/* bench/mem_watch_sim.c — 宿主「边播监控取证」阈值/峰值验证（agent 32bit OOM 取证）。
 *
 * 归属演进（2026-09-02 定案，ARCHITECTURE_PRINCIPLES ③混合）：**降载决策上收通用层**——
 *   A + C 分别归 SDK meow_cachegov / meow_svc_perf；本 sim 只验证 mem_watch 的**取证**语义：
 *   三档 level 标注滞回（normal→high→critical→滞回→normal）+ song_end 重置峰值 + song_begin 起算。
 *   （旧版「dl_paused/prefetch_paused 降载断言」已随降载上收移除——那由 meow_cachegov_sim
 *    与 svc_perf test_cachegov_monitor 覆盖。）
 *
 * 依赖：仅 app/play/mem_watch.c（+ meow_log 桩）。
 * 编译（ncm_app 目录下）：
 *   gcc -O2 -Wall -Wextra -DJSMN_HEADER -I. -I../sdk -I../meow_launcherd \
 *       -c bench/mem_watch_sim.c -o /tmp/mw.o
 *   gcc -O2 -Wall -Wextra -I. -I../sdk -c app/play/mem_watch.c -o /tmp/mw_mod.o
 *   gcc -O2 -o mem_watch_sim /tmp/mw.o /tmp/mw_mod.o -lpthread -lm
 * 运行：./mem_watch_sim        （exit 0=PASS / 1=FAIL）
 */
#include "../app/play/mem_watch.h"
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

/* meow_log 桩：打印（便于看阈值过渡；sim 仅验证 mem_watch 逻辑，非真实日志系统） */
void meow_log(int lvl, const char *fmt, ...)
{
    (void)lvl;
    char b[256]; va_list ap; va_start(ap, fmt);
    vsnprintf(b, sizeof b, fmt, ap); va_end(ap);
    printf("  [mem.log] %s\n", b);
}

static int fails;
#define CHECK(cond, msg) do { \
    if (!(cond)) { printf("FAIL  %s\n", msg); fails++; } \
    else         { printf("ok    %s\n", msg); } } while (0)

/* 等监控线程至少走过 2 个周期（feed 后确保已采样） */
static void settle_ms(int m) { usleep((useconds_t)m * 1000u); }

int main(void)
{
    /* 用 env 设定短周期（50ms）与干净阈值，加速确定性判定 */
    setenv("NCM_MEM_WATCH_PERIOD_MS", "50", 1);
    setenv("NCM_MEM_WATCH_HIGH_KB", "30720", 1);      /* 30MB */
    setenv("NCM_MEM_WATCH_LOW_KB", "20480", 1);       /* 20MB */
    setenv("NCM_MEM_WATCH_CRITICAL_KB", "40960", 1);  /* 40MB */

    if (mem_watch_start() != 0) { printf("FAIL  mem_watch_start\n"); return 1; }
    printf("started (period=50ms H=30M L=20M C=40M)\n");

    /* 1) 正常区 */
    mem_watch_set_forced_kb(10000);
    settle_ms(150);
    CHECK(mem_watch_level() == NCM_MEM_LVL_NORMAL, "level==NORMAL @10MB");

    /* 2) 升到 HIGH */
    mem_watch_set_forced_kb(35000);
    settle_ms(150);
    CHECK(mem_watch_level() == NCM_MEM_LVL_HIGH, "level==HIGH @35MB");

    /* 3) 升到 CRITICAL */
    mem_watch_set_forced_kb(45000);
    settle_ms(150);
    CHECK(mem_watch_level() == NCM_MEM_LVL_CRITICAL, "level==CRITICAL @45MB");

    /* 4) 滞回：落在 LOW..HIGH 之间 -> 保持 CRITICAL（防抖动） */
    mem_watch_set_forced_kb(25000);
    settle_ms(150);
    CHECK(mem_watch_level() == NCM_MEM_LVL_CRITICAL, "level stays CRITICAL @25MB (hysteresis)");

    /* 5) 回到正常：低于 LOW -> NORMAL */
    mem_watch_set_forced_kb(15000);
    settle_ms(150);
    CHECK(mem_watch_level() == NCM_MEM_LVL_NORMAL, "level==NORMAL @15MB");

    /* 6) 调度器释放钩子：song_end 重置峰值 + song_begin 起算 + rss_anon 反映注入值 */
    mem_watch_set_forced_kb(20000);
    settle_ms(100);
    mem_watch_song_begin();
    mem_watch_set_forced_kb(37000);   /* 本曲峰值冲到 37MB */
    settle_ms(100);
    long anon = mem_watch_rss_anon_kb();
    CHECK(anon == 37000, "rss_anon_kb reflects forced value");
    mem_watch_song_end();             /* 释放钩子：落峰值+重置 */
    settle_ms(100);
    mem_watch_song_begin();
    mem_watch_set_forced_kb(12000);   /* 新曲：峰值应从新起算 */
    settle_ms(100);
    CHECK(mem_watch_level() == NCM_MEM_LVL_NORMAL, "after song_end+begin, level resets to NORMAL");

    mem_watch_stop();
    printf("mem_watch_sim: %s\n", fails ? "FAIL" : "PASS");
    return fails ? 1 : 0;
}