📐 Arquitectura — Caso 20: 🍎 Swift → 🌉 n8n → 🎯 Dart (Shelf) + 🔥 Firestore emulator#

Stack mobile-backend server-side: emisor Swift (Linux) y receptor Dart/Shelf que persiste en el emulador de Firestore vía su API REST v1. Firebase local, sin nube.

🧭 Ficha técnica#

Atributo	Valor
ID	`20`
Origen	Swift (Linux) — `origin/Sources/Publisher/main.swift`
Puente	n8n — `case-20-swift-to-dart.json`
Destino	Dart / Shelf (AOT) — `dest/bin/server.dart`
Persistencia	Firestore (Firebase Emulator Suite)
Puerto (dashboard)	`http://localhost:8100`
Perfil Docker	`case20`

🗺️ Diagrama de arquitectura#

diagrama mermaid

%%{init: {'theme':'base','themeVariables':{'fontSize':'26px','fontFamily':'Segoe UI, Arial, sans-serif'},'flowchart':{'useMaxWidth':true,'htmlLabels':false,'nodeSpacing':55,'rankSpacing':70,'padding':16,'diagramPadding':16}}%%
flowchart TB
    subgraph ORIGIN["ORIGEN - Swift (Linux)"]
        S["main.swift"]
    end

    subgraph BRIDGE["PUENTE - n8n + Guardrails"]
        C(["Webhook"]) --> IDEM{"Idempotencia + circuit breaker"}
        IDEM -->|nuevo| FWD["HTTP forward + reintentos"]
        FWD -.->|error| DLQ["Dead Letter Queue (/errors)"]
    end

    subgraph DEST["DESTINO - Dart/Shelf + Firestore"]
        FWD --> D["server.dart (Shelf)"]
        D -->|REST v1 PATCH/GET| DB[("Firestore emulator")]
        DB --> DASH["Dashboard :8100"]
    end

    S -->|POST JSON| C

    classDef origin fill:#FA7343,stroke:#333,color:#fff
    classDef bridge fill:#EA4B71,stroke:#333,color:#fff
    classDef dest fill:#0175C2,stroke:#333,color:#fff
    classDef db fill:#FFCA28,stroke:#333,color:#000
    class S origin
    class C,IDEM,FWD,DLQ bridge
    class D,DASH dest
    class DB db

🔁 Diagrama de secuencia (ciclo de una publicación)#

diagrama mermaid

%%{init: {'theme':'base','themeVariables':{'fontSize':'24px','fontFamily':'Segoe UI, Arial, sans-serif'},'sequence':{'useMaxWidth':true,'actorFontSize':22,'messageFontSize':20,'noteFontSize':18,'actorMargin':90,'boxMargin':16,'width':180}}}%%
sequenceDiagram
    autonumber
    participant SW as main.swift (Swift)
    participant N8N as n8n
    participant DART as Dart/Shelf
    participant FS as Firestore emulator

    SW->>N8N: POST /webhook (post vencido)
    N8N->>N8N: Circuit breaker + idempotencia
    N8N->>DART: HTTP POST /webhook (reintentos x3)
    DART->>FS: PATCH /v1/.../social_posts/{id} (upsert)
    FS-->>DART: 200 documento
    DART-->>N8N: 200 OK
    Note over DART,FS: GET /logs -> GET /v1/.../social_posts -> ordena por created_at desc

🧩 Componentes#

🍎 Origen — Swift (Linux)#

origin/Sources/Publisher/main.swift reenvía los posts vencidos a n8n con URLSession (Foundation). Swift Package Manager, binario nativo.

🌉 Puente — n8n#

Guardrails canónicos: fingerprint → circuit breaker → idempotencia → HTTP forward con reintentos → DLQ.

🎯 Destino — Dart/Shelf + Firestore#

dest/bin/server.dart (Shelf, compilado AOT) traduce el contrato REST a la API REST v1 de Firestore: PATCH para upsert, GET para listar. Documentos con fields tipados.

▶️ Cómo levantarlo#

bash

docker-compose --profile case20 up -d          # emulador Firestore + receptor Dart

Dashboard: http://localhost:8100

🔗 Enlaces#

Diagramas en Mermaid — se renderizan nativamente en GitHub. Parte de Social Bot Scheduler.

← Toda la documentación Portada Esta carpeta en GitHub