/* backlight.c — MeowOS launcher 拆分模块（LAUNCHER_SPLIT_PLAN 拆分）。*/
/* 本文件由拆分工具从 meow_launcherd.c 按职责搬移；逻辑与原文 0-diff（仅 static 可见性按跨模块需求调整）。*/
#include "meow_launcher_internal.h"


/* ---- MeowOS 面板自持（M2.6：播放器已死，MeowOS 拥有面板/背光，无拔河）----
 * 电源键按时长三分：单击（短按松开）= 息屏/亮屏；3s=电源菜单；8s=强制关机。
 * 息屏 = 亮度0 + FBIOBLANK(4)（面板下电，同时挂起 goodix 触摸，无误触）；
 * 亮屏 = FBIOBLANK(0) + 恢复亮度。 */
int meow_screen_on = 1;

int meow_saved_brightness = 60;

int meow_auto_slept = 0;      /* M2.17：当前是否「超时自动息屏」置位（手动电源息屏不置位） */


/* brightness save/restore (defined below, used by run_menu) */
int saved_brightness = -1;


/* M2.53：MeowOS 主屏接管时把亮度强制压回用户设置值（display.brightness，经
 * meow_settings_brightness_clamped() —— 下限 brightness_min 默认 1、上限 100），
 * 覆盖 HibyOS 播放器写入 sysfs 的背光下限（16/25）。仅应在「MeowOS 真正接管画面」
 * （播放器已死、主屏常驻，即 run_menu 的 had_player==0）时调用；播放器会话期间的
 * 覆盖菜单（had_player==1）不去抢亮度——尊重播放器背光（§红线）。 */
void apply_user_brightness(void)
{
    int v = meow_settings_brightness_clamped();
    if (v <= 0) v = 60;   /* 防御：clamp 后不可能 ≤0，仅兜底 */
    write_brightness(v);
    g_sys.brightness = v;
    logmsg("apply user brightness (MeowOS takeover) -> %d", v);
}


/* ---- backlight save/restore ---- */
int read_brightness(void)
{
    int fd = open(BACKLIGHT, O_RDONLY);
    if (fd < 0) return -1;
    char buf[16];
    int n = read(fd, buf, sizeof buf - 1);
    close(fd);
    if (n <= 0) return -1;
    buf[n] = 0;
    return atoi(buf);
}


static void write_file(const char *path, const char *val)
{
    int fd = open(path, O_WRONLY);
    if (fd < 0) return;
    int l = strlen(val);
    if (write(fd, val, l) < 0)
        logmsg("write %s <- %s: %s", path, val, strerror(errno));
    close(fd);
}


void write_brightness(int val)
{
    char buf[8];
    int l = snprintf(buf, sizeof buf, "%d\n", val);
    int fd = open(BACKLIGHT, O_WRONLY);
    if (fd < 0) { logmsg("backlight open fail: %s", strerror(errno)); return; }
    if (write(fd, buf, l) < 0) logmsg("backlight write %d: %s", val, strerror(errno));
    close(fd);
}


/* Bring the panel up for the menu, but ONLY when it is actually dark:
 * brightness 0 (the player's own screen-off/standby writes brightness 0
 * then FBIOBLANK(4); on this device bl_power stays 0, so brightness==0 is
 * the reliable indicator — keep the bl_power check as a belt-and-suspenders
 * for other states). A normal brightness is left completely untouched so
 * the menu never yanks the brightness up (Bug A).
 *
 * CRITICAL (2026-08-28 hotfix): we NEVER touch FBIOBLANK here — the panel
 * blank state belongs to the player's display state machine. fb_open()
 * already unblanks for the menu (the menu must be visible); forcibly
 * unblanking while the player thinks the screen is blanked leaves the
 * player's state machine inconsistent (it stops drawing, UI freezes —
 * this is the Bug B keeper deadlock, do not reintroduce). */
void ensure_backlight(void)
{
    int cur = read_brightness();
    int blp = read_file_int(BACKLIGHT_POWER);
    if (cur > 0 && blp <= 0) {
        logmsg("backlight: screen on (%d), leave untouched", cur);
        return;
    }
    int target = (saved_brightness > 0) ? saved_brightness : 60;
    logmsg("backlight off (cur=%d bl_power=%d) -> %d", cur, blp, target);
    if (cur <= 0) write_brightness(target);
    if (blp > 0) write_file(BACKLIGHT_POWER, "0\n");
}


/* Restore the backlight after the player resumes (app exit / SIGTERM).
 * Minimal duty after the 2026-08-28 hotfix:
 *  - if the menu opened while the player had blanked the panel (screen
 *    timeout), re-blank it (brightness 0 + FBIOBLANK(4)) so the physical
 *    panel matches the player's display state machine — no frozen frame,
 *    and the player still owns the blank state;
 *  - otherwise only write brightness back when it reads 0, and never
 *    unblank (unblanking behind the player's back wedges its display state
 *    machine — see ensure_backlight). A normal brightness is left
 *    completely untouched (Bug A: no forced brightness raise). */
void restore_backlight(void)
{
    if (menu_opened_blank) {
        logmsg("restore: panel was blanked at menu open, re-blank (0 + FBIOBLANK 4)");
        write_brightness(0);
        int fbfd = open(FB_DEV, O_RDWR);
        if (fbfd >= 0) { ioctl(fbfd, FBIOBLANK, 4); close(fbfd); }
        menu_opened_blank = 0;
        return;
    }
    int cur = read_brightness();
    int blp = read_file_int(BACKLIGHT_POWER);
    if (cur <= 0 || blp > 0) {
        int target = (saved_brightness > 0) ? saved_brightness : 60;
        logmsg("restore backlight (cur=%d bl_power=%d) -> %d (saved=%d)",
               cur, blp, target, saved_brightness);
        if (cur <= 0) write_brightness(target);
        if (blp > 0) write_file(BACKLIGHT_POWER, "0\n");
    }
}