import gradio as gr
import torch
from PIL import Image
import pandas as pd
from lavis.models import load_model_and_preprocess
from lavis.processors import load_processor
from transformers import AutoTokenizer, AutoModelForCausalLM, AutoProcessor
import tensorflow as tf
import tensorflow_hub as hub
import io
from sklearn.metrics.pairwise import cosine_similarity
import tempfile # Add this import
import logging

# Configure logging
logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')

# Load model and preprocessors for Image-Text Matching (LAVIS)
device = torch.device("cuda") if torch.cuda.is_available() else "cpu"
model_itm, vis_processors, text_processors = load_model_and_preprocess("blip2_image_text_matching", "pretrain", device=device, is_eval=True)

# Load tokenizer and model for Image Captioning (TextCaps)
git_processor_large_textcaps = AutoProcessor.from_pretrained("microsoft/git-large-r-textcaps")
git_model_large_textcaps = AutoModelForCausalLM.from_pretrained("microsoft/git-large-r-textcaps")

# Load Universal Sentence Encoder model for textual similarity calculation
embed = hub.load("https://tfhub.dev/google/universal-sentence-encoder/4")

# Define a function to compute textual similarity between caption and statement
def compute_textual_similarity(caption, statement):
    # Convert caption and statement into sentence embeddings
    caption_embedding = embed([caption])[0].numpy()
    statement_embedding = embed([statement])[0].numpy()

    # Calculate cosine similarity between sentence embeddings
    similarity_score = cosine_similarity([caption_embedding], [statement_embedding])[0][0]
    return similarity_score

# Read statements from the external file 'statements.txt'
with open('statements.txt', 'r') as file:
    statements = file.read().splitlines()

# Function to compute ITM scores for the image-statement pair
def compute_itm_score(image, statement):
    logging.info('Starting compute_itm_score')
    pil_image = Image.fromarray(image.astype('uint8'), 'RGB')
    img = vis_processors["eval"](pil_image.convert("RGB")).unsqueeze(0).to(device)
    # Pass the statement text directly to model_itm
    itm_output = model_itm({"image": img, "text_input": statement}, match_head="itm")
    itm_scores = torch.nn.functional.softmax(itm_output, dim=1)
    score = itm_scores[:, 1].item()
    logging.info('Finished compute_itm_score')
    return score

def generate_caption(processor, model, image):
    logging.info('Starting generate_caption')
    inputs = processor(images=image, return_tensors="pt").to(device)
    generated_ids = model.generate(pixel_values=inputs.pixel_values, max_length=50)
    generated_caption = processor.batch_decode(generated_ids, skip_special_tokens=True)[0]
    logging.info('Finished generate_caption')
    return generated_caption

def save_dataframe_to_csv(df):
    csv_buffer = io.StringIO()
    df.to_csv(csv_buffer, index=False)
    csv_string = csv_buffer.getvalue()

    # Save the CSV string to a temporary file
    with tempfile.NamedTemporaryFile(mode="w+", delete=False, suffix=".csv") as temp_file:
        temp_file.write(csv_string)
        temp_file_path = temp_file.name # Get the file path

    # Return the file path (no need to reopen the file with "rb" mode)
    return temp_file_path

# Main function to perform image captioning and image-text matching
def process_images_and_statements(image):
    logging.info('Starting process_images_and_statements')

    # Generate image caption for the uploaded image using git-large-r-textcaps
    caption = generate_caption(git_processor_large_textcaps, git_model_large_textcaps, image)

    # Define weights for combining textual similarity score and image-statement ITM score (adjust as needed)
    weight_textual_similarity = 0.5
    weight_statement = 0.5

    # Initialize an empty list to store the results
    results_list = []

    # Loop through each predefined statement
    for statement in statements:
        # Compute textual similarity between caption and statement
        textual_similarity_score = (compute_textual_similarity(caption, statement) * 100) # Multiply by 100

        # Compute ITM score for the image-statement pair
        itm_score_statement = (compute_itm_score(image, statement) * 100) # Multiply by 100

        # Combine the two scores using a weighted average
        final_score = ((weight_textual_similarity * textual_similarity_score) +
                       (weight_statement * itm_score_statement))

        # Append the result to the results_list
        results_list.append({
            'Statement': statement,
            'Generated Caption': caption, # Include the generated caption
            'Textual Similarity Score': f"{textual_similarity_score:.2f}%", # Format as percentage with two decimal places
            'ITM Score': f"{itm_score_statement:.2f}%", # Format as percentage with two decimal places
            'Final Combined Score': f"{final_score:.2f}%" # Format as percentage with two decimal places
        })

    # Convert the results_list to a DataFrame using pandas.concat
    results_df = pd.concat([pd.DataFrame([result]) for result in results_list], ignore_index=True)

    logging.info('Finished process_images_and_statements')

    # Save results_df to a CSV file
    csv_results = save_dataframe_to_csv(results_df)

    # Return both the DataFrame and the CSV data for the Gradio interface
    return results_df, csv_results # <--- Return results_df and csv_results

# Gradio interface
image_input = gr.inputs.Image()
output_df = gr.outputs.Dataframe(type="pandas", label="Results")
output_csv = gr.outputs.File(label="Download CSV")

iface = gr.Interface(
    fn=process_images_and_statements,
    inputs=image_input,
    outputs=[output_df, output_csv], # Include both the DataFrame and CSV file outputs
    title="Image Captioning and Image-Text Matching",
    theme='sudeepshouche/minimalist',
    css=".output { flex-direction: column; } .output .outputs { width: 100%; }" # Custom CSS
)

iface.launch()