_created' => 0,
        'profiles_updated' => 0,
        'errors' => 0,
        'skipped' => 0
    ];
    
    public static function run_migration($dry_run = false) {
        $migration_id = uniqid('migration_');
        $start_time = microtime(true);
        
        self::log_message("Starting trainer profile migration (ID: {$migration_id})", 'info');
        
        if ($dry_run) {
            self::log_message("Running in DRY RUN mode - no changes will be made", 'info');
        }
        
        // Initialize migration tracking
        if (!$dry_run) {
            update_option('hvac_migration_status', [
                'id' => $migration_id,
                'status' => 'in_progress',
                'start_time' => time(),
                'dry_run' => false
            ]);
        }
        
        try {
            // Get all users with trainer roles
            $trainers = get_users([
                'role__in' => ['hvac_trainer', 'hvac_master_trainer', 'event_trainer'], // Include legacy role
                'meta_query' => [
                    'relation' => 'OR',
                    [
                        'key' => 'trainer_profile_id',
                        'compare' => 'NOT EXISTS'
                    ],
                    [
                        'key' => 'trainer_profile_id',
                        'value' => '',
                        'compare' => '='
                    ]
                ]
            ]);
            
            self::$migration_stats['total_users'] = count($trainers);
            self::log_message("Found " . count($trainers) . " trainer users to migrate", 'info');
            
            foreach ($trainers as $user) {
                try {
                    self::migrate_user_to_profile($user, !$dry_run);
                } catch (Exception $e) {
                    self::$migration_stats['errors']++;
                    self::log_message("Error migrating user {$user->ID} ({$user->user_email}): " . $e->getMessage(), 'error');
                }
            }
            
            // Migrate any existing CSV import data
            self::migrate_csv_data(!$dry_run);
            
            // Complete migration
            if (!$dry_run) {
                self::complete_migration($migration_id);
            }
            
            $end_time = microtime(true);
            $duration = round($end_time - $start_time, 2);
            
            self::log_message("Migration completed in {$duration} seconds", 'info');
            self::log_message("Statistics: " . json_encode(self::$migration_stats), 'info');
            
        } catch (Exception $e) {
            if (!$dry_run) {
                self::fail_migration($migration_id, $e->getMessage());
            }
            self::log_message("Migration failed: " . $e->getMessage(), 'error');
            throw $e;
        }
        
        return [
            'success' => true,
            'stats' => self::$migration_stats,
            'log' => self::$migration_log
        ];
    }
    
    private static function migrate_user_to_profile($user, $commit = true) {
        // Check if user already has a profile
        $existing_profile_id = get_user_meta($user->ID, 'trainer_profile_id', true);
        if ($existing_profile_id && get_post($existing_profile_id)) {
            self::log_message("User {$user->ID} already has profile {$existing_profile_id}, skipping", 'info');
            self::$migration_stats['skipped']++;
            return $existing_profile_id;
        }
        
        self::log_message("Migrating user {$user->ID} ({$user->user_email})", 'info');
        
        if (!$commit) {
            self::log_message("DRY RUN: Would create trainer profile for user {$user->ID}", 'info');
            self::$migration_stats['profiles_created']++;
            return true;
        }
        
        // Create trainer profile post
        $profile_data = [
            'post_type' => 'trainer_profile',
            'post_title' => $user->display_name . ' - Trainer Profile',
            'post_status' => 'publish',
            'post_author' => $user->ID,
            'post_content' => get_user_meta($user->ID, 'description', true) ?: get_user_meta($user->ID, 'biographical_info', true) ?: ''
        ];
        
        $profile_id = wp_insert_post($profile_data);
        
        if (is_wp_error($profile_id)) {
            throw new Exception("Failed to create profile post: " . $profile_id->get_error_message());
        }
        
        // Establish relationships
        update_post_meta($profile_id, 'user_id', $user->ID);
        update_user_meta($user->ID, 'trainer_profile_id', $profile_id);
        
        // Migrate user meta to profile meta
        $migrated_fields = self::migrate_user_meta_fields($user->ID, $profile_id);
        
        // Set default visibility
        update_post_meta($profile_id, 'is_public_profile', '1');
        
        // Trigger geocoding if address data exists
        $address_fields = ['trainer_city', 'trainer_state', 'trainer_country'];
        $has_address = false;
        foreach ($address_fields as $field) {
            if (get_post_meta($profile_id, $field, true)) {
                $has_address = true;
                break;
            }
        }
        
        if ($has_address) {
            wp_schedule_single_event(time() + 5, 'hvac_geocode_address', [$profile_id]);
            self::log_message("Scheduled geocoding for profile {$profile_id}", 'info');
        }
        
        self::$migration_stats['profiles_created']++;
        self::log_message("Created profile {$profile_id} for user {$user->ID}, migrated " . count($migrated_fields) . " fields", 'info');
        
        return $profile_id;
    }
    
    private static function migrate_user_meta_fields($user_id, $profile_id) {
        $user = get_userdata($user_id);
        $migrated_fields = [];
        
        // Synchronized fields (user ↔ profile)
        $sync_fields = [
            'first_name' => 'trainer_first_name',
            'last_name' => 'trainer_last_name',
            'display_name' => 'trainer_display_name'
        ];
        
        foreach ($sync_fields as $user_field => $profile_field) {
            $value = $user->$user_field;
            if ($value) {
                update_post_meta($profile_id, $profile_field, $value);
                $migrated_fields[] = $profile_field;
            }
        }
        
        // Profile-exclusive fields with potential user meta mappings
        $profile_field_mappings = [
            'linkedin_profile_url' => ['user_linkedin', 'linkedin_profile_url', 'linkedin_url'],
            'personal_accreditation' => ['personal_accreditation', 'accreditation'],
            'biographical_info' => ['biographical_info', 'bio', 'description'],
            'training_audience' => ['training_audience', 'target_audience'],
            'training_formats' => ['training_formats', 'training_methods'],
            'training_locations' => ['training_locations', 'training_areas'],
            'training_resources' => ['training_resources', 'resources'],
            'annual_revenue_target' => ['annual_revenue_target', 'revenue_target'],
            'application_details' => ['application_details', 'application_reason'],
            'date_certified' => ['date_certified', 'certification_date'],
            'certification_type' => ['certification_type', 'cert_type'],
            'certification_status' => ['certification_status', 'cert_status'],
            'trainer_city' => ['user_city', 'trainer_city', 'city'],
            'trainer_state' => ['user_state', 'trainer_state', 'state'],
            'trainer_country' => ['user_country', 'trainer_country', 'country'],
            'role' => ['role', 'job_role', 'position'],
            'years_experience' => ['years_experience', 'experience_years']
        ];
        
        foreach ($profile_field_mappings as $profile_field => $possible_meta_keys) {
            $value = null;
            
            // Try each possible meta key until we find a value
            foreach ($possible_meta_keys as $meta_key) {
                $temp_value = get_user_meta($user_id, $meta_key, true);
                if (!empty($temp_value)) {
                    $value = $temp_value;
                    break;
                }
            }
            
            if ($value) {
                update_post_meta($profile_id, $profile_field, $value);
                $migrated_fields[] = $profile_field;
                
                // Clean up old user meta fields to prevent confusion
                foreach ($possible_meta_keys as $old_key) {
                    if ($old_key !== $profile_field) { // Don't delete if same name
                        delete_user_meta($user_id, $old_key);
                    }
                }
            }
        }
        
        // Handle business type (migrate from organizer category if available)
        $organizer_id = get_user_meta($user_id, 'organizer_id', true);
        if ($organizer_id) {
            $organizer = get_post($organizer_id);
            if ($organizer) {
                $organizer_category = get_post_meta($organizer_id, '_hvac_organizer_category', true);
                if ($organizer_category) {
                    // Try to match with existing business type terms
                    $term = get_term_by('name', $organizer_category, 'business_type');
                    if (!$term) {
                        // Create the term if it doesn't exist
                        $term_result = wp_insert_term($organizer_category, 'business_type');
                        if (!is_wp_error($term_result)) {
                            $term = get_term($term_result['term_id'], 'business_type');
                        }
                    }
                    
                    if ($term && !is_wp_error($term)) {
                        wp_set_post_terms($profile_id, [$term->term_id], 'business_type');
                        $migrated_fields[] = 'business_type';
                    }
                }
            }
        }
        
        // Set default certification status if not provided
        if (!get_post_meta($profile_id, 'certification_status', true)) {
            // Determine default status based on user role
            $user_roles = $user->roles;
            if (in_array('hvac_master_trainer', $user_roles)) {
                update_post_meta($profile_id, 'certification_status', 'Active');
                update_post_meta($profile_id, 'certification_type', 'Certified measureQuick Champion');
            } else {
                update_post_meta($profile_id, 'certification_status', 'Active');
                update_post_meta($profile_id, 'certification_type', 'Certified measureQuick Trainer');
            }
            $migrated_fields[] = 'certification_status';
            $migrated_fields[] = 'certification_type';
        }
        
        return $migrated_fields;
    }
    
    private static function migrate_csv_data($commit = true) {
        // Check if there's any CSV import data to migrate
        $csv_import_log = get_option('hvac_csv_import_log', []);
        
        if (empty($csv_import_log)) {
            self::log_message("No CSV import data found to migrate", 'info');
            return;
        }
        
        self::log_message("Found CSV import data, processing additional mappings", 'info');
        
        foreach ($csv_import_log as $import_session) {
            if (isset($import_session['imported_users'])) {
                foreach ($import_session['imported_users'] as $user_data) {
                    if (isset($user_data['user_id'])) {
                        $user_id = $user_data['user_id'];
                        $profile_id = get_user_meta($user_id, 'trainer_profile_id', true);
                        
                        if ($profile_id && $commit) {
                            // Update any CSV-specific fields that might have been missed
                            if (isset($user_data['csv_data'])) {
                                self::update_profile_from_csv($profile_id, $user_data['csv_data']);
                            }
                        }
                    }
                }
            }
        }
    }
    
    private static function update_profile_from_csv($profile_id, $csv_data) {
        $csv_field_mappings = [
            'Organization Name' => 'organization_name',
            'Organization Logo URL' => 'organization_logo_url',
            'Headquarters City' => 'trainer_city',
            'Headquarters State' => 'trainer_state',
            'Headquarters Country' => 'trainer_country',
            'Organizer Category' => 'business_type',
            'Training Experience' => 'training_experience',
            'Specialization' => 'specialization'
        ];
        
        foreach ($csv_field_mappings as $csv_key => $profile_field) {
            if (isset($csv_data[$csv_key]) && !empty($csv_data[$csv_key])) {
                if ($profile_field === 'business_type') {
                    // Handle taxonomy
                    $term = get_term_by('name', $csv_data[$csv_key], 'business_type');
                    if ($term) {
                        wp_set_post_terms($profile_id, [$term->term_id], 'business_type');
                    }
                } else {
                    update_post_meta($profile_id, $profile_field, sanitize_text_field($csv_data[$csv_key]));
                }
            }
        }
    }
    
    private static function complete_migration($migration_id) {
        update_option('hvac_migration_status', [
            'id' => $migration_id,
            'status' => 'completed',
            'end_time' => time(),
            'stats' => self::$migration_stats
        ]);
        
        // Clean up any scheduled events that might conflict
        wp_clear_scheduled_hook('hvac_verify_sync_integrity');
        
        // Schedule sync verification
        if (!wp_next_scheduled('hvac_verify_sync_integrity')) {
            wp_schedule_event(time() + 300, 'hourly', 'hvac_verify_sync_integrity');
        }
    }
    
    private static function fail_migration($migration_id, $error_message) {
        update_option('hvac_migration_status', [
            'id' => $migration_id,
            'status' => 'failed',
            'end_time' => time(),
            'error' => $error_message,
            'stats' => self::$migration_stats
        ]);
    }
    
    private static function log_message($message, $level = 'info') {
        $timestamp = date('Y-m-d H:i:s');
        $log_entry = "[{$timestamp}] [{$level}] {$message}";
        
        self::$migration_log[] = $log_entry;
        
        // Also log to WordPress debug log if enabled
        if (defined('WP_DEBUG') && WP_DEBUG) {
            error_log("HVAC Profile Migration: " . $log_entry);
        }
    }
    
    public static function get_migration_status() {
        return get_option('hvac_migration_status', ['status' => 'not_started']);
    }
    
    public static function rollback_migration($migration_id = null) {
        $migration_status = self::get_migration_status();
        
        if (!$migration_id) {
            $migration_id = $migration_status['id'] ?? null;
        }
        
        if (!$migration_id) {
            throw new Exception('No migration ID provided for rollback');
        }
        
        self::log_message("Starting rollback for migration {$migration_id}", 'info');
        
        // Get all trainer profiles created by this migration
        $profiles = get_posts([
            'post_type' => 'trainer_profile',
            'posts_per_page' => -1,
            'fields' => 'ids'
        ]);
        
        $rolled_back = 0;
        foreach ($profiles as $profile_id) {
            $user_id = get_post_meta($profile_id, 'user_id', true);
            
            if ($user_id) {
                // Remove the relationship
                delete_user_meta($user_id, 'trainer_profile_id');
                
                // Delete the profile
                wp_delete_post($profile_id, true);
                
                $rolled_back++;
            }
        }
        
        // Update migration status
        update_option('hvac_migration_status', [
            'id' => $migration_id,
            'status' => 'rolled_back',
            'rollback_time' => time(),
            'profiles_removed' => $rolled_back
        ]);
        
        self::log_message("Rollback completed: removed {$rolled_back} profiles", 'info');
        
        return $rolled_back;
    }
}

// CLI Command support
if (defined('WP_CLI') && WP_CLI) {
    WP_CLI::add_command('hvac migrate-profiles', function($args, $assoc_args) {
        $dry_run = isset($assoc_args['dry-run']) && $assoc_args['dry-run'];
        
        WP_CLI::line('Starting HVAC Trainer Profile Migration...');
        
        try {
            $result = HVAC_Trainer_Profile_Migration::run_migration($dry_run);
            
            WP_CLI::success('Migration completed successfully!');
            WP_CLI::line('Statistics:');
            WP_CLI::line('  Total users: ' . $result['stats']['total_users']);
            WP_CLI::line('  Profiles created: ' . $result['stats']['profiles_created']);
            WP_CLI::line('  Profiles updated: ' . $result['stats']['profiles_updated']);
            WP_CLI::line('  Errors: ' . $result['stats']['errors']);
            WP_CLI::line('  Skipped: ' . $result['stats']['skipped']);
            
            if (!empty($result['log'])) {
                WP_CLI::line("\nDetailed log:");
                foreach ($result['log'] as $log_entry) {
                    WP_CLI::line('  ' . $log_entry);
                }
            }
            
        } catch (Exception $e) {
            WP_CLI::error('Migration failed: ' . $e->getMessage());
        }
    });
    
    WP_CLI::add_command('hvac rollback-profiles', function($args, $assoc_args) {
        $migration_id = $assoc_args['migration-id'] ?? null;
        
        WP_CLI::line('Starting HVAC Trainer Profile Migration Rollback...');
        
        try {
            $rolled_back = HVAC_Trainer_Profile_Migration::rollback_migration($migration_id);
            WP_CLI::success("Rollback completed! Removed {$rolled_back} profiles.");
            
        } catch (Exception $e) {
            WP_CLI::error('Rollback failed: ' . $e->getMessage());
        }
    });
}