Assist_Design/specs/codebase-refactoring/requirements.md

# Requirements Document

## Introduction

This document outlines the requirements for refactoring the customer portal codebase to eliminate redundancies, improve maintainability, and create a modern, optimal structure. The current codebase has significant structural issues including duplicate components, inconsistent patterns, scattered business logic, and poor separation of concerns.

## Requirements

### Requirement 1

**User Story:** As a developer, I want a clean component architecture, so that I can easily maintain and extend the codebase without duplicating functionality.

#### Acceptance Criteria

1. WHEN components are created THEN they SHALL follow a consistent atomic design pattern (atoms, molecules, organisms)
2. WHEN UI components are needed THEN they SHALL be reused from a centralized design system
3. WHEN business logic is implemented THEN it SHALL be separated from presentation components
4. WHEN similar functionality exists THEN it SHALL be consolidated into reusable components
5. IF a component handles both UI and business logic THEN it SHALL be split into separate concerns

### Requirement 2

**User Story:** As a developer, I want consistent page layouts and routing patterns, so that the application has a predictable structure and user experience.

#### Acceptance Criteria

1. WHEN pages are created THEN they SHALL use standardized layout components
2. WHEN routing is implemented THEN it SHALL follow consistent naming conventions
3. WHEN page components are built THEN they SHALL separate data fetching from presentation
4. WHEN similar pages exist THEN they SHALL share common layout and behavior patterns
5. IF pages have duplicate functionality THEN they SHALL be consolidated or abstracted

### Requirement 3

**User Story:** As a developer, I want centralized state management and data fetching, so that application state is predictable and API calls are optimized.

#### Acceptance Criteria

1. WHEN data is fetched THEN it SHALL use centralized API services
2. WHEN state is managed THEN it SHALL follow consistent patterns across the application
3. WHEN API calls are made THEN they SHALL be cached and optimized to prevent redundant requests
4. WHEN business logic is implemented THEN it SHALL be encapsulated in service layers
5. IF duplicate API calls exist THEN they SHALL be consolidated into shared hooks or services

### Requirement 4

**User Story:** As a developer, I want a modular feature-based architecture, so that related functionality is grouped together and easily maintainable.

#### Acceptance Criteria

1. WHEN features are implemented THEN they SHALL be organized in self-contained modules
2. WHEN components belong to a feature THEN they SHALL be co-located with related business logic
3. WHEN shared functionality is needed THEN it SHALL be extracted to common utilities
4. WHEN features interact THEN they SHALL use well-defined interfaces
5. IF feature boundaries are unclear THEN they SHALL be clearly defined and documented

### Requirement 5

**User Story:** As a developer, I want consistent TypeScript types and interfaces, so that the codebase is type-safe and self-documenting.

#### Acceptance Criteria

1. WHEN types are defined THEN they SHALL be centralized and reusable
2. WHEN API responses are handled THEN they SHALL have corresponding TypeScript interfaces
3. WHEN components accept props THEN they SHALL have properly typed interfaces
4. WHEN business entities are used THEN they SHALL have consistent type definitions
5. IF duplicate types exist THEN they SHALL be consolidated into shared type definitions

### Requirement 6

**User Story:** As a developer, I want optimized build performance and bundle size, so that the application loads quickly and development is efficient.

#### Acceptance Criteria

1. WHEN components are imported THEN they SHALL support tree-shaking and code splitting
2. WHEN dependencies are added THEN they SHALL be evaluated for bundle size impact
3. WHEN code is bundled THEN it SHALL be optimized for production deployment
4. WHEN development builds run THEN they SHALL have fast hot-reload capabilities
5. IF unused code exists THEN it SHALL be identified and removed

### Requirement 7

**User Story:** As a developer, I want consistent styling and theming, so that the UI is cohesive and maintainable.

#### Acceptance Criteria

1. WHEN styles are applied THEN they SHALL use a consistent design token system
2. WHEN components are styled THEN they SHALL follow established design patterns
3. WHEN themes are implemented THEN they SHALL be centrally managed
4. WHEN CSS is written THEN it SHALL follow naming conventions and be scoped appropriately
5. IF duplicate styles exist THEN they SHALL be consolidated into reusable classes or components

### Requirement 8

**User Story:** As a developer, I want improved testing capabilities, so that the codebase is reliable and regressions are prevented.

#### Acceptance Criteria

1. WHEN components are created THEN they SHALL be designed for testability
2. WHEN business logic is implemented THEN it SHALL be unit testable
3. WHEN API integrations are built THEN they SHALL be mockable for testing
4. WHEN user interactions are implemented THEN they SHALL be integration testable
5. IF testing utilities are needed THEN they SHALL be centralized and reusable

### Requirement 9

**User Story:** As a developer, I want the existing business logic to be intact and the core business logics should not be changed

#### Acceptance Criteria

1. WHEN redisning or refactoring always check the existing implementation and do not miss out on their business logic
2. WHEN business logic is implemented THEN it SHALL follow a similar way to the original logic
3. WHEN API integrations are built THEN they SHALL follow our business logic