import tkinter as tk
import serial
import serial.tools.list_ports
import threading
from PIL import Image, ImageTk
from io import BytesIO
import queue

def connect() -> serial.Serial:
    while True:
        ports: list = serial.tools.list_ports.comports()
        for i, port in enumerate(ports):
            print(f"{i}: {port.device} - {port.description}")
        
        selected_port: str = input("Which port to use?\n")
        if selected_port.__len__() < 1: continue
        if(not "0123456789".__contains__(selected_port[0])): continue
        
        selected_port_idx: int = int(selected_port[0])
        if selected_port_idx >= ports.__len__() or selected_port_idx < 0: continue
        
        s: serial.Serial = serial.Serial(port=ports[selected_port_idx].device, baudrate=921600, timeout=1)
        try_counter: int = 0
        while not s.is_open:
            if try_counter == 10:
                print("Failed to open port for 10 times -> stopping thread")
                return
            try:
                s.open()
            except:
                print("Opening port failed!")
                print(f"Try {try_counter}")
                try_counter += 1
                
        print(f"Connected successfully! ({ports[selected_port_idx].device})")
        try:
            s.reset_input_buffer()
        except Exception: pass
        return s
        

def receiver_thread(s: serial.Serial, kill_thread_event: threading.Event, image_queue: queue.Queue) -> None:
        buf: bytearray = bytearray()
        delimiter: str = b"\x04\r\n"
        
        while s.is_open and not kill_thread_event.is_set():
            try:
                n = s.in_waiting
            except Exception: 
                n = 1
            
            chunk = s.read(n)
            
            if kill_thread_event.is_set(): return
            if chunk: buf.extend(chunk)

            while True:                
                idx = buf.find(delimiter)
                if idx == -1: break
            
                jpg: bytes = bytes(buf[:idx])
                del buf[: idx + delimiter.__len__()]
                if not jpg: continue
                
                try:
                    image_queue.put_nowait(jpg)
                except queue.Full:
                    try:
                        _ = image_queue.get_nowait()
                    except queue.Empty: pass
                    
                    try:
                        image_queue.put_nowait(jpg)
                    except queue.Full: pass
                
            if buf.__len__() > 5000000: buf.clear()
        
    
def detect_motion(last_image: bytes, new_image: bytes) -> bool:
    length1: int = last_image.__len__()
    length2: int = new_image.__len__()
    length = length1
    if length1 < length2:
        new_image = new_image[:length1]
    elif length2 < length1:
        last_image = last_image[:length2]
        length = length2
    
    def diff(pixel1, pixel2) -> int:
        return pixel1 - pixel2
    
    sum: int = 0
    for i in range(length):
        sum += diff(last_image[i], new_image[i])
    
    norm = sum / length
    ret = norm <= -1 or norm >= 1
    # print(f"Norm: {norm}")
    return ret

def main():
    kill_thread_event: threading.Event = threading.Event()
    image_queue: queue.Queue = queue.Queue(maxsize=2)
    
    s: serial.Serial = connect()
    
    receiver = threading.Thread(target=receiver_thread, daemon=True, args=(s, kill_thread_event, image_queue))
    receiver.start()
        
    root = tk.Tk()
    root.title("ESP32-CAM Stream")
    root.geometry("1280x720")
    lbl = tk.Label(root)
    lbl.pack(fill="both", expand=True)
    
    state = {"photo": None}
    
    last_image: bytes | None = None
    
    def poll_image():
        nonlocal last_image
        jpg = None
        while True:
            try:
                jpg = image_queue.get_nowait()
            except queue.Empty:
                break

        if jpg is not None:
            if last_image is not None and detect_motion(last_image, jpg):
                print("Motion detected!")
            
            last_image = jpg
            
            try:
                img = Image.open(BytesIO(jpg)).convert("RGB")
                
                w = lbl.winfo_width()
                h = lbl.winfo_height()
                if w > 1 and h > 1:
                    img = img.resize((w, h), Image.BILINEAR)
                    
                photo = ImageTk.PhotoImage(img)
                state["photo"] = photo
                lbl.configure(image=photo)
            except Exception: pass
            
        root.after(10, poll_image)
    
    def on_close():
        kill_thread_event.set()
        root.destroy()
        print("Closing!")

    root.protocol("WM_DELETE_WINDOW", on_close)
    poll_image()
    root.mainloop()
    s.close()

if __name__ == '__main__':
    main()