Kiến trúc tổng quan

LMS là modular monolith: backend là Spring Boot theo Clean Architecture/DDD, frontend là Angular 20 theo feature-based structure, database là PostgreSQL/Flyway, media dùng R2/Shaka, offline dùng PWA + IndexedDB/Dexie.

Runtime map

Layer	Công nghệ	Vai trò
Browser	Angular 20, Signals, PWA	UI cho student, teacher, admin
API	Spring Boot 3.2, Java 21	Auth, course, learning, assessment, payment, AI bridge
Database	PostgreSQL 16, Flyway	Source of truth cho user/course/progress/payment
Storage	Cloudflare R2/S3-compatible	File upload, video package, offline profile
Media	Shaka Player, HLS/DASH	Adaptive video playback
Edge	Caddy, Cloudflare Worker	HTTPS, reverse proxy, media auth
AI	Wiii embed/API	Chat assistant, Pointy, lesson/course generation

Request flow backend

Angular component
  -> Angular service/API client
  -> REST controller
  -> application use case
  -> domain model/repository port
  -> infrastructure adapter/JPA entity
  -> PostgreSQL

Quy tắc quan trọng: domain model không phải JPA entity. JPA chỉ nằm trong infrastructure.

Vì sao chọn Just the Docs

Just the Docs là Jekyll theme cho documentation, có built-in search và sidebar. Theo tài liệu chính thức, cách dùng gọn là gem-based: Gemfile + theme: just-the-docs, không cần clone theme vào repo.