# 🚧 Carrramba! Encore rrraté! 🚧

Resident of the Ile-de-France,

- Tired of missing your bus/train/metro ?
- Tired of having to walk to know where your bus/train/metro will stop ?
- Are you looking to display its next passages in the same way as Ile De France Mobilité ?

**Visit [carrramba.adrien.run](https://carrramba.adrien.run/)**

[![Presentation](medias/presentation.png)](medias/presentation.mp4)

# Technical stack

The following figure list the building blocks (docker images) and their interactions to provide the service:

```plantuml
@startuml
!include <C4/C4_Container>

!define ICONURL https://raw.githubusercontent.com/tupadr3/plantuml-icon-font-sprites/v2.4.0
!includeurl ICONURL/common.puml

!includeurl ICONURL/font-awesome-5/users.puml
!includeurl ICONURL/devicons2/redis.puml
!includeurl ICONURL/devicons2/sqlalchemy.puml
!includeurl ICONURL/devicons2/postgresql.puml

title Carrramba-encore-rate - Back-end

LAYOUT_WITH_LEGEND()

Person(user, "User", "The service user", $sprite="users")

System_Boundary(cb1, "carrramba-encore-rate") {
  Container(app, "SPA", "SolidJS", "The graphical interface used by users to consume services provided")
  Container(api, "carrramba-encore-rate-api", "FastAPI / Pydantic 2 / SQLAlchemy 2", "Provides the functionalities serving API endpoints", $sprite="sqlalchemy")
  ContainerDb(db, "Postgres", "PostgreSQL database", "Stores stops/stop areas/lines/shapes and associations information.", $sprite="postgresql")
  ContainerDb(cache, "In-Memory cache", "Redis", "Store previously computed results (stop, line, destination, next passages, shapes).", $sprite="redis")

  Container(db_updater, "db-updater", "Sync the service static data with the IDFM ones")
}

System_Boundary(idfm, "IDFM") {
  Container_Ext(static_, "Static data")
  Container_Ext(dynamic_, "Dynamic data")
}

Rel(user, app, "Uses")

Rel(app, api, "Uses", "JSON/HTTPS")

Rel_R(api, db, "Reads from", "sync, PSQL")
Rel_L(api, cache, "Reads from and writes to", "sync, REdis Serialization Protocol")
Rel(api, dynamic_, "Get next passages", "JSON/HTTPS")

Rel_L(db_updater, db, "Writes to", "sync, PSQL")
Rel(db_updater, static_, "Get stops, lines andshapes")
@enduml
```

## Back-end

Conventional but efficient:

- [FastAPI](https://fastapi.tiangolo.com/): _FastAPI is a modern, fast (high-performance), web framework for building
   APIs with Python 3.8+ based on standard Python type hints._
- [Pydantic 2](https://docs.pydantic.dev/latest/): _Pydantic is the most widely used data validation library for
   Python._
- [Sqlalchemy 2](https://www.sqlalchemy.org/): _SQLAlchemy is the Python SQL toolkit and Object Relational Mapper that
   gives application developers the full power and flexibility of SQL._

The [Msgspec](https://github.com/jcrist/msgspec) library is used to serialize JSON objects collected from IDFM API
endpoints, this library being faster than Pydantic.

## Front-end

The component is developed using the [SolidJS](https://www.solidjs.com/) library. It brings the following interesting specificities:

- Share with React the same programmatic structures and support for component.
- Fine-grained reactivity architecture: no virtual DOM used to update the components, the browser DOM is directly
  updated by SolidJS.

The front-end tries to be as close as possible to the design defined by the IDFM for the displays deployed by the
transport operators in Ile-de-France. These specifications are public and available here:
[PRIM-IDFM](https://prim.iledefrance-mobilites.fr/en/chartes-et-prescriptions).


# TODO

## Features

- [ ] Integration with [Matrix.org](https://matrix.org/ecosystem/integrations/) ecosystem: make the app able to send message to a room when a bus/train/metro will
      arriving in X minutes.
- [ ] Add the capability for the users to pin his/her favorite stops.
- [ ] Add the address to the stop location.

## Front-end

- [ ] Add unit tests.
- [ ] Make the StopNameInput component liquid.
- [ ] Liquid to responsive Design.

## Back-end

- [ ] Add unit tests.
- [ ] Use [alembic](https://alembic.sqlalchemy.org/en/latest/) to manage the future updates of the database schemas.
- [ ] Add the capability to reload the application configuration on configuration file update (e.g.: credential update by the vault).
- [ ] Rework how the database is updated with the IDFM data: For now the database is cleaned before refilling. It could
      be useful to avoid to empty the database and only apply deltas (update/add/remove rows).
- [ ] Could be nice to compare FastAPI with [Litestar](https://litestar.dev/).

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