#include "includes.h"

/* ============================================================================
 * app_touch 实现
 *
 * 状态机（与原 Touch_Process 一致）：
 *   IDLE → PRESS_WAIT_STABLE → PRESS_STABLE → SLIDING
 *
 * 时序参数：
 *   稳定判定  20ms     (TOUCH_STABLE_TIME)
 *   滑动阈值  10px     (TOUCH_SLIDE_THRESH)
 *   滑动步进  5px      (TOUCH_SLIDE_STEP)
 *   长按触发  1000ms   (TOUCH_LONG_PRESS_TIME)
 *   长按重复  120ms    (TOUCH_REPEAT_INTERVAL)
 * ==========================================================================*/

/* ==================== 状态机枚举 ==================== */
typedef enum {
    TOUCH_IDLE,                /* 空闲 */
    TOUCH_PRESS_WAIT_STABLE,   /* 按下，等待稳定判定 */
    TOUCH_PRESS_STABLE,        /* 稳定按下（可长按） */
    TOUCH_SLIDING              /* 滑动中 */
} touch_state_t;

/* ==================== 时序参数 ==================== */
#define TOUCH_STABLE_TIME        20     /* 按下稳定判定时间 ms */
#define TOUCH_SLIDE_THRESH       10     /* 进入滑动的最小位移 px */
#define TOUCH_SLIDE_STEP         5      /* 滑动事件最小步进 px */
#define TOUCH_LONG_PRESS_TIME    1000   /* 长按触发 ms */
#define TOUCH_REPEAT_INTERVAL    120    /* 长按重复间隔 ms */

/* ==================== 状态变量 ==================== */
static touch_state_t touch_state = TOUCH_IDLE;
static uint16_t down_x = 0;
static uint16_t down_y = 0;
static uint32_t touch_tick = 0;
static uint32_t repeat_tick = 0;
static uint8_t  long_press_fired = 0;
static uint16_t last_slide_x = 0;
static uint16_t last_slide_y = 0;

/* 取绝对值（避免引入 math.h） */
static inline uint16_t abs_diff(int16_t a, int16_t b)
{
    int16_t d = a - b;
    return (d < 0) ? (uint16_t)(-d) : (uint16_t)d;
}

/* ==================== 重置 ==================== */

void app_touch_reset(void)
{
    touch_state = TOUCH_IDLE;
    down_x = down_y = 0;
    touch_tick = repeat_tick = 0;
    long_press_fired = 0;
    last_slide_x = last_slide_y = 0;
}

/* ==================== 手势识别 ==================== */

app_touch_result_t app_touch_process(uint16_t x, uint16_t y, uint8_t pressed)
{
    app_touch_result_t r;
    r.gesture = GESTURE_NONE;
    r.x = x; r.y = y;
    r.down_x = down_x; r.down_y = down_y;

    uint32_t now = rt_tick_get();

    /* ---------- 抬起处理 ---------- */
    if (!pressed) {
        /* 若曾稳定按下且未触发长按 → 释放（可当作 TAP） */
        if (touch_state == TOUCH_PRESS_STABLE && !long_press_fired) {
            r.gesture = GESTURE_RELEASE;
            r.x = down_x; r.y = down_y;   /* 用按下点作为释放坐标 */
        }
        touch_state = TOUCH_IDLE;
        down_x = down_y = 0;
        last_slide_x = last_slide_y = 0;
        touch_tick = repeat_tick = 0;
        long_press_fired = 0;
        return r;
    }

    /* ---------- 按下处理 ---------- */
    switch (touch_state)
    {
        case TOUCH_IDLE:
            down_x = x;
            down_y = y;
            touch_tick = now;
            long_press_fired = 0;
            repeat_tick = 0;
            touch_state = TOUCH_PRESS_WAIT_STABLE;
            break;

        case TOUCH_PRESS_WAIT_STABLE:
            if ((now - touch_tick) >= TOUCH_STABLE_TIME) {
                /* 位移小 → 进入稳定 */
                if (abs_diff(x, down_x) < 8 && abs_diff(y, down_y) < 8) {
                    touch_state = TOUCH_PRESS_STABLE;
                    last_slide_x = down_x;
                    last_slide_y = down_y;
                    touch_tick = now;
                    MainTask_Sendmsg(MSG_ID_TOUCH, 1, down_x, down_y);
                } else {
                    /* 位移大 → 视为误触，回到空闲 */
                    touch_state = TOUCH_IDLE;
                }
            }
            break;

        case TOUCH_PRESS_STABLE:
        {
            /* ----- 长按检测 ----- */
            if (!long_press_fired && (now - touch_tick) >= TOUCH_LONG_PRESS_TIME) {
                long_press_fired = 1;
                repeat_tick = now;
                r.gesture = GESTURE_LONG_PRESS;
                MainTask_Sendmsg(MSG_ID_TOUCH_LONG_REPEAT, 1, down_x, down_y);
                return r;
            }
            /* ----- 长按重复 ----- */
            if (long_press_fired && (now - repeat_tick) >= TOUCH_REPEAT_INTERVAL) {
                repeat_tick = now;
                r.gesture = GESTURE_REPEAT;
                MainTask_Sendmsg(MSG_ID_TOUCH_LONG_REPEAT, 1, down_x, down_y);
                return r;
            }
            /* ----- 位移进入滑动 ----- */
            if (abs_diff(x, down_x) >= TOUCH_SLIDE_THRESH ||
                abs_diff(y, down_y) >= TOUCH_SLIDE_THRESH) {
                touch_state = TOUCH_SLIDING;
                last_slide_x = x;
                last_slide_y = y;
            }
            break;
        }

        case TOUCH_SLIDING:
        {
            /* 位移超过步进 → 产生拖动事件 */
            if (abs_diff(x, last_slide_x) >= TOUCH_SLIDE_STEP ||
                abs_diff(y, last_slide_y) >= TOUCH_SLIDE_STEP) {
                r.gesture = GESTURE_DRAG;
                r.down_x = last_slide_x;   /* 记录上次位置，便于消费端算增量 */
                r.down_y = last_slide_y;
                MainTask_Sendmsg(MSG_ID_TOUCH, 1, x, y);
                last_slide_x = x;
                last_slide_y = y;
                return r;
            }
            break;
        }

        default:
            touch_state = TOUCH_IDLE;
            break;
    }

    return r;   /* 无手势 */
}