<?php

namespace App\RSpade\SchemaQuality\Rules;

class SessionIdForeignKeyRule extends Schema_Rule_Abstract
{
    public function get_id(): string
    {
        return 'SCHEMA-FK-01';
    }
    
    public function get_name(): string
    {
        return 'Session ID Foreign Key Rule';
    }
    
    public function get_description(): string
    {
        return 'Ensures session_id columns have proper foreign key constraints to sessions.id with ON DELETE CASCADE';
    }
    
    public function check(array $schema): void
    {
        foreach ($schema['tables'] as $table_name => $table_info) {
            if ($this->is_excluded_table($table_name)) {
                continue;
            }
            
            // Check each column for session_id
            foreach ($table_info['columns'] as $column) {
                if ($column['name'] === 'session_id') {
                    // Check if nullable
                    if ($column['nullable'] !== 'YES') {
                        $this->add_violation(
                            $table_name,
                            'session_id',
                            'Column session_id must be nullable',
                            'ALTER TABLE ' . $table_name . ' MODIFY session_id VARCHAR(255) NULL'
                        );
                    }
                    
                    // Check for foreign key
                    $has_proper_fk = false;
                    foreach ($table_info['foreign_keys'] as $fk) {
                        if ($fk['column'] === 'session_id' && 
                            $fk['referenced_table'] === 'sessions' && 
                            $fk['referenced_column'] === 'id' &&
                            $fk['delete_rule'] === 'CASCADE') {
                            $has_proper_fk = true;
                            break;
                        }
                    }
                    
                    if (!$has_proper_fk) {
                        $this->add_violation(
                            $table_name,
                            'session_id',
                            'Column session_id must have foreign key to sessions.id with ON DELETE CASCADE',
                            'ALTER TABLE ' . $table_name . ' ADD CONSTRAINT fk_' . $table_name . '_session ' .
                            'FOREIGN KEY (session_id) REFERENCES sessions(id) ON DELETE CASCADE'
                        );
                    }
                }
            }
        }
    }
}