import os
import cv2
import numpy as np
import torch
from ultralytics import YOLO
from sort import Sort
import gradio as gr

# Load YOLOv12x model
MODEL_PATH = "setosys_yolov12x.pt"
model = YOLO(MODEL_PATH)

# COCO dataset class ID for people
PEOPLE_CLASS_ID = 0  # "people"

# Initialize SORT tracker
tracker = Sort()

# Minimum confidence threshold for detection
CONFIDENCE_THRESHOLD = 0.4  # Lowered for better detection

# Distance threshold to avoid duplicate counts
DISTANCE_THRESHOLD = 50

# Dictionary to define keyword-based time intervals
TIME_INTERVALS = {
    "one": 1, "two": 2, "three": 3, "four": 4, "five": 5,
    "six": 6, "seven": 7, "eight": 8, "nine": 9, "ten": 10, "eleven": 11
}

def determine_time_interval(video_filename):
    """ Determines frame skip interval based on keywords in the filename. """
    print(f"Checking filename: {video_filename}")  # Debugging
    for keyword, interval in TIME_INTERVALS.items():
        if keyword in video_filename:
            print(f"Matched keyword: {keyword} -> Interval: {interval}")  # Debugging
            return interval
    print("No keyword match, using default interval: 5")  # Debugging
    return 5  # Default interval

def count_unique_people(video_path):
    """ Counts unique people in a video using YOLOv12x and SORT tracking. """
    cap = cv2.VideoCapture(video_path)
    if not cap.isOpened():
        return {"Error": "Unable to open video file."}

    # Reset variables at the start of each analysis
    unique_people_ids = set()
    people_history = {}

    # Get FPS of the video
    fps = int(cap.get(cv2.CAP_PROP_FPS))

    # Extract filename from the path and convert to lowercase
    video_filename = os.path.basename(video_path).lower()

    # Determine the dynamic time interval based on filename keywords
    time_interval = determine_time_interval(video_filename)

    # Get total frames in the video
    total_frames = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))

    # Ensure frame_skip does not exceed total frames
    frame_skip = min(fps * time_interval, total_frames // 2)  # Reduced skipping

    frame_count = 0

    # Reinitialize the tracker to clear any previous state
    tracker = Sort()

    while True:
        ret, frame = cap.read()
        if not ret:
            break  # End of video

        frame_count += 1
        if frame_count % frame_skip != 0:
            continue  # Skip frames based on interval

        # Run YOLOv12x inference
        results = model(frame, verbose=False)

        detections = []
        for result in results:
            for box in result.boxes:
                class_id = int(box.cls.item())  # Get class ID
                confidence = float(box.conf.item())  # Get confidence score

                # Track only people
                if class_id == PEOPLE_CLASS_ID and confidence > CONFIDENCE_THRESHOLD:
                    x1, y1, x2, y2 = map(int, box.xyxy[0])  # Get bounding box
                    detections.append([x1, y1, x2, y2, confidence])

        # Debugging: Check detections
        print(f"Frame {frame_count}: Detections -> {detections}")

        if len(detections) > 0:
            detections = np.array(detections)
            tracked_objects = tracker.update(detections)
        else:
            tracked_objects = []  # Prevent tracker from resetting

        # Debugging: Check tracked objects
        print(f"Frame {frame_count}: Tracked Objects -> {tracked_objects}")

        for obj in tracked_objects:
            people_id = int(obj[4])  # Unique ID assigned by SORT
            x1, y1, x2, y2 = obj[:4]  # Get the bounding box coordinates

            people_center = (x1 + x2) / 2, (y1 + y2) / 2  # Calculate people center

            # If people is already in history, check movement distance
            if people_id in people_history:
                last_position = people_history[people_id]["position"]
                distance = np.linalg.norm(np.array(people_center) - np.array(last_position))

                if distance > DISTANCE_THRESHOLD:
                    unique_people_ids.add(people_id)  # Add only if moved significantly

            else:
                # If people is not in history, add it
                people_history[people_id] = {
                    "frame_count": frame_count,
                    "position": people_center
                }
                unique_people_ids.add(people_id)

    cap.release()
    return {"Total Unique People": len(unique_people_ids)}


# Gradio UI function
def analyze_video(video_file):
    result = count_unique_people(video_file)
    return "\n".join([f"{key}: {value}" for key, value in result.items()])

# Define Gradio interface
iface = gr.Interface(
    fn=analyze_video,
    inputs=gr.Video(label="Upload Video"),
    outputs=gr.Textbox(label="Analysis Result"),
    title="YOLOv12x Unique People Counter",
    description="Upload a video to count unique people using YOLOv12x and SORT tracking."
)

# Launch the Gradio app
if __name__ == "__main__":
    iface.launch()