services

Service Layer & Data Management Rules

Service Layer Organization

File Structure

src/lib/
├── utils.ts          # General utilities (keep cn function)
├── types.ts          # Shared TypeScript interfaces
├── constants.ts      # App-wide constants
├── validations/      # Zod schemas
│   ├── user.ts
│   ├── product.ts
│   └── common.ts
└── services/         # API service layer
    ├── api.ts        # Base API client
    ├── userService.ts
    └── productService.ts

Service Layer Pattern

// services/userService.ts
export const userService = {
  async getAll(): Promise<User[]> {
    const response = await fetch('/api/users')
    if (!response.ok) throw new Error('Failed to fetch users')
    return response.json()
  },
  
  async getById(id: string): Promise<User> {
    const response = await fetch(`/api/users/${id}`)
    if (!response.ok) throw new Error('Failed to fetch user')
    return response.json()
  },
  
  async create(data: CreateUserData): Promise<User> {
    const response = await fetch('/api/users', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(data)
    })
    if (!response.ok) throw new Error('Failed to create user')
    return response.json()
  },
  
  async update(id: string, data: Partial<User>): Promise<User> {
    const response = await fetch(`/api/users/${id}`, {
      method: 'PATCH',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(data)
    })
    if (!response.ok) throw new Error('Failed to update user')
    return response.json()
  }
}

Shared Types (lib/types.ts)

export interface User {
  id: string
  email: string
  name: string
  avatar?: string
  role: UserRole
  createdAt: string
  updatedAt: string
}

export interface ApiResponse<T> {
  data: T
  message: string
  success: boolean
  meta?: {
    total: number
    page: number
    limit: number
  }
}

export type UserRole = 'admin' | 'user' | 'guest'
export type Theme = 'light' | 'dark' | 'system'
export type LoadingState = 'idle' | 'loading' | 'success' | 'error'