/**
 * @file    app_controller.c
 * @brief   应用控制器实现 — 层级状态机 (HSM)
 *
 * 事件路由表:
 *   当前状态       │ 事件               │ 下一状态        │ 动作
 *   ──────────────┼───────────────────┼────────────────┼────────────────
 *   OFF           │ SINGLE_CLICK      │ ON             │ Led_On()
 *   ON            │ SINGLE_CLICK      │ OFF            │ Led_Off()
 *   ON            │ DOUBLE_CLICK      │ BLINK_SLOW     │ Led_SetBlink(1000)
 *   BLINK_SLOW    │ DOUBLE_CLICK      │ BLINK_FAST     │ Led_SetBlink(200)
 *   BLINK_FAST    │ DOUBLE_CLICK      │ OFF            │ Led_Off()
 *   任意非 BREATH │ LONG_PRESS_START  │ BREATHING      │ Led_SetBreathing()
 *   BREATHING     │ LONG_PRESS_START  │ OFF            │ Led_Off()
 */
#include "app_controller.h"
#include <string.h>
#include <stdio.h>
#include <stdarg.h>

/* ======== 内部结构体 ======== */
struct AppCtrl_S {
    LedDriver_S*  led;
    Btn_FSM*      btn;
    AppState_E    state;
};

/* ======== 静态内存池 ======== */
static AppCtrl_S g_app_pool[APP_MAX_INSTANCES];
static uint8_t   g_app_used[APP_MAX_INSTANCES];

/* ======== 调试日志（PC 模拟时打印） ======== */
#ifdef APP_DEBUG_LOG
static void app_log(const char* fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    vprintf(fmt, ap);
    va_end(ap);
}
#else
#define app_log(...) ((void)0)
#endif

/* ======== 状态转换函数 ======== */

static void transition_to(AppCtrl_S* me, AppState_E new_state) {
    AppState_E old = me->state;

    /* 退出动作 (exit action) */
    switch (old) {
    case APP_STATE_BLINK_SLOW:
    case APP_STATE_BLINK_FAST:
        /* 退出闪烁前无特殊清理 */
        break;
    case APP_STATE_BREATHING:
        /* 退出呼吸灯前无特殊清理 */
        break;
    default:
        break;
    }

    /* 进入动作 (entry action) */
    switch (new_state) {
    case APP_STATE_OFF:
        Led_Off(me->led);
        app_log("[APP] OFF\n");
        break;

    case APP_STATE_ON:
        Led_On(me->led);
        app_log("[APP] ON\n");
        break;

    case APP_STATE_BLINK_SLOW:
        Led_SetBlink(me->led, 1000);  /* 1 秒周期 */
        app_log("[APP] BLINK_SLOW (1s)\n");
        break;

    case APP_STATE_BLINK_FAST:
        Led_SetBlink(me->led, 200);   /* 0.2 秒周期 */
        app_log("[APP] BLINK_FAST (0.2s)\n");
        break;

    case APP_STATE_BREATHING:
        Led_SetBreathing(me->led);
        app_log("[APP] BREATHING\n");
        break;

    default:
        break;
    }

    me->state = new_state;
}

/* ======== 按键事件回调 ======== */

static void on_single_click(Btn_FSM* btn, void* user_data) {
    AppCtrl_S* me = (AppCtrl_S*)user_data;
    (void)btn;

    app_log("[BTN] SINGLE_CLICK in state=%d\n", me->state);

    switch (me->state) {
    case APP_STATE_OFF:
        transition_to(me, APP_STATE_ON);
        break;
    case APP_STATE_ON:
        transition_to(me, APP_STATE_OFF);
        break;
    case APP_STATE_BLINK_SLOW:
    case APP_STATE_BLINK_FAST:
        transition_to(me, APP_STATE_OFF);
        break;
    case APP_STATE_BREATHING:
        transition_to(me, APP_STATE_OFF);
        break;
    default:
        break;
    }
}

static void on_double_click(Btn_FSM* btn, void* user_data) {
    AppCtrl_S* me = (AppCtrl_S*)user_data;
    (void)btn;

    app_log("[BTN] DOUBLE_CLICK in state=%d\n", me->state);

    switch (me->state) {
    case APP_STATE_ON:
        transition_to(me, APP_STATE_BLINK_SLOW);
        break;
    case APP_STATE_BLINK_SLOW:
        transition_to(me, APP_STATE_BLINK_FAST);
        break;
    case APP_STATE_BLINK_FAST:
        transition_to(me, APP_STATE_OFF);
        break;
    case APP_STATE_OFF:
        /* OFF 状态双击 → 直接快闪 */
        transition_to(me, APP_STATE_BLINK_FAST);
        break;
    case APP_STATE_BREATHING:
        /* 呼吸灯中双击 → 退出到 OFF */
        transition_to(me, APP_STATE_OFF);
        break;
    default:
        break;
    }
}

static void on_long_press(Btn_FSM* btn, void* user_data) {
    AppCtrl_S* me = (AppCtrl_S*)user_data;
    (void)btn;

    app_log("[BTN] LONG_PRESS_START in state=%d\n", me->state);

    switch (me->state) {
    case APP_STATE_BREATHING:
        /* 呼吸灯中长按 → 退出到 OFF */
        transition_to(me, APP_STATE_OFF);
        break;
    default:
        /* 其他任意状态长按 → 进入呼吸灯 */
        transition_to(me, APP_STATE_BREATHING);
        break;
    }
}

/* ======== 公开 API ======== */

AppCtrl_S* AppCtrl_Create(LedDriver_S* led, Btn_FSM* btn) {
    if (led == (void*)0 || btn == (void*)0) return (void*)0;

    for (uint8_t i = 0; i < APP_MAX_INSTANCES; i++) {
        if (g_app_used[i] == 0) {
            g_app_used[i] = 1;
            AppCtrl_S* me = &g_app_pool[i];
            memset(me, 0, sizeof(AppCtrl_S));
            me->led   = led;
            me->btn   = btn;
            me->state = APP_STATE_OFF;
            return me;
        }
    }
    return (void*)0;
}

void AppCtrl_Destroy(AppCtrl_S* me) {
    if (me == (void*)0) return;
    Led_Off(me->led);
    for (uint8_t i = 0; i < APP_MAX_INSTANCES; i++) {
        if (&g_app_pool[i] == me) {
            g_app_used[i] = 0;
            break;
        }
    }
}

void AppCtrl_Init(AppCtrl_S* me) {
    if (me == (void*)0) return;

    /* 注册按键回调 */
    Btn_Attach(me->btn, BTN_EVT_SINGLE_CLICK,     on_single_click, me);
    Btn_Attach(me->btn, BTN_EVT_DOUBLE_CLICK,     on_double_click, me);
    Btn_Attach(me->btn, BTN_EVT_LONG_PRESS_START, on_long_press,   me);

    /* 初始状态 */
    Led_Off(me->led);
    me->state = APP_STATE_OFF;

    app_log("[APP] Initialized, state=OFF\n");
}

void AppCtrl_Poll(AppCtrl_S* me, uint32_t now_ms) {
    if (me == (void*)0) return;
    Led_Poll(me->led, now_ms);
}

AppState_E AppCtrl_GetState(const AppCtrl_S* me) {
    if (me == (void*)0) return APP_STATE_OFF;
    return me->state;
}

const char* AppCtrl_StateName(AppState_E state) {
    static const char* names[] = {
        "OFF",
        "ON",
        "BLINK_SLOW",
        "BLINK_FAST",
        "BREATHING"
    };
    if (state < APP_STATE_COUNT) {
        return names[state];
    }
    return "UNKNOWN";
}