/* demo_box_scroll.c — 宿主离屏 demo：§12.1 meow_box 布局 + §12.3 meow_scroll fling 端到端。
 * 渲染一屏「标题(固定) / 列表(weight 撑满) / 底栏(固定)」的 box 布局（cross 拉伸），
 * 再对列表跑一次 fling（速度跟踪→惯性滑动到停止处），并 dump PPM 供目检。
 *
 * 编译（宿主 gcc，链真实 SDK 源 + 打桩 font/global）：
 *   gcc -o demo_box_scroll demo_box_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_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：MEOW_UI_DUMP=/tmp/demo_box.ppm ./demo_box_scroll
 */
#include "meow_ui.h"
#include "meow_ui_internal.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define NROW 60
#define ITEM 44
static int src(int idx, char *label, int len, void *ctx)
{
    (void)ctx;
    if (idx < 0 || idx >= NROW) return 0;
    snprintf(label, (size_t)len, "item %d", idx);
    return 1;
}

int main(void)
{
    /* 离屏 dump */
    setenv("MEOW_UI_DUMP", "/tmp/demo_box.ppm", 1);
    meow_ui_opts o = { 480, 720 };
    if (meow_ui_init(&o) != 0) { printf("DEMO FAIL: init\n"); return 1; }
    const meow_theme *th = meow_theme_get();
    meow_ui_clear(th->bg);

    /* ---- box 布局：标题(固定) / 列表(weight) / 底栏(固定)，交叉轴拉伸 ---- */
    meow_box *bx = meow_box_new(MEOW_BOX_V);
    meow_box_set_rect(bx, 0, 0, 480, 720);
    meow_box_set_padding(bx, 12, 12, 12, 12);
    meow_box_set_gap(bx, 8);
    meow_box_set_align(bx, MEOW_BOX_ALIGN_START, MEOW_BOX_CROSS_STRETCH);

    meow_widget *header = meow_btn_create(0, 0, 480, 44, "Header (fixed)");
    meow_widget *list   = meow_list_create(0, 0, 480, 100, NROW, src, NULL);
    meow_list_set_item_h(list, ITEM);
    meow_widget *footer = meow_btn_create(0, 0, 480, 52, "Footer (fixed)");

    meow_box_add(bx, header, MEOW_BOX_FIXED, 0);
    meow_box_add(bx, list,   MEOW_BOX_WEIGHT, 1);
    meow_box_add(bx, footer, MEOW_BOX_FIXED, 0);
    meow_box_arrange(bx);

    int hr[4], lr[4], fr[4];
    meow_widget_rect(header, hr);
    meow_widget_rect(list,   lr);
    meow_widget_rect(footer, fr);
    printf("DEMO layout: header(%d,%d,%d,%d) list(%d,%d,%d,%d) footer(%d,%d,%d,%d)\n",
           hr[0], hr[1], hr[2], hr[3], lr[0], lr[1], lr[2], lr[3], fr[0], fr[1], fr[2], fr[3]);

    meow_widget_draw(header);
    meow_widget_draw(list);
    meow_widget_draw(footer);
    meow_ui_flush();   /* 上屏并 MEOW_UI_DUMP 写 PPM *//* （host 离屏无 fb → 只落盘） */

    /* ---- fling：对列表做一次惯性下滑（速度跟踪→减速→停）---- */
    meow_scroll *s = meow_scroll_wrap(list, 0);
    int maxs = meow_list_max_scroll(list);
    uint64_t t = meow_ui_time_ms();
    for (int i = 0; i < 14; i++) meow_scroll_track(s, 40, t + (uint64_t)i * 16);
    meow_scroll_fling(s);
    int guard = 0;
    while (meow_scroll_active(s) && guard++ < 300) { meow_anim_tick(); usleep(10000); }
    meow_anim_tick();
    int end = meow_scroll_offset(s);
    printf("DEMO fling: max_scroll=%d final=%d (active=%d)\n", maxs, end, meow_scroll_active(s));

    meow_scroll_free(s);
    meow_box_free(bx);
    meow_widget_free(list);
    meow_widget_free(header);
    meow_widget_free(footer);
    meow_ui_shutdown();
    printf("DEMO OK\n");
    return 0;
}