#define SSH_TRANSPORT_MAX_SESSIONS 2U
enum { SSH_TRANSPORT_SESSION_FREE=0, SSH_TRANSPORT_SESSION_ACTIVE=2,
       SSH_TRANSPORT_ROUTE_ADMIN_CONSOLE=2 };
enum { USER_AUTH_METHOD_PASSWORD=0 };
typedef struct {
    uint32_t session_id, generation, broker_client_id;
    int state, route, socket_fd;
    uint8_t console_slot_index;
    bool authenticated, principal_valid, writer, close_requested;
    size_t rx_length, rx_offset, tx_length, tx_offset;
    user_principal_t principal;
    char peer[48];
} ssh_slot_t;
typedef struct {
    bool active, tx_pending, rx_pending, authenticated, principal_valid, close_requested;
    bool writer, admin_command_pending;
    uint32_t session_id, generation, broker_client_id, admin_output_pending;
    int state, route, socket_fd, user_role, auth_method;
    char username[USER_DATABASE_USERNAME_CAPACITY+1U], peer[48];
} ssh_transport_session_snapshot_t;
static ssh_transport_session_snapshot_t s_session_snapshots[2];
static user_principal_t s_console_principals[2];
static uint8_t s_console_slot_indices[2];
static uint32_t s_external_close_id[2];
static unsigned stopped, disconnected, rotated, reset, restarted;
static esp_err_t ssh_transport_stop(void) { ++stopped; return ESP_OK; }
static esp_err_t ssh_transport_disconnect(uint32_t id) { disconnected=id; return ESP_OK; }
static esp_err_t ssh_transport_replace_host_key(bool r) { if(r) ++reset; else ++rotated; return ESP_OK; }
static void esp_restart(void) { ++restarted; }
static void publish_slot(const ssh_slot_t *, size_t);
static bool admin_console_drained(const admin_ssh_console_token_t *);
static bool admin_console_is_current(const admin_ssh_console_token_t *, const user_principal_t *);
static bool consume_external_close(const ssh_slot_t *, size_t);
static esp_err_t admin_console_perform(const admin_ssh_console_token_t *, admin_ssh_deferred_action_type_t, uint32_t);
static void test_adapter(void)
{
    admin_ssh_console_token_t token={ .slot_index=0, .session_id=7, .slot_generation=3 };
    user_principal_t admin={ .role=USER_ROLE_ADMIN, .user_id=11, .auth_generation=2,
                                .username_length=5, .username="admin" };
    assert(admin_ssh_console_init()==ESP_OK);
    assert(admin_ssh_console_start_uart_frontend()==ESP_OK);
    assert(admin_ssh_console_open(&token,&admin)==ESP_OK);
    assert(!admin_console_drained(&token));
    s_session_snapshots[0]=(ssh_transport_session_snapshot_t){ .active=true, .session_id=7, .generation=3 };
    assert(!admin_console_drained(&token)); /* No published console binding. */
    assert(!admin_console_is_current(&token,&admin));
    ssh_slot_t active={ .session_id=7, .generation=3, .authenticated=true,
        .principal_valid=true, .state=SSH_TRANSPORT_SESSION_ACTIVE,
        .route=SSH_TRANSPORT_ROUTE_ADMIN_CONSOLE, .principal=admin };
    publish_slot(&active,0);
    assert(admin_console_is_current(&token,&admin));
    /* Production publication carries both console output and principal binding. */
    assert(s_session_snapshots[0].tx_pending && s_session_snapshots[0].admin_output_pending);
    assert(!strcmp(s_session_snapshots[0].username,"admin"));
    uint8_t output[4096]; size_t n;
    assert(admin_ssh_console_read_output(&token,output,sizeof(output),&n)==ESP_OK && n);
    publish_slot(&active,0);
    assert(admin_console_drained(&token));
    active.state=SSH_TRANSPORT_SESSION_FREE; active.principal_valid=false;
    publish_slot(&active,0);
    user_principal_t empty={0};
    assert(!memcmp(&s_console_principals[0],&empty,sizeof(empty)));
    assert(!admin_console_is_current(&token,&admin));
    active.state=SSH_TRANSPORT_SESSION_ACTIVE; active.principal_valid=true;
    publish_slot(&active,0);
    assert(admin_console_is_current(&token,&admin));
    admin.username[0]='A'; assert(!admin_console_is_current(&token,&admin)); admin.username[0]='a';
    active.route=0; publish_slot(&active,0); assert(!admin_console_is_current(&token,&admin));
    active.route=SSH_TRANSPORT_ROUTE_ADMIN_CONSOLE;
    active.authenticated=false; publish_slot(&active,0); assert(!admin_console_is_current(&token,&admin));
    active.authenticated=true; publish_slot(&active,0);
    s_external_close_id[0]=7; assert(!admin_console_is_current(&token,&admin));
    ssh_slot_t closing={.session_id=7, .state=SSH_TRANSPORT_SESSION_ACTIVE};
    assert(consume_external_close(&closing,0) && !s_external_close_id[0]);
    assert(!admin_console_is_current(&token,&admin));
    s_session_snapshots[0].close_requested=true;
    assert(!admin_console_is_current(&token,&admin)); s_session_snapshots[0].close_requested=false;
    ++admin.auth_generation; assert(!admin_console_is_current(&token,&admin)); --admin.auth_generation;
    ++admin.user_id; assert(!admin_console_is_current(&token,&admin)); --admin.user_id;
    ++admin.method; assert(!admin_console_is_current(&token,&admin)); --admin.method;
    admin.username_length=1; assert(!admin_console_is_current(&token,&admin)); admin.username_length=5;
    token.transport=1; assert(!admin_console_drained(&token));
    assert(!admin_console_is_current(&token,&admin));
    assert(admin_ssh_console_open(&token,&admin)==ESP_ERR_INVALID_ARG);
    token.transport=0; token.slot_generation=4; assert(!admin_console_drained(&token));
    assert(!admin_console_is_current(&token,&admin));
    assert(admin_console_perform(&token,ADMIN_SSH_DEFER_STOP,0)==ESP_ERR_NOT_FOUND && stopped==0);
    token.slot_generation=3;
    /* Same physical session can be assigned the other console slot. */
    admin_ssh_console_close(&token);
    token.slot_index=1;
    assert(admin_ssh_console_open(&token,&admin)==ESP_OK);
    active.console_slot_index=1; publish_slot(&active,0);
    assert(admin_console_is_current(&token,&admin));
    assert(s_console_slot_indices[0]==1);
    admin_ssh_console_token_t wrong=token; wrong.slot_index=0;
    assert(!admin_console_is_current(&wrong,&admin) && !admin_console_drained(&wrong));
    assert(admin_console_perform(&wrong,ADMIN_SSH_DEFER_STOP,0)==ESP_ERR_NOT_FOUND);
    /* A colliding published ID with a stale generation cannot steal the lookup. */
    s_session_snapshots[1]=s_session_snapshots[0];
    ++s_session_snapshots[1].generation; s_console_slot_indices[1]=0;
    assert(admin_console_is_current(&token,&admin));
    assert(admin_ssh_console_read_output(&token,output,sizeof(output),&n)==ESP_OK && n);
    publish_slot(&active,0);
    s_session_snapshots[0].tx_pending=true;
    assert(!admin_console_drained(&token)); s_session_snapshots[0].tx_pending=false;
    assert(admin_console_perform(&token,ADMIN_CONSOLE_DEFER_SELF_CLOSE,99)==ESP_OK && disconnected==7);
    assert(admin_console_perform(&token,ADMIN_SSH_DEFER_DISCONNECT,99)==ESP_OK && disconnected==99);
    assert(admin_console_perform(&token,ADMIN_SSH_DEFER_STOP,0)==ESP_OK && stopped==1);
    assert(admin_console_perform(&token,ADMIN_SSH_DEFER_HOST_KEY_ROTATE,0)==ESP_OK && rotated==1);
    assert(admin_console_perform(&token,ADMIN_SSH_DEFER_HOST_KEY_RESET,0)==ESP_OK && reset==1);
    assert(admin_console_perform(&token,ADMIN_SSH_DEFER_REBOOT,0)==ESP_OK && restarted==1);
    puts("PASS: actual SSH snapshot/principal publication and wiping, adapter identity/drain checks, legacy admission and lifecycle action routing");
}