import pygame
import qrcode
import cv2
import json
import base64
import time
import random
import string
from io import BytesIO

def gen_id():
    return ''.join(random.choice(string.ascii_uppercase + string.digits) for _ in range(10))

def make_qr(data, size):
    qr = qrcode.QRCode(box_size=8, border=2)
    qr.add_data(data)
    qr.make(fit=True)
    img = qr.make_image(fill="black", back_color="white").convert("RGB")
    img = img.resize((size, size))
    buf = BytesIO()
    img.save(buf, format="PNG")
    buf.seek(0)
    return pygame.image.load(buf)

def pack(session, seq, msg):
    payload = {
        "s": session,
        "q": seq,
        "m": base64.b64encode(msg.encode()).decode()
    }
    return json.dumps(payload)

pygame.init()

screen = pygame.display.set_mode((0,0), pygame.FULLSCREEN)
w, h = screen.get_size()

cap = cv2.VideoCapture(0)
detector = cv2.QRCodeDetector()

session_id = gen_id()

seq = 0
msg = ""

qr = None

last_decode = []
stable = ""
last_seq = -1

qr_size = h // 2

running = True
while running:
    for e in pygame.event.get():
        if e.type == pygame.KEYDOWN:
            if e.key == pygame.K_ESCAPE:
                running = False

            if e.key == pygame.K_RETURN:
                msg = input("msg: ")
                seq += 1

    ret, frame = cap.read()

    if ret:
        data, _, _ = detector.detectAndDecode(frame)

        if data:
            try:
                obj = json.loads(data)

                if obj.get("s"):

                    if obj["s"] != session_id:
                        pass
                    else:
                        text = base64.b64decode(obj["m"]).decode()

                        last_decode.append((obj["q"], text))
                        if len(last_decode) > 5:
                            last_decode.pop(0)

                        # stabiliteit check
                        counts = {}
                        for _, t in last_decode:
                            counts[t] = counts.get(t, 0) + 1

                        for t, c in counts.items():
                            if c >= 3:
                                stable = t

            except:
                pass

    if msg:
        qr = make_qr(pack(session_id, seq, msg), qr_size)

    screen.fill((0,0,0))

    if qr:
        screen.blit(qr, (w//4 - qr_size//2, h//4))

    font = pygame.font.SysFont(None, 36)

    screen.blit(font.render("SESSION: " + session_id[:6], True, (0,255,0)), (20,20))
    screen.blit(font.render("SENT: " + msg[:30], True, (255,255,0)), (20,80))
    screen.blit(font.render("RECV: " + stable[:30], True, (0,255,0)), (w//2+20,20))

    cam_surface = pygame.surfarray.make_surface(
        cv2.cvtColor(cv2.flip(frame,1), cv2.COLOR_BGR2RGB).swapaxes(0,1)
    )

    screen.blit(pygame.transform.scale(cam_surface, (w//2, h)), (w//2,0))

    pygame.display.flip()
    pygame.time.Clock().tick(30)

cap.release()
pygame.quit()