sequenceDiagram
    autonumber

    actor Cliente
    participant GW as API Gateway<br/>(Nginx)
    participant US as Upload Service<br/>(FastAPI + PostgreSQL)
    participant S3 as AWS S3
    participant SQS as AWS SQS
    participant AI as AI Processing Worker<br/>(LangChain + Gemini)
    participant Gemini as Gemini 2.5 Flash Lite<br/>(Google API)
    participant RS as Report Service<br/>(FastAPI + MongoDB)

    rect rgb(220, 235, 255)
        Note over Cliente,SQS: Fase 1 — Upload e Enfileiramento
        Cliente->>GW: POST /api/v1/uploads<br/>X-API-Key: ***<br/>body: multipart/form-data (arquivo)
        GW->>GW: Valida X-API-Key<br/>Rate limit (10 req/s, burst 20)
        GW->>US: POST /api/v1/uploads (proxy)
        US->>US: Valida MIME type (whitelist PNG/JPEG/PDF)
        US->>US: Valida magic bytes (assinatura binária)
        US->>US: Valida tamanho ≤ 20 MB
        US->>S3: PUT s3://bucket/{uuid}/{filename}
        S3-->>US: 200 OK
        US->>US: INSERT upload (id, filename, s3_key,<br/>status=RECEIVED) → PostgreSQL
        US->>SQS: SendMessage<br/>{upload_id, s3_key, content_type}
        SQS-->>US: MessageId
        US-->>GW: 202 {upload_id, status: "RECEIVED"}
        GW-->>Cliente: 202 {upload_id, status: "RECEIVED"}
    end

    rect rgb(240, 240, 240)
        Note over Cliente,US: Fase 2 — Polling de Status (assíncrono)
        loop Até status = ANALYZED ou ERROR
            Cliente->>GW: GET /api/v1/uploads/{upload_id}/status<br/>X-API-Key: ***
            GW->>US: GET /uploads/{upload_id}/status (proxy)
            US->>US: SELECT upload WHERE id = upload_id → PostgreSQL
            US-->>GW: 200 {upload_id, status, updated_at}
            GW-->>Cliente: 200 {upload_id, status, updated_at}
        end
    end

    rect rgb(255, 240, 220)
        Note over SQS,RS: Fase 3 — Processamento Assíncrono (Worker)
        AI->>SQS: ReceiveMessage (long polling)
        SQS-->>AI: {upload_id, s3_key, content_type}
        AI->>US: PATCH /uploads/{upload_id}/status<br/>X-Internal-Token: ***<br/>body: {status: "PROCESSING"}
        US->>US: UPDATE upload SET status=PROCESSING → PostgreSQL
        US-->>AI: 200 OK
        AI->>S3: GetObject s3://bucket/{s3_key}
        S3-->>AI: bytes do arquivo
        alt content_type = application/pdf
            AI->>AI: pdf2image → converte PDF para PNG
        end
        AI->>AI: base64.encode(image_bytes)
        AI->>Gemini: ChatMessage [SystemPrompt + UserPrompt + image_base64]<br/>response_mime_type: application/json
        Gemini-->>AI: JSON {summary, components[], risks[], recommendations[]}
        AI->>AI: Guardrail 1: Pydantic schema validation<br/>(campos obrigatórios, enums HIGH/MEDIUM/LOW)
        AI->>AI: Guardrail 2: sanitize strings<br/>(strip + truncate 2000 chars)
        alt Guardrails OK
            AI->>RS: POST /reports<br/>X-Internal-Token: ***<br/>body: {upload_id, summary, components,<br/>risks, recommendations, ai_model,<br/>processing_time_seconds}
            RS->>RS: INSERT report → MongoDB
            RS-->>AI: 201 {report_id, upload_id}
            AI->>US: PATCH /uploads/{upload_id}/status<br/>X-Internal-Token: ***<br/>body: {status: "ANALYZED"}
            US->>US: UPDATE upload SET status=ANALYZED → PostgreSQL
            US-->>AI: 200 OK
        else Guardrails FALHOU
            AI->>US: PATCH /uploads/{upload_id}/status<br/>X-Internal-Token: ***<br/>body: {status: "ERROR", error_message: "..."}
            US->>US: UPDATE upload SET status=ERROR → PostgreSQL
            US-->>AI: 200 OK
        end
        AI->>SQS: DeleteMessage (remove da fila)
    end

    rect rgb(220, 255, 230)
        Note over Cliente,RS: Fase 4 — Consulta do Relatório
        Cliente->>GW: GET /api/v1/reports/{upload_id}<br/>X-API-Key: ***
        GW->>GW: Valida X-API-Key<br/>Rate limit
        GW->>RS: GET /reports/{upload_id} (proxy)
        RS->>RS: db.reports.findOne({upload_id}) → MongoDB
        RS-->>GW: 200 {report_id, summary, components[],<br/>risks[], recommendations[],<br/>ai_model, processing_time_seconds}
        GW-->>Cliente: 200 {relatório completo}
    end