/* ui/browser.c — 目录浏览页（ACT_BROWSER，根页）view + 控制器。
 *
 * 职责：
 *   - 持有目录态（g_cur 当前目录 / g_entries 缓存快照 / g_err 空态码）；
 *   - 内容区用 SDK 结构化列表（meow_listview，§5.5 W_LISTVIEW）虚拟化渲染
 *     「图标 + 名称 + 大小/时间 + 右侧 ⋯ 操作钮」行：行数据源 browser_src2 逐行填充
 *     meow_list_item（icon_kind=目录/文件符号、副标题=大小/时间、right=⋯）。滚动/选中命中由
 *     SDK 收口（视口裁剪、局部 dirty、disabled 不响应），App 只在 on_tap/touch_move 驱动
 *     scroll/sel 并分发：行体=进目录/开预览；右侧 ⋯ → BottomSheet；**长按=SDK 通用长按事件
 *     （§6.3，≥500ms 未抬手且位移≤容忍）** 由 SDK 判定后经 on_long_press 回调带坐标交给本页，
 *     App 据此行命中打开同一 BottomSheet（App 层长按计时逻辑已删，交给 SDK）；
 *   - 空态/错误（无卡/空目录/权限）与底部信息行用 meow_draw_custom_register 注册为非控件绘制物
 *     （app_draw_empty / app_draw_footer）——列表视口不含页脚，行不压页脚；invalidate/paint_full
 *     自动重画它们；
 *   - 写操作只经 logic（fsx_*），且在卡内校验后执行。
 *
 * 颜色全部读 meow_theme_get() 语义色（§8.1），不硬编码。
 */
#include "files_internal.h"

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

typedef struct { meow_view *view; int active; } browser_ctrl;
static browser_ctrl g_bc;

static fsx_entry g_entries[FSX_MAX_ENTRIES];
static int       g_n;               /* 当前目录项数 */
static char      g_cur[FSX_MAX_PATH];
static int       g_err;             /* fsx_scan_dir 返回（0=ok，<0=空态码） */
static int       g_press_row;       /* 按下行（-1=无）；按下高亮 + 拖动识别（长按已交 SDK §6.3） */
static int       g_press_delta;     /* 按下后累计位移（>阈值清除按下高亮） */
static int       g_dragging;        /* 本次触摸起点是否在列表（拖动滚列表） */
static int       g_drag_last_y;     /* 拖拽上一帧 y */

static meow_widget *g_tb;           /* TopAppBar（chrome） */
static meow_widget *g_list;         /* 内容区结构化列表（meow_listview，W_LISTVIEW） */
static app_rect_t   r_content;      /* 顶部栏之下 → 屏底（含页脚带） */
static app_rect_t   r_list;         /* 列表视口 = 内容区去掉页脚带（行不压页脚） */
static int          g_empty_id;     /* 空态/错误绘制物（非控件） */
static int          g_footer_id;    /* 底部信息行绘制物（非控件） */
static char         g_title[FSX_MAX_PATH];

/* 预览/操作辅助（前向声明） */
static void browser_open_sheet(int row);
void        browser_on_long_press(int x, int y);   /* 跨 TU（app.c 经 §6.3 回调调用）；files_internal.h */
static void browser_enter_dir(const char *path);
static void browser_open_file(const char *path);
static void browser_rename_entry(const fsx_entry *e);
static void browser_delete_entry(const fsx_entry *e);
static void browser_props_entry(const fsx_entry *e);
static void browser_new_folder_in(const char *dirpath);
static void browser_report_ret(int r);

/* 本轮按下状态复位（每次 on_tap / on_touch_down 前清）。 */
static void browser_drag_reset(void)
{
    g_press_row = -1;
    g_press_delta = 0;
    g_dragging = 0;
    g_drag_last_y = 0;
}

/* ---- 列表行数据源：逐行填 meow_list_item（图标/名称/大小时间/⋯ ），轻量不 IO（§5.5）---- */
static int browser_src2(int idx, meow_list_item *out, void *ctx)
{
    (void)ctx;
    if (idx < 0 || idx >= g_n) return 0;
    fsx_entry *e = &g_entries[idx];
    static char sub[FSX_MAX_NAME + 48];   /* 行内瞬时字符串（绘制即刻用，重复填充无碍） */
    char sz[32], tm[32];
    out->icon_kind = e->is_dir ? MEOW_LIST_ICON_FOLDER : MEOW_LIST_ICON_FILE;
    out->title = e->name;
    if (e->is_dir) {
        fsx_fmt_time(e->mtime, tm, sizeof tm);
        snprintf(sub, sizeof sub, "Folder   %s", tm);
    } else {
        fsx_fmt_size(e->size, sz, sizeof sz);
        fsx_fmt_time(e->mtime, tm, sizeof tm);
        snprintf(sub, sizeof sub, "%s   %s", sz, tm);
    }
    out->subtitle = sub;
    out->right  = MEOW_LIST_RIGHT_MORE;   /* 右侧 ⋯ 详情钮（行右 1/3 判操作） */
    out->on     = 0;
    out->enabled = 1;
    return 1;
}

/* ---- 空态/错误绘制物（非控件；非空态时无输出）----
 * ⚠️ custom 绘制物无 owner 闸门（不同于 widget，见 meow_ui_draw.c draw_order）：
 * 必须显式按「本页是否为当前 active activity」守门，否则切到 viewer 页会跨页泄漏绘制。 */
static void browser_draw_empty(void *ctx)
{
    (void)ctx;
    if (meow_ui_activity_active() != ACT_BROWSER) return;   /* 非本页 active 不画（防跨页泄漏） */
    if (g_err == 0 && g_n != 0) return;
    if (g_err == FSX_ERR_NOENT)
        app_draw_empty(r_list, "NO STORAGE CARD", "insert a TF card / mount sd_0");
    else if (g_err == FSX_ERR_EACCES)
        app_draw_empty(r_list, "ACCESS DENIED", "cannot read this folder");
    else if (g_err)
        app_draw_empty(r_list, "CANNOT OPEN", "unexpected error");
    else
        app_draw_empty(r_list, "EMPTY FOLDER", g_cur);
}

/* ---- 底部信息行绘制物（非控件）：项数/路径/截断提示 ---- */
static void browser_draw_footer(void *ctx)
{
    (void)ctx;
    if (meow_ui_activity_active() != ACT_BROWSER) return;   /* 非本页 active 不画（防跨页泄漏） */
    if (g_err != 0) return;
    char foot[96];
    if (g_n == 0)
        snprintf(foot, sizeof foot, "0 items");
    else if (g_n >= FSX_MAX_ENTRIES)
        snprintf(foot, sizeof foot, "%d items (showing first %d)", g_n, FSX_MAX_ENTRIES);
    else
        snprintf(foot, sizeof foot, "%d items   %s", g_n, g_cur);
    app_draw_footer(r_content, foot);
}

/* ---- 导航 ---- */

static void browser_update_title(void)
{
    const char *name = fsx_basename(g_cur);
    if (fsx_is_root(g_cur)) snprintf(g_title, sizeof g_title, "SD Card");
    else                    snprintf(g_title, sizeof g_title, "%s", name);
    if (g_title[0] == '\0') snprintf(g_title, sizeof g_title, "Files");
    if (g_tb) meow_topappbar_set_title(g_tb, g_title);
}

void browser_reload(void)
{
    int r = fsx_scan_dir(g_cur, g_entries, FSX_MAX_ENTRIES, &g_n);
    g_err = (r < 0) ? r : 0;
    if (g_err != 0) g_n = 0;
    if (g_list) {
        meow_listview_set_count(g_list, g_n);   /* 行数动态更新（§5.5） */
        meow_listview_set_scroll(g_list, 0);
        meow_listview_set_sel(g_list, -1);
    }
    browser_update_title();
    const meow_theme *th = meow_theme_get();
    meow_ui_set_page_bg(th->bg);
    meow_ui_paint_full();   /* 重画全注册绘制物（行/空态/页脚/topbar） */
}

void browser_enter_dir(const char *path)
{
    if (!path) return;
    strncpy(g_cur, path, sizeof g_cur - 1);
    g_cur[sizeof g_cur - 1] = '\0';
    browser_reload();
}

int browser_go_up(void)
{
    if (fsx_is_root(g_cur)) return 0;
    char up[FSX_MAX_PATH];
    if (fsx_dirname(g_cur, up, sizeof up) != 0) return 0;
    browser_enter_dir(up);
    return 1;
}

int browser_at_root(void) { return fsx_is_root(g_cur); }
int browser_is_active(void) { return g_bc.active; }
const char *browser_current_dir(void) { return g_cur; }
int browser_entry_count(void) { return g_n; }

/* ---- 行操作 ---- */

static void browser_report_ret(int r)
{
    if (r == 0) return;
    const char *msg = strerror(-r);
    meow_dialog *d = meow_dialog_create(MEOW_DLG_INFO, "Action failed");
    const char *msgs[1];
    msgs[0] = msg ? msg : "error";
    meow_dialog_set_items(d, msgs, 1, -1);
    meow_dialog_show(d);
    meow_dialog_free(d);
}

static void browser_rename_entry(const fsx_entry *e)
{
    meow_ime_ctx ime;
    memset(&ime, 0, sizeof ime);
    ime.mode = MEOW_IME_ASCII;
    strncpy(ime.buf, e->name, sizeof ime.buf - 1);
    ime.maxlen = 120;
    meow_ui_text_input(&ime);
    char nb[FSX_MAX_NAME];
    if (fsx_sanitize_name(ime.buf, nb, sizeof nb) == 0 && strcmp(ime.buf, e->name) != 0) {
        int r = fsx_rename_into(e->path, nb);
        browser_report_ret(r);
    }
}

static void browser_delete_entry(const fsx_entry *e)
{
    char m[192];
    snprintf(m, sizeof m, "Really delete \"%s\"%s?",
             e->name, e->is_dir ? " (folder must be empty)" : "");
    meow_dialog *d = meow_dialog_create(MEOW_DLG_CONFIRM, "Delete");
    const char *msgs[1];
    msgs[0] = m;
    meow_dialog_set_items(d, msgs, 1, -1);
    int yes = meow_dialog_confirm(d);
    meow_dialog_free(d);
    if (yes) { int r = fsx_delete(e->path); browser_report_ret(r); }
}

static void browser_props_entry(const fsx_entry *e)
{
    fsx_entry st;
    if (fsx_stat_path(e->path, &st) != 0) return;
    char size[32], tm[32], l1[64], l2[64], l3[64];
    fsx_fmt_size(st.size, size, sizeof size);
    fsx_fmt_time(st.mtime, tm, sizeof tm);
    snprintf(l1, sizeof l1, "Type: %s", st.is_dir ? "Directory" : "File");
    snprintf(l2, sizeof l2, "Size: %s", st.is_dir ? "-" : size);
    snprintf(l3, sizeof l3, "Modified: %s", tm);
    const char *msgs[3];
    msgs[0] = l1; msgs[1] = l2; msgs[2] = l3;
    meow_dialog *d = meow_dialog_create(MEOW_DLG_INFO, st.name);
    meow_dialog_set_items(d, msgs, 3, -1);
    meow_dialog_show(d);
    meow_dialog_free(d);
}

static void browser_new_folder_in(const char *dirpath)
{
    meow_ime_ctx ime;
    memset(&ime, 0, sizeof ime);
    ime.mode = MEOW_IME_ASCII;
    ime.maxlen = 120;
    meow_ui_text_input(&ime);
    char nb[FSX_MAX_NAME];
    if (fsx_sanitize_name(ime.buf, nb, sizeof nb) == 0) {
        int r = fsx_mkdir(dirpath, nb);
        browser_report_ret(r);
        if (r == 0 && browser_is_active()) browser_reload();
    }
}

static void browser_new_folder(void)  /* 当前目录下新建 */
{
    browser_new_folder_in(g_cur);
}

/* BottomSheet：按行类型建不同选项清单。 */
static void browser_open_sheet(int row)
{
    fsx_entry *e = &g_entries[row];
    char title[128];
    snprintf(title, sizeof title, "%s: %s", e->is_dir ? "Folder" : "File", e->name);

    meow_sheet *s = meow_sheet_create(title, 0);
    if (e->is_dir) {
        meow_sheet_add_item(s, "Open");
        meow_sheet_add_item(s, "New Folder");
        meow_sheet_add_item(s, "Rename");
        meow_sheet_add_item(s, "Delete");
        meow_sheet_add_item(s, "Properties");
    } else {
        meow_sheet_add_item(s, "Open");
        meow_sheet_add_item(s, "Rename");
        meow_sheet_add_item(s, "Delete");
        meow_sheet_add_item(s, "Properties");
    }
    int op = meow_sheet_open(s);
    meow_sheet_free(s);

    if (op < 0) return;
    if (op == 0) {                                   /* Open */
        if (e->is_dir) browser_enter_dir(e->path);
        else           browser_open_file(e->path);
    } else if (e->is_dir) {
        if (op == 1) browser_new_folder_in(e->path);
        else if (op == 2) browser_rename_entry(e);
        else if (op == 3) browser_delete_entry(e);
        else if (op == 4) browser_props_entry(e);
    } else {
        if (op == 1) browser_rename_entry(e);
        else if (op == 2) browser_delete_entry(e);
        else if (op == 3) browser_props_entry(e);
    }
    if (browser_is_active()) browser_reload();       /* 写操作后重扫（Open 文件时 viewer 前台则跳过） */
}

/* 打开文件：文本→预览页；否则提示。 */
static void browser_open_file(const char *path)
{
    if (fsx_is_text_path(path)) {
        if (viewer_open_file(path) == 0) return;     /* 已 push 预览页 */
        browser_report_ret(-EIO);
        return;
    }
    meow_dialog *d = meow_dialog_create(MEOW_DLG_INFO, "Preview");
    const char *msgs[1];
    msgs[0] = "This is not a text file.\nNo preview available.";
    meow_dialog_set_items(d, msgs, 1, -1);
    meow_dialog_show(d);
    meow_dialog_free(d);
}

/* ---- 输入分发 ---- */

int browser_on_tap(int x, int y)
{
    if (g_tb) {
        int ah = meow_topappbar_hit(g_tb, x, y);
        if (ah == MEOW_TOPBAR_BACK) { browser_drag_reset(); browser_go_up(); return 1; }
        if (ah >= 0) { browser_drag_reset(); browser_new_folder(); return 1; }   /* NEW */
    }
    if (g_err != 0 || g_n == 0) return 0;
    if (meow_widget_hit(g_list, x, y)) {
        int row = meow_listview_hit(g_list, x, y);   /* 行号（含滚动换算；禁用行 -1） */
        if (row < 0) { browser_drag_reset(); return 1; }   /* 命中列表但无有效行（空隙） */
        int op = meow_listview_hit_op(g_list, x, y);       /* 行右 1/3 = 操作区 */
        if (op) {
            if (!picker_active()) browser_open_sheet(row);   /* §6.2 二期：picker 模式不弹 sheet */
        } else {
            fsx_entry *e = &g_entries[row];
            if (e->is_dir) browser_enter_dir(e->path);
            else if (picker_active()) picker_return_file(e->path);   /* picker：点文件=返回路径 */
            else           browser_open_file(e->path);
        }
        browser_drag_reset();
        return 1;
    }
    return 0;
}

/* 触摸拖拽滚动（滚列表不滚页；topbar 不拖）。 */
void browser_touch_down(int x, int y)
{
    browser_drag_reset();
    if (g_err != 0 || g_n == 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;
            meow_listview_set_sel(g_list, row);   /* 按下高亮（§5.8.3 selected） */
        }
        g_dragging = 1;
        g_drag_last_y = y;
        meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
    }
}

void browser_touch_move(int x, int y)
{
    (void)x;
    if (!g_dragging) return;
    if (g_press_row >= 0) {                          /* 拖动超阈值：清除按下高亮 */
        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;
            meow_listview_set_sel(g_list, -1);       /* 拖动清除按下高亮 */
        }
    }
    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);            /* set_scroll 内部 clamp 到 [0,max] */
    if (meow_listview_scroll(g_list) != before)
        meow_ui_invalidate(r_list.x, r_list.y, r_list.w, r_list.h);
}

void browser_swipe(int dir, int dist)
{
    if (dir != MEOW_SWIPE_UP && dir != MEOW_SWIPE_DOWN) return;
    if (g_err != 0 || g_n == 0) return;
    int del = (dir == MEOW_SWIPE_UP) ? dist : -dist;  /* 上滑→显示更低内容 */
    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);
}

/* SDK 通用长按（§6.3，≥阈值未抬手且位移≤容忍）→ 打开该行 BottomSheet。
 * App 层长按计时已删（g_press_ms/g_press_tapped 移除）；长按触发后 SDK 已抑制其抬手
 * TAP（不再触发行体/打开动作），故这里无需再吞后续 tap；打开前清按下高亮与拖动态。 */
void browser_on_long_press(int x, int y)
{
    if (picker_active()) return;   /* §6.2 二期：picker 模式无长按 BottomSheet */
    if (g_err != 0 || g_n == 0) return;
    if (!meow_widget_hit(g_list, x, y)) return;
    int row = meow_listview_hit(g_list, x, y);
    if (row < 0) return;
    g_press_row = -1;
    g_dragging = 0;
    meow_listview_set_sel(g_list, -1);   /* 清除按下高亮（sheet 打开在即） */
    browser_open_sheet(row);             /* 内部：写操作后自行 reload */
}

/* ---- 页 view 生命周期 ---- */

static void browser_page_create(meow_view *v, void *ctx)
{
    (void)v;
    ((browser_ctrl *)ctx)->view = v;
    r_content = app_content_rect();
    r_list = AR(r_content.x, r_content.y, r_content.w, r_content.h - APP_FOOTER_H);
    if (r_list.h < 0) r_list.h = 0;
    strncpy(g_cur, FSX_SD_ROOT, sizeof g_cur - 1);
    g_cur[sizeof g_cur - 1] = '\0';
    /* §6.2 二期：picker 模式 topbar 标题「Pick a file」且无 NEW 动作（点文件即选）。 */
    if (picker_active())
        g_tb = app_topbar_create("Pick a file", 1, NULL);
    else
        g_tb = app_topbar_create("Files", 1, "NEW");
    /* 结构化列表：行数据源 browser_src2；单选模式（行高亮用 selected，§5.8.3） */
    g_list = meow_listview_create(r_list.x, r_list.y, r_list.w, r_list.h, 0,
                                  browser_src2, NULL, MEOW_LIST_SEL_SINGLE);
    meow_listview_set_item_h(g_list, APP_ROW_H);
    /* 空态/页脚注册为非控件绘制物（列表视口不含页脚；invalidate/paint_full 自动重画） */
    g_empty_id  = meow_draw_custom_register(1, r_list.x, r_list.y, r_list.w, r_list.h,
                                            browser_draw_empty, NULL);
    g_footer_id = meow_draw_custom_register(1, r_content.x, r_content.y + r_content.h - APP_FOOTER_H,
                                            r_content.w, APP_FOOTER_H, browser_draw_footer, NULL);
    g_press_row = -1;
    browser_reload();   /* 扫首个目录（count/scroll/sel 由 reload 写入 listview） */
}

static void browser_page_enter(meow_view *v, void *ctx)
{
    (void)v;
    ((browser_ctrl *)ctx)->active = 1;
    const meow_theme *th = meow_theme_get();
    meow_ui_set_page_bg(th->bg);
    meow_ui_paint_full();
}

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

static void browser_page_destroy(meow_view *v, void *ctx)
{
    (void)v; (void)ctx;
    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 *browser_view_create(void)
{
    static const meow_view_hooks h = {
        .on_create  = browser_page_create,
        .on_enter   = browser_page_enter,
        .on_leave   = browser_page_leave,
        .on_destroy = browser_page_destroy,
    };
    return meow_view_create(ACT_BROWSER, MEOW_VIEW_ACTIVITY, &h, &g_bc);
}