/* app/reader.c — 阅读页：W_CUSTOM 画布 + 三栏交互 + 中央菜单占位 + 顶栏进度/章节名 + 进度持久化。
 *
 * 渲染：W_CUSTOM 画布覆盖全屏；render_cb 画帧 = 填底色 → 翻页 blit（FreeType 页位图缓存 / 
 * 无字体则 SDK 位图字库兜底直绘）→ 顶栏 → 菜单覆盖层。翻页 = 局部脏区（flush_region）。
 * 交互：点击左/右 1/3 翻页；中央唤菜单（字号±/行距±/返回）；左滑=下一页、右滑=上一页。
 * 进度：打开自动续读；换字号重排回锚（段,字符偏移）；离开/翻页时保存。
 */
#include "../reader_internal.h"
#include "meow_ui_internal.h"     /* back_buf/pitch/bpp 访问器（决策见报告） */
#include "book.h"
#include "progress.h"
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <time.h>

#define RD_MENU_H 64
#define RD_MENU_BTN 6

static rd_book *g_book;
static int  g_reader_active;
static meow_widget *g_canvas;
static int  g_pw, g_ph, g_top, g_mx, g_my;
static int  g_fs, g_ls;
#define RD_PAGE_CACHE 3
#define RD_PAGE_SLOT_CUR 1
static uint16_t *g_page_buf[RD_PAGE_CACHE];  /* [0]=prev [1]=cur [2]=next（FreeType 页位图） */
static int  g_has_font;                  /* 1=FreeType 路径；0=SDK 字库兜底 */
static int  g_menu_open;
static int  g_dir_open;                  /* 目录覆盖层 */
static int  g_dir_top, g_dir_row_h;      /* 目录列表几何（rdsrc 目录项） */
static char g_font_path[400];
static int  g_notice_ms;

static uint32_t g_page_bg, g_page_fg;    /* 正文页底/字色（24bit） */
static char g_chapter[128];              /* 顶栏章节名（TXT 无章节=文件名） */

#define RD_READER_DEFAULT_FS 20
#define RD_READER_DEFAULT_LS 130

/* 前向声明（reader_reflow* 依赖 reader_refill/redraw，定义在后） */
static void reader_redraw(void);
static int  reader_refill_page(void);
static void reader_reflow_persist(void);

/* ---------- 工具 ---------- */
static uint16_t rgb565(uint32_t c)
{
    int r = (c >> 16) & 0xFF, g = (c >> 8) & 0xFF, b = c & 0xFF;
    return (uint16_t)(((r >> 3) << 11) | ((g >> 2) << 5) | (b >> 3));
}

/* 递归（深度≤3）扫 MeowOS/fonts/ 找第一个 .otf/.ttf。0=找到。 */
static int find_font_rec(const char *dir, int depth)
{
    if (depth > 3) return 0;
    DIR *dp = opendir(dir);
    if (!dp) return 0;
    struct dirent *de;
    int found = 0;
    while ((de = readdir(dp)) && !found) {
        if (de->d_name[0] == '.') continue;
        char full[480];
        if (snprintf(full, sizeof full, "%s/%s", dir, de->d_name) >= (int)sizeof full) continue;
        struct stat st;
        if (stat(full, &st) != 0) continue;
        if (S_ISDIR(st.st_mode)) { found = find_font_rec(full, depth + 1); }
        else {
            const char *d = strrchr(de->d_name, '.');
            if (d && (strcasecmp(d, ".otf") == 0 || strcasecmp(d, ".ttf") == 0)) {
                if (strlen(full) < sizeof g_font_path) {
                    strcpy(g_font_path, full);
                    found = 1;
                }
            }
        }
    }
    closedir(dp);
    return found;
}
static const char *resolve_font(void)
{
    g_font_path[0] = 0;
    if (find_font_rec(READER_SD_ROOT "/MeowOS/fonts", 0)) return g_font_path;
    return NULL;
}

static void chapter_name(void)
{
    /* TXT 无章节 → 文件名；R1 固定。 */
    snprintf(g_chapter, sizeof g_chapter, "%s", rd_book_basename(g_book));
}

static void reader_reflow(void)
{
    if (!g_book) return;
    int seg = 0; int32_t ch = 0;
    rd_book_anchor(g_book, &seg, &ch);          /* 记录当前锚，重排后回锚 */
    rd_book_jump_to_anchor(g_book, seg, ch, g_fs, g_ls);
    reader_refill_page();
    reader_redraw();
    reader_reflow_persist();
}

static void reader_reflow_persist(void)
{
    if (!g_book) return;
    int seg = 0; int32_t ch = 0;
    rd_book_anchor(g_book, &seg, &ch);
    rdprog p;
    p.valid = 1; p.seg = seg; p.ch = ch; p.fs = g_fs; p.ls = g_ls; p.ts = (uint64_t)time(NULL);
    rdprog_save(rd_book_path(g_book), &p);
}

/* ---------- 渲染（W_CUSTOM render_cb） ---------- */
static void reader_draw_line_atlas(int x, int y, const char *utf8, int len, void *ctx)
{
    (void)ctx; (void)len;
    meow_ui_text(x, y, utf8, (g_fs <= 20) ? 20 : 28, g_page_fg);
}

static void reader_canvas_render(meow_widget *w, const meow_theme *th, void *ctx)
{
    (void)w; (void)ctx;
    meow_ui_clear(g_page_bg);
    if (g_book) {
        int page = rd_book_current(g_book);
        if ((g_has_font || rd_book_is_image(g_book)) && g_page_buf[RD_PAGE_SLOT_CUR]) {
            /* 翻页 blit：行拷贝当前页位图 → back_buf（局部脏区由 flush_region 上屏） */
            unsigned char *bb = meow_ui_back_buf();
            int pitch = meow_ui_back_buf_pitch();
            int bpp = meow_ui_back_buf_bpp();
            uint16_t *src = g_page_buf[RD_PAGE_SLOT_CUR];
            if (bb && pitch > 0 && bpp == 16) {
                for (int y = 0; y < g_ph; y++)
                    memcpy(bb + (size_t)y * pitch, src + (size_t)y * g_pw, (size_t)g_pw * 2);
            }
        } else {
            rd_book_render_text(g_book, page, reader_draw_line_atlas, NULL);
        }
    }
    /* 顶栏：进度% + 章节名（避开系统状态栏） */
    int sbh = meow_ui_statusbar_height();
    int pages = rd_book_pages(g_book);
    int page = rd_book_current(g_book);
    char pct[16];
    int p = pages > 0 ? (page * 100 / pages) : 0;
    snprintf(pct, sizeof pct, "%d%%", p);
    meow_ui_fill_rect(0, sbh, g_pw, (g_top - 4 - sbh), g_page_bg);
    meow_ui_text(16, sbh + 4, g_chapter[0] ? g_chapter : "阅读", 20, th->fg);
    meow_ui_text_right(g_pw - 16, sbh + 4, pct, 20, th->fg);
    meow_ui_draw_rect(0, g_top - 5, g_pw, 1, th->outline);

    if (g_menu_open) {
        int y = g_ph - RD_MENU_H;
        meow_ui_fill_rect_alpha(0, y, g_pw, RD_MENU_H, 0x000000, 160);
        /* 6 按钮：返回 | 目录 | 字− | 字+ | 距− | 距+ */
        int bw = g_pw / RD_MENU_BTN;
        const char *labels[RD_MENU_BTN] = { "返回", "目录", "字-", "字+", "距-", "距+" };
        for (int i = 0; i < RD_MENU_BTN; i++) {
            int bx = i * bw;
            meow_ui_fill_rect(bx + 4, y + 12, bw - 8, RD_MENU_H - 24, th->surfaceContainer);
            meow_ui_text_center(bx + bw / 2, y + (RD_MENU_H - 20) / 2 - 6, labels[i], 20, th->fg);
        }
    }
    if (g_dir_open && g_book) {
        /* 目录覆盖层：半透明底 + 条目列表（当前行高亮） */
        int n = rd_book_toc_n(g_book);
        if (n > 0) {
            int top = g_top + 8;
            int row = 34;
            int maxshow = (g_ph - top - 70) / row;
            if (maxshow < 1) maxshow = 1;
            if (maxshow > n) maxshow = n;
            g_dir_top = top; g_dir_row_h = row;
            meow_ui_fill_rect_alpha(0, g_top, g_pw, g_ph - g_top, 0x000000, 150);
            char t[96]; int sg; int32_t cch;
            int page = rd_book_current(g_book);
            for (int i = 0; i < maxshow; i++) {
                if (rd_book_toc(g_book, i, t, sizeof t, &sg, &cch) != 0) continue;
                int y0 = top + i * row;
                if (page == sg) meow_ui_fill_rect(0, y0, g_pw, row - 4, th->surfaceContainer);
                meow_ui_text(24, y0, t, 20, th->fg);
                meow_ui_draw_rect(12, y0 + row - 6, g_pw - 24, 1, th->outline);
            }
            meow_ui_text(20, g_ph - 34, "点条目跳转 · 点空白关闭", 16, th->dim);
        } else {
            g_dir_open = 0;
            meow_ui_text(20, g_top + 40, "本书无目录", 20, th->dim);
        }
    }
}

static void reader_redraw(void)
{
    if (!g_canvas) return;
    meow_widget_draw(g_canvas);              /* → render_cb 画帧 */
    meow_ui_flush_region(0, 0, g_pw, g_ph);
}

static void reader_free_page_bufs(void)
{
    for (int i = 0; i < RD_PAGE_CACHE; i++) { free(g_page_buf[i]); g_page_buf[i] = NULL; }
}

/* 渲染当前页 + 前后各一页到 3 槽缓存（对齐设计「当前±前±后」；动画档为 无/滑动/淡入 R1 默认无）。 */
static int reader_refill_page(void)
{
    if (!g_book) return -1;
    if ((g_has_font || rd_book_is_image(g_book)) && g_page_buf[RD_PAGE_SLOT_CUR]) {
        uint16_t bg = rgb565(g_page_bg), fg = rgb565(g_page_fg);
        int cur = rd_book_current(g_book);
        int np = rd_book_pages(g_book);
        int slots[RD_PAGE_CACHE] = { cur - 1, cur, cur + 1 };
        for (int i = 0; i < RD_PAGE_CACHE; i++) {
            int p = slots[i];
            if (p >= 0 && p < np) rd_book_render(g_book, p, g_page_buf[i], g_pw * 2, bg, fg);
            else for (int y = 0; y < g_ph; y++)   /* 空白槽填背景 */
                for (int x = 0; x < g_pw; x++) g_page_buf[i][(size_t)y * g_pw + x] = bg;
        }
        return 0;
    }
    return 0;   /* 兜底路径：render_text 直绘 */
}

/* ---------- 打开 ---------- */
void reader_open(const char *path)
{
    if (!path || !path[0]) return;
    if (g_book) { rd_book_close(g_book); g_book = NULL; }
    reader_free_page_bufs();

    const char *fp = resolve_font();
    g_has_font = (fp != NULL);
    g_fs = RD_READER_DEFAULT_FS; g_ls = RD_READER_DEFAULT_LS;

    /* 进度（含字号/行距偏好） */
    rdprog prog;
    int hasprog = (rdprog_load(path, &prog) == 1) && prog.valid;
    if (hasprog) { if (prog.fs >= 14 && prog.fs <= 40) g_fs = prog.fs; if (prog.ls >= 100 && prog.ls <= 200) g_ls = prog.ls; }

    int sbh = meow_ui_statusbar_height();
    g_pw = meow_ui_width(); g_ph = meow_ui_height();
    g_top = sbh + 34; g_mx = 16; g_my = 20;

    const meow_theme *th = meow_theme_get();
    g_page_bg = th->surface; g_page_fg = th->onSurface;

    /* 开书（FreeType 路径带齐几何；无字体则 g_has_font=0 → atlas 兜底） */
    int rc = rd_book_open(&g_book, path, fp, g_fs, g_ls, g_pw, g_ph, g_mx, g_my, g_top);
    if (rc != 0) {
        meow_log(MEOW_LOG_WARN, "book open failed rc=%d path=%s", rc, path);
        g_book = NULL; g_has_font = 0;
        g_notice_ms = 3000;
        return;
    }
    chapter_name();

    if (g_has_font || rd_book_is_image(g_book)) {
        reader_free_page_bufs();
        for (int i = 0; i < RD_PAGE_CACHE; i++)
            g_page_buf[i] = (uint16_t *)malloc((size_t)g_pw * (size_t)g_ph * 2);
        if (!g_page_buf[RD_PAGE_SLOT_CUR]) { reader_free_page_bufs(); g_has_font = 0; }
    }

    /* 续读：进度锚（段,字符偏移）→ 跳页 */
    if (hasprog && g_book) {
        rd_book_jump_to_anchor(g_book, prog.seg, prog.ch, g_fs, g_ls);
    }

    reader_refill_page();

    g_menu_open = 0; g_dir_open = 0;
    if (g_reader_active) reader_redraw();
}

/* ---------- 视图生命周期 ---------- */
static void reader_on_create(meow_view *v, void *ctx) { (void)v; (void)ctx; }
static void reader_on_enter(meow_view *v, void *ctx)
{
    (void)v; (void)ctx;
    g_reader_active = 1;
    if (g_book) { reader_refill_page(); chapter_name(); }
    reader_redraw();
}
static void reader_on_leave(meow_view *v, void *ctx)
{
    (void)v; (void)ctx;
    reader_reflow_persist();          /* 离开保存进度 */
    g_reader_active = 0;
}
static void reader_on_destroy(meow_view *v, void *ctx)
{
    (void)v; (void)ctx;
    if (g_book) rd_book_close(g_book);
    g_book = NULL;
    reader_free_page_bufs();
    g_menu_open = 0; g_dir_open = 0; g_reader_active = 0;
}

meow_view *reader_view_create(void)
{
    static meow_view_hooks hooks = { reader_on_create, reader_on_enter, reader_on_leave,
                                     reader_on_destroy, NULL, NULL, NULL };
    meow_view *v = meow_view_create(ACT_READER, MEOW_VIEW_ACTIVITY, &hooks, NULL);
    g_canvas = meow_widget_custom_create(0, 0, 480, 720, reader_canvas_render, NULL, NULL);
    meow_view_add_widget(v, g_canvas);
    return v;
}

int reader_is_active(void) { return g_reader_active; }

void reader_on_tap(int x, int y)
{
    if (!g_book) { return; }
    if (g_dir_open) {
        /* 目录覆盖层：点条目跳转，点空白关闭 */
        int n = rd_book_toc_n(g_book);
        if (n > 0 && x >= 0 && y >= g_dir_top) {
            int row = g_dir_row_h > 0 ? g_dir_row_h : 34;
            int idx = (y - g_dir_top) / row;
            if (idx < n && idx >= 0) {
                char t[96]; int sg; int32_t cch;
                if (rd_book_toc(g_book, idx, t, sizeof t, &sg, &cch) == 0) {
                    if (g_book && sg >= 0) {
                        rd_book_jump_to_anchor(g_book, sg, cch, g_fs, g_ls);
                        g_dir_open = 0; g_menu_open = 0;
                        snprintf(g_chapter, sizeof g_chapter, "%s", t);
                        reader_refill_page();
                        reader_redraw();
                        reader_reflow_persist();
                        return;
                    }
                }
            }
        }
        g_dir_open = 0; reader_redraw();
        return;
    }
    if (g_menu_open) {
        /* 菜单按钮命中 */
        int y0 = g_ph - RD_MENU_H;
        if (y >= y0) {
            int bw = g_pw / RD_MENU_BTN;
            int idx = x / bw;
            switch (idx) {
                case 0: /* 返回书架 */
                    g_menu_open = 0;
                    reader_reflow_persist();
                    meow_view_page_pop();
                    return;
                case 1: /* 目录 */
                    if (rd_book_toc_n(g_book) > 0) { g_dir_open = 1; g_menu_open = 0; reader_redraw(); }
                    else { g_menu_open = 0; reader_redraw(); }
                    return;
                case 2: if (g_fs > 14) { g_fs -= 2; reader_reflow(); } break;
                case 3: if (g_fs < 40) { g_fs += 2; reader_reflow(); } break;
                case 4: if (g_ls > 100) { g_ls -= 5; reader_reflow(); } break;
                case 5: if (g_ls < 200) { g_ls += 5; reader_reflow(); } break;
            }
            if (y >= y0) return;
        }
        g_menu_open = 0;              /* 点菜单外关闭 */
        reader_redraw();
        return;
    }
    /* 三栏：左 1/3 上一页、右 1/3 下一页、中央唤菜单 */
    if (x < g_pw / 3) { rd_book_turn(g_book, -1); reader_refill_page(); reader_redraw(); }
    else if (x > g_pw * 2 / 3) { rd_book_turn(g_book, 1); reader_refill_page(); reader_redraw(); }
    else { g_menu_open = 1; reader_redraw(); }
}

void reader_on_swipe(int dir, int dx, int dy)
{
    (void)dx; (void)dy;
    if (!g_book) return;
    if (g_menu_open) { g_menu_open = 0; reader_redraw(); return; }
    if (dir == MEOW_SWIPE_LEFT)  { rd_book_turn(g_book, 1); }
    else if (dir == MEOW_SWIPE_RIGHT) { rd_book_turn(g_book, -1); }
    else return;
    reader_refill_page(); reader_redraw();
}

void reader_on_tick(uint64_t now)
{
    (void)now;
    if (g_notice_ms > 0) { g_notice_ms--; if (g_notice_ms == 0) reader_redraw(); }
}