import os
from typing import List, Tuple
import multiprocessing

import numpy as np
import pandas as pd
import streamlit as st
import torch
from torch import Tensor
from decord import VideoReader, cpu
from transformers import AutoFeatureExtractor, TimesformerForVideoClassification

np.random.seed(0)

st.set_page_config(
    page_title="TimeSFormer",
    page_icon="🧊",
    layout="wide",
    initial_sidebar_state="expanded",
    menu_items={
        "Get Help": "https://www.extremelycoolapp.com/help",
        "Report a bug": "https://www.extremelycoolapp.com/bug",
        "About": "# This is a header. This is an *extremely* cool app!",
    },
)


def sample_frame_indices(
    clip_len: int, frame_sample_rate: float, seg_len: int
) -> np.ndarray:
    converted_len = int(clip_len * frame_sample_rate)
    end_idx = np.random.randint(converted_len, seg_len)
    start_idx = end_idx - converted_len
    indices = np.linspace(start_idx, end_idx, num=clip_len)
    indices = np.clip(indices, start_idx, end_idx - 1).astype(np.int64)
    return indices


@st.cache_resource
def load_model():
    feature_extractor = AutoFeatureExtractor.from_pretrained(
        "MCG-NJU/videomae-base-finetuned-kinetics"
    )
    model = TimesformerForVideoClassification.from_pretrained(
        "facebook/timesformer-base-finetuned-k400"
    )
    return feature_extractor, model


feature_extractor, model = load_model()


def inference(file_path: str):
    videoreader = VideoReader(VIDEO_TMP_PATH, num_threads=1, ctx=cpu(0))

    # sample 8 frames
    videoreader.seek(0)
    indices = sample_frame_indices(
        clip_len=8, frame_sample_rate=4, seg_len=len(videoreader)
    )
    video = videoreader.get_batch(indices).asnumpy()

    inputs = feature_extractor(list(video), return_tensors="pt")

    with torch.no_grad():
        outputs = model(**inputs)
        logits: Tensor = outputs.logits

    # model predicts one of the 400 Kinetics-400 classes
    predicted_label = logits.argmax(-1).item()
    print(model.config.id2label[predicted_label])

    TOP_K = 5
    # logits = np.squeeze(logits)
    logits = logits.squeeze().numpy()
    indices = np.argsort(logits)[::-1][:TOP_K]
    values = logits[indices]

    results: List[Tuple[str, float]] = []
    for index, value in zip(indices, values):
        predicted_label = model.config.id2label[index]
        print(f"Label: {predicted_label} - {value:.2f}%")
        results.append((predicted_label, value))

    return pd.DataFrame(results, columns=("Label", "Confidence"))


st.title("TimeSFormer")

with st.expander("INTRODUCTION"):
    st.text(
        f"""Streamlit demo for TimeSFormer. 
        Author: Hiep Phuoc Secondary High School
        Number of CPU(s): {multiprocessing.cpu_count()}
    """
    )

VIDEO_TMP_PATH = os.path.join("tmp", "tmp.mp4")
uploadedfile = st.file_uploader("Upload file", type=["mp4"])

if uploadedfile is not None:
    with st.spinner():
        with open(VIDEO_TMP_PATH, "wb") as f:
            f.write(uploadedfile.getbuffer())

    with st.spinner("Processing..."):
        df = inference(VIDEO_TMP_PATH)
    st.dataframe(df)
    st.video(VIDEO_TMP_PATH)