#include "includes.h"

/* 按下即发点击；抬起仅补发未发出的短按 */

typedef enum {
    TOUCH_IDLE,
    TOUCH_PRESS_WAIT_STABLE,
    TOUCH_PRESS_STABLE,
    TOUCH_SLIDING
} touch_state_t;

#define TOUCH_STABLE_TIME        8
#define TOUCH_SLIDE_THRESH       12
#define TOUCH_SLIDE_STEP         5
#define TOUCH_LONG_PRESS_TIME    800
#define TOUCH_REPEAT_INTERVAL    120

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 uint8_t  click_sent = 0;
static uint16_t last_slide_x = 0;
static uint16_t last_slide_y = 0;

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;
}

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

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();

    if (!pressed) {
        if (!long_press_fired && !click_sent &&
            (touch_state == TOUCH_PRESS_WAIT_STABLE ||
             touch_state == TOUCH_PRESS_STABLE))
        {
            r.gesture = GESTURE_RELEASE;
            r.x = down_x;
            r.y = down_y;
            MainTask_Sendmsg(MSG_ID_TOUCH, 1, down_x, down_y);
        }
        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;
        click_sent = 0;
        return r;
    }

    switch (touch_state)
    {
        case TOUCH_IDLE:
            down_x = x;
            down_y = y;
            touch_tick = now;
            long_press_fired = 0;
            click_sent = 0;
            repeat_tick = 0;
            touch_state = TOUCH_PRESS_WAIT_STABLE;
            /* 第一帧就发点击，模式选择等页跟手 */
            click_sent = 1;
            MainTask_Sendmsg(MSG_ID_TOUCH, 1, down_x, down_y);
            break;

        case TOUCH_PRESS_WAIT_STABLE:
            if ((now - touch_tick) >= TOUCH_STABLE_TIME) {
                if (abs_diff(x, down_x) < 24 && abs_diff(y, down_y) < 24)
                    touch_state = TOUCH_PRESS_STABLE;
                else {
                    down_x = x;
                    down_y = y;
                    touch_tick = now;
                }
            }
            break;

        case TOUCH_PRESS_STABLE:
            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;
            }
            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;
            }
            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:
            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;
                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;
}