specification:
  functional_requirements:
    - id: "FR-001"
      description: "System shall authenticate users via OAuth2"
      priority: "high"
      acceptance_criteria:
        - "Users can login with Google/GitHub"
        - "Session persists for 24 hours"
        - "Refresh tokens auto-renew"
      
  non_functional_requirements:
    - id: "NFR-001"
      category: "performance"
      description: "API response time <200ms for 95% of requests"
      measurement: "p95 latency metric"
    
    - id: "NFR-002"
      category: "security"
      description: "All data encrypted in transit and at rest"
      validation: "Security audit checklist"

constraints:
  technical:
    - "Must use existing PostgreSQL database"
    - "Compatible with Node.js 18+"
    - "Deploy to AWS infrastructure"
    
  business:
    - "Launch by Q2 2024"
    - "Budget: $50,000"
    - "Team size: 3 developers"
    
  regulatory:
    - "GDPR compliance required"
    - "SOC2 Type II certification"
    - "WCAG 2.1 AA accessibility"

use_cases:
  - id: "UC-001"
    title: "User Registration"
    actor: "New User"
    preconditions:
      - "User has valid email"
      - "User accepts terms"
    flow:
      1. "User clicks 'Sign Up'"
      2. "System displays registration form"
      3. "User enters email and password"
      4. "System validates inputs"
      5. "System creates account"
      6. "System sends confirmation email"
    postconditions:
      - "User account created"
      - "Confirmation email sent"
    exceptions:
      - "Invalid email: Show error"
      - "Weak password: Show requirements"
      - "Duplicate email: Suggest login"

Feature: User Authentication

  Scenario: Successful login
    Given I am on the login page
    And I have a valid account
    When I enter correct credentials
    And I click "Login"
    Then I should be redirected to dashboard
    And I should see my username
    And my session should be active

  Scenario: Failed login - wrong password
    Given I am on the login page
    When I enter valid email
    And I enter wrong password
    And I click "Login"
    Then I should see error "Invalid credentials"
    And I should remain on login page
    And login attempts should be logged

# System Requirements Specification

## 1. Introduction
### 1.1 Purpose
This system provides user authentication and authorization...

### 1.2 Scope
- User registration and login
- Role-based access control
- Session management
- Security audit logging

### 1.3 Definitions
- **User**: Any person with system access
- **Role**: Set of permissions assigned to users
- **Session**: Active authentication state

## 2. Functional Requirements

### 2.1 Authentication
- FR-2.1.1: Support email$password login
- FR-2.1.2: Implement OAuth2 providers
- FR-2.1.3: Two-factor authentication

### 2.2 Authorization
- FR-2.2.1: Role-based permissions
- FR-2.2.2: Resource-level access control
- FR-2.2.3: API key management

## 3. Non-Functional Requirements

### 3.1 Performance
- NFR-3.1.1: 99.9% uptime SLA
- NFR-3.1.2: <200ms response time
- NFR-3.1.3: Support 10,000 concurrent users

### 3.2 Security
- NFR-3.2.1: OWASP Top 10 compliance
- NFR-3.2.2: Data encryption (AES-256)
- NFR-3.2.3: Security audit logging

entities:
  User:
    attributes:
      - id: uuid (primary key)
      - email: string (unique, required)
      - passwordHash: string (required)
      - createdAt: timestamp
      - updatedAt: timestamp
    relationships:
      - has_many: Sessions
      - has_many: UserRoles
    
  Role:
    attributes:
      - id: uuid (primary key)
      - name: string (unique, required)
      - permissions: json
    relationships:
      - has_many: UserRoles
    
  Session:
    attributes:
      - id: uuid (primary key)
      - userId: uuid (foreign key)
      - token: string (unique)
      - expiresAt: timestamp
    relationships:
      - belongs_to: User

openapi: 3.0.0
info:
  title: Authentication API
  version: 1.0.0

paths:
  $auth$login:
    post:
      summary: User login
      requestBody:
        required: true
        content:
          application$json:
            schema:
              type: object
              required: [email, password]
              properties:
                email:
                  type: string
                  format: email
                password:
                  type: string
                  minLength: 8
      responses:
        200:
          description: Successful login
          content:
            application$json:
              schema:
                type: object
                properties:
                  token: string
                  user: object
        401:
          description: Invalid credentials