digraph MercadoPagoShunt {
    rankdir=LR;
    compound=true;
    fontname="Helvetica";
    node [fontname="Helvetica", fontsize=11, shape=box, style="rounded,filled"];
    edge [fontname="Helvetica", fontsize=10];

    labelloc="t";
    label="MercadoPago Shunt - Mock Payment Flow";
    fontsize=16;

    // Client App
    subgraph cluster_client {
        label="Managed Room (e.g., AMAR)";
        style=filled;
        color="#E8F5E9";
        fillcolor="#E8F5E9";

        backend [label="Backend\n(Django/FastAPI)", fillcolor="#C8E6C9"];
    }

    // Shunt
    subgraph cluster_shunt {
        label="Shunt (artery/shunts/mercadopago)";
        style=filled;
        color="#FFF3E0";
        fillcolor="#FFF3E0";

        mock_api [label="Mock API\n/payments\n/preferences", fillcolor="#FFCC80"];
        config_ui [label="Config UI\n(set responses)", fillcolor="#FFB74D"];
        state [label="State\n(pending payments)", fillcolor="#FFA726"];
    }

    // Fake responses
    subgraph cluster_responses {
        label="Configurable Responses";
        style=dashed;
        color=gray;

        approved [label="approved", fillcolor="#C8E6C9"];
        pending [label="pending", fillcolor="#FFF9C4"];
        rejected [label="rejected", fillcolor="#FFCDD2"];
    }

    // Real (bypassed)
    subgraph cluster_real {
        label="Real MercadoPago (bypassed)";
        style=dashed;
        color="#BDBDBD";

        real_api [label="api.mercadopago.com", fillcolor="#E0E0E0", fontcolor="#9E9E9E"];
    }

    // Flow
    backend -> mock_api [label="POST /payments"];
    mock_api -> state [label="store"];
    config_ui -> state [label="configure"];

    state -> approved [style=dashed];
    state -> pending [style=dashed];
    state -> rejected [style=dashed];

    mock_api -> backend [label="webhook callback", style=dashed];
}