/* ui/cache.c — 已缓存列表页（ACT_CACHE，首页顶栏「已缓存」钮进入）。
 *
 * 数据源：songs/ 音频池（键=歌曲ID+请求档位，NCM_CACHE_DESIGN §2.5）。扫描在 worker：
 *   ncm_cache_scan（读目录 + 文件头 tag + 音频参数探测）→ appstate 快照；
 *   UI 线程只读快照（零磁盘 IO），列表由 meow_listview 虚拟化。
 * 行：歌名 / 歌手 · **实际档位** · 大小。**档位显示实际档而非请求档**：缓存名里的档位段只是
 * 请求档（真机存在 song_<id>_hires.mp3 = 无损请求被降级链落到 exhigh mp3），实际档由
 * 文件头（FLAC bps/采样率、MP3 首帧码率）推断。
 * 交互：点行=点播（NCM_QUEUE_CACHE，上/下一首在缓存列表内循环）；行右「删除」=单曲删除；
 * 顶栏「清空」=清空缓存池（确认框，与设置页「清理缓存」同语义）。
 * 主题/控件惯例同 queue.c：圆角卡 + 红 mini-vinyl + 按压红条 + 当前播放行高亮。
 * 左缘返回=弹回首页（app.c）。
 */
#include "../ncm_app_internal.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <pthread.h>

typedef struct { meow_view *view; int active; } cache_ctrl;
static cache_ctrl g_cc;

static meow_widget *g_tb, *g_list;
static ncm_rect_t   r_cont, r_list;
static int          g_bg_id, g_draw_id, g_empty_id, g_footer_id;
static int          g_press_row, g_press_delta, g_dragging, g_drag_last_y;
static int          g_last_count;

/* 扫描 worker（磁盘 IO 不进 UI 线程；gen 计数做完成信号） */
static pthread_mutex_t g_cmu = PTHREAD_MUTEX_INITIALIZER;
static pthread_t       g_cthr;
static int             g_cthr_on;
static volatile int    g_cgen, g_cacked;
static volatile int    g_cloading;
static volatile int    g_cerr;

static void c_drag_reset(void)
{
    g_press_row = -1; g_press_delta = 0; g_dragging = 0; g_drag_last_y = 0;
}

/* 字节数 → "12.3 MB"（整数运算，不引浮点 printf；MIPS 软浮点省体积）。 */
static void fmt_size(uint64_t n, char *out, size_t sz)
{
    if (n >= (1024ULL * 1024ULL * 1024ULL)) {
        uint64_t t = (n * 10ULL + 512ULL * 1024ULL * 1024ULL) / (1024ULL * 1024ULL * 1024ULL);
        snprintf(out, sz, "%llu.%llu GB", (unsigned long long)(t / 10), (unsigned long long)(t % 10));
    } else if (n >= 1024ULL * 1024ULL) {
        uint64_t t = (n * 10ULL + 512ULL * 1024ULL) / (1024ULL * 1024ULL);
        snprintf(out, sz, "%llu.%llu MB", (unsigned long long)(t / 10), (unsigned long long)(t % 10));
    } else {
        snprintf(out, sz, "%llu KB", (unsigned long long)(n / 1024ULL));
    }
}

static const char *level_label(int lv)
{
    return (lv >= 0) ? ncm_level_name(lv) : "未知档";
}

/* 列表数据源（逐行快照读取，零 IO）。 */
static int c_src2(int idx, meow_list_item *out, void *ctx)
{
    (void)ctx;
    static ncm_cache_item_t it;
    static char sub[192];
    static char title[100];
    char sz[24];

    if (appstate_cache_item(idx, &it) != NCM_OK) return 0;
    fmt_size(it.size, sz, sizeof sz);
    snprintf(sub, sizeof sub, "%s · %s · %s",
             it.artist[0] ? it.artist : "-", level_label(it.actual_level), sz);
    snprintf(title, sizeof title, "%s", it.name[0] ? it.name : "（未知歌曲）");
    out->icon_kind = MEOW_LIST_ICON_NONE;      /* 图标槽由红 overlays 画迷你黑胶 */
    out->title = title;
    out->subtitle = sub;
    out->right  = MEOW_LIST_RIGHT_NONE;        /* 右侧「删除」由 z=60 叠层自绘 */
    out->on = 0; out->enabled = 1;
    return 1;
}

/* 行背景（z=5，画在 listview 文本之下）：圆角卡 + 当前播放行红色高亮。 */
static void c_row_bg(void *ctx)
{
    (void)ctx;
    if (meow_ui_activity_active() != ACT_CACHE) return;
    int cnt = appstate_cache_count();
    if (cnt <= 0) return;
    const meow_theme *th = meow_theme_get();
    const ncm_pal_t  *pa = ncm_palette(g_dark);
    int item  = APP_ROW_H;
    int off   = meow_listview_scroll(g_list);
    int first = off / item, last = (off + r_list.h) / item + 1;
    if (last > cnt) last = cnt;
    int cur = (appstate_get_queue() == NCM_QUEUE_CACHE) ? player_manager_playing_song() : -1;
    for (int i = first; i < last; i++) {
        int ry = ncm_row_card_y(item, i, off, r_list.y);
        int th2 = ncm_row_card_h(item);
        if (ry < r_list.y || ry + th2 > r_list.y + r_list.h) continue;   /* 只画完整落在视口内的行 */
        if (i == cur) {
            ncm_fill_round(r_list.x, ry, r_list.w, th2, 12, pa->red_ctr);
            meow_ui_fill_rect(r_list.x + 2, ry + 4, 4, th2 - 8, pa->red);
        } else {
            ncm_fill_round(r_list.x, ry, r_list.w, th2, 12, th->surfaceContainer);
        }
    }
}

/* 主绘制（z=60）：迷你黑胶缩略 + 行右「删除」+ 按压红条；文本由 listview z=10 画。 */
static void c_draw(void *ctx)
{
    (void)ctx;
    if (meow_ui_activity_active() != ACT_CACHE) return;
    const meow_theme *th = meow_theme_get();
    const ncm_pal_t *pa  = ncm_palette(g_dark);
    int cnt = appstate_cache_count();
    if (cnt <= 0) return;
    int item = APP_ROW_H, isz = 24;
    int off   = meow_listview_scroll(g_list);
    int first = off / item, last = (off + r_list.h) / item + 1;
    if (last > cnt) last = cnt;
    for (int i = first; i < last; i++) {
        int ry = ncm_row_card_y(item, i, off, r_list.y);
        int th2 = ncm_row_card_h(item);
        if (ry < r_list.y || ry + th2 > r_list.y + r_list.h) continue;
        int icy = ry + (th2 - isz) / 2, bx = r_list.x + 16;
        ncm_fill_round(bx, icy, isz, isz, 6, pa->red);
        meow_ui_fill_rect(bx + isz / 2 - 2, icy + isz / 2 - 2, 4, 4, pa->on_red);   /* 盘芯 */
        /* 行右「删除」（触达区 = 右 48px，见 cache_on_tap） */
        meow_ui_text_right(r_list.x + r_list.w - APP_PAD,
                           ry + (th2 - 18) / 2, "删除", 18, pa->red);
        if (g_press_row == i) {
            meow_ui_fill_rect(r_list.x, ry, 4, th2, pa->red);
            meow_ui_fill_rect_alpha(r_list.x, ry, r_list.w, th2, pa->red, 26);
        }
        /* 擦除 z=10 的 SDK 行分隔线（现落进卡片间空隙）：以页底色填空隙带；不越出列表视口底。 */
        int gy = ry + th2, gh = NCM_ROW_GAP;
        if (gy + gh > r_list.y + r_list.h) gh = r_list.y + r_list.h - gy;
        if (gh > 0) meow_ui_fill_rect(r_list.x, gy, r_list.w, gh, th->bg);
    }
}

static void c_draw_empty(void *ctx)
{
    (void)ctx;
    if (meow_ui_activity_active() != ACT_CACHE) return;
    if (appstate_cache_count() != 0) return;
    if (g_cloading) { ncm_draw_empty(r_list, "LOADING", "正在扫描缓存..."); return; }
    if (g_cerr)     { ncm_draw_empty(r_list, "ERROR", "缓存目录读取失败"); return; }
    ncm_draw_empty(r_list, "暂无缓存", "播放过的歌曲会自动缓存");
}

static void c_draw_footer(void *ctx)
{
    (void)ctx;
    if (meow_ui_activity_active() != ACT_CACHE) return;
    int n = appstate_cache_count();
    if (n <= 0) return;
    uint64_t total = 0;
    ncm_cache_item_t it;
    for (int i = 0; i < n; i++)
        if (appstate_cache_item(i, &it) == NCM_OK) total += it.size;
    char sz[24], foot[128];
    fmt_size(total, sz, sizeof sz);
    snprintf(foot, sizeof foot, "%d 首 · 合计 %s%s", n, sz,
             appstate_is_offline() ? " · 离线模式（可播放）" : "");
    ncm_draw_footer(r_cont, foot);
}

static void c_apply(void)
{
    if (!g_list) return;
    int n = appstate_cache_count();
    meow_listview_set_count(g_list, n);
    if (n != g_last_count) {
        g_last_count = n;
        meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
    }
    const meow_theme *th = meow_theme_get();
    meow_ui_set_page_bg(th->bg);
}

static void *cache_worker(void *arg)
{
    (void)arg;
    int rc = appstate_cache_list_load();   /* 扫描 + 文件内 tag + 旁路补名：全部磁盘 IO */
    pthread_mutex_lock(&g_cmu);
    g_cerr = (rc < 0) ? rc : 0;
    g_cloading = 0;
    g_cgen++;
    pthread_mutex_unlock(&g_cmu);
    return NULL;
}

void cache_reload(void)
{
    if (g_host_mock) {           /* 宿主渲染：同步扫描（无线程/无延时，截图确定） */
        int rc = appstate_cache_list_load();
        g_cerr = (rc < 0) ? rc : 0;
        g_cloading = 0;
        meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
        return;
    }
    if (g_cthr_on) return;
    g_cloading = 1;
    g_cthr_on = 1;
    if (ncm_thread_create(&g_cthr, cache_worker, NULL) != 0) {
        g_cthr_on = 0; g_cloading = 0;
        g_cerr = NCM_ERR_IO;
    }
    meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
}

/* 单曲删除（行右「删除」）：删文件 + 摘除快照项 + 提示。 */
static void cache_delete_row(int row)
{
    ncm_cache_item_t it;
    if (appstate_cache_item(row, &it) != NCM_OK) return;
    char name[96], msg[160];
    ncm_strlcpy(name, it.name[0] ? it.name : it.id, sizeof name);
    if (appstate_cache_remove(row) == 0) {
        snprintf(msg, sizeof msg, "已删除：%s", name);
        ncm_snack(msg);
        c_apply();
        meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
    } else {
        ncm_snack("删除失败");
    }
}

/* 清空（顶栏「清空」）：确认框（设置页「清理缓存」同语义：删除全部音频 + 封面缓存条目）。 */
static void cache_confirm_clear(void)
{
    int n = appstate_cache_count();
    if (n <= 0) { ncm_snack("缓存已为空"); return; }
    uint64_t total = 0;
    ncm_cache_item_t it;
    for (int i = 0; i < n; i++)
        if (appstate_cache_item(i, &it) == NCM_OK) total += it.size;
    char sz[24], msg[192];
    fmt_size(total, sz, sizeof sz);
    snprintf(msg, sizeof msg, "将删除全部 %d 首已缓存歌曲 (%s) 及封面缓存。\n已播放的歌曲需重新下载。",
             n, sz);
    meow_dialog *d = meow_dialog_create(MEOW_DLG_CONFIRM, "清空缓存？");
    const char *msgs[1];
    msgs[0] = msg;
    meow_dialog_set_items(d, msgs, 1, -1);
    int yes = meow_dialog_confirm(d);
    meow_dialog_free(d);
    if (!yes) return;
    appstate_cache_clear();
    ncm_snack("缓存已清理");
    c_apply();
    meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
}

void cache_open(void)
{
    meow_view_page_push(ACT_CACHE);
    cache_reload();
    c_apply();
    meow_ui_paint_full();
}

int cache_is_active(void) { return g_cc.active; }

int cache_on_tap(int x, int y)
{
    if (g_tb) {
        int ah = meow_topappbar_hit(g_tb, x, y);
        if (ah == MEOW_TOPBAR_BACK) { c_drag_reset(); meow_view_page_pop(); return 1; }
        if (ah == 0) { c_drag_reset(); cache_confirm_clear(); return 1; }   /* 文本动作「清空」 */
    }
    if (meow_widget_hit(g_list, x, y)) {
        int was_drag = (g_press_delta > 10);
        int row = (g_press_row >= 0) ? g_press_row : meow_listview_hit(g_list, x, y);
        int del = (x >= r_list.x + r_list.w - APP_OP_W);
        c_drag_reset();
        if (row < 0 || was_drag) return 1;
        if (del) { cache_delete_row(row); return 1; }
        player_play_cache_song(row);
        return 1;
    }
    return 0;
}

void cache_touch_down(int x, int y)
{
    c_drag_reset();
    if (appstate_cache_count() <= 0) return;
    if (meow_widget_hit(g_list, x, y)) {
        int row = meow_listview_hit(g_list, x, y);
        if (row >= 0) g_press_row = row;
        g_dragging = 1; g_drag_last_y = y;
        meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
    }
}

void cache_touch_move(int x, int y)
{
    (void)x;
    if (!g_dragging) return;
    if (g_press_row >= 0) {
        int d = y - g_drag_last_y; if (d < 0) d = -d;
        g_press_delta += d;
        if (g_press_delta > 10) g_press_row = -1;
    }
    int dy = y - g_drag_last_y; g_drag_last_y = y;
    if (dy == 0) return;
    int before = meow_listview_scroll(g_list);
    meow_listview_scroll_by(g_list, -dy);
    if (meow_listview_scroll(g_list) != before)
        meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
}

void cache_swipe(int dir, int dist)
{
    if (dir != MEOW_SWIPE_UP && dir != MEOW_SWIPE_DOWN) return;
    if (appstate_cache_count() <= 0) return;
    int del = (dir == MEOW_SWIPE_UP) ? dist : -dist;
    int before = meow_listview_scroll(g_list);
    meow_listview_scroll_by(g_list, del);
    if (meow_listview_scroll(g_list) != before)
        meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
}

void cache_tick(uint64_t now)
{
    (void)now;
    chrome_tick();
    if (!g_cc.active) return;
    if (!g_cthr_on) return;
    int gen, acked;
    pthread_mutex_lock(&g_cmu);
    gen = g_cgen; acked = g_cacked;
    pthread_mutex_unlock(&g_cmu);
    if (gen == acked) return;
    pthread_mutex_lock(&g_cmu);
    g_cacked = gen;
    pthread_mutex_unlock(&g_cmu);
    g_cthr_on = 0;
    if (g_cerr) ncm_snack("缓存读取失败");
    c_apply();
    meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
}

/* 生命周期 */
static void c_page_create(meow_view *v, void *ctx)
{
    (void)v;
    ((cache_ctrl *)ctx)->view = v;
    r_cont = ncm_content_rect();
    r_list = NR(16, r_cont.y + 8, r_cont.w - 32,
                r_cont.y + r_cont.h - APP_FOOTER_H - (r_cont.y + 8));
    if (r_list.h < 0) r_list.h = 0;
    meow_ui_activity_push(ACT_CACHE);
    g_tb = ncm_topbar_create("已缓存", 1, "清空");   /* 文本动作(动作0)=清空缓存 */
    g_list = meow_listview_create(r_list.x, r_list.y, r_list.w, r_list.h, 0,
                                  c_src2, NULL, MEOW_LIST_SEL_NONE);
    meow_listview_set_item_h(g_list, APP_ROW_H);
    meow_ui_activity_pop();
    meow_widget_set_z(g_list, 10);
    g_bg_id    = meow_draw_custom_register(5, r_list.x, r_list.y, r_list.w, r_list.h,
                                           c_row_bg, NULL);
    g_draw_id  = meow_draw_custom_register(60, r_cont.x, r_cont.y, r_cont.w, r_cont.h,
                                           c_draw, NULL);
    g_empty_id = meow_draw_custom_register(1, r_list.x, r_list.y, r_list.w, r_list.h,
                                           c_draw_empty, NULL);
    g_footer_id = meow_draw_custom_register(1, r_cont.x, r_cont.y + r_cont.h - APP_FOOTER_H,
                                            r_cont.w, APP_FOOTER_H, c_draw_footer, NULL);
    c_drag_reset();
}

static void c_page_enter(meow_view *v, void *ctx)
{
    (void)v;
    ((cache_ctrl *)ctx)->active = 1;
    const meow_theme *th = meow_theme_get();
    meow_ui_set_page_bg(th->bg);
    g_last_count = -1;
    cache_reload();          /* 每次进入重扫（播放/删除后 LRU 变化） */
    c_apply();
    meow_ui_paint_full();
}

static void c_page_leave(meow_view *v, void *ctx)
{
    (void)v;
    ((cache_ctrl *)ctx)->active = 0;
}

static void c_page_destroy(meow_view *v, void *ctx)
{
    (void)v; (void)ctx;
    if (g_bg_id)     { meow_draw_unregister(g_bg_id);     g_bg_id = 0; }
    if (g_draw_id)   { meow_draw_unregister(g_draw_id);   g_draw_id = 0; }
    if (g_empty_id)  { meow_draw_unregister(g_empty_id);  g_empty_id = 0; }
    if (g_footer_id) { meow_draw_unregister(g_footer_id); g_footer_id = 0; }
    if (g_list) { meow_widget_free(g_list); g_list = NULL; }
    if (g_tb)   { meow_widget_free(g_tb);   g_tb = NULL; }
}

meow_view *cache_view_create(void)
{
    static const meow_view_hooks h = {
        .on_create  = c_page_create,
        .on_enter   = c_page_enter,
        .on_leave   = c_page_leave,
        .on_destroy = c_page_destroy,
    };
    return meow_view_create(ACT_CACHE, MEOW_VIEW_ACTIVITY, &h, &g_cc);
}