/* meow_ui_nav.c — App 侧 M3 导航上报封装（SDK 公共件；见 meow_ui_nav.h）。
 *
 * 只做「组装 m_nav_t + 经 meow_notify_ipc 一次性发送 MSG_NAV」，不维护连接/订阅循环；
 * launcher 主循环单写者消费（回复 ACK）。全部失败路径优雅降级（无 socket/写失败/超时
 * → 静默返回，不崩）。状态（栈深/顶层/app_id）仅进程内缓存，无并发写（App 页面线程调用）。
 */
#include "meow_ui_nav.h"
#include "meow_ipc.h"
#include "meow_notify_ipc.h"   /* meow_notify_ipc_send_raw（复用其一次性帧传输层） */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

static char g_app_id[MEOW_APP_ID_MAX] = "";
static int  g_depth = 0;
static char g_top[MEOW_ACT_MAX] = "";
static int  g_inited = 0;

/* app_id：env MEOW_LOG_APP（与 meow_ui_log/meow_notify_ipc 取值口径一致），缺省 "app"。 */
static const char *nav_app_id(void)
{
    if (!g_app_id[0]) {
        const char *s = getenv("MEOW_LOG_APP");
        snprintf(g_app_id, sizeof g_app_id, "%s", (s && s[0]) ? s : "app");
    }
    return g_app_id;
}

int meow_ui_nav_init(void)
{
    if (g_inited) return g_depth;
    g_inited = 1;
    nav_app_id();
    const char *chain = getenv("MEOW_CHAIN");
    if (chain && chain[0]) {
        g_depth = 1;
        for (const char *p = chain; *p; p++) if (*p == ';') g_depth++;
    }
    const char *act = getenv("MEOW_ACTIVITY");
    if (act && act[0]) snprintf(g_top, sizeof g_top, "%s", act);
    return g_depth;
}

int meow_ui_nav_depth(void) { meow_ui_nav_init(); return g_depth; }
const char *meow_ui_nav_top(void) { meow_ui_nav_init(); return g_top; }

void meow_ui_nav_report(uint32_t depth, const char *top)
{
    meow_ui_nav_init();
    m_nav_t n;
    memset(&n, 0, sizeof n);
    snprintf(n.app_id, sizeof n.app_id, "%s", nav_app_id());
    n.nav_type = MEOW_NAV_REPORT;
    n.depth = depth;
    if (top) snprintf(n.current, sizeof n.current, "%s", top);
    (void)meow_notify_ipc_send_raw(MSG_NAV, &n, (uint32_t)sizeof n, 1);
    /* 进程内镜像：App 侧也维持当前栈深/顶层（跨 TU 只读用） */
    g_depth = (int)depth;
    if (top) snprintf(g_top, sizeof g_top, "%s", top);
}

void meow_ui_nav_request_exit(void)
{
    meow_ui_nav_init();
    m_nav_t n;
    memset(&n, 0, sizeof n);
    snprintf(n.app_id, sizeof n.app_id, "%s", nav_app_id());
    n.nav_type = MEOW_NAV_EXIT;
    n.depth = 0;
    (void)meow_notify_ipc_send_raw(MSG_NAV, &n, (uint32_t)sizeof n, 1);
    g_depth = 0;
    g_top[0] = 0;
}