/* bench/pagination_sim.c — 三期第三批 滑动窗口 基本语义离线回归（0 网络请求）。
 * （§14 版为「分页 append 到 NCM_SONG_MAX=1000 截断」回归；§17 起分页被滑动窗口取代，
 *  本文件随之改测兼容入口 appstate_load_playlist_songs_page 的新语义。）
 *
 * 直接驱动 App 的真实函数 appstate_load_playlist_songs_page()（app/logic/appstate.c），
 * 仅把两个网络端点（ncm_api_playlist_detail / ncm_api_song_detail）替换成本地 stub
 * （合成 trackIds / 合成歌曲对象），验证：
 *   ① offset=0 重建索引（song_ids[]←全量 trackIds，track_ids_count）并物化首段；
 *   ② offset>0 物化 [offset,offset+limit)（滑窗 + song_detail 批补载）；
 *   ③ 尾部（offset≥track_ids_count）无操作；④ 大歌单不再截断（索引全量 5191，
 *      窗口内有效槽位 ≤ NCM_SONG_WINDOW）；⑤ 占位/出窗槽 song_copy 失败、入窗成功。
 * 风控纪律：本验证 0 次真实 NCM 请求（离线 stub；cache_dir 置空 → songmeta 全部 miss/不落盘）。
 *
 * 编译（宿主）：$CC_HOST -O2 -ffunction-sections -DJSMN_HEADER -I. -I../sdk -I../meow_launcherd \
 *      -Icore -I../vendor/jsmn -c bench/pagination_sim.c -o /tmp/ps.o
 *      $CC_HOST -O2 -ffunction-sections -DJSMN_HEADER -I. -I../sdk -I../meow_launcherd \
 *      -Icore -I../vendor/jsmn -c app/logic/appstate.c -o /tmp/ps_app.o
 *      $CC_HOST -O2 -ffunction-sections -DJSMN_HEADER -I. -I../sdk -I../meow_launcherd \
 *      -Icore -I../vendor/jsmn -c app/logic/songmeta.c -o /tmp/ps_meta.o
 *      $CC_HOST -O2 -Wl,--gc-sections -o pagination_sim /tmp/ps.o /tmp/ps_app.o /tmp/ps_meta.o -lpthread
 * 运行：./pagination_sim  （0 网络；PASS/FAIL 退出码）
 */
#include "../app/ncm_app_internal.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

/* appstate.c 依赖的全局（app.c 提供；本 bench 只测窗口路径，仅 g_st 被用到） */
ncm_app_state_t g_st;
ncm_play_run_t  g_play = { .mu = PTHREAD_MUTEX_INITIALIZER, .state = NCM_PC_STOPPED, .cur_song = -1 };
volatile int g_app_quit = 0;
volatile int g_net_ready = 0;
int          g_host_mock = 0;

/* ncm_strlcpy：appstate_apply_playlist_cover 用到（从 core ncm_common 借；此处最小内联实现） */
size_t ncm_strlcpy(char *dst, const char *src, size_t sz)
{
    size_t n = 0;
    if (sz) {
        while (src[n] && n < sz - 1) { dst[n] = src[n]; n++; }
        dst[n] = 0;
    }
    while (src[n]) n++;
    return n;
}

/* ---- 网络端点 stub（离线，合成数据） ---- */
static int g_pid_total;      /* detail 应返回的 trackIds 总数（供测试注入） */
static int g_detail_calls;
static int g_song_calls;

int ncm_api_playlist_detail(const char *device_id, const char *cookie, const char *playlist_id,
                            char *name, size_t name_sz, char *cover, size_t cover_sz,
                            int64_t *ids, int id_cap, int *out_id_n)
{
    (void)device_id; (void)cookie; (void)cover_sz; (void)playlist_id;
    g_detail_calls++;
    if (name) snprintf(name, name_sz, "Sim Playlist");
    if (cover) cover[0] = 0;
    int n = (g_pid_total < id_cap) ? g_pid_total : id_cap;
    for (int i = 0; i < n; i++) ids[i] = 1000000LL + i;   /* 合成连续 id */
    *out_id_n = n;
    return NCM_OK;
}

int ncm_api_song_detail(const char *device_id, const char *cookie, const int64_t *ids, int n,
                        ncm_song_t *out, int max, int *out_n)
{
    (void)device_id; (void)cookie;
    g_song_calls++;
    int m = (n < max) ? n : max;
    for (int i = 0; i < m; i++) {
        snprintf(out[i].id, sizeof out[i].id, "%lld", (long long)ids[i]);
        snprintf(out[i].name, sizeof out[i].name, "Song%lld", (long long)ids[i]);
        snprintf(out[i].art_name, sizeof out[i].art_name, "Artist%lld", (long long)ids[i]);
        snprintf(out[i].al_pic, sizeof out[i].al_pic, "http://p.music.126.net/cov%lld.jpg", (long long)ids[i]);
    }
    *out_n = m;
    return NCM_OK;
}

/* ---- 驱动：重头 + 逐段 ensure 到尾部，返回 track_ids_count ---- */
static int load_all(int pid_total, int *detail_calls, int *song_calls)
{
    memset(&g_st, 0, sizeof g_st);
    g_st.playlist_count = 1;
    snprintf(g_st.playlists[0].id, sizeof g_st.playlists[0].id, "pl0");
    g_st.playlists[0].track_count = pid_total;
    g_pid_total = pid_total;
    g_detail_calls = 0; g_song_calls = 0;

    int rc = appstate_load_playlist_songs_page(0, 0, NCM_SONG_BATCH);
    if (rc != NCM_OK) { printf("  page0 rc=%d\n", rc); return -1; }
    for (int off = NCM_SONG_BATCH; off < g_st.track_ids_count; off += NCM_SONG_BATCH) {
        rc = appstate_load_playlist_songs_page(0, off, NCM_SONG_BATCH);
        if (rc != NCM_OK) { printf("  page(%d) rc=%d\n", off, rc); return -1; }
    }
    if (detail_calls) *detail_calls = g_detail_calls;
    if (song_calls)   *song_calls   = g_song_calls;
    return g_st.track_ids_count;
}

static int g_fail = 0;
#define CHECK(cond, fmt, ...) do { \
    if (cond) printf("  PASS  " fmt "\n", ##__VA_ARGS__); \
    else { printf("  FAIL  " fmt "\n", ##__VA_ARGS__); g_fail = 1; } \
} while (0)

int main(void)
{
    printf("ncm_song_t=%zuB  window=%zuKB(%d首)  trackIds idx=%zuKB(%d首)\n",
           sizeof(ncm_song_t),
           sizeof g_st.songs / 1024, NCM_SONG_WINDOW,
           sizeof g_st.song_ids / 1024, NCM_TRACKID_MAX);

    /* (a) 130 首（< 窗口）：读全程后 130 槽全有效（窗口装得下，无需滑窗）。 */
    printf("== case A: 130 songs (whole list fits window) ==\n");
    int dc = 0, sc = 0;
    int n = load_all(130, &dc, &sc);
    CHECK(n == 130, "track_ids_count=%d (expect 130)", n);
    CHECK(g_st.song_count == 130, "valid slots=%d (expect 130, all in window)", g_st.song_count);
    CHECK(g_st.window_base == 0, "window_base=%d (expect 0)", g_st.window_base);
    CHECK(dc == 1, "detail calls=%d (expect 1, index fetched once)", dc);
    CHECK(sc == 2, "song_detail calls=%d (expect 2 = batches 0-99 + 100-129)", sc);
    ncm_song_t sq;
    CHECK(appstate_song_copy(129, &sq) == 0 && strcmp(sq.name, "Song1000129") == 0,
          "last song copy name='%s'", sq.name);
    CHECK(sq.al_pic[0] != 0, "last song has al_pic='%s'", sq.al_pic);
    /* 越过尾部再 load：应无操作（不越界） */
    int rc = appstate_load_playlist_songs_page(0, 130, NCM_SONG_BATCH);
    CHECK(rc == NCM_OK && g_st.song_count == 130, "load past tail: rc=%d valid=%d", rc, g_st.song_count);

    /* (b) 5191 首（>> 窗口）：索引全量不截断（§17 取消 NCM_SONG_MAX=1000 上限），
     *     窗口有效槽恒 ≤ NCM_SONG_WINDOW，末段滑窗后末首可达。 */
    printf("== case B: 5191 songs (no cap; window slides) ==\n");
    dc = sc = 0;
    n = load_all(5191, &dc, &sc);
    CHECK(n == 5191, "track_ids_count=%d (expect 5191, 不再 1000 截断)", n);
    CHECK(g_st.song_count <= NCM_SONG_WINDOW, "valid slots=%d ≤ window %d", g_st.song_count, NCM_SONG_WINDOW);
    CHECK(dc == 1, "detail calls=%d", dc);
    CHECK(sc == (5191 + NCM_SONG_BATCH - 1) / NCM_SONG_BATCH,
          "song_detail calls=%d (expect %d grid batches)", sc, (5191 + NCM_SONG_BATCH - 1) / NCM_SONG_BATCH);
    CHECK(appstate_song_copy(5190, &sq) == 0 && strcmp(sq.name, "Song1005190") == 0,
          "tail song copy name='%s'", sq.name);
    CHECK(appstate_song_copy(0, &sq) != 0, "head song evicted (out of window) -> copy fails");
    /* 越界再 load：应 NCM_OK 但不动窗口 */
    int valid_before = g_st.song_count;
    rc = appstate_load_playlist_songs_page(0, 5191, NCM_SONG_BATCH);
    CHECK(rc == NCM_OK && g_st.song_count == valid_before, "load past tail: rc=%d valid=%d", rc, g_st.song_count);

    /* (c) 空歌单（0 首） */
    printf("== case C: empty playlist ==\n");
    n = load_all(0, &dc, &sc);
    CHECK(n == 0 && g_st.song_count == 0, "empty: track_ids_count=%d valid=%d", n, g_st.song_count);

    printf("%s\n", g_fail ? "RESULT: FAIL" : "RESULT: PASS");
    return g_fail ? 1 : 0;
}