# SummerCMS Technology Stack

## Philosophy

**Direct-style Scala 3 on JDK 21 virtual threads.** No monadic effect systems (no ZIO, no Cats Effect). Virtual threads make blocking IO cheap, so you write normal imperative-looking code that scales. This is the simplest possible modern Scala stack.

---

## Core Stack

| Layer | Technology | Why |
|-------|-----------|-----|
| **Language** | Scala 3.3+ LTS | VirtusLab maintains the compiler. Scala 3 has cleaner syntax, given/using for DI, extension methods, enums, union types |
| **Runtime** | JDK 21+ with Project Loom | Virtual threads = millions of lightweight threads, no async/callback hell |
| **HTTP Server** | Tapir + JDK HttpServer | Tapir gives type-safe endpoint definitions with auto-generated OpenAPI docs. JDK HttpServer with `Executors.newVirtualThreadPerTaskExecutor()` is the lightest possible server |
| **Concurrency** | Ox | Structured concurrency, Go-like channels, error supervision, retries, rate limiting. Built on virtual threads |
| **Database** | Magnum | Scala 3 native, typesafe SQL interpolator, auto-generated CRUD, no dependencies, works with any JDBC database |
| **Migrations** | Flyway | Industry standard, JVM-native, works with any JDBC database |

## Supporting Libraries

| Concern | Library | Notes |
|---------|---------|-------|
| **JSON** | uPickle or Circe | Serialization/deserialization for API + config |
| **Config** | Typesafe Config (HOCON) | Industry standard JVM config, supports YAML-like nesting, env var substitution |
| **Logging** | SLF4J + Logback | Standard JVM logging |
| **Caching** | Caffeine (in-memory) + Jedis/Lettuce (Redis) | Caffeine is the fastest JVM cache; Redis for distributed |
| **Hashing** | jBCrypt + JDK crypto | Password hashing + general encryption |
| **Email** | Jakarta Mail | Standard JVM email |
| **Admin Frontend** | Vue.js 3 + TypeScript | SPA admin panel consuming Tapir API |
| **OpenAPI codegen** | Tapir -> OpenAPI -> openapi-typescript | Auto-generated TS types for Vue frontend |
| **Template Engine** | Scalate (Mustache/SSP) or Twirl | Server-rendered public-facing themes |
| **CLI** | Decline or Scopt | Console command parsing for scaffolding |
| **Testing** | MUnit or ScalaTest + Tapir test utils | Unit + integration testing |
| **Build (project)** | sbt | Multi-module build for the 20+ subprojects |
| **Build (scripts)** | scala-cli | Quick scripts, prototyping, dev tooling. VirtusLab maintains it |

---

## Module Mapping: Laravel Illuminate -> SummerCMS

Each module = separate sbt subproject, publishable independently (like Illuminate packages).

| Illuminate Package | SummerCMS Module | Implementation Approach |
|-------------------|-----------------|------------------------|
| **Container** | `summer-container` | Scala 3 `given`/`using` for compile-time DI + lightweight runtime registry for plugins |
| **Contracts** | `summer-contracts` | Scala traits — all public APIs defined here |
| **Support** | `summer-support` | Extension methods, utility types, base classes |
| **Config** | `summer-config` | Typesafe Config wrapper, HOCON files |
| **Pipeline** | `summer-pipeline` | Function composition `(A => A)*` — trivial in Scala |
| **Events** | `summer-events` | Simple event bus with typed events + Ox channels for async |
| **Http** | `summer-http` | Tapir endpoint definitions, request/response wrappers |
| **Routing** | `summer-routing` | Tapir endpoints are already type-safe routes — combine with auto-discovery |
| **Database** | `summer-database` | Magnum repos + case class models + query builder |
| **Auth** | `summer-auth` | JWT tokens (for API) + session cookies (for admin), guards as traits |
| **Validation** | `summer-validation` | Compile-time via Scala types + runtime rules engine (inspired by fields.yaml) |
| **Cache** | `summer-cache` | Caffeine + Redis, driver-based via trait |
| **Queue** | `summer-queue` | Ox channels + virtual threads for workers, persistent queue via DB or Redis |
| **Mail** | `summer-mail` | Jakarta Mail wrapper with template support |
| **Console** | `summer-console` | CLI command framework for scaffolding (`summer create:plugin`, etc.) |
| **Session** | `summer-session` | Cookie/DB-backed sessions for admin panel |
| **Filesystem** | `summer-filesystem` | `java.nio.file` + S3 adapter |
| **Translation** | `summer-translation` | i18n with HOCON/JSON locale files |
| **View** | `summer-view` | Template engine for admin panel rendering |
| **Log** | `summer-log` | SLF4J facade, minimal wrapper |
| **Collections** | *(not needed)* | Scala stdlib collections are already excellent |
| **Pagination** | `summer-pagination` | Generic paginator for Magnum query results |

---

## Plugin & Theme System

### Plugins

Each plugin = a directory with a `Plugin.scala` descriptor (same lifecycle as WinterCMS).

- Descriptor declares: models, controllers, components, console commands, event listeners, navigation items
- Plugins discovered at boot via classpath scanning or manifest
- Plugins can extend other plugins' models via Scala 3 extension methods + event hooks
- Plugin lifecycle: `register()` -> `boot()`

### Components

- Components are defined in plugins and placed in theme templates (like WinterCMS)
- Each component = a class with `onRun()`, properties, and a partial template
- Components handle their own data fetching and expose variables to templates
- Registered via plugin descriptor, auto-discovered by the theme engine

### Themes

- Theme = directory of templates + assets + config
- Templates rendered server-side (Scalate/Twirl) or served as SPA shell
- Components (from plugins) can be placed in theme templates

---

## Admin Backend

- Tapir endpoints serve as the admin API
- **YAML/JSON-driven forms** — same concept as WinterCMS `fields.yaml` / `columns.yaml`:
  - Plugin defines `fields.yaml` for model forms
  - Backend returns form schema as JSON, Vue frontend renders it
  - Field types: text, textarea, dropdown, relation, repeater, etc.
- **Admin frontend: Full SPA in Vue.js 3 + TypeScript** — consumes Tapir-generated typed API
  - TypeScript types auto-generated from Tapir OpenAPI spec
  - Vue components for form builder, list columns, relation managers, etc.

---

## Frontend-Backend Communication

- **Tapir-generated typed API** — all communication is via typed JSON endpoints
- OpenAPI spec auto-generated from Tapir endpoint definitions
- TypeScript client types generated from OpenAPI for the Vue admin SPA
- Public-facing sites can use the same API (headless mode) or server-rendered templates
- Headless mode: admin panel + API controllers serve as a superuser data presentation layer, frontend is fully decoupled

---

## Scaffolding Commands

```
summer create:plugin vendor.pluginname
summer create:model vendor.pluginname ModelName
summer create:controller vendor.pluginname ControllerName
summer create:component vendor.pluginname ComponentName
summer create:command vendor.pluginname CommandName
summer create:job vendor.pluginname JobName
summer create:migration vendor.pluginname description
```

---

## Project Structure

```
summercms/
  build.sbt                    # Multi-project sbt build
  modules/
    summer-container/
    summer-contracts/
    summer-support/
    summer-config/
    summer-pipeline/
    summer-events/
    summer-http/               # Tapir integration
    summer-routing/
    summer-database/           # Magnum integration
    summer-auth/
    summer-validation/
    summer-cache/
    summer-queue/              # Ox integration
    summer-mail/
    summer-console/
    summer-session/
    summer-filesystem/
    summer-translation/
    summer-view/
    summer-log/
    summer-pagination/
  app/                         # Full CMS application (depends on all modules)
    summer-cms/                # Assembled CMS with admin panel
  plugins/                     # Example/core plugins
    summer-plugin-user/
    summer-plugin-blog/
    summer-plugin-pages/
```