DenTalk

Multi-Identity System Implementation

The User table is one of the most frequently queried resources in the system. To reduce query overhead and JSON data consumption, we store multiple identity information in a single column using a Bitmask approach.

Bitmask Implementation

Below is the EnumIdentity implementation, which defines 12 different identity types using bitwise operations (1 << n), including dentists, clinics, hospitals, instructors, and students. Each identity corresponds to an independent bit position and can be combined using bitwise OR operations.

<?php

namespace App\Enum;

use Illuminate\Support\Collection;

enum EnumIdentity: int
{
    case NULL = 0;
    case DENTIST = 1 << 0;              // Dentist
    case DENTAL_ASSISTANT = 1 << 1;     // Dental Assistant
    case DENTAL_HYGIENIST = 1 << 2;     // Dental Hygienist
    case DENTAL_TECHNICIAN = 1 << 3;    // Dental Technician
    case INTERN = 1 << 4;                // Intern
    case STUDENT = 1 << 5;               // Student
    case CLINIC = 1 << 6;                // Clinic
    case HOSPITAL = 1 << 7;              // Hospital
    case VENDOR = 1 << 8;                // Vendor
    case INSTRUCTOR = 1 << 9;            // Instructor
    case ASSOCIATION = 1 << 10;          // Association
    case SOCIETY = 1 << 11;              // Society

    public function getLabel(): string { /* ... */ }
    public function getGroup(): string { /* ... */ }

    // Permission check methods
    public function isJobProvider(): bool { /* Hospital, Clinic */ }
    public function isJobSeeker(): bool { /* Dentist, Assistant, etc */ }
    public function isCourseProvider(): bool { /* Instructor */ }
    public function canSell(): bool { /* Sales permission */ }

    // Bitmask bidirectional conversion
    public static function fromBitmask(int $bitmask): Collection
    {
        // Convert integer to identity collection
        return collect(self::cases())
            ->filter(fn ($case) => ($bitmask & $case->value) !== 0);
    }

    public static function toBitmask(array|Collection $identities): int
    {
        // Convert identity collection to integer
        return collect($identities)
            ->map(fn ($identity) => $identity->value)
            ->reduce(fn ($carry, $val) => $carry | $val, 0);
    }
}

Technical Advantages

• Database Performance - Single column storage reduces JOIN queries and improves query speed
• Flexible Combination - Users can have multiple identities simultaneously (e.g., Dentist + Instructor)
• Permission Management - Quick permission checks via methods like isJobProvider(), canSell()
• Identity Grouping - getGroup() method categorizes related identities (e.g., Dental-related Personnel)

Order State Management

The marketplace feature involves complex order state transitions, from placement to payment, shipping, and completion. Each stage has strict state constraints. To avoid code cluttered with numerous if/else conditional statements, this project adopts the State Machine design pattern.

State Machine Advantages

• Clear State Definition - Explicitly defines all possible order states (Pending Payment, Paid, Shipping, Completed, Cancelled, etc.)
• Strict Transition Rules - Restricts state transitions to follow predefined rules, preventing illegal states
• Easy Maintenance - Avoids complex nested conditionals, making it safer to add states or modify workflows
• Code Readability - Centralized state transition logic makes it easier to understand the overall business process

Through the State Machine pattern, even complex order workflows remain clean and maintainable.