/* 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 / g_scroll）；
 *   - 内容区用 meow_widget_custom_create 自绘「虚拟化列表」：只画可见行（fsx_visible_range），
 *     行=图标(目录/文件)+名称+大小/时间+右侧 ⋯ 操作钮；不一次全读进内存（entries 有界缓存）；
 *   - 空态/错误（无卡/空目录/权限）由 render_cb 内 app_draw_empty 画；
 *   - 触摸：行 body=进目录/开预览；右侧操作钮或长按 → BottomSheet（删除/重命名/新建/属性）；
 *   - 滑动：LEFT=返回上级（App 层处理）；UP/DOWN=列表滚动（本页）；
 *   - 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_scroll;          /* 列表滚动（px） */
static int       g_sel;             /* 当前选中行（-1=无） */
static int       g_press_row;       /* 按下行（-1=无）；长按检测 */
static uint64_t  g_press_ms;
static int       g_press_tapped;    /* 长按已消费本按 */
static int       g_press_delta;     /* 按下后累计位移（>阈值取消长按） */
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;         /* 内容区虚拟化列表（custom widget） */
static app_rect_t   r_content;
static char         g_title[FSX_MAX_PATH];

/* 预览/操作辅助（前向声明） */
static void browser_open_sheet(int row);
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_tapped = 0;
    g_press_delta = 0;
    g_dragging = 0;
    g_drag_last_y = 0;
}

/* ---- 通用文本绘制：宽度限 maxw 内截断（超出加 "..."）---- */
static void browser_text_trunc(int x, int y, const char *s, int maxw, int size, uint32_t col)
{
    int full = meow_ui_text_width(s, size);
    if (full <= maxw) { meow_ui_text(x, y, s, size, col); return; }
    const char *dots = "...";
    int dw = meow_ui_text_width(dots, size);
    char tmp[FSX_MAX_NAME + 4];
    int i;
    for (i = 0; s[i] && i < FSX_MAX_NAME - 4; i++) {
        tmp[i] = s[i];
        tmp[i + 1] = '\0';
        if (meow_ui_text_width(tmp, size) > maxw - dw) break;
    }
    if (i >= FSX_MAX_NAME - 4) i = FSX_MAX_NAME - 4;
    memcpy(tmp + i, dots, 4);
    meow_ui_text(x, y, tmp, size, col);
}

/* ---- 列表行图标：目录=filled 矩形+页签；文件=空心矩形+折角 ---- */
static void browser_draw_icon(const meow_theme *th, int x, int y, int is_dir, int sel)
{
    uint32_t col = sel ? 0xFFFFFF : (is_dir ? th->primary : th->onSurfaceVariant);
    if (is_dir) {
        meow_ui_fill_rect(x, y + 6, 26, 18, col);            /* 主体 */
        meow_ui_fill_rect(x, y + 2, 12, 6, col);             /* 页签 */
    } else {
        meow_ui_draw_rect(x + 4, y + 4, 18, 22, col);        /* 页体 */
        meow_ui_fill_rect(x + 4, y + 4, 7, 4, col);          /* 文件名横条 */
    }
}

/* 行区视口高（底部留页脚，行不压到页脚）。 */
static int browser_vp_h(void) { return r_content.h - APP_FOOTER_H; }

/* ---- 列表 render_cb：虚拟化画可见行 + 空态 + 页脚 ---- */
static void browser_render(meow_widget *w, const meow_theme *th, void *ctx)
{
    (void)w; (void)ctx;
    /* 空态/错误 */
    if (g_err != 0) {
        if (g_err == FSX_ERR_NOENT)
            app_draw_empty(r_content, "NO STORAGE CARD", "insert a TF card / mount sd_0");
        else if (g_err == FSX_ERR_EACCES)
            app_draw_empty(r_content, "ACCESS DENIED", "cannot read this folder");
        else
            app_draw_empty(r_content, "CANNOT OPEN", "unexpected error");
        return;
    }
    if (g_n == 0) {
        app_draw_empty(r_content, "EMPTY FOLDER", g_cur);
        app_draw_footer(r_content, "0 items");
        return;
    }

    int vp = browser_vp_h();
    int first, last;
    fsx_visible_range(g_n, APP_ROW_H, g_scroll, vp, &first, &last);
    int thh = meow_ui_text_height(th->font_body);
    int namew = r_content.w - APP_PAD - APP_ICON_W - APP_PAD - APP_OP_W - APP_PAD; /* 名称区 */
    char size[32], tm[32];

    for (int i = first; i < last; i++) {
        fsx_entry *e = &g_entries[i];
        int ry = r_content.y + (i * APP_ROW_H - g_scroll);
        if (ry + APP_ROW_H <= r_content.y) continue;
        if (ry >= r_content.y + vp) break;

        int hilite = (i == g_sel || i == g_press_row);
        if (hilite) meow_ui_fill_rect(r_content.x, ry, r_content.w, APP_ROW_H, th->primary);

        browser_draw_icon(th, r_content.x + APP_PAD, ry + (APP_ROW_H - 24) / 2, e->is_dir, hilite);

        uint32_t namecol = hilite ? 0xFFFFFF : th->onSurface;
        uint32_t subcol  = hilite ? 0xFFFFFF : th->dim;
        browser_text_trunc(r_content.x + APP_PAD + APP_ICON_W + APP_PAD, ry + 6,
                           e->name, namew, th->font_body, namecol);

        if (e->is_dir) {
            fsx_fmt_time(e->mtime, tm, sizeof tm);
            snprintf(size, sizeof size, "Folder   %s", tm);
        } else {
            fsx_fmt_size(e->size, size, sizeof size);
            fsx_fmt_time(e->mtime, tm, sizeof tm);
            snprintf(size, sizeof size, "%s   %s", size, tm);
        }
        browser_text_trunc(r_content.x + APP_PAD + APP_ICON_W + APP_PAD, ry + 6 + thh + 2,
                           size, namew, 20, subcol);

        /* 右侧 ⋯ 操作钮（三个点） */
        int ox = r_content.x + r_content.w - APP_OP_W / 2 - 1;
        int oy = ry + APP_ROW_H / 2 - 8;
        for (int d = 0; d < 3; d++)
            meow_ui_fill_rect(ox, oy + d * 6, 4, 4, hilite ? 0xFFFFFF : th->onSurfaceVariant);

        /* 分隔线 */
        int sy = ry + APP_ROW_H - 1;
        if (sy >= r_content.y && sy < r_content.y + r_content.h)
            meow_ui_fill_rect(r_content.x, sy, r_content.w, 1, th->outlineVariant);
    }

    char foot[96];
    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);
}

/* 列表 hit_cb：落点是否在内容区（行判定在 on_tap 里做）。 */
static int browser_hit(meow_widget *w, int x, int y, void *ctx)
{
    (void)w; (void)ctx;
    return x >= r_content.x && x < r_content.x + r_content.w &&
           y >= r_content.y && y < r_content.y + r_content.h;
}

/* ---- 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;
    g_scroll = 0;
    g_sel = -1;
    browser_update_title();
    const meow_theme *th = meow_theme_get();
    meow_ui_set_page_bg(th->bg);
    meow_ui_paint_full();
}

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_press_tapped) { browser_drag_reset(); return 1; }
    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 op = (x >= r_content.x + r_content.w - APP_OP_W);
        int row = (y - r_content.y + g_scroll) / APP_ROW_H;
        if (row < 0 || row >= g_n) { browser_drag_reset(); return 1; }
        g_sel = row;
        if (op) browser_open_sheet(row);
        else {
            fsx_entry *e = &g_entries[row];
            if (e->is_dir) browser_enter_dir(e->path);
            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 = (y - r_content.y + g_scroll) / APP_ROW_H;
        if (row >= 0 && row < g_n) {
            g_press_row = row;
            g_press_ms = meow_ui_time_ms();
        }
        g_dragging = 1;
        g_drag_last_y = y;
        meow_ui_invalidate(r_content.x, r_content.y, r_content.w, r_content.h);
    }
}

void browser_touch_move(int x, int y)
{
    (void)x;
    if (!g_dragging) return;
    if (g_press_row >= 0) {                          /* 拖动取消长按 */
        int d = y - g_drag_last_y;
        if (d < 0) d = -d;
        if (d > 0) 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 ns = g_scroll - dy;
    int ms = fsx_max_scroll(g_n, APP_ROW_H, browser_vp_h());
    if (ns < 0) ns = 0;
    if (ns > ms) ns = ms;
    if (ns != g_scroll) {
        g_scroll = ns;
        meow_ui_invalidate(r_content.x, r_content.y, r_content.w, r_content.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 ns = g_scroll + del;
    int ms = fsx_max_scroll(g_n, APP_ROW_H, browser_vp_h());
    if (ns < 0) ns = 0;
    if (ns > ms) ns = ms;
    if (ns != g_scroll) {
        g_scroll = ns;
        meow_ui_invalidate(r_content.x, r_content.y, r_content.w, r_content.h);
    }
}

/* on_tick：长按（≥500ms 未拖动）→ 打开该行 BottomSheet。 */
void browser_tick(uint64_t now)
{
    if (g_press_row >= 0 && !g_press_tapped && now - g_press_ms >= 500) {
        g_press_tapped = 1;
        int row = g_press_row;
        g_press_row = -1;
        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();
    strncpy(g_cur, FSX_SD_ROOT, sizeof g_cur - 1);
    g_cur[sizeof g_cur - 1] = '\0';
    g_tb = app_topbar_create("Files", 1, "NEW");
    g_list = meow_widget_custom_create(r_content.x, r_content.y, r_content.w, r_content.h,
                                       browser_render, browser_hit, NULL);
    g_sel = -1;
    g_press_row = -1;
    browser_reload();
}

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_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);
}