# main.py — ESP32 Smart Parking (4 Slots) + Blynk IoT (Push + Dashboard)
# ตรงกับผัง: TRIG=[5,18,19,23], ECHO=[32,33,34,35], LED_G=[2,12,14,27], LED_R=[4,13,26,25]

from machine import Pin, time_pulse_us
import time, network

# ===================== USER CONFIG =====================
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASS = ""

THRESH_CM = 100.0          # ระยะ < THRESH → "มีรถ"
STABLE_N  = 3              # จำนวนครั้งยืนยันสถานะ
READ_INTERVAL_MS  = 400    # รอบใหญ่
BETWEEN_SENSOR_MS = 60     # เว้นระหว่างอ่านแต่ละตัว

BLYNK_TOKEN = "dO2XWKU2jpSzxG3QiS0SrBRl3HI0J-6B"
# สำหรับ Wokwi (จำลอง) แนะนำ HTTP region โดยตรง (เสถียรกว่า):
BLYNK_API   = "http://sgp1.blynk.cloud/external/api"
# ถ้าเป็นบอร์ดจริง ให้ใช้ HTTPS:
# BLYNK_API   = "https://blynk.cloud/external/api"

EVENT_CODE = "slot_change"
EVENT_GAP_MS = 800         # กันยิง event ถี่เกินไป
BATCH_PUSH_GAP_MS = 20000   # ส่งค่า V0–V5 แบบ batch ทุก ~2 วินาที
# =======================================================

# ---------- Wi-Fi ----------
def wifi_connect():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        wlan.connect(WIFI_SSID, WIFI_PASS)
        print("Connecting Wi-Fi", end="")
        t0 = time.ticks_ms()
        while not wlan.isconnected() and time.ticks_diff(time.ticks_ms(), t0) < 15000:
            print(".", end=""); time.sleep(0.25)
    print("\n✅ WiFi:", wlan.ifconfig())

# ---------- HTTP helpers (retry + ปิด connection เร็ว) ----------
def _http_get(url, tries=3, delay_ms=250):
    import urequests
    last_err = None
    for _ in range(tries):
        try:
            r = urequests.get(url)
            sc = r.status_code
            txt = r.text
            r.close()
            return sc, txt
        except Exception as e:
            last_err = e
            time.sleep_ms(delay_ms)
    raise last_err

def urlencode_utf8(s: str) -> str:
    # percent-encode UTF-8 ให้รองรับภาษาไทย
    if not isinstance(s, str):
        s = str(s)
    b = s.encode("utf-8")
    SAFE = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_.~"
    out = []
    for c in b:
        if c in SAFE:
            out.append(chr(c))
        else:
            out.append("%{:02X}".format(c))
    return "".join(out)

def blynk_log_event(code, description=""):
    try:
        url = f"{BLYNK_API}/logEvent?token={BLYNK_TOKEN}&code={code}"
        if description:
            url += f"&description={urlencode_utf8(description)}"
        sc, txt = _http_get(url, tries=3, delay_ms=250)
        print("logEvent:", sc, txt)
        return sc == 200
    except Exception as e:
        print("logEvent error:", e)
        return False

def blynk_update_v(pin, value):
    try:
        if isinstance(value, str):
            value = urlencode_utf8(value)
        url = f"{BLYNK_API}/update?token={BLYNK_TOKEN}&V{pin}={value}"
        sc, _ = _http_get(url, tries=2, delay_ms=200)
        return sc == 200
    except Exception as e:
        print(f"update V{pin} error:", e)
        return False

def blynk_batch_update(map_v):
    try:
        parts = []
        for k, v in map_v.items():
            if isinstance(v, str):
                v = urlencode_utf8(v)
            parts.append(f"V{k}={v}")
        url = f"{BLYNK_API}/batch/update?token={BLYNK_TOKEN}&" + "&".join(parts)
        sc, txt = _http_get(url, tries=2, delay_ms=200)
        # print("batch:", sc, txt)  # debug ถ้าต้องการ
        return sc == 200
    except Exception as e:
        print("batch update error:", e)
        return False

def blynk_get_v(pin, default=1):
    try:
        url = f"{BLYNK_API}/get?token={BLYNK_TOKEN}&V{pin}"
        sc, txt = _http_get(url, tries=2, delay_ms=200)
        if sc != 200 or not txt:
            print(f"get V{pin} -> HTTP {sc}, txt='{txt}'")
            return default
        raw = txt.strip()
        # ปกติ Blynk คืน ["0"] หรือ ["1"]
        if raw.startswith('["') and raw.endswith('"]'):
            raw = raw[2:-2]
        val = int(float(raw))
        print(f"get V{pin} -> {val}")  # debug ดูใน Serial
        return val
    except Exception as e:
        print(f"get V{pin} error:", e)
        return default

# ---------- GPIO mapping ----------
TRIG_PINS = [5, 18, 19, 23]
ECHO_PINS = [32, 33, 34, 35]      # input-only เหมาะเป็น ECHO
LED_GREEN_PINS = [2, 12, 14, 27]  # ว่าง
LED_RED_PINS   = [4, 13, 26, 25]  # มีรถ

trigs = [Pin(p, Pin.OUT, value=0) for p in TRIG_PINS]
echos = [Pin(p, Pin.IN) for p in ECHO_PINS]
led_g = [Pin(p, Pin.OUT, value=0) for p in LED_GREEN_PINS]
led_r = [Pin(p, Pin.OUT, value=0) for p in LED_RED_PINS]

# ---------- HC-SR04 ----------
def raw_cm(i):
    t = trigs[i]; e = echos[i]
    t.value(0); time.sleep_us(2)
    t.value(1); time.sleep_us(10)
    t.value(0)
    dur = time_pulse_us(e, 1, 30000)   # us
    if dur <= 0:
        return 9999.0
    return (dur * 0.0343) / 2.0

def median3(a,b,c):
    if a>b: a,b=b,a
    if b>c: b,c=c,b
    if a>b: a,b=b,a
    return b

def read_cm(i):
    d1 = raw_cm(i); time.sleep_ms(5)
    d2 = raw_cm(i); time.sleep_ms(5)
    d3 = raw_cm(i)
    return median3(d1,d2,d3)

def set_led(i, occupied):
    # True → แดง, False → เขียว
    led_r[i].value(1 if occupied else 0)
    led_g[i].value(0 if occupied else 1)

def pretty_state(state):
    return "[" + " ".join(("X" if s else "O") for s in state) + "] (X=CAR,O=FREE)"

# ---------- Main ----------
def main():
    wifi_connect()

    # แจ้งเตือนครั้งแรกเพื่อยืนยันเส้นทาง
    blynk_log_event(EVENT_CODE, "⚙️ ระบบเริ่มทำงานแล้ว")

    occupied   = [False]*4
    last_state = [None]*4
    stable_cnt = [0]*4

    for i in range(4):
        set_led(i, False)  # เริ่ม “ว่าง” ทุกช่อง

    last_loop       = time.ticks_ms()
    last_batch_push = time.ticks_ms()
    last_ctrl_pull  = time.ticks_ms()
    last_event_ms   = 0
    prev_free_count = 4
    first_summary   = False

    # อ่านสวิตช์คุมระบบจากแอป (V20)
    system_enabled = blynk_get_v(20, default=1)

    print("Slots=4 | THRESH={:.1f}cm | STABLE_N={} | INTERVAL={}ms".format(
        THRESH_CM, STABLE_N, READ_INTERVAL_MS))

    while True:
        now = time.ticks_ms()
        if time.ticks_diff(now, last_loop) < READ_INTERVAL_MS:
            time.sleep_ms(5)
            continue
        last_loop = now

        # ดึงสถานะสวิตช์ทุก ~2 วินาที
        if time.ticks_diff(now, last_ctrl_pull) >= 2000:
            system_enabled = blynk_get_v(20, default=1)
            print("system_enabled =", system_enabled)  # debug
            last_ctrl_pull = now

        if not system_enabled:
            # OFF → แสดงว่างทั้งหมด + ขึ้นข้อความ System OFF
            for i in range(4):
                set_led(i, False)
                occupied[i] = False
                stable_cnt[i] = 0
                if last_state[i] is None:
                    last_state[i] = False

            if time.ticks_diff(now, last_batch_push) >= BATCH_PUSH_GAP_MS:
                blynk_batch_update({0:0,1:0,2:0,3:0,4:4,5:"System OFF"})
                last_batch_push = now

            print("System OFF | State:", pretty_state(occupied), "| FREE = 4")
            time.sleep_ms(BETWEEN_SENSOR_MS)
            continue

        # -------- System ON: อ่านเซนเซอร์ --------
        free_slots = []
        for i in range(4):
            d = read_cm(i)
            cur = (d < THRESH_CM)  # True=มีรถ
            if not cur:
                free_slots.append(str(i+1))

            if last_state[i] is None:
                last_state[i] = cur
                occupied[i] = cur
                set_led(i, cur)
            else:
                if cur != occupied[i]:
                    stable_cnt[i] += 1
                    if stable_cnt[i] >= STABLE_N:
                        occupied[i] = cur
                        set_led(i, cur)
                        stable_cnt[i] = 0

                        # กันยิงถี่ด้วย EVENT_GAP_MS
                        if time.ticks_diff(now, last_event_ms) >= EVENT_GAP_MS:
                            msg = "ช่อง {}: {}".format(i+1, ("มีรถเข้าจอด" if cur else "ว่างแล้ว"))
                            blynk_log_event(EVENT_CODE, msg)
                            last_event_ms = now

                        # อัปเดตรายช่องทันที
                        blynk_update_v(i, 1 if cur else 0)
                else:
                    stable_cnt[i] = 0

            time.sleep_ms(BETWEEN_SENSOR_MS)

        free_count = len(free_slots)
        summary = ("ว่าง {}/4 ช่อง ({})".format(free_count, ", ".join(free_slots))
                   if free_count > 0 else "เต็มทั้งหมด")

        # แจ้งเหตุการณ์ตอนเปลี่ยนผ่าน 0
        if free_count == 0 and prev_free_count > 0:
            blynk_log_event(EVENT_CODE, "ลานจอดเต็มทั้งหมด")
        elif free_count > 0 and prev_free_count == 0:
            blynk_log_event(EVENT_CODE, "มีที่ว่างแล้ว {} ช่อง".format(free_count))
        prev_free_count = free_count

        # ส่งชุดแรกหลังบูต
        if not first_summary:
            blynk_batch_update({
                0:1 if occupied[0] else 0,
                1:1 if occupied[1] else 0,
                2:1 if occupied[2] else 0,
                3:1 if occupied[3] else 0,
                4:free_count,
                5:summary
            })
            first_summary = True

        # ส่งแบบ batch เป็นช่วง ๆ
        if time.ticks_diff(now, last_batch_push) >= BATCH_PUSH_GAP_MS:
            blynk_batch_update({
                0:1 if occupied[0] else 0,
                1:1 if occupied[1] else 0,
                2:1 if occupied[2] else 0,
                3:1 if occupied[3] else 0,
                4:free_count,
                5:summary
            })
            last_batch_push = now

        print("System ON |", summary)

if __name__ == "__main__":
    main()