import streamlit as st
import os
from fpdf import FPDF
import uuid

# Initialize session state variables
if 'session_id' not in st.session_state:
    st.session_state.session_id = str(uuid.uuid4())

if 'questions' not in st.session_state:
    st.session_state.questions = []
if 'current_index' not in st.session_state:
    st.session_state.current_index = 0
if 'current_module' not in st.session_state:
    st.session_state.current_module = None
if 'correct_count' not in st.session_state:
    st.session_state.correct_count = 0
if 'module_correct_count' not in st.session_state:
    st.session_state.module_correct_count = {}
if 'module_question_count' not in st.session_state:
    st.session_state.module_question_count = {}
if 'pdf_data' not in st.session_state:
    st.session_state.pdf_data = None
if 'selected_answer' not in st.session_state:
    st.session_state.selected_answer = None
if 'button_label' not in st.session_state:
    st.session_state.button_label = "Submit/New"

def reset_pdf_cache():
    st.session_state.pdf_data = None

def generate_pdf_report():
    pdf = FPDF()
    pdf.add_page()
    pdf.set_font("Arial", size=12)
    
    pdf.cell(200, 10, txt="Quiz Report", ln=True, align="C")
    pdf.ln(10)

    for module, data in st.session_state.module_question_count.items():
        correct_count = st.session_state.module_correct_count.get(module, 0)
        total_count = data
        pdf.cell(200, 10, txt=f"Module: {module}", ln=True, align="L")
        pdf.ln(5)
        pdf.cell(200, 10, txt=f"Correct Answers: {correct_count}/{total_count}", ln=True, align="L")
        pdf.ln(5)

        for entry in st.session_state.questions:
            if entry['module'] == module:
                question, options, selected, correct, explanation, step_by_step_solution = (
                    entry['question'], 
                    entry['options'], 
                    entry['selected'] if entry['selected'] is not None else "Not Answered",
                    entry['correct_answer'], 
                    entry['explanation'],
                    entry['step_by_step_solution']
                )
                pdf.multi_cell(0, 10, f"Q: {question}")
                for option in options:
                    if option == correct:
                        pdf.set_text_color(0, 128, 0)  # Green for correct
                        pdf.multi_cell(0, 10, f"{option}")
                    elif option == selected:
                        pdf.set_text_color(255, 0, 0)  # Red for incorrect
                        pdf.multi_cell(0, 10, f"{option}")
                    else:
                        pdf.set_text_color(0, 0, 0)  # Default color for others
                        pdf.multi_cell(0, 10, f"   {option}")
                pdf.set_text_color(0, 0, 0)  # Reset color
                pdf.multi_cell(0, 10, f"Explanation: {explanation}")
                pdf.ln(5)
                pdf.multi_cell(0, 10, "Step-by-Step Solution:")
                for step in step_by_step_solution:
                    pdf.multi_cell(0, 10, step)
                pdf.ln(10)

        pdf.ln(10)  # Add space after each module

    return pdf.output(dest='S').encode('latin1', 'replace')

def load_modules():
    modules = {}
    module_dir = "modules"
    for filename in os.listdir(module_dir):
        if filename.endswith(".py") and filename != "__init__.py":
            module_name = filename[:-3]
            # Dynamically import the module only when needed
            module = __import__(f"{module_dir}.{module_name}", fromlist=[''])
            modules[module_name] = {
                "title": getattr(module, "title", module_name),
                "description": getattr(module, "description", "No description available."),
                "generate_question": module.generate_question  # Access the generate_question function
            }
    return modules

def generate_new_question(module_name, module):
    question_data = module['generate_question']()
    question_data['answered'] = False
    question_data['module'] = module_name
    question_data['selected'] = None
    if len(question_data['options']) != 4:
        st.warning(f"Question in module '{module_name}' does not have 4 options. Found {len(question_data['options'])}.")
    return question_data

def navigate_question(direction):
    if direction == "prev" and st.session_state.current_index > 0:
        st.session_state.current_index -= 1
    elif direction == "next" and st.session_state.current_index < len(st.session_state.questions) - 1:
        st.session_state.current_index += 1

# Load all modules dynamically
modules = load_modules()

# Streamlit interface
st.sidebar.title("Quiz Modules")
module_name = st.sidebar.radio("Choose a module:", [modules[module]["title"] for module in modules], index=0)

selected_module = None
for module in modules:
    if modules[module]["title"] == module_name:
        selected_module = module
        break

if selected_module != st.session_state.current_module:
    st.session_state.current_module = selected_module
    st.session_state.current_index = 0
    st.session_state.questions = [generate_new_question(selected_module, modules[selected_module])]
    st.session_state.module_question_count[selected_module] = 0
    st.session_state.module_correct_count[selected_module] = 0
    st.session_state.selected_answer = None
    st.session_state.button_label = "Submit/New"

# Load the current module's question
current_question = st.session_state.questions[st.session_state.current_index]

# Display module title and description
st.title(modules[selected_module]["title"])
st.write(modules[selected_module]["description"])

# Navigation and PDF report buttons
col1, col2, col3 = st.columns([1, 1, 2])
with col1:
    if st.button("⬅️ Prev", disabled=st.session_state.current_index == 0):
        navigate_question("prev")
with col2:
    if st.button("➡️ Next", disabled=st.session_state.current_index >= len(st.session_state.questions) - 1):
        navigate_question("next")
with col3:
    if len(st.session_state.questions) > 0:
        pdf = generate_pdf_report()
        st.session_state.pdf_data = pdf  # Reset PDF cache
        st.download_button(
            label="Download PDF Report 📄",
            data=st.session_state.pdf_data,
            file_name="quiz_report.pdf",
            mime="application/pdf"
        )

st.write(current_question["question"])

# Create the form for the question
with st.form(key=f'question_form_{st.session_state.current_index}'):
    selected_answer = st.radio(
        "Choose an answer:", 
        options=current_question['options'], 
        key=f"question_{st.session_state.current_index}_options",
        index=None  # Ensure no option is pre-selected
    )
    
    submit_button = st.form_submit_button(label=st.session_state.button_label)

# Handle button state and answer submission
if submit_button and st.session_state.button_label == "Submit/New":
    if selected_answer is not None:
        # Process the answer
        current_question['selected'] = selected_answer
        current_question['answered'] = True
        st.session_state.module_question_count[selected_module] += 1

        if selected_answer == current_question['correct_answer']:
            st.session_state.correct_count += 1
            st.session_state.module_correct_count[selected_module] += 1

        st.session_state.button_label = "Next Question"
    else:
        st.warning("Please select an option before submitting.", icon="⚠️")
        st.stop()

# Show correct/incorrect feedback after submission
if current_question.get('answered', False):
    for option in current_question['options']:
        if option == current_question['correct_answer']:
            st.markdown(f"<span style='color:green;'>{option} ✅</span>", unsafe_allow_html=True)
        elif option == current_question['selected']:
            st.markdown(f"<span style='color:red;'>{option} ❌</span>", unsafe_allow_html=True)
        else:
            st.markdown(f"{option}")
    
    st.write(f"**Explanation:** {current_question['explanation']}")
    st.write("**Step-by-Step Solution:**")
    for step in current_question['step_by_step_solution']:
        st.write(step)

# Disable options and button when navigating through previous questions
if st.session_state.current_index < len(st.session_state.questions) - 1:
    st.session_state.button_label = "Next Question"
else:
    st.session_state.button_label = "Submit/New"

if st.session_state.current_index > 0:
    st.session_state.button_label = "Next Question"
    st.session_state.selected_answer = None
    st.form_submit_button(label=st.session_state.button_label, disabled=True)
    st.radio("Choose an answer:", options=current_question['options'], index=None, disabled=True)