/* test_meow_ui_scroll.c — §12.3 meow_scroll 滚动物理宿主验证：
 * 跟手拖动（track 跟随与 clamp）、速度跟踪→松手 fling（位移序列/停止位置/单调/不越界）、
 * 边界过冲 clamp + 简单回弹、snap。时间推进用真实 usleep（meow_anim_tick 驱动 fling）。
 *
 * 编译（宿主 gcc，链真实 gfx/sys/theme/vol/log/widget/draw/activity/ime + 打桩 font/global）：
 *   gcc -o test_meow_ui_scroll test_meow_ui_scroll.c test_host_stub.c \
 *       meow_ui_gfx.c meow_ui_sys.c meow_ui_theme.c meow_ui_vol.c meow_ui_log.c \
 *       meow_ui_widget.c meow_ui_input.c meow_ui_activity.c meow_ui_dialog.c meow_ui_ime.c meow_ui_str.c \
 *       meow_pinyin.c meow_ui_draw.c meow_ui_view.c meow_ui_box.c meow_ui_anim.c meow_ui_scroll.c \
 *       meow_ui_img.c meow_ui_media.c meow_notify_ipc.c stb_image.c \
 *       -I. -I../meow_launcherd -DMEOW_UI_HOST_TEST -pthread -lm
 * 运行：./test_meow_ui_scroll
 */
#include "meow_ui.h"
#include "meow_ui_internal.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static int g_pass = 0, g_fail = 0;
#define CHECK(cond, ...) do { \
    if (cond) { g_pass++; } \
    else { g_fail++; printf("FAIL %s:%d  ", __FILE__, __LINE__); printf(__VA_ARGS__); printf("\n"); } \
} while (0)

#define LIST_H 400
#define ITEM_H 44
#define COUNT 50
/* max_scroll = COUNT*ITEM_H - LIST_H = 2200 - 400 = 1800 */
#define MAXS (COUNT * ITEM_H - LIST_H)

static int src(int idx, char *label, int len, void *ctx)
{
    (void)ctx;
    if (idx < 0 || idx >= COUNT) return 0;
    snprintf(label, (size_t)len, "row %d", idx);
    return 1;
}

static meow_widget *make_list(void)
{
    meow_widget *lv = meow_list_create(0, 0, 480, LIST_H, COUNT, src, NULL);
    meow_list_set_item_h(lv, ITEM_H);
    return lv;
}

/* 喂一串向下（正）速度采样，模拟快速下划 */
static void feed_drag(meow_scroll *s, int step, int n)
{
    uint64_t now = meow_ui_time_ms();
    for (int i = 0; i < n; i++) {
        meow_scroll_track(s, step, now + (uint64_t)i * 16);
    }
    /* 最后用一个真实稍晚时刻的 track 让采样时间戳真实（保持一致钟） */
    meow_scroll_track(s, 0, meow_ui_time_ms());
}

static void pump_until_idle(meow_scroll *s, int *max_off, int *mono_ok)
{
    int prev = meow_scroll_offset(s);
    int guard = 0;
    while (meow_scroll_active(s) && guard++ < 300) {
        meow_anim_tick();
        int cur = meow_scroll_offset(s);
        if (*max_off < cur) *max_off = cur;
        if (cur < prev) *mono_ok = 0;   /* 下划 fling 应单调不减（回弹段除外：此处只测无回弹） */
        prev = cur;
        usleep(10000);
    }
    meow_anim_tick();
}

static void test_track_follow(void)
{
    meow_widget *lv = make_list();
    meow_scroll *s = meow_scroll_wrap(lv, 0);
    CHECK(s != NULL, "wrap");
    CHECK(meow_scroll_offset(s) == 0, "init offset 0");
    meow_scroll_track(s, 10, meow_ui_time_ms());
    CHECK(meow_scroll_offset(s) == 10, "follow +10 got %d", meow_scroll_offset(s));
    /* 超量拖到底：clamp 到 max */
    meow_scroll_track(s, 100000, meow_ui_time_ms());
    CHECK(meow_scroll_offset(s) == MAXS, "clamp to max got %d", meow_scroll_offset(s));
    meow_scroll_free(s);
    meow_widget_free(lv);
}

static void test_fling_no_boundary(void)
{
    meow_widget *lv = make_list();
    meow_scroll *s = meow_scroll_wrap(lv, 0);
    /* 从 0 起拖 ~300px，建正初速 */
    uint64_t t = meow_ui_time_ms();
    for (int i = 0; i < 12; i++) meow_scroll_track(s, 25, t + (uint64_t)i * 16);
    int start = meow_scroll_offset(s);
    CHECK(start > 0, "dragged start>0 got %d", start);
    meow_scroll_fling(s);
    CHECK(meow_scroll_active(s) == 1, "fling active");
    int max_off = start, mono = 1, prev = start;
    int guard = 0;
    while (meow_scroll_active(s) && guard++ < 300) {
        meow_anim_tick();
        int cur = meow_scroll_offset(s);
        if (max_off < cur) max_off = cur;
        if (cur < prev) mono = 0;
        prev = cur;
        usleep(10000);
    }
    meow_anim_tick();
    int end = meow_scroll_offset(s);
    CHECK(mono == 1, "monotonic non-decreasing during fling");
    CHECK(end >= start, "fling advances end=%d start=%d", end, start);
    CHECK(end <= MAXS, "no overflow end=%d max=%d", end, MAXS);
    CHECK(meow_scroll_active(s) == 0, "settles idle");
    meow_scroll_free(s);
    meow_widget_free(lv);
}

static void test_fling_boundary_bounce(void)
{
    meow_widget *lv = make_list();
    meow_scroll *s = meow_scroll_wrap(lv, 0);
    /* 先拖到近底（~1700） */
    meow_list_set_scroll(lv, 1700);
    /* 快速下划，冲过底界 */
    uint64_t t = meow_ui_time_ms();
    for (int i = 0; i < 8; i++) meow_scroll_track(s, 40, t + (uint64_t)i * 16);
    meow_scroll_fling(s);
    int max_off = 0, mono = 1;
    pump_until_idle(s, &max_off, &mono);
    int end = meow_scroll_offset(s);
    CHECK(max_off <= MAXS, "never exceed max, max_off=%d max=%d", max_off, MAXS);
    CHECK(end == MAXS, "bounce settles at bottom end=%d", end);   /* 回弹后回到底 */
    CHECK(meow_scroll_active(s) == 0, "idle after bounce");
    meow_scroll_free(s);
    meow_widget_free(lv);
}

static void test_snap(void)
{
    meow_widget *lv = make_list();
    meow_scroll *s = meow_scroll_wrap(lv, 0);
    meow_scroll_set_snap(s, ITEM_H);   /* 吸附到行边界 */
    /* 慢拖到某非边界位置并给 small velocity → fling 结束 snap 到行倍数 */
    uint64_t t = meow_ui_time_ms();
    for (int i = 0; i < 6; i++) meow_scroll_track(s, 20, t + (uint64_t)i * 16);
    meow_scroll_fling(s);
    int max_off = 0, mono = 1;
    pump_until_idle(s, &max_off, &mono);
    int end = meow_scroll_offset(s);
    CHECK((end % ITEM_H) == 0, "snap to item multiple got %d", end);
    CHECK(end <= MAXS, "snap in range %d", end);
    meow_scroll_free(s);
    meow_widget_free(lv);
}

static void test_stop(void)
{
    meow_widget *lv = make_list();
    meow_scroll *s = meow_scroll_wrap(lv, 0);
    uint64_t t = meow_ui_time_ms();
    for (int i = 0; i < 6; i++) meow_scroll_track(s, 20, t + (uint64_t)i * 16);
    meow_scroll_fling(s);
    CHECK(meow_scroll_active(s) == 1, "fling active (stop test)");
    meow_scroll_stop(s);
    CHECK(meow_scroll_active(s) == 0, "stopped immediately");
    meow_scroll_free(s);
    meow_widget_free(lv);
}

int main(void)
{
    meow_ui_opts o = { 480, 720 };
    if (meow_ui_init(&o) != 0) { printf("init failed\n"); return 1; }
    test_track_follow();
    test_fling_no_boundary();
    test_fling_boundary_bounce();
    test_snap();
    test_stop();
    meow_ui_shutdown();
    printf("scroll: %d pass / %d fail\n", g_pass, g_fail);
    return g_fail ? 1 : 0;
}