# io8 System Architect Agent - Customized for This Project

## Project-Specific Instructions

```json
{
  "file_creation": {
    "filename": ".sureai/.io8architect_agent_weather_app_weather_app_20250926_094440.md",
    "content": "## io8Architect Agent Prompt: Weather Application Architecture Design\n\n**Project Name:** Weather Application (Extension of Angular Clarity Boilerplate)\n**User Prompt:** weather app\n**Timestamp:** 2025-09-26T09:44:40.087454\n\n### 1. Architecture Design Methodology Specific to this Project Type\n\nFor the Weather Application, which extends an existing Angular Clarity Boilerplate, a **Hybrid Top-Down and Bottom-Up Approach** will be utilized:\n\n*   **Top-Down (Strategic):** Start with the overall system vision (weather app functionality, user experience) and identify high-level components (Frontend, Backend Proxy, External API). Define the interactions and data flows between these main components.\n*   **Bottom-Up (Tactical):** Leverage the existing Angular Clarity Boilerplate's modular structure (`CoreModule`, `SharedModule`, `FeatureModules`). Integrate new functionalities (weather data display, search, unit conversion) by building upon these foundational modules and extending them with new services, components, and data models specific to weather. The backend proxy will be designed with a clear focus on API key security, data aggregation, and efficient communication with the external weather API.\n\nThis methodology ensures that the new features are well-integrated into the existing, robust boilerplate while meeting the new functional and non-functional requirements.\n\n### 2. Technical Architecture Approach for this Particular User Request\n\nThe technical architecture will follow a **Client-Server Architecture with an API Gateway/Proxy Pattern**:\n\n*   **Frontend (Angular Clarity):** This will be a Single-Page Application (SPA) responsible for user interaction, displaying weather data, handling search inputs, and managing UI state. It will leverage the Clarity Design System for a consistent and responsive user interface.\n*   **Backend (Node.js/Express.js Proxy):** A lightweight backend service will act as a proxy between the Angular frontend and the external weather API. This proxy is crucial for:\n    *   **Security:** Hiding the external weather API key from the client-side.\n    *   **Abstraction:** Providing a consistent API to the frontend, abstracting away the complexities or potential changes of the external API.\n    *   **Data Transformation:** Normalizing data from the external API into a format suitable for the frontend.\n    *   **Performance/Scalability:** Implementing caching (e.g., Redis) to reduce redundant calls to the external API and improve response times.\n    *   **Rate Limiting:** Managing requests to the external API to comply with rate limits.\n*   **External Weather API:** A reliable third-party API (e.g., OpenWeatherMap) will provide the actual weather data.\n\n### 3. System Design Framework\n\n*   **Modular Design (Frontend):** Adhering to the Angular best practices of modularity, with dedicated feature modules for weather-related functionality, `CoreModule` for singleton services (e.g., `WeatherApiService`, `ErrorHandlerService`), and `SharedModule` for reusable UI components (e.g., `TemperatureUnitToggleComponent`, `LoadingSpinnerComponent`).\n*   **Layered Architecture (Backend Proxy):** A simple layered structure for the backend proxy:\n    *   **API Layer:** Defines and handles HTTP routes (e.g., `/api/current-weather`, `/api/forecast`).\n    *   **Service Layer:** Contains business logic for interacting with the external weather API, data transformation, and caching.\n    *   **External API Integration Layer:** Dedicated client for making HTTP requests to the external weather service.\n*   **Containerization:** Both frontend and backend services will be containerized using Docker for consistent development, testing, and deployment environments.\n\n### 4. Technology Selection Strategy\n\nTechnology selection will prioritize:\n\n*   **Leveraging Existing Stack:** Continue with Angular and Clarity Design System for the frontend to maintain consistency with the boilerplate.\n*   **Ecosystem Fit:** Choose backend technologies that integrate well with the existing frontend (e.g., Node.js with Express.js for a JavaScript/TypeScript full-stack environment). Python with Flask/FastAPI is also a strong contender for its simplicity and robustness in microservices.\n*   **Simplicity and Efficiency:** Opt for lightweight frameworks suitable for a proxy service (e.g., Express.js or Flask) over heavier enterprise solutions.\n*   **Scalability:** Include technologies known for scalability (Docker, Redis for caching).\n*   **Reliability:** Select a well-documented and widely supported external weather API.\n*   **Security:** Prioritize solutions that enable secure handling of sensitive data (e.g., environment variables for API keys).\n\n### 5. Customized io8architect Workflow for this Project\n\n1.  **Analyze Updated Documents:** Thoroughly review `analysis_document.md` and `requirements_document.md` for weather app specific functional, non-functional, data, and interface requirements, paying close attention to the new user stories and business rules.\n2.  **Refine High-Level Architecture:** Solidify the Client-Server architecture with the API Gateway/Proxy pattern, detailing the responsibilities of each main component (Angular Frontend, Node.js/Express Backend Proxy, External Weather API).\n3.  **Detailed Frontend Architecture:**\n    *   **Module Design:** Identify specific Angular modules (e.g., `WeatherModule`) and their contents (components, services, routing).\n    *   **Component Hierarchy:** Define components for search, current weather display, forecast display, unit toggle, loading indicators, and error messages, ensuring Clarity Design System adherence.\n    *   **State Management:** Propose a suitable state management approach (e.g., Angular services with RxJS for reactive data flow).\n4.  **Detailed Backend Proxy Architecture:**\n    *   **API Endpoints:** Define specific RESTful endpoints for current weather and forecast, including parameters (location, units) and expected JSON response structures.\n    *   **External API Integration:** Outline how the proxy will communicate with the chosen external weather API, including error handling, retries, and rate limit considerations.\n    *   **Caching Strategy:** Propose a caching mechanism (e.g., Redis) for weather data, specifying cache keys, expiration policies, and invalidation strategies.\n    *   **Security:** Detail API key management using environment variables and HTTPS enforcement.\n5.  **Data Architecture:** Define TypeScript interfaces for `Location`, `CurrentWeather`, `ForecastDay` on the frontend, and corresponding data structures/DTOs for the backend proxy's internal use and external API interaction.\n6.  **Technology Stack Definition:** Select concrete technologies for each layer based on the strategy, justifying choices (e.g., Node.js/Express for backend, Redis for caching, OpenWeatherMap for external API, Docker for containerization).\n7.  **Scalability and Reliability:** Elaborate on strategies for horizontal scaling, load balancing, robust error handling, and monitoring for both frontend and backend services.\n8.  **Security Measures:** Document specific security considerations like CORS, input validation, and secure configuration.\n9.  **Document Updates:** Append all architectural and technology stack details to `.sureai/architecture_document.md` and `.sureai/tech_stack_document.md` with clear section headers and timestamps, referencing the analyzed requirements.\n\n### 6. Architecture and Tech Stack Instructions Based on User Prompt\n\n*   **Frontend (`.sureai/architecture_document.md`):** Detail the Angular components required (Search, CurrentWeatherCard, ForecastList, UnitToggle, ErrorAlert, LoadingSpinner), how they interact, and their integration with the `WeatherService`. Emphasize Clarity UI components.\n*   **Backend (`.sureai/architecture_document.md`):** Design the Express.js proxy with clear routes (`/api/current-weather`, `/api/forecast`), handlers, external API client, caching logic, and error handling for external API failures.\n*   **Data Models (`.sureai/architecture_document.md`):** Provide example TypeScript interfaces for `CurrentWeather` and `ForecastDay` that represent the data structure consumed by the frontend.\n*   **API Design (`.sureai/architecture_document.md`):** Specify request/response formats for the backend API endpoints, including query parameters for location and units.\n*   **Security (`.sureai/architecture_document.md`):** Mandate environment variables for external API keys on the backend and HTTPS for all communication.\n*   **Scalability (`.sureai/architecture_document.md`):** Outline containerization (Docker) and the use of Redis for backend caching to enhance performance and reduce external API calls.\n*   **Frontend Technologies (`.sureai/tech_stack_document.md`):** Confirm Angular, Clarity, RxJS. Explicitly mention browser's Geolocation API.\n*   **Backend Technologies (`.sureai/tech_stack_document.md`):** Specify Node.js, Express.js. Identify a preferred external weather API (e.g., OpenWeatherMap).\n*   **Database Technologies (`.sureai/tech_stack_document.md`):** Identify Redis for caching.\n*   **Infrastructure (`.sureai/tech_stack_document.md`):** Specify Docker and potential cloud deployment platforms (e.g., AWS Fargate/ECR).\n*   **Development Tools (`.sureai/tech_stack_document.md`):** Add tools for backend API development and testing (e.g., Postman/Insomnia).\n\nEnsure all appended content directly addresses the requirements and elaborates on how the existing boilerplate is extended."
  },
  "architecture": "\n\n# Architecture Document\nGenerated: 2025-09-26T09:44:40.087454\n\n## System Overview - Weather Application Extension\nBuilding upon the existing Angular Clarity Boilerplate, this system extends its capabilities to a fully functional Weather Application. The architecture comprises a responsive Angular frontend, a dedicated backend proxy service, and integration with an external third-party weather API. The frontend, built with Angular and Clarity Design System, handles user interactions, displays current weather and multi-day forecasts. The backend proxy, developed with Node.js and Express.js, acts as a secure intermediary, managing API keys, abstracting external API complexities, and enabling data caching to enhance performance and scalability. This setup ensures a robust, secure, and performant weather information delivery system.\n\n## Architecture Pattern - Client-Server with API Gateway/Proxy\nTo fulfill the requirements of integrating an external API securely and efficiently, the system adopts a **Client-Server Architecture** with a prominent **API Gateway/Proxy Pattern** for the backend:\n\n*   **Frontend (Client):** The Angular application serves as the client, responsible for the user interface, presentation logic, and making API requests to the backend proxy.\n*   **Backend Proxy (API Gateway):** A dedicated lightweight service (Node.js/Express.js) sits between the frontend and the external weather API. Its responsibilities include:\n    *   **Security:** Protecting the external weather API key by not exposing it to the client-side.\n    *   **Abstraction:** Providing a single, consistent set of API endpoints to the frontend, decoupling it from the external API's specifics.\n    *   **Data Transformation:** Mapping external API responses to a standardized format consumed by the frontend.\n    *   **Performance:** Implementing caching mechanisms (e.g., Redis) to store frequently requested weather data, reducing redundant external API calls and improving response times (NFR-001, NFR-005).\n    *   **Rate Limiting:** Managing requests to the external API to comply with usage policies (Business Rule 2).\n    *   **Error Handling:** Centralized handling of external API failures before responses are sent to the frontend (FR-007, NFR-004).\n*   **External Weather API:** A third-party service (e.g., OpenWeatherMap) provides the raw weather data.\n\nThis pattern enhances security, simplifies frontend development by providing a consistent interface, and improves scalability and reliability through caching and centralized error management.\n\n## Component Design - Weather Application\n\n### Frontend (Angular) Components:\nBuilding upon the existing modular structure (FR-002, FR-003, FR-004):\n*   **`AppModule`**: The root module, handling application bootstrapping and core layout. Imports `CoreModule` and `SharedModule`.\n*   **`CoreModule`**: Contains singleton services and `HttpInterceptors` for global concerns.\n    *   `WeatherApiService`: Handles all HTTP requests to the backend proxy for weather data.\n    *   `UnitConversionService`: Manages temperature unit conversion logic and state (Celsius/Fahrenheit).\n    *   `ErrorHandlerInterceptor`: Intercepts and processes global API errors, displaying user-friendly messages (FR-007).\n    *   `GeolocationService`: Wraps browser's Geolocation API to fetch user's location (FR-003).\n*   **`SharedModule`**: Contains reusable UI components, directives, and pipes.\n    *   `LoadingSpinnerComponent`: Generic spinner for data loading states (FR-006).\n    *   `ErrorAlertComponent`: Displays general error messages (FR-007).\n    *   `TemperatureUnitToggleComponent`: A UI component (e.g., toggle switch) for switching between Celsius/Fahrenheit (FR-005).\n*   **`WeatherFeatureModule` (Lazy-Loaded):** Encapsulates all weather-specific functionality.\n    *   `WeatherPageComponent`: Main smart component orchestrating data flow, integrating search, current weather, and forecast displays.\n    *   `LocationSearchComponent`: Contains the search input field and trigger for geolocation (FR-002, FR-003).\n    *   `CurrentWeatherCardComponent`: Displays current weather conditions (temperature, description, humidity, wind) for a location (FR-001). Utilizes Clarity Card component.\n    *   `ForecastListComponent`: Displays the multi-day forecast (FR-004). May use Clarity List or multiple Clarity Card components.\n    *   `WeatherIconComponent`: Displays appropriate weather icons based on conditions.\n\n### Backend (Node.js/Express.js Proxy) Components:\n*   **`server.js` (or `app.ts`):** Main entry point, sets up Express app, middleware (CORS, body-parser), and registers routes.\n*   **`routes/weatherRoutes.js`:** Defines API endpoints for weather data (`/api/current-weather`, `/api/forecast`) and maps them to controller functions (FR-008).\n*   **`controllers/weatherController.js`:** Handles incoming requests, validates input, interacts with `WeatherService`, and sends responses.\n*   **`services/weatherService.js`:** Core business logic.\n    *   Calls the `ExternalWeatherApiClient`.\n    *   Performs data transformation/normalization from external API response to internal models.\n    *   Interacts with `CacheService` for data caching (NFR-005, Business Rule 3).\n*   **`clients/externalWeatherApiClient.js`:** Specific client for making HTTP requests to the chosen external weather API (e.g., using `axios` or `node-fetch`). Handles API key injection from environment variables (NFR-002, Business Rule 1).\n*   **`services/cacheService.js`:** Abstracts Redis interactions for caching weather data.\n*   **`config/env.js`:** Manages environment variables for API keys and other configurations.\n\n## Data Architecture\n\n### Frontend (TypeScript Interfaces):\nData models on the frontend will be defined using TypeScript interfaces to ensure strong typing and data consistency, aligning with the `requirements_document.md` Data Requirements section.\n```typescript\n// src/app/shared/models/location.model.ts\nexport interface Location {\n  name: string;\n  country?: string; // Optional, as some APIs might only provide city\n  latitude: number;\n  longitude: number;\n}\n\n// src/app/shared/models/current-weather.model.ts\nexport interface CurrentWeather {\n  location: Location;\n  temperature: number;\n  unit: 'Celsius' | 'Fahrenheit';\n  condition: string;\n  description: string;\n  icon: string; // URL or icon code\n  humidity: number;\n  windSpeed: number;\n  timestamp: number; // Unix timestamp or ISO string\n}\n\n// src/app/shared/models/forecast-day.model.ts\nexport interface ForecastDay {\n  location: Location;\n  date: string; // ISO date string, e.g., 'YYYY-MM-DD'\n  tempHigh: number;\n  tempLow: number;\n  unit: 'Celsius' | 'Fahrenheit';\n  condition: string;\n  description: string;\n  icon: string; // URL or icon code\n}\n```\n\n### Backend (Data Transformation & Caching):\n*   The backend proxy will receive raw data from the external weather API and transform it into the `CurrentWeather` and `ForecastDay` models defined above before sending it to the frontend.\n*   **Caching Database (Redis):** Redis will be used as an in-memory data store for caching weather data (NFR-005, Business Rule 3). Cache keys will be constructed based on location (city, latitude/longitude) and unit, with a configurable time-to-live (TTL) to ensure data freshness while reducing external API calls. For example, a key could be `weather:london:celsius:current` or `weather:london:fahrenheit:forecast`.\n\n## API Design - Backend Proxy Endpoints\n\nThe backend proxy will expose RESTful API endpoints, allowing the frontend to fetch weather data. All responses will be in JSON format.\n\n*   **Base URL:** `/api`\n*   **Endpoints (FR-008):**\n    *   `GET /api/current-weather?location={city}[&lat={latitude}&lon={longitude}][&units={metric|imperial}]`\n        *   **Description:** Retrieves current weather conditions for a specified location (city name or geographic coordinates).\n        *   **Parameters:**\n            *   `location`: (Required if `lat` and `lon` are not provided) City name (e.g., `London`).\n            *   `lat`: (Optional, with `lon`) Latitude for geolocation search.\n            *   `lon`: (Optional, with `lat`) Longitude for geolocation search.\n            *   `units`: (Optional) `metric` (Celsius, m/s) or `imperial` (Fahrenheit, miles/hour). Defaults to `metric`.\n        *   **Response (200 OK):** `CurrentWeather` object.\n        *   **Error Responses:** 400 Bad Request (invalid parameters), 404 Not Found (location not found), 500 Internal Server Error (external API issue).\n\n    *   `GET /api/forecast?location={city}[&lat={latitude}&lon={longitude}][&units={metric|imperial}]`\n        *   **Description:** Retrieves a multi-day weather forecast for a specified location.\n        *   **Parameters:** Same as `/api/current-weather`.\n        *   **Response (200 OK):** An array of `ForecastDay` objects.\n        *   **Error Responses:** Same as `/api/current-weather`.\n\n## Security Architecture\n\n*   **API Key Management (NFR-002, Business Rule 1):** External weather API keys will be stored as environment variables on the backend server and never committed to version control or exposed to the client-side. The backend proxy will inject these keys into its requests to the external API.\n*   **HTTPS (NFR-002):** All communication between the Angular frontend and the Node.js/Express.js backend proxy, and ideally between the proxy and the external weather API (if supported), will use HTTPS/SSL to ensure data encryption in transit.\n*   **Input Validation (Business Rule 4, NFR-002):** Both frontend and backend will perform input validation on user-provided location data to prevent injection attacks or invalid requests. The backend proxy will sanitize and validate all parameters before forwarding them to the external weather API.\n*   **CORS Configuration:** The Express.js backend will be configured with appropriate Cross-Origin Resource Sharing (CORS) headers to allow requests only from the Angular frontend's domain, preventing unauthorized cross-origin requests.\n*   **Error Handling:** The backend will avoid exposing sensitive internal error details to the client. Generic, user-friendly error messages will be returned instead (FR-007).\n\n## Scalability Considerations\n\n*   **Frontend Scalability:** Angular's default build optimizations (tree-shaking, minification, lazy loading of feature modules) ensure efficient client-side performance. The modular architecture facilitates independent development and scaling of features.\n*   **Backend Scalability (NFR-005):**\n    *   **Containerization (Docker):** The Express.js backend service will be containerized using Docker, allowing for easy deployment and orchestration in cloud environments (e.g., Kubernetes, AWS Fargate, Azure Container Instances).\n    *   **Horizontal Scaling:** The stateless nature of the backend proxy (apart from caching) enables horizontal scaling, where multiple instances can run concurrently behind a load balancer to handle increased request load.\n    *   **Caching (Redis):** Implementing Redis caching significantly reduces the load on the external weather API and improves response times, especially for frequently requested locations, thereby enhancing throughput and scalability (NFR-001, NFR-005, Business Rule 3).\n    *   **External API Rate Limiting (Business Rule 2):** The backend proxy will implement mechanisms to respect the external weather API's rate limits, potentially queueing or throttling requests to avoid service interruptions.\n*   **Reliability (NFR-004):** The backend will incorporate retry mechanisms with exponential backoff for transient failures when communicating with the external weather API. Circuit breakers can be considered for more resilient handling of persistent external API outages.\n",
  "tech_stack": "\n\n# Technology Stack Document\nGenerated: 2025-09-26T09:44:40.087454\n\n## Frontend Technologies\n-   **Framework:** Angular (v16+, building on existing boilerplate)\n-   **Styling:** Clarity Design System (v15+, existing integration)\n-   **State Management:** Angular Services with RxJS (for reactive data flow and component communication, simple global state)\n-   **HTTP Client:** Angular's `HttpClient` module\n-   **Geolocation:** Browser's built-in Geolocation API (`navigator.geolocation`)\n\n## Backend Technologies\n-   **Language:** Node.js (v18+ LTS)\n-   **Framework:** Express.js (v4+, for building RESTful API endpoints)\n-   **API:** RESTful API\n-   **HTTP Client (for external API calls):** `axios` or `node-fetch`\n-   **Environment Variables:** `dotenv` package for local development\n-   **CORS Middleware:** `cors` package\n-   **External Weather API:** OpenWeatherMap (or similar free-tier friendly service like WeatherAPI.com, AccuWeather API for robust features)\n\n## Database Technologies\n-   **Primary Database:** None (Backend is a stateless proxy)\n-   **Caching:** Redis (v6+ for in-memory data caching of weather data)\n\n## Infrastructure\n-   **Deployment:** Docker (for containerization of both frontend and backend services)\n-   **Local Orchestration:** Docker Compose (for simplified local multi-container setup)\n-   **Hosting:** Cloud provider such as AWS (e.g., AWS Fargate, ECR), Azure (Azure Container Instances, Azure Kubernetes Service), or GCP (Google Cloud Run, Google Kubernetes Engine) for hosting Docker containers.\n\n## Development Tools\n-   **Version Control:** Git\n-   **IDE:** Visual Studio Code (with Angular and Node.js extensions)\n-   **Package Manager:** npm / yarn\n-   **Frontend Testing:** Jest / Karma / Jasmine (as per Angular defaults)\n-   **Backend Testing:** Mocha / Chai / Jest\n-   **API Testing:** Postman / Insomnia (for testing backend proxy and external API interactions)\n-   **CI/CD:** GitHub Actions / GitLab CI / Jenkins (for automated testing and deployment pipelines)\n"
}
```

## Base Agent Prompt Reference

This agent is based on the standard io8architect agent with project-specific customizations above.
Refer to the base io8architect agent prompt for general principles and workflow instructions.
