/**
  ******************************************************************************
  * @file    input_scan.c
  * @brief   编码器/按键扫描模块实现
  *          SW_KEY(PF3): 短按切换音源, 长按5s断开蓝牙
  *          SW1_KEY(PB8): 短按低音静音
  *          SW2_KEY(PA15): 短按快速静音
  *          SW1编码器(PA5/PA6): 低音音量
  *          SW2编码器(PB0/PA7): 主音量LR
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "input_scan.h"
#include "app_state.h"
#include "led_driver.h"
#include "uart_protocol.h"

/* Private define ------------------------------------------------------------*/

/* ========== 按钮 / 编码器引脚定义 (外部上拉, 低电平有效) ========== */
#define SW_KEY_PIN     GPIO_PIN_3
#define SW_KEY_PORT    GPIOF

#define SW1_A_PIN      GPIO_PIN_5
#define SW1_A_PORT     GPIOA
#define SW1_B_PIN      GPIO_PIN_6
#define SW1_B_PORT     GPIOA
#define SW1_KEY_PIN    GPIO_PIN_8
#define SW1_KEY_PORT   GPIOB

#define SW2_A_PIN      GPIO_PIN_0
#define SW2_A_PORT     GPIOB
#define SW2_B_PIN      GPIO_PIN_7
#define SW2_B_PORT     GPIOA
#define SW2_KEY_PIN    GPIO_PIN_15
#define SW2_KEY_PORT   GPIOA

/* 长按时间 */
#define LONG_PRESS_MS   5000u   /* SW_KEY 长按 5s 断开蓝牙 */

/* 编码器变速参数 (按单脉冲间隔计算) */
#define ENC_SLOW_PULSE_MS     200u    /* 单脉冲 >200ms: 慢速, 需4脉冲 */
#define ENC_FAST_PULSE_MS     75u     /* 单脉冲 <75ms: 快速, 需1脉冲 */

/* Private variables ---------------------------------------------------------*/

/* ========== 按键事件标志 (由 main.c 读取处理) ========== */
volatile uint8_t  g_swKeyEdge      = 0u;
volatile uint8_t  g_sw1KeyEdge     = 0u;
volatile uint8_t  g_sw2KeyEdge     = 0u;
volatile uint8_t  g_swKeyLongPress = 0u;

/* ========== 双键同按状态 ========== */
volatile uint8_t  g_bothPressFlag  = 0u;
volatile uint16_t g_bothPressMs    = 0u;

/* ========== 按键内部状态 ========== */
static volatile uint8_t g_swKeyLast       = 1u; /* 前一次稳定电平 (0=按下, 1=释放) */
static volatile uint8_t g_sw1KeyLast      = 1u;
static volatile uint8_t g_sw2KeyLast      = 1u;
static volatile uint8_t g_swKeyHeld       = 0u; /* SW_KEY 正在被按住 */
static volatile uint16_t g_swKeyPressMs   = 0u; /* SW_KEY 按下持续时间 */
static volatile uint8_t g_swKeyPressed_1  = 0u; /* 见过按下标志 */
static volatile uint8_t g_sw1KeyPressed_1 = 0u;
static volatile uint8_t g_sw2KeyPressed_1 = 0u;

/* ========== 编码器内部状态 ========== */
/* 编码器前一次AB状态 (位1=B, 位0=A) */
static volatile uint8_t  g_enc1PrevAB  = 0u;
static volatile uint8_t  g_enc2PrevAB  = 0u;
/* 脉冲计数器 */
static volatile int8_t   g_enc1PulseCnt = 0;
static volatile int8_t   g_enc2PulseCnt = 0;
/* 上次触发时间 (ms) */
static volatile uint32_t g_enc1LastMs   = 0u;
static volatile uint32_t g_enc2LastMs   = 0u;

/* ========== 编码器正交解码查找表 ========== */
/* index = (prevAB << 2) | currAB */
/* value: 0=无变化, -1=A方向(顺时针), 1=B方向(逆时针)  [AB方向已反转] */
static const int8_t s_encTable[16] = {
     0,  1, -1,  0,   /* prev=00 */
    -1,  0,  0,  1,   /* prev=01 */
     1,  0,  0, -1,   /* prev=10 */
     0, -1,  1,  0    /* prev=11 */
};

/* Private function prototypes -----------------------------------------------*/
static uint8_t Encoder_ReadAB(uint8_t encIdx);
static int8_t  Encoder_Decode(uint8_t encIdx, uint8_t currAB);
static uint8_t ProcessOneEncoder(int8_t dir,
                   volatile int8_t  *pPulseCnt,
                   volatile int16_t *pLevel,
                   volatile uint32_t *pLastMs);

/* ========== 初始化 ========== */

/**
  * @brief  读取编码器和按键的初始状态
  *         防止 MCU 复位时按着的按键松开后产生误触发
  */
void InputScan_Init(void)
{
    /* 记录编码器初始 AB 状态 */
    g_enc1PrevAB = (uint8_t)(
        ((HAL_GPIO_ReadPin(SW1_B_PORT, SW1_B_PIN) == GPIO_PIN_SET) ? 2u : 0u) |
        ((HAL_GPIO_ReadPin(SW1_A_PORT, SW1_A_PIN) == GPIO_PIN_SET) ? 1u : 0u));
    g_enc2PrevAB = (uint8_t)(
        ((HAL_GPIO_ReadPin(SW2_B_PORT, SW2_B_PIN) == GPIO_PIN_SET) ? 2u : 0u) |
        ((HAL_GPIO_ReadPin(SW2_A_PORT, SW2_A_PIN) == GPIO_PIN_SET) ? 1u : 0u));

    /* 按键初始状态与引脚一致 */
    g_swKeyLast  = (HAL_GPIO_ReadPin(SW_KEY_PORT,  SW_KEY_PIN)  == GPIO_PIN_RESET) ? 0u : 1u;
    g_sw1KeyLast = (HAL_GPIO_ReadPin(SW1_KEY_PORT, SW1_KEY_PIN) == GPIO_PIN_RESET) ? 0u : 1u;
    g_sw2KeyLast = (HAL_GPIO_ReadPin(SW2_KEY_PORT, SW2_KEY_PIN) == GPIO_PIN_RESET) ? 0u : 1u;

    /* 清除边缘标志 */
    g_swKeyEdge  = 0u;
    g_sw1KeyEdge = 0u;
    g_sw2KeyEdge = 0u;
}

/* ========== 按键扫描 ========== */

/**
  * @brief  扫描所有按键 (TIM3 中断中每 1ms 调用)
  */
void ScanButtons(void)
{
    uint8_t swVal;

    /* ----- SW_KEY (PF3): 短按音源切换, 长按5s断开蓝牙 ----- */
    swVal = (HAL_GPIO_ReadPin(SW_KEY_PORT, SW_KEY_PIN) == GPIO_PIN_RESET) ? 0u : 1u;
    if (swVal == 0u)
    {
        if (g_swKeyLast == 1u)
        {
            g_swKeyLast      = 0u;
            g_swKeyHeld      = 1u;
            g_swKeyPressMs   = 0u;
            g_swKeyPressed_1 = 1u;
        }
        if (g_swKeyHeld)
        {
            g_swKeyPressMs++;
            if (g_swKeyPressMs >= LONG_PRESS_MS && g_swKeyLongPress == 0u)
            {
                g_swKeyLongPress = 1u;
                g_swKeyPressMs   = 0u;
            }
        }
    }
    else if (g_swKeyLast == 0u)
    {
        g_swKeyLast = 1u;
        g_swKeyHeld = 0u;
        /* 必须完整 1→0→1, 且长按已处理则不触发短按 */
        if (g_swKeyPressed_1 && g_swKeyLongPress == 0u)
        {
            g_swKeyEdge = 1u;
        }
        g_swKeyLongPress = 0u;
        g_swKeyPressed_1 = 0u;
        g_swKeyPressMs   = 0u;
    }

    /* ----- SW1_KEY (PB8): 静音按键 (完整1→0→1才触发) ----- */
    swVal = (HAL_GPIO_ReadPin(SW1_KEY_PORT, SW1_KEY_PIN) == GPIO_PIN_RESET) ? 0u : 1u;
    if (swVal == 0u && g_sw1KeyLast == 1u)
    {
        g_sw1KeyLast      = 0u;
        g_sw1KeyPressed_1 = 1u;
    }
    else if (swVal == 1u && g_sw1KeyLast == 0u)
    {
        g_sw1KeyLast = 1u;
        if (g_sw1KeyPressed_1)
        {
            g_sw1KeyPressed_1 = 0u;
            g_sw1KeyEdge      = 1u;
        }
    }

    /* ----- SW2_KEY (PA15): 快速静音 (完整1→0→1才触发) ----- */
    swVal = (HAL_GPIO_ReadPin(SW2_KEY_PORT, SW2_KEY_PIN) == GPIO_PIN_RESET) ? 0u : 1u;
    if (swVal == 0u && g_sw2KeyLast == 1u)
    {
        g_sw2KeyLast      = 0u;
        g_sw2KeyPressed_1 = 1u;
    }
    else if (swVal == 1u && g_sw2KeyLast == 0u)
    {
        g_sw2KeyLast = 1u;
        if (g_sw2KeyPressed_1)
        {
            g_sw2KeyPressed_1 = 0u;
            g_sw2KeyEdge      = 1u;
        }
    }

    /* ----- 双键同按检测: 两键均按下持续10s触发软复位 ----- */
    if (HAL_GPIO_ReadPin(SW1_KEY_PORT, SW1_KEY_PIN) == GPIO_PIN_RESET
     && HAL_GPIO_ReadPin(SW2_KEY_PORT, SW2_KEY_PIN) == GPIO_PIN_RESET)
    {
        if (!g_bothPressFlag)
        {
            g_bothPressFlag = 1u;
            g_bothPressMs   = 0u;
        }
    }
    else
    {
        if (g_bothPressFlag)
        {
            g_bothPressFlag = 0u;
            g_bothPressMs   = 0u;
        }
    }
}

/* ========== 编码器扫描 ========== */

/**
  * @brief  扫描所有编码器 (TIM3 中断中每 1ms 调用)
  */
void ScanEncoders(void)
{
    int8_t dir;

    /* ----- SW1编码器: 低音音量 ----- */
    dir = Encoder_Decode(0u, Encoder_ReadAB(0u));
    if (ProcessOneEncoder(dir, &g_enc1PulseCnt, &g_volBassLevel, &g_enc1LastMs))
    {
        g_flagSendVolBass = 1u;
    }

    /* ----- SW2编码器: 主音量LR ----- */
    dir = Encoder_Decode(1u, Encoder_ReadAB(1u));
    if (dir != 0 && g_mutedByBtn)
    {
        g_mutedByBtn = 0u;
        g_flagSendDacUnmute = 1u;
    }
    if (ProcessOneEncoder(dir, &g_enc2PulseCnt, &g_volLRLevel, &g_enc2LastMs))
    {
        g_flagSendVolLR = 1u;
    }
}

/* ========== 私有函数 ========== */

/**
  * @brief  读取编码器AB引脚
  * @param  encIdx 0=编码器1(SW1), 1=编码器2(SW2)
  * @retval (B<<1 | A) 值 0-3
  */
static uint8_t Encoder_ReadAB(uint8_t encIdx)
{
    uint8_t a, b;
    if (encIdx == 0u)
    {
        a = (HAL_GPIO_ReadPin(SW1_A_PORT, SW1_A_PIN) == GPIO_PIN_SET) ? 1u : 0u;
        b = (HAL_GPIO_ReadPin(SW1_B_PORT, SW1_B_PIN) == GPIO_PIN_SET) ? 1u : 0u;
    }
    else
    {
        a = (HAL_GPIO_ReadPin(SW2_A_PORT, SW2_A_PIN) == GPIO_PIN_SET) ? 1u : 0u;
        b = (HAL_GPIO_ReadPin(SW2_B_PORT, SW2_B_PIN) == GPIO_PIN_SET) ? 1u : 0u;
    }
    return (uint8_t)((b << 1u) | a);
}

/**
  * @brief  解码编码器旋转方向
  * @param  encIdx 0=编码器1, 1=编码器2
  * @param  currAB 当前AB状态
  * @retval 1=A方向, -1=B方向, 0=无变化
  */
static int8_t Encoder_Decode(uint8_t encIdx, uint8_t currAB)
{
    volatile uint8_t *pPrevAB;
    uint8_t  prevAB;
    uint8_t  index;
    int8_t   result;

    pPrevAB = (encIdx == 0u) ? &g_enc1PrevAB : &g_enc2PrevAB;
    prevAB  = *pPrevAB;
    index   = (uint8_t)((prevAB << 2u) | currAB);
    result  = s_encTable[index];

    if (result != 0)
    {
        *pPrevAB = currAB;
    }
    return result;
}

/**
  * @brief  单编码器处理: 累计脉冲, 根据单脉冲速度动态调整阈值
  * @retval 1: 触发了音量改变, 0: 未触发
  */
static uint8_t ProcessOneEncoder(int8_t dir,
    volatile int8_t  *pPulseCnt,
    volatile int16_t *pLevel,
    volatile uint32_t *pLastMs)
{
    if (dir == 0) return 0u;

    uint32_t now = g_sysMs;
    uint32_t interval = now - *pLastMs;
    *pLastMs = now;

    if (dir > 0)
    {
        (*pPulseCnt)++;
    }
    else
    {
        (*pPulseCnt)--;
    }

    /* 速度判定基于相邻两次脉冲的间隔 */
    uint8_t threshold;
    if (interval > ENC_SLOW_PULSE_MS)       threshold = 4u; /* 慢速: 需4脉冲 */
    else if (interval < ENC_FAST_PULSE_MS)  threshold = 1u; /* 快速: 需1脉冲 */
    else                                    threshold = 2u; /* 中速: 需2脉冲 */

    if (*pPulseCnt >= (int8_t)threshold)
    {
        *pPulseCnt = 0;
        int16_t level = *pLevel;
        if (level < 100)
        {
            *pLevel = level + 1;
            g_userActive = 1u;
            g_idleTimer  = 0u;
            return 1u;
        }
    }
    else if (*pPulseCnt <= -(int8_t)threshold)
    {
        *pPulseCnt = 0;
        int16_t level = *pLevel;
        if (level > 0)
        {
            *pLevel = level - 1;
            g_userActive = 1u;
            g_idleTimer  = 0u;
            return 1u;
        }
    }
    return 0u;
}