import gradio as gr
import pandas as pd
from mcq_generator import ImprovedMCQGenerator, is_suitable_for_students
import io
import tempfile # <-- Import tempfile
import traceback # <-- Optional: for better error logging

# Initialize MCQ Generator (Keep this outside the function for efficiency)
try:
    mcq_generator = ImprovedMCQGenerator()
    print("✅ MCQ Generator Initialized Successfully")
except Exception as e:
    print(f"❌ Failed to initialize MCQ Generator: {e}")
    # You might want to stop the app or handle this more gracefully
    mcq_generator = None

def generate_mcqs_ui(paragraph, num_questions):
    # Check if generator initialized properly
    if mcq_generator is None:
        return None, None, None, "❌ Error: MCQ Generator failed to initialize. Check server logs."

    # --- Input Validation ---
    if not paragraph or not paragraph.strip():
        return None, None, None, "⚠️ Please enter a valid paragraph."

    print("\n--- Checking Suitability ---") # Add logging
    if not is_suitable_for_students(paragraph):
        print("❌ Paragraph deemed unsuitable.") # Add logging
        # Return None for HTML and both file paths, plus the status message
        return None, None, None, "❌ The paragraph is not suitable for MCQ generation (due to bias/toxicity/short length)."
    print("✅ Paragraph suitable.") # Add logging

    try:
        print(f"--- Generating {num_questions} MCQs ---") # Add logging
        # Generate MCQs using the generator
        mcqs = mcq_generator.generate_mcqs(paragraph, num_questions)

        if not mcqs:
             print("⚠️ No MCQs generated (potentially issue in generator logic).") # Add logging
             return None, None, None, "⚠️ Could not generate MCQs for this text. Try different content or fewer questions."

        print(f"✅ Generated {len(mcqs)} MCQs successfully.") # Add logging

        # --- Create Pretty HTML Output ---
        pretty_mcqs_html = ""
        for idx, mcq in enumerate(mcqs):
            options = ""
            # Ensure options exist and handle potential errors
            mcq_options = mcq.get('options', [])
            answer_index = mcq.get('answer_index', -1)
            question_text = mcq.get('question', '[No Question Text]')

            for opt_idx, option in enumerate(mcq_options):
                options += f"<b>{chr(65+opt_idx)}.</b> {option}<br>"

            question_html = f"<div style='margin-bottom:20px; padding:10px; border:1px solid #ccc; border-radius:10px; background:#f9f9f9;'>"
            question_html += f"<b>Q{idx+1}:</b> {question_text}<br><br>{options}"
            if 0 <= answer_index < len(mcq_options):
                 question_html += f"<i><b>Answer:</b> {chr(65+answer_index)}</i>"
            else:
                 question_html += f"<i><b>Answer:</b> [Invalid Answer Index]</i>"
            question_html += "</div>"
            pretty_mcqs_html += question_html

        # --- Prepare Text Output and CSV Data ---
        txt_output = ""
        csv_data = []

        for idx, mcq in enumerate(mcqs):
            mcq_options = mcq.get('options', [])
            answer_index = mcq.get('answer_index', -1)
            question_text = mcq.get('question', '[No Question Text]')

            txt_output += f"Q{idx+1}: {question_text}\n"
            for opt_idx, option in enumerate(mcq_options):
                txt_output += f"   {chr(65+opt_idx)}. {option}\n"

            if 0 <= answer_index < len(mcq_options):
                txt_output += f"Answer: {chr(65+answer_index)}\n\n"
            else:
                txt_output += f"Answer: [Invalid Answer Index]\n\n"

            # Ensure 4 options for CSV, padding if necessary
            options_padded = mcq_options + [''] * (4 - len(mcq_options))
            csv_row = {
                'Question': question_text,
                'Option A': options_padded[0],
                'Option B': options_padded[1],
                'Option C': options_padded[2],
                'Option D': options_padded[3],
                'Answer': chr(65+answer_index) if 0 <= answer_index < len(mcq_options) else '[Invalid]'
            }
            csv_data.append(csv_row)

        # --- Create In-Memory Buffers (Still useful for structuring data) ---
        txt_buffer = io.StringIO()
        txt_buffer.write(txt_output)
        txt_buffer.seek(0)

        csv_buffer = io.StringIO()
        pd.DataFrame(csv_data).to_csv(csv_buffer, index=False)
        csv_buffer.seek(0)

        # --- Create Temporary Files and Get Paths ---
        print("--- Creating temporary files ---") # Add logging
        # Use delete=False so Gradio can access the file after the 'with' block closes it.
        # Gradio should handle the cleanup of these temporary files.
        with tempfile.NamedTemporaryFile(mode="w", suffix=".txt", delete=False, encoding='utf-8') as temp_txt:
            temp_txt.write(txt_buffer.getvalue())
            txt_filepath = temp_txt.name
            print(f"Created TXT temp file: {txt_filepath}") # Add logging

        with tempfile.NamedTemporaryFile(mode="w", suffix=".csv", delete=False, encoding='utf-8') as temp_csv:
            temp_csv.write(csv_buffer.getvalue())
            csv_filepath = temp_csv.name
            print(f"Created CSV temp file: {csv_filepath}") # Add logging

        # --- Return HTML, File Paths, and Status ---
        # Return order must match the `outputs` list in demo.launch()
        return pretty_mcqs_html, txt_filepath, csv_filepath, "✅ MCQs generated successfully!"

    except Exception as e:
        print(f"❌ Error during MCQ generation process: {e}") # Add logging
        print(traceback.format_exc()) # Print detailed traceback for debugging
        # Return None for HTML and both file paths, plus the error message
        return None, None, None, f"❌ Error generating MCQs: {str(e)}"


# --- Define Gradio Interface ---
with gr.Blocks(theme=gr.themes.Soft()) as demo: # Added a theme for aesthetics
    gr.Markdown("<h1 style='text-align:center;'>📚 Smart MCQ Generator</h1>")
    gr.Markdown("Enter a paragraph of study material, choose the number of questions, and get MCQs instantly!") # Added description

    with gr.Row():
        paragraph_input = gr.Textbox(
            lines=10, # Increased lines
            label="Enter Paragraph for MCQs",
            placeholder="Paste your study material here (ideally 50-500 words)...",
            elem_id="paragraph-input" # Added elem_id for potential CSS styling
        )

    with gr.Row():
        num_questions_slider = gr.Slider(
            minimum=1, # Explicit minimum
            maximum=10, # Explicit maximum
            step=1,
            value=5,
            label="Number of Questions to Generate",
            elem_id="num-questions-slider"
        )

    with gr.Row():
        generate_btn = gr.Button("🚀 Generate MCQs", variant="primary") # Made button primary

    # Status box
    status = gr.Textbox(label="Status", interactive=False, placeholder="Generation status will appear here...", elem_id="status-box")

    # Use Accordion for tidier output section
    with gr.Accordion("Generated MCQs & Downloads", open=True): # Default to open
        # MCQ HTML output
        mcq_output = gr.HTML(label="Generated MCQs")

        # Download links - SEPARATED
        with gr.Row():
            download_txt = gr.File(label="Download MCQs (.txt)")
            download_csv = gr.File(label="Download MCQs (.csv)")

    # Set up the button click event
    generate_btn.click(
        fn=generate_mcqs_ui,
        inputs=[paragraph_input, num_questions_slider],
        # Outputs must match the return order of generate_mcqs_ui
        outputs=[mcq_output, download_txt, download_csv, status],
        api_name="generate_mcqs" # Added api_name for potential API usage
    )

# --- Launch the app ---
# share=True generates a public link (useful for HF Spaces)
# server_name="0.0.0.0" makes it accessible within the container network
# server_port=7860 is the standard Gradio port for Spaces
print("--- Launching Gradio App ---")
demo.launch(share=True, server_name="0.0.0.0", server_port=7860)