/* app/shelf.c — 书架：扫 TF 卡 `Books/`，识别 TXT/FB2/EPUB/MOBI/CBZ（R1 仅 TXT 可开，
 * 其它显示「R2 支持」占位）；MD3 布局（meow_topappbar + list/grid）+ 最近阅读置顶 + 段头分组。
 *
 * 布局（README §3.2，用户 2026-09-04 拍板）：
 *   - 默认 list（meow_listview_set_container(on) MD3 圆角卡），可切 grid（meow_lazygrid 4 列封面卡）；
 *     布局存 reader.conf `ui.shelf_layout`（rdconf_get()->shelf）；
 *   - 顶栏 meow_topappbar：标题「书架」+ 动作（布局切换 / 刷新 / App 设置入口）；
 *   - 无书也渲染完整骨架（顶栏 + 内容区 + 居中空态卡 + 指引 + 支持格式）；
 *   - 封面：MVP 无封面提取（engine F1）；无则圆角占位（surfaceContainerHigh + 格式徽标）。
 */
#include "../reader_internal.h"
#include "progress.h"
#include "reader_conf.h"
#include "meow_ui_internal.h"   /* meow_gfx_fill_round（宫格卡圆角填充） */
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

#define SHELF_APPBAR_H 56
#define SHELF_LIST_X   0
#define SHELF_LIST_W   480

typedef struct shelf_book {
    char  path[400];
    char  title[128];
    char  sub[160];
    int   fmt;          /* 0 txt,1 fb2,2 epub,3 mobi,4 cbz */
    long  size;
    uint64_t ts;        /* 最近阅读 unix；无=0 */
} shelf_book;

static shelf_book g_books[256];
static int        g_nbooks;
static int        g_active;
static meow_widget *g_list;      /* listview（布局=list） */
static meow_lazygrid *g_grid;    /* lazygrid（布局=grid） */
static meow_widget *g_appbar;    /* meow_topappbar */
static int        g_layout;      /* 0=list 1=grid（读 rdconf->shelf） */
static uint32_t    g_bg, g_fg, g_dim;
static char        g_notice[160];   /* 提示（opendir 失败等） */
static int         g_notice_ms;     /* 剩余显示 ms（0=无） */

/* 段头行（list 模式）：把扫描结果排队为 [段头(fmt), 书, 书, ..., 段头, ...]。
 * 书量小用段头（README §3.2），格式分组（TXT/FB2/EPUB/MOBI/CBZ）。 */
#define SHELF_MAX_ROWS 520
typedef struct shelf_row { char section; int fmt; int book; } shelf_row;
static shelf_row g_rows[SHELF_MAX_ROWS];
static int       g_nrows;

static const char *fmt_name(int f)
{
    switch (f) { case 0: return "TXT"; case 1: return "FB2"; case 2: return "EPUB";
                 case 3: return "MOBI"; case 4: return "CBZ"; default: return "?"; }
}
static int fmt_from_ext(const char *name)
{
    const char *d = strrchr(name, '.');
    if (!d) return -1;
    if (strcasecmp(d, ".txt") == 0) return 0;
    if (strcasecmp(d, ".fb2") == 0) return 1;
    if (strcasecmp(d, ".epub") == 0) return 2;
    if (strcasecmp(d, ".mobi") == 0) return 3;
    if (strcasecmp(d, ".cbz") == 0) return 4;
    return -1;
}
static void fmt_size(char *out, int outsz, long s)
{
    if (s >= 1 << 20) snprintf(out, outsz, "%.1fMB", (double)s / (1 << 20));
    else if (s >= 1 << 10) snprintf(out, outsz, "%.0fKB", (double)s / (1 << 10));
    else snprintf(out, outsz, "%ldB", s);
}

static int cmp_recent_then_name(const void *a, const void *b)
{
    const shelf_book *x = (const shelf_book *)a, *y = (const shelf_book *)b;
    if (x->ts != y->ts) return (x->ts < y->ts) ? 1 : -1;   /* 最近在前 */
    return strcasecmp(x->title, y->title);
}

/* 递归收集 Books/ 下（含子目录，深度 ≤2）的书。只在 scan_books 里调用。 */
static void scan_dir(const char *dir, int depth)
{
    if (depth > 2) return;                 /* 防深嵌套/循环 */
    DIR *dp = opendir(dir);
    if (!dp) return;
    struct dirent *de;
    while ((de = readdir(dp)) && g_nbooks < 256) {
        if (de->d_name[0] == '.') continue;
        char path[256];
        if (snprintf(path, sizeof path, "%s/%s", dir, de->d_name) >= (int)sizeof path) continue;
        struct stat st;
        if (stat(path, &st) != 0) continue;
        if (S_ISDIR(st.st_mode)) { scan_dir(path, depth + 1); continue; }
        int f = fmt_from_ext(de->d_name);
        if (f < 0) continue;
        shelf_book *b = &g_books[g_nbooks];
        snprintf(b->path, sizeof b->path, "%s", path);
        strncpy(b->title, de->d_name, sizeof b->title - 1); b->title[sizeof b->title - 1] = 0;
        char *dot = strrchr(b->title, '.');
        if (dot) *dot = 0;                     /* 标题去扩展名 */
        b->fmt = f;
        b->size = (long)st.st_size;
        rdprog p;
        b->ts = (rdprog_load(b->path, &p) == 1) ? p.ts : 0;
        char sz[24]; fmt_size(sz, sizeof sz, b->size);
        snprintf(b->sub, sizeof b->sub, "%s  ·  %s%s", fmt_name(f), sz,
                 b->ts ? "  ·  读" : "");
        g_nbooks++;
    }
    closedir(dp);
}

static void scan_books(void)
{
    const char *dir = READER_SD_ROOT "/Books";
    g_nbooks = 0;
    DIR *dp = opendir(dir);
    if (!dp) {
        snprintf(g_notice, sizeof g_notice, "未找到 %s 目录，请放入书籍（TXT）", dir);
        g_notice_ms = 4000;
        return;
    }
    closedir(dp);
    scan_dir(dir, 0);                        /* 递归：含 Books/<子目录>/ 下书籍（用户可能按目录组织） */
    qsort(g_books, (size_t)g_nbooks, sizeof(shelf_book), cmp_recent_then_name);
}

/* 排队段头（按格式）：为 list 模式生成 [段头(fmt) | 书] 序列。 */
static void build_rows(void)
{
    g_nrows = 0;
    static const int fmts[] = { 0, 1, 2, 3, 4 };
    for (size_t fi = 0; fi < sizeof fmts / sizeof fmts[0]; fi++) {
        int fmt = fmts[fi];
        int have = 0;
        if (g_nrows >= SHELF_MAX_ROWS) break;
        for (int i = 0; i < g_nbooks; i++) {
            if (g_books[i].fmt != fmt) continue;
            if (!have) {
                if (g_nrows >= SHELF_MAX_ROWS) break;
                g_rows[g_nrows].section = 1; g_rows[g_nrows].fmt = fmt; g_rows[g_nrows].book = -1;
                g_nrows++;
                have = 1;
            }
            if (g_nrows >= SHELF_MAX_ROWS) break;
            g_rows[g_nrows].section = 0; g_rows[g_nrows].fmt = fmt; g_rows[g_nrows].book = i;
            g_nrows++;
        }
    }
}

/* ---- list 数据源（vsource + 段头；container on） ---- */
static int shelf_list_count(void *ctx) { (void)ctx; return g_nrows; }
static void shelf_list_bind(int idx, meow_lv_item *item, void *ctx)
{
    (void)ctx;
    item->icon = NULL;
    item->icon_kind = MEOW_LIST_ICON_NONE;
    item->right = MEOW_LIST_RIGHT_NONE;
    item->on = 0;
    item->enabled = 1;
    item->user = NULL;
    item->title = NULL;
    item->subtitle = NULL;
    item->section = 0;
    if (idx < 0 || idx >= g_nrows) return;
    if (g_rows[idx].section) {
        item->section = 1;
        item->title = fmt_name(g_rows[idx].fmt);
        item->enabled = 0;
    } else {
        int bi = g_rows[idx].book;
        if (bi < 0 || bi >= g_nbooks) return;
        item->title = g_books[bi].title;
        item->subtitle = g_books[bi].sub;
        item->icon_kind = MEOW_LIST_ICON_FILE;
        item->right = MEOW_LIST_RIGHT_ARROW;
    }
}
static void shelf_list_tapcb(int idx, int op, void *ctx)
{
    (void)op; (void)ctx;
    if (idx < 0 || idx >= g_nrows || g_rows[idx].section) return;
    int bi = g_rows[idx].book;
    if (bi < 0 || bi >= g_nbooks) return;
    /* 点书开读：reader_open 打开书（含页位图）→ push ACT_READER 让阅读页成为 view activity，
     * 驱动 reader_on_enter/on_leave（重建/释放页位图）；「返回书架」/左缘返回走 page_pop 回书架。 */
    if (reader_open(g_books[bi].path) == 0) meow_view_page_push(ACT_READER);
}

/* ---- grid 数据源（meow_lazygrid，4 列封面卡） ---- */
static int shelf_grid_count(void *ctx) { (void)ctx; return g_nbooks; }
static void shelf_grid_bind(int idx, meow_lazygrid_item *item, void *ctx)
{
    (void)ctx;
    item->title = NULL; item->subtitle = NULL; item->icon = NULL;
    item->enabled = 1; item->user = NULL;
    if (idx < 0 || idx >= g_nbooks) return;
    item->title = g_books[idx].title;
    item->subtitle = g_books[idx].sub;
}
/* 标题截断（格内防溢出）：按字节收窄（UTF-8 截断可能断码，但仅显示用，断码由字库兜底为 tofu；
 * 更稳妥在这里按格子宽度自适应——MVP 简单截 8 字节 + "…"）。 */
static void grid_title_cut(const char *src, char *out, int outsz)
{
    int n = 0;
    while (src[n] && n < (int)sizeof g_books[0].title - 1 && n < 7 * 3) n++;   /* ≤7 个 3 字节字 */
    if ((size_t)n >= strlen(src)) { strncpy(out, src, (size_t)outsz - 1); out[outsz - 1] = 0; return; }
    int m = n; while (m > 0 && ((unsigned char)src[m]) > 0x7F && m > n - 2) m--;   /* 断码回退 */
    if (m < 0) m = 0;
    strncpy(out, src, (size_t)m); out[m] = 0;
    size_t L = strlen(out);
    if (L + 4 < (size_t)outsz) { out[L] = ' '; out[L + 1] = ' '; out[L + 2] = '.'; out[L + 3] = '.'; out[L + 4] = '.';
        out[L + 5] = 0; }
}
static void shelf_grid_draw(int index, int x, int y, int w, int h, int state, void *ctx)
{
    (void)ctx;
    const meow_theme *th = meow_theme_get();
    if (index < 0 || index >= g_nbooks) return;
    const shelf_book *b = &g_books[index];
    uint32_t card = th->surfaceContainerLow;
    if (state & MEOW_LAZYGRID_ST_SELECTED) card = th->primaryContainer;
    meow_gfx_fill_round(x, y, w, h, th->radius_card, card);
    int pad = 8;
    int cw = w - 2 * pad, chh = h - 2 * pad - meow_ui_text_height(16) - 6;
    int cx = x + pad, cy = y + pad;
    if (cw > 0 && chh > 0) {
        meow_gfx_fill_round(cx, cy, cw, chh, MEOW_SHAPE_SMALL, th->surfaceContainerHigh);
        /* 格式徽标（居中） */
        char fc[16]; int fs = 24;
        snprintf(fc, sizeof fc, "%s", fmt_name(b->fmt));
        meow_ui_text_center(cx + cw / 2, cy + (chh - meow_ui_text_height(fs)) / 2, fc, fs, th->primary);
    }
    char t[128]; grid_title_cut(b->title, t, sizeof t);
    meow_ui_text_center(x + w / 2, y + h - meow_ui_text_height(16) - 2, t, 16, th->onSurface);
    if (state & MEOW_LAZYGRID_ST_SELECTED) {
        meow_gfx_fill_round_alpha(x, y, w, h, th->radius_card, th->primary, 26);
    }
}
static void shelf_grid_tapcb(int idx, void *ctx)
{
    (void)ctx;
    if (idx < 0 || idx >= g_nbooks) return;
    if (reader_open(g_books[idx].path) == 0) meow_view_page_push(ACT_READER);
}

/* ---- 控件装配（按当前布局重建 list / grid） ---- */
static void shelf_build_content(void)
{
    const meow_theme *th = meow_theme_get();
    int sbh = meow_ui_statusbar_height();
    int top = sbh + SHELF_APPBAR_H;
    int list_y = top + 22;              /* 副题区下 */
    int list_h = 720 - list_y;
    if (list_h < 0) list_h = 0;

    if (g_list) { meow_widget_free(g_list); g_list = NULL; }
    if (g_grid) { meow_lazygrid_free(g_grid); g_grid = NULL; }

    if (g_layout == 1) {                /* grid */
        int cols = 4, gap = 8;
        int cw = (SHELF_LIST_W - (cols + 1) * 8) / cols;   /* 16 边距 */
        int chh = cw + 30;               /* 封面 + 标题 */
        g_grid = meow_lazygrid_create(SHELF_LIST_X, list_y, SHELF_LIST_W, list_h, cols, cw, chh, gap);
        if (g_grid) {
            meow_lazygrid_set_vsource(g_grid, shelf_grid_count, shelf_grid_bind, NULL);
            meow_lazygrid_set_item_draw(g_grid, shelf_grid_draw, NULL);
            meow_lazygrid_set_on_tap(g_grid, shelf_grid_tapcb, NULL);
        }
    } else {                             /* list */
        g_list = meow_listview_create(SHELF_LIST_X, list_y, SHELF_LIST_W, list_h,
                                      g_nrows, NULL, NULL, MEOW_LIST_SEL_SINGLE);
        if (g_list) {
            meow_listview_set_vsource(g_list, shelf_list_count, shelf_list_bind, NULL);
            meow_listview_set_container(g_list, 1);
            meow_listview_set_item_tier(g_list, 2);
            meow_listview_set_on_tap(g_list, shelf_list_tapcb, NULL);
        }
    }
    (void)th;
}

/* 顶栏动作：0=布局切换 1=刷新 2=设置。布局切换动作标签 = 将切换到的布局。 */
static void shelf_appbar_build(void)
{
    int sbh = meow_ui_statusbar_height();
    if (g_appbar) { meow_widget_free(g_appbar); g_appbar = NULL; }
    g_appbar = meow_topappbar_create(0, sbh, 480, SHELF_APPBAR_H, "书架");
    if (!g_appbar) return;
    meow_topappbar_add_action(g_appbar, g_layout ? "列表" : "宫格");  /* 0 布局切换 */
    meow_topappbar_add_action(g_appbar, "刷新");                      /* 1 刷新 */
    meow_topappbar_add_action(g_appbar, "设置");                      /* 2 设置 */
    meow_topappbar_set_item_icon(g_appbar, 1, MEOW_ICON_REFRESH);
    meow_topappbar_set_item_icon(g_appbar, 2, MEOW_ICON_SETTINGS);
}

/* view 生命周期 */
static void shelf_on_create(meow_view *v, void *ctx) { (void)v; (void)ctx; }
static void shelf_on_enter(meow_view *v, void *ctx)
{
    (void)v; (void)ctx;
    g_active = 1;
    scan_books();                     /* 回到书架即重扫（新增/最近读置顶刷新） */
    build_rows();
    const meow_theme *th = meow_theme_get();
    g_bg = th->bg; g_fg = th->fg; g_dim = th->dim;

    /* 布局：读 reader.conf ui.shelf_layout（A） */
    const rdconf *c = rdconf_get();
    g_layout = (c && c->shelf[0] && strcmp(c->shelf, "grid") == 0) ? 1 : 0;

    shelf_appbar_build();
    shelf_build_content();
    shelf_redraw();
}
static void shelf_on_leave(meow_view *v, void *ctx) { (void)v; (void)ctx; g_active = 0; }
static void shelf_on_destroy(meow_view *v, void *ctx)
{
    (void)v; (void)ctx;
    if (g_list) { meow_widget_free(g_list); g_list = NULL; }
    if (g_grid) { meow_lazygrid_free(g_grid); g_grid = NULL; }
    if (g_appbar) { meow_widget_free(g_appbar); g_appbar = NULL; }
}

meow_view *shelf_view_create(void)
{
    static meow_view_hooks hooks = { shelf_on_create, shelf_on_enter, shelf_on_leave,
                                     shelf_on_destroy, NULL, NULL, NULL };
    return meow_view_create(ACT_SHELF, MEOW_VIEW_ACTIVITY, &hooks, NULL);
}

int shelf_is_active(void) { return g_active; }

/* 切换 list/grid（书架顶栏「布局切换」动作；改 reader.conf 并重建）。 */
void shelf_set_view(int grid)
{
    rdconf *c = rdconf_get();
    if (!c) return;
    strcpy(c->shelf, grid ? "grid" : "list");
    rdconf_persist();
    g_layout = grid ? 1 : 0;
    if (g_active) {
        shelf_appbar_build();
        shelf_build_content();
        shelf_redraw();
    }
}

void shelf_redraw(void)
{
    const meow_theme *th = meow_theme_get();
    g_bg = th->bg; g_fg = th->fg; g_dim = th->dim;
    meow_ui_clear(g_bg);
    if (g_appbar) meow_widget_draw(g_appbar);

    /* 副题：Books/ · N 本（有书时显示格式说明；无书并入空态卡） */
    if (g_nbooks > 0) {
        char sub[96]; snprintf(sub, sizeof sub, "Books/ · %d 本", g_nbooks);
        int sbh = meow_ui_statusbar_height();
        meow_ui_text(24, sbh + SHELF_APPBAR_H + 3, sub, 16, g_dim);
    }

    if (g_nbooks > 0) {
        if (g_list) meow_widget_draw(g_list);
        if (g_grid) meow_lazygrid_draw(g_grid, th);
    } else {
        /* 无书也渲染完整骨架（顶栏已在）+ 居中空态卡 + 指引 + 支持格式 */
        int sbh = meow_ui_statusbar_height();
        int top = sbh + SHELF_APPBAR_H;
        int area_h = 720 - top;
        int cw = 360, chh = 200;
        int cx = (480 - cw) / 2;
        int cy = top + (area_h - chh) / 2;
        if (cy < top) cy = top;
        meow_gfx_fill_round(cx, cy, cw, chh, th->radius_card, th->surfaceContainer);
        meow_ui_text_center(480 / 2, cy + 40, "书架为空", 28, th->fg);
        meow_ui_text_center(480 / 2, cy + 76, "请往 TF 卡 Books/ 放书籍", 20, th->onSurfaceVariant);
        meow_ui_text_center(480 / 2, cy + 104, "支持 TXT / FB2 / EPUB / MOBI / CBZ", 20, th->onSurfaceVariant);
        /* 「去放书」文本按钮（提示） */
        meow_ui_text_center(480 / 2, cy + 150, "Books/ 目录", 20, th->primary);
    }
    if (g_notice_ms > 0) {
        meow_ui_fill_rect(0, 620, 480, 44, g_bg);
        meow_ui_text(20, 630, g_notice, 20, th->primary);
    }
    meow_ui_flush();
}

int shelf_on_tap(int x, int y)
{
    /* 顶栏动作先命中 */
    if (g_appbar) {
        int bi = meow_topappbar_hit(g_appbar, x, y);
        if (bi == 0) {              /* 布局切换 */
            shelf_set_view(g_layout ? 0 : 1);
            return 1;
        } else if (bi == 1) {       /* 刷新：重扫 */
            scan_books(); build_rows();
            shelf_build_content();
            shelf_redraw();
            return 1;
        } else if (bi == 2) {       /* App 设置入口 */
            meow_view_page_push(ACT_SETTINGS);
            return 1;
        }
    }
    if (g_nbooks <= 0) { shelf_redraw(); return 0; }
    if (g_layout == 1 && g_grid) {
        int idx = meow_lazygrid_tap_at(g_grid, x, y);
        if (idx >= 0) shelf_redraw();
        return 0;
    }
    if (g_list) {
        int idx = meow_listview_tap_at(g_list, x, y);
        if (idx >= 0) shelf_redraw();
        return 0;
    }
    return 0;
}

/* 书架的滚动（list/grid；app.c on_swipe 路由到本页时调用）。 */
void shelf_on_swipe(int dir, int dx, int dy)
{
    (void)dir; (void)dx;
    if (g_nbooks <= 0) return;
    if (g_layout == 1 && g_grid) { meow_lazygrid_scroll_by(g_grid, dy); meow_lazygrid_draw(g_grid, meow_theme_get()); meow_ui_flush(); }
    else if (g_list) { meow_listview_scroll_by(g_list, dy); meow_widget_draw(g_list); meow_ui_flush(); }
}