/* bg_page.c — 批③ 后台管理页（桌面顶栏居右按钮进入）。
 *
 * 容器：sub_page_t 脚手架（subpage.c，与 wifi_page/bt_page 同款）。顶栏＝meow_topappbar：
 *   返回箭头 + 标题「后台管理」（+ 右上无开关）。
 * 列表（live=1 约 2s 重扫，实时增删）：
 *   - 首行「一键清除后台」SUB_ACT（act 回调 → bgmgr_kill_all，**不杀框架/当前前台/非后台**）；
 *   - 每后台 App 一行 SUB_ROW：label=名字，sub=「CPU x% · yMB · 状态」，tap（detail 回调）→ 确认后
 *     kill（走 meow_bg_terminate 的 SIGTERM→SIGKILL 真退序列，**带 !framework 门控**）。
 *   - 空态「无后台 App」。
 * 数据源＝amsd FG/BG 注册表（后台常驻集＝launcher meow_bg 表，EV BG/FG 上报进 amsd）+ 每进程
 * pcpu/rss（meow_svc_perf 同源 /proc 聚合，本页在 launcher 内同口径取）。
 *
 * 说明（与「每行最右 kill 按钮 + 顶栏右侧清除按钮」的像素级差异）：sub_page_t 行无内嵌按钮、
 * 顶栏仅返回+开关；故 kill 用「点行→确认」，清除用「顶置动作行」。像素级自绘版见 design 备忘。
 */
#include "meow_launcher_internal.h"
#include "meow_bgplay.h"
#include "meow_bgmgr.h"
#include <ctype.h>

#define BGMR_CLR_ACT   9999     /* 一键清除动作码 */
#define BGMR_KILL_BASE 1000     /* kill app i：BGMR_KILL_BASE+i */

typedef struct {
    struct app *apps;
    int         napps;
    bgmgr_row_t rows[MEOW_BGMR_ROW_MAX];
    int         n;
    char        toast[64];
    long        toast_ms;
} bgm_ctx_t;

/* 找 struct app（launcher 应用表）by id */
static struct app *bgm_app_find(struct app *apps, int napps, const char *app_id)
{
    if (!apps || !app_id) return NULL;
    for (int i = 0; i < napps; i++)
        if (apps[i].id[0] && !strcmp(apps[i].id, app_id)) return &apps[i];
    return NULL;
}

/* ---- meow_bgmgr ops 注入（UI 侧真实实现）---- */
static int bgm_app_meta(void *ctx, const char *app_id, pid_t pid,
                        char *name, int nl, char *icon, int il,
                        char *framework, int *is_fg)
{
    (void)pid;
    bgm_ctx_t *b = ctx;
    struct app *a = bgm_app_find(b->apps, b->napps, app_id);
    *framework = 0;
    *is_fg     = 0;
    if (!a) return -1;                          /* 未注册 → name 回退 app_id */
    if (a->name[0]) snprintf(name, nl, "%s", a->name);
    if (icon && il > 0) snprintf(icon, il, "%s", a->icon[0] ? a->icon : "");
    *framework = (a->framework == '1') ? '1' : 0;
    return 0;
}

static int bgm_enumerate(void *ctx, bgmgr_row_t *rows, int max)
{
    (void)ctx;
    int n = meow_bg_count();
    if (n > max) n = max;
    for (int i = 0; i < n; i++) {
        const meow_bg_entry_t *e = meow_bg_at(i);
        if (!e || !e->used || !e->app_id[0]) continue;
        memset(&rows[i], 0, sizeof rows[i]);
        snprintf(rows[i].app_id, sizeof rows[i].app_id, "%s", e->app_id);
        rows[i].pid         = e->pid;
        rows[i].keepalive   = (e->keepalive ? 1 : 0);
        rows[i].on_card     = (e->on_card ? 1 : 0);
        rows[i].bg_since_ms = e->bg_since_ms;
    }
    return n;
}

/* proc_sample：/proc/<pid>/stat(utime+stime 差分) + /proc/<pid>/status(VmRSS)。
 * 与 meow_svc_perf 897-983 每进程 pcpu/rss 聚合同口径（同 /proc 源）。 */
static long    g_cpu_pid[MEOW_BG_MAX] = {0};
static unsigned long long g_cpu_tick[MEOW_BG_MAX] = {0};

static int bgm_proc_sample(void *ctx, pid_t pid, double *pcpu, long *rss_kb)
{
    (void)ctx;
    if (pid <= 0) return -1;
    char path[64], line[512];
    long rss = 0;
    snprintf(path, sizeof path, "/proc/%d/status", pid);
    int fd = open(path, O_RDONLY);
    if (fd >= 0) {
        ssize_t nr = read(fd, line, sizeof line - 1); close(fd);
        if (nr > 0) { line[nr] = 0;
            char *p = strstr(line, "VmRSS:");
            if (p) p = strchr(p, ' ');
            if (p) { while (*p == ' ' || *p == '\t') p++; rss = atol(p); }
        }
    }
    double pc = 0.0;
    snprintf(path, sizeof path, "/proc/%d/stat", pid);
    fd = open(path, O_RDONLY);
    if (fd >= 0) {
        ssize_t nr = read(fd, line, sizeof line - 1); close(fd);
        if (nr > 0) {
            line[nr] = 0;
            char *rp = strrchr(line, ')');
            if (rp) {
                char *p = rp + 2;
                unsigned long long ut[2] = {0, 0};
                for (int f = 0; f < 14; f++) {
                    while (*p == ' ') p++;
                    char *end; unsigned long long v = strtoull(p, &end, 10);
                    if (end == p) { p++; continue; }
                    p = end;
                    if (f == 11) ut[0] = v;      /* utime */
                    if (f == 12) ut[1] = v;      /* stime */
                }
                unsigned long long cur = ut[0] + ut[1];
                static double hz = 0.0;
                if (hz <= 0) { hz = (double)sysconf(_SC_CLK_TCK); if (hz <= 0) hz = 100.0; }
                unsigned long long prev = 0; int had = 0, slot = -1;
                for (int i = 0; i < MEOW_BG_MAX; i++) {
                    if (g_cpu_pid[i] == pid) { prev = g_cpu_tick[i]; had = 1; slot = i; break; }
                }
                if (!had) {
                    for (int i = 0; i < MEOW_BG_MAX; i++) if (g_cpu_pid[i] == 0) { slot = i; break; }
                    if (slot < 0) slot = 0;
                }
                if (slot >= 0) { g_cpu_pid[slot] = pid; g_cpu_tick[slot] = cur; }
                if (had) { pc = 100.0 * (double)(cur - prev) / hz; if (pc < 0) pc = 0; }
            }
        }
    }
    *pcpu = pc;
    *rss_kb = rss;
    return 0;
}

/* ---- rows（填 sub_row_t 列表）---- */
static int bgm_rows(void *ctx, sub_row_t *rbuf, int max)
{
    bgm_ctx_t *b = ctx;
    bgmgr_ops_t ops;
    memset(&ops, 0, sizeof ops);
    ops.ctx = b;
    ops.enumerate   = bgm_enumerate;
    ops.app_meta    = bgm_app_meta;
    ops.proc_sample = bgm_proc_sample;
    b->n = bgmgr_collect(&ops, b->rows, MEOW_BGMR_ROW_MAX);

    int r = 0;
    if (r < max) {
        rbuf[r].kind = SUB_ACT;
        rbuf[r].label = "一键清除后台";
        rbuf[r].sub  = NULL;
        rbuf[r].act  = BGMR_CLR_ACT;
        r++;
    }
    if (b->n == 0) {
        if (r < max) {
            rbuf[r].kind = SUB_ROW;
            rbuf[r].label = meow_str_zh("bgmgr.empty", "无后台 App");
            rbuf[r].sub  = NULL;
            rbuf[r].act  = -1;
            r++;
        }
        return r;
    }
    for (int i = 0; i < b->n && r < max; i++) {
        char sub[80];
        snprintf(sub, sizeof sub, "CPU %.1f%% · %s · %s", b->rows[i].pcpu,
                 bgmgr_mem_str(b->rows[i].rss_kb), bgmgr_status_str(&b->rows[i]));
        rbuf[r].kind  = SUB_ROW;
        rbuf[r].label = b->rows[i].name[0] ? b->rows[i].name : b->rows[i].app_id;
        rbuf[r].sub   = sub;
        rbuf[r].act   = i;                     /* detail 回调用 i 定位行 */
        r++;
    }
    return r;
}

/* kill 通道（bgmgr_kill_all 的函数指针签名：void(*)(const char*)） */
static void bgm_kill_fn(const char *app_id) { meow_bg_terminate(app_id); }

/* ---- detail（点 SUB_ROW 行＝kill 该后台 App）---- */
static int bgm_detail(void *ctx, int idx, int act)
{
    (void)idx;
    bgm_ctx_t *b = ctx;
    int i = act;
    if (i < 0 || i >= b->n) return 0;
    if (!bgmgr_can_kill(&b->rows[i])) {
        snprintf(b->toast, sizeof b->toast, "该 App 不可杀（框架/前台）");
        b->toast_ms = (long)now_ms();
        return 1;
    }
    meow_bg_terminate(b->rows[i].app_id);
    snprintf(b->toast, sizeof b->toast, "已请求终止 %s", b->rows[i].app_id);
    b->toast_ms = (long)now_ms();
    return 1;
}

/* ---- act（点 SUB_ACT：一键清除）---- */
static int bgm_act(void *ctx, int idx, int act)
{
    (void)idx;
    bgm_ctx_t *b = ctx;
    if (act == BGMR_CLR_ACT) {
        bgmgr_ops_t ops;
        memset(&ops, 0, sizeof ops);
        ops.ctx = b;
        ops.enumerate = bgm_enumerate;                    /* 行已由 bgm_rows 建 */
        int k = bgmgr_kill_all(&ops, b->rows, b->n, bgm_kill_fn);
        if (k > 0) snprintf(b->toast, sizeof b->toast, "已清 %d 个后台 App", k);
        else       snprintf(b->toast, sizeof b->toast, "无后台 App 可清");
        b->toast_ms = (long)now_ms();
        return 1;
    }
    return 0;
}

/* ---- 入口：运行后台管理页（阻塞到返回）---- */
int run_bg_page(struct app *apps, int napps)
{
    static bgm_ctx_t b;
    memset(&b, 0, sizeof b);
    b.apps  = apps;
    b.napps = napps;
    sub_page_t p;
    memset(&p, 0, sizeof p);
    p.title  = "后台管理";
    p.rows   = bgm_rows;
    p.detail = bgm_detail;
    p.act    = bgm_act;
    p.live   = 1;                       /* 后台表/进程变化实时重扫 */
    p.ctx    = &b;
    meow_subpage_run(&p);

    /* 清除 CPU 差分缓存（页面会话结束） */
    memset(g_cpu_pid, 0, sizeof g_cpu_pid);
    memset(g_cpu_tick, 0, sizeof g_cpu_tick);
    return 0;
}