import cv2
import numpy as np
import mediapipe as mp
from scipy.spatial import distance as dist

def eye_aspect_ratio(eye_landmarks, landmarks, image_shape):
    eye = [
        landmarks[eye_landmarks[0]],  # P1 (left)
        landmarks[eye_landmarks[1]],  # P2 (top-left)
        landmarks[eye_landmarks[2]],  # P3 (top-right)
        landmarks[eye_landmarks[3]],  # P4 (right)
        landmarks[eye_landmarks[4]],  # P5 (bottom-right)
        landmarks[eye_landmarks[5]]   # P6 (bottom-left)
    ]
    eye = [(int(p.x * image_shape[1]), int(p.y * image_shape[0])) for p in eye]
    
    A = dist.euclidean(eye[1], eye[5])
    B = dist.euclidean(eye[2], eye[4])
    C = dist.euclidean(eye[0], eye[3])
    ear = (A + B) / (2.0 * C)
    return ear, eye

class BlinkDetector:
    def __init__(self):
        self.mp_face_mesh = mp.solutions.face_mesh
        self.face_mesh = self.mp_face_mesh.FaceMesh(
            max_num_faces=1,
            refine_landmarks=True,  # Required for iris landmarks
            min_detection_confidence=0.5,
            min_tracking_confidence=0.5
        )
        self.EAR_THRESHOLD = 0.25
        self.EAR_CONSEC_FRAMES = 3
    
    def detect_blinks(self, frame):
        image_rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
        results = self.face_mesh.process(image_rgb)
        
        if not results.multi_face_landmarks:
            return None, None, None, None, None, None
        
        landmarks = results.multi_face_landmarks[0].landmark
        h, w = frame.shape[:2]
        
        LEFT_EYE = [33, 160, 158, 133, 153, 144]
        RIGHT_EYE = [362, 385, 387, 263, 373, 380]
        LEFT_IRIS = 473  # Left iris center
        RIGHT_IRIS = 468  # Right iris center
        
        left_ear, left_eye_points = eye_aspect_ratio(LEFT_EYE, landmarks, (h, w))
        right_ear, right_eye_points = eye_aspect_ratio(RIGHT_EYE, landmarks, (h, w))
        avg_ear = (left_ear + right_ear) / 2.0
        
        nose_tip = landmarks[1]
        head_pose = (nose_tip.x - 0.5) * 2
        
        # Iris coordinates
        left_iris = (int(landmarks[LEFT_IRIS].x * w), int(landmarks[LEFT_IRIS].y * h))
        right_iris = (int(landmarks[RIGHT_IRIS].x * w), int(landmarks[RIGHT_IRIS].y * h))
        
        return avg_ear, left_eye_points, right_eye_points, head_pose, left_iris, right_iris
    
    def __del__(self):
        self.face_mesh.close()