digraph public_api_ownership {
    rankdir=TB;
    fontname="Helvetica";
    node [fontname="Helvetica", fontsize=11, shape=record, style=filled];
    edge [fontname="Helvetica", fontsize=10];

    label="Public API: Ownership Model";
    labelloc=t;
    fontsize=14;

    subgraph cluster_user {
        label="User Code";
        style=dashed;
        color=gray60;
        fontcolor=gray40;

        user_code [label="User", shape=ellipse, fillcolor="#e8e8e8"];
    }

    subgraph cluster_public_api {
        label="Public API (include/)";
        style=filled;
        color="#dce8f5";
        fillcolor="#f0f6ff";

        storage [label="{storage_t|unique_ptr\<impl\>\l|+ get_storage_version()\l}", fillcolor="#c8ddf0"];
        writer [label="{writer_t|unique_ptr\<impl\>\l|+ register_*_info()\l+ insert_*_data()\l+ flush_in_memory_data_to_disk()\l}", fillcolor="#c8ddf0"];
        reader [label="{reader_t|unique_ptr\<impl\>\l|+ get_all_*()\l+ get_events*()\l+ get_*_details()\l}", fillcolor="#c8ddf0"];
    }

    subgraph cluster_types {
        label="Type Namespaces";
        style=filled;
        color="#e5ddf0";
        fillcolor="#f5f0ff";

        writer_types [label="writer_types\n(const char*, input)", shape=box, fillcolor="#ddd0f0"];
        reader_types [label="reader_types\n(std::string, output)", shape=box, fillcolor="#ddd0f0"];
        shared_types [label="shared_types\n(call_stack, source_context)", shape=box, fillcolor="#ddd0f0"];
        version [label="version_t", shape=box, fillcolor="#ddd0f0"];
    }

    subgraph cluster_hidden {
        label="Hidden (source/) — Pimpl boundary";
        style=filled;
        color="#f5e0e0";
        fillcolor="#fff0f0";

        storage_impl [label="storage_t::impl", shape=box, fillcolor="#f0d0d0"];
        writer_impl [label="writer_t::impl", shape=box, fillcolor="#f0d0d0"];
        reader_impl [label="reader_t::impl", shape=box, fillcolor="#f0d0d0"];
    }

    user_code -> storage [label="  creates  ", style=bold];
    user_code -> writer [label="  unique_ptr<storage_t>  ", style=bold, color="#2060a0", fontcolor="#2060a0"];
    user_code -> reader [label="  unique_ptr<storage_t>  ", style=bold, color="#2060a0", fontcolor="#2060a0"];

    storage -> storage_impl [label="  m_impl  ", style=dashed, color=gray50];
    writer -> writer_impl [label="  m_impl  ", style=dashed, color=gray50];
    reader -> reader_impl [label="  m_impl  ", style=dashed, color=gray50];

    writer -> writer_types [style=dotted, color=gray50, arrowhead=none];
    reader -> reader_types [style=dotted, color=gray50, arrowhead=none];
    writer_types -> shared_types [style=dotted, color=gray50, arrowhead=none];
    reader_types -> shared_types [style=dotted, color=gray50, arrowhead=none];
    storage -> version [style=dotted, color=gray50, arrowhead=none];
}