c4-architecture-documentation

# C4 Architecture Documentation Skill ## Purpose Document CIA platform architecture using C4 model for different abstraction levels. ## When to Use - ✅ Documenting system architecture - ✅ Onboarding new developers - ✅ Architecture decision records - ✅ Security architecture reviews ## C4 Model Levels ### Level 1: System Context ``` [External Users] --uses--> [CIA Platform] --uses--> [Riksdagen API] [CIA Platform] --uses--> [World Bank API] [CIA Platform] --uses--> [PostgreSQL Database] ``` ### Level 2: Container Diagram ``` [Web Browser] --HTTPS--> [Spring MVC App] --JDBC--> [PostgreSQL] [Spring MVC App] --HTTPS--> [External APIs] [Spring MVC App] --uses--> [Redis Cache] ``` ### Level 3: Component Diagram ```java // Service Layer Components @Component PoliticianService --uses--> @Repository PoliticianRepository @Component VotingAnalysisService --uses--> @Repository VotingRecordRepository @Component RiksdagenClient --calls--> [External Riksdagen API] ``` ### Level 4: Code ```java // Detailed class design public class PoliticianService { private final PoliticianRepository repository; private final RiksdagenClient riksdagenClient; // Implementation details... } ``` ## PlantUML Diagrams ```plantuml @startuml !include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml Person(user, "Citizen", "Wants political transparency") System_Boundary(cia, "CIA Platform") { Container(web, "Web Application", "Spring MVC, Vaadin 8", "Provides UI") ContainerDb(db, "Database", "PostgreSQL", "Stores data") } System_Ext(riksdagen, "Riksdagen API", "Government data") Rel(user, web, "Uses", "HTTPS") Rel(web, db, "Reads/Writes", "JDBC") Rel(web, riksdagen, "Fetches data", "HTTPS/REST") @enduml ``` ## References - C4 Model: https://c4model.com/ - ARCHITECTURE.md - FUTURE_ARCHITECTURE.md