/**
 * @file    led_driver.c
 * @brief   LED 驱动实现 — OOPC 不透明指针模式
 *
 * 内部结构体定义在本文件，外部不可见
 * 静态内存池分配，无 malloc
 */
#include "led_driver.h"
#include <string.h>

/* ======== 内部结构体（不透明指针的真身） ======== */
struct LedDriver_S {
    GPIO_Port_TypeDef port;
    GPIO_Pin_TypeDef  pin;
    uint8_t           active_low;      /* 1=低电平点亮 */
    volatile LedState_E state;
    volatile uint8_t    brightness;    /* 0-100 */

    /* 闪烁参数 */
    uint16_t          blink_period_ms;
    uint32_t          blink_last_toggle;
    uint8_t           blink_on;

    /* 呼吸灯参数 */
    uint16_t          breath_step;     /* 0-200 三角波步数 */
    uint8_t           breath_dir;      /* 0=渐亮, 1=渐暗 */
    uint32_t          breath_last_tick;
};

/* ======== 静态内存池 ======== */
static LedDriver_S g_led_pool[LED_MAX_INSTANCES];
static uint8_t     g_led_used[LED_MAX_INSTANCES];

/* ======== 内部辅助函数 ======== */
static void led_hw_on(LedDriver_S* me) {
    GPIO_PinState_TypeDef s = me->active_low ? GPIO_PIN_RESET : GPIO_PIN_SET;
    HAL_GPIO_WritePin(me->port, me->pin, s);
}

static void led_hw_off(LedDriver_S* me) {
    GPIO_PinState_TypeDef s = me->active_low ? GPIO_PIN_SET : GPIO_PIN_RESET;
    HAL_GPIO_WritePin(me->port, me->pin, s);
}

static void led_hw_set_pwm(LedDriver_S* me, uint8_t percent) {
    /*
     * 真实硬件: 设置 TIM 占空比
     * TIM_SetCompare(me->h_tim, me->channel, percent * ARR / 100);
     *
     * PC 模拟: 简化为 ON/OFF 模拟亮度
     */
    me->brightness = percent;
    if (percent >= 50) {
        led_hw_on(me);
    } else {
        led_hw_off(me);
    }
}

/* ======== 公开 API 实现 ======== */

LedDriver_S* Led_Create(GPIO_Port_TypeDef port, GPIO_Pin_TypeDef pin, uint8_t active_low) {
    for (uint8_t i = 0; i < LED_MAX_INSTANCES; i++) {
        if (g_led_used[i] == 0) {
            g_led_used[i] = 1;
            LedDriver_S* me = &g_led_pool[i];
            memset(me, 0, sizeof(LedDriver_S));

            me->port       = port;
            me->pin        = pin;
            me->active_low = active_low;
            me->state      = LED_STATE_OFF;

            /* 硬件初始化 */
            HAL_GPIO_Init(port, pin, GPIO_MODE_OUTPUT);
            led_hw_off(me);

            return me;
        }
    }
    return NULL;  /* 内存池满 */
}

void Led_Destroy(LedDriver_S* me) {
    if (me == NULL) return;
    led_hw_off(me);
    for (uint8_t i = 0; i < LED_MAX_INSTANCES; i++) {
        if (&g_led_pool[i] == me) {
            g_led_used[i] = 0;
            break;
        }
    }
}

void Led_On(LedDriver_S* me) {
    if (me == NULL) return;
    me->state      = LED_STATE_ON;
    me->brightness = 100;
    led_hw_on(me);
}

void Led_Off(LedDriver_S* me) {
    if (me == NULL) return;
    me->state      = LED_STATE_OFF;
    me->brightness = 0;
    led_hw_off(me);
}

void Led_SetBlink(LedDriver_S* me, uint16_t period_ms) {
    if (me == NULL) return;
    me->state           = LED_STATE_BLINK;
    me->blink_period_ms = period_ms;
    me->blink_last_toggle = 0;  /* 将在 Poll 中重置 */
    me->blink_on        = 1;
}

void Led_SetBreathing(LedDriver_S* me) {
    if (me == NULL) return;
    me->state           = LED_STATE_BREATHING;
    me->breath_step     = 0;
    me->breath_dir      = 0;     /* 从暗开始渐亮 */
    me->breath_last_tick = 0;
}

void Led_Poll(LedDriver_S* me, uint32_t now_ms) {
    if (me == NULL) return;

    switch (me->state) {
    case LED_STATE_OFF:
    case LED_STATE_ON:
        /* 静态状态，无需处理 */
        break;

    case LED_STATE_BLINK: {
        uint16_t half = me->blink_period_ms / 2;
        if (half == 0) half = 1;

        if (me->blink_last_toggle == 0) {
            me->blink_last_toggle = now_ms;
        }
        if ((now_ms - me->blink_last_toggle) >= half) {
            me->blink_last_toggle = now_ms;
            me->blink_on = !me->blink_on;
            if (me->blink_on) {
                led_hw_on(me);
                me->brightness = 100;
            } else {
                led_hw_off(me);
                me->brightness = 0;
            }
        }
        break;
    }

    case LED_STATE_BREATHING: {
        /*
         * 呼吸灯: 三角波 0→100→0
         * 每 15ms 变化 1 步, 200 步一个完整周期 ≈ 3 秒
         */
        if (me->breath_last_tick == 0) {
            me->breath_last_tick = now_ms;
        }
        if ((now_ms - me->breath_last_tick) >= 15) {
            me->breath_last_tick = now_ms;

            if (me->breath_dir == 0) {
                /* 渐亮 */
                me->breath_step++;
                if (me->breath_step >= 100) {
                    me->breath_dir = 1;
                }
            } else {
                /* 渐暗 */
                if (me->breath_step == 0) {
                    me->breath_dir = 0;
                } else {
                    me->breath_step--;
                }
            }
            led_hw_set_pwm(me, (uint8_t)me->breath_step);
        }
        break;
    }
    }
}

LedState_E Led_GetState(const LedDriver_S* me) {
    if (me == NULL) return LED_STATE_OFF;
    return me->state;
}

uint8_t Led_GetBrightness(const LedDriver_S* me) {
    if (me == NULL) return 0;
    return me->brightness;
}