# Ensure system dependencies are installed
import os
import tempfile
from utils.parsing_utils import extract_text_from_file, parse_cv_content
from utils.latex_utils import generate_latex, compile_latex_to_pdf
from utils.gemini_utils import generate_ats_optimized_content
from pygments import highlight
from pygments.lexers import TexLexer
from pygments.formatters import HtmlFormatter

import streamlit as st
import os

# Hugging Face Spaces specific configuration
if os.environ.get('IS_HF_SPACE'):
    from streamlit.web import cli as stcli
    import sys
    
    def main():
        sys.argv = [
            "streamlit", 
            "run", 
            "app.py", 
            "--server.port=7860", 
            "--server.address=0.0.0.0",
            "--server.headless=true",
            "--browser.gatherUsageStats=false",
            "--server.enableXsrfProtection=false"
        ]
        sys.exit(stcli.main())

    if __name__ == "__main__":
        main()

# Set page config
st.set_page_config(
    page_title="ATS-Friendly CV Builder",
    page_icon="📄",
    layout="centered",
    initial_sidebar_state="expanded"
)

# Custom CSS
def local_css(file_name):
    with open(file_name) as f:
        st.markdown(f'<style>{f.read()}</style>', unsafe_allow_html=True)

local_css("style.css")

# Initialize session state
if 'original_cv_data' not in st.session_state:
    st.session_state.original_cv_data = {}
if 'edited_cv_data' not in st.session_state:
    st.session_state.edited_cv_data = {}
if 'job_description' not in st.session_state:
    st.session_state.job_description = ""
if 'generated_latex' not in st.session_state:
    st.session_state.generated_latex = ""

# App header
st.title("📄 ATS-Friendly CV Builder")
st.markdown("""
Upload your existing CV, customize it, and generate an optimized ATS-friendly resume tailored to any job description.
""")

# File upload section
st.header("1. Upload Your Existing CV")
uploaded_file = st.file_uploader(
    "Upload your CV (PDF, DOCX, or TXT)",
    type=["pdf", "docx", "txt"],
    help="We'll extract the information to create your base resume"
)

if uploaded_file:
    with st.spinner("Extracting information from your CV..."):
        try:
            # Extract text from uploaded file
            file_content = extract_text_from_file(uploaded_file)
            
            # Parse the CV content into structured data
            cv_data = parse_cv_content(file_content)
            
            # Store in session state
            st.session_state.original_cv_data = cv_data
            st.session_state.edited_cv_data = cv_data.copy()
            
            st.success("CV information extracted successfully!")
            
            # Show extracted data for verification
            with st.expander("View extracted information"):
                st.json(cv_data, expanded=False)
                
        except Exception as e:
            st.error(f"Error processing your file: {str(e)}")

# Edit CV section
if st.session_state.original_cv_data:
    st.header("2. Edit Your Information")
    
    # Personal Information
    with st.expander("Personal Information", expanded=True):
        cols = st.columns(2)
        with cols[0]:
            st.session_state.edited_cv_data['name'] = st.text_input(
                "Full Name", 
                value=st.session_state.edited_cv_data.get('name', '')
            )
            st.session_state.edited_cv_data['email'] = st.text_input(
                "Email", 
                value=st.session_state.edited_cv_data.get('email', '')
            )
        with cols[1]:
            st.session_state.edited_cv_data['phone'] = st.text_input(
                "Phone", 
                value=st.session_state.edited_cv_data.get('phone', '')
            )
            st.session_state.edited_cv_data['linkedin'] = st.text_input(
                "LinkedIn URL", 
                value=st.session_state.edited_cv_data.get('linkedin', '')
            )
    
    # Professional Summary
    st.session_state.edited_cv_data['summary'] = st.text_area(
        "Professional Summary",
        value=st.session_state.edited_cv_data.get('summary', ''),
        height=100,
        help="A brief overview of your professional background and skills"
    )
    
    # Skills
    skills = st.text_area(
        "Skills (comma separated)",
        value=", ".join(st.session_state.edited_cv_data.get('skills', [])),
        help="List your technical and soft skills"
    )
    st.session_state.edited_cv_data['skills'] = [s.strip() for s in skills.split(",") if s.strip()]
    
    # Experience
    st.subheader("Work Experience")
    if 'experience' not in st.session_state.edited_cv_data:
        st.session_state.edited_cv_data['experience'] = []
    
    for i, exp in enumerate(st.session_state.edited_cv_data['experience']):
        with st.expander(f"Experience {i+1}", expanded=i==0):
            cols = st.columns(2)
            with cols[0]:
                exp['title'] = st.text_input(
                    "Job Title", 
                    value=exp.get('title', ''),
                    key=f"exp_title_{i}"
                )
                exp['company'] = st.text_input(
                    "Company", 
                    value=exp.get('company', ''),
                    key=f"exp_company_{i}"
                )
            with cols[1]:
                exp['start_date'] = st.text_input(
                    "Start Date", 
                    value=exp.get('start_date', ''),
                    key=f"exp_start_{i}"
                )
                exp['end_date'] = st.text_input(
                    "End Date", 
                    value=exp.get('end_date', ''),
                    key=f"exp_end_{i}"
                )
            exp['description'] = st.text_area(
                "Description", 
                value=exp.get('description', ''),
                height=100,
                key=f"exp_desc_{i}"
            )
    
    # Add new experience
    if st.button("➕ Add Another Position"):
        st.session_state.edited_cv_data['experience'].append({
            'title': '',
            'company': '',
            'start_date': '',
            'end_date': '',
            'description': ''
        })
        st.experimental_rerun()
    
    # Education
    st.subheader("Education")
    if 'education' not in st.session_state.edited_cv_data:
        st.session_state.edited_cv_data['education'] = []
    
    for i, edu in enumerate(st.session_state.edited_cv_data['education']):
        with st.expander(f"Education {i+1}", expanded=i==0):
            cols = st.columns(2)
            with cols[0]:
                edu['degree'] = st.text_input(
                    "Degree", 
                    value=edu.get('degree', ''),
                    key=f"edu_degree_{i}"
                )
                edu['institution'] = st.text_input(
                    "Institution", 
                    value=edu.get('institution', ''),
                    key=f"edu_institution_{i}"
                )
            with cols[1]:
                edu['start_date'] = st.text_input(
                    "Start Date", 
                    value=edu.get('start_date', ''),
                    key=f"edu_start_{i}"
                )
                edu['end_date'] = st.text_input(
                    "End Date", 
                    value=edu.get('end_date', ''),
                    key=f"edu_end_{i}"
                )
    
    # Add new education
    if st.button("➕ Add Another Education"):
        st.session_state.edited_cv_data['education'].append({
            'degree': '',
            'institution': '',
            'start_date': '',
            'end_date': ''
        })
        st.experimental_rerun()
    
    # Projects
    st.subheader("Projects")
    if 'projects' not in st.session_state.edited_cv_data:
        st.session_state.edited_cv_data['projects'] = []
    
    for i, proj in enumerate(st.session_state.edited_cv_data['projects']):
        with st.expander(f"Project {i+1}", expanded=i==0):
            proj['title'] = st.text_input(
                "Project Title", 
                value=proj.get('title', ''),
                key=f"proj_title_{i}"
            )
            proj['description'] = st.text_area(
                "Description", 
                value=proj.get('description', ''),
                height=100,
                key=f"proj_desc_{i}"
            )
    
    # Add new project
    if st.button("➕ Add Another Project"):
        st.session_state.edited_cv_data['projects'].append({
            'title': '',
            'description': ''
        })
        st.experimental_rerun()

# Job Description and Optimization
if st.session_state.edited_cv_data:
    st.header("3. Optimize for a Job")
    st.session_state.job_description = st.text_area(
        "Paste the Job Description",
        value=st.session_state.job_description,
        height=200,
        help="Paste the job description you're applying for to get tailored recommendations"
    )
    
    # In your app.py where you have the rerun call
    if st.button("✨ Optimize for This Job"):
        if not st.session_state.job_description:
            st.warning("Please enter a job description first")
        else:
            with st.spinner("Generating ATS-optimized content..."):
                try:
                    optimized_data = generate_ats_optimized_content(
                        st.session_state.edited_cv_data,
                        st.session_state.job_description
                    )
                    st.session_state.edited_cv_data = optimized_data
                    st.success("Optimization complete! Review the changes below.")
                    st.experimental_rerun()  # Remove this line
                    st.rerun()  # Use this instead
                except Exception as e:
                    st.error(f"Error during optimization: {str(e)}")

# Generate LaTeX and PDF
if st.session_state.edited_cv_data:
    st.header("4. Generate Your ATS-Friendly Resume")
    
    if st.button("🔄 Generate LaTeX Code"):
        with st.spinner("Generating LaTeX code..."):
            try:
                latex_code = generate_latex(st.session_state.edited_cv_data)
                st.session_state.generated_latex = latex_code
            except Exception as e:
                st.error(f"Error generating LaTeX: {str(e)}")
    
    if st.session_state.generated_latex:
        # Display LaTeX code with syntax highlighting
        st.subheader("Generated LaTeX Code")
        st.markdown("""
        Review and edit the LaTeX code below if needed before generating your PDF.
        """)
        
        # Syntax highlighting
        formatter = HtmlFormatter(style="colorful")
        styled_code = highlight(
            st.session_state.generated_latex, 
            TexLexer(), 
            formatter
        )
        st.markdown(styled_code, unsafe_allow_html=True)
        
        # Download LaTeX
        st.download_button(
            label="📥 Download LaTeX File",
            data=st.session_state.generated_latex,
            file_name="resume.tex",
            mime="text/plain"
        )
        
        # Generate and download PDF
        if st.button("🖨️ Generate PDF"):
            with st.spinner("Compiling PDF..."):
                try:
                    with tempfile.TemporaryDirectory() as tempdir:
                        tex_file = os.path.join(tempdir, "resume.tex")
                        with open(tex_file, "w") as f:
                            f.write(st.session_state.generated_latex)
                        
                        pdf_path = compile_latex_to_pdf(tex_file, tempdir)
                        
                        if pdf_path and os.path.exists(pdf_path):
                            with open(pdf_path, "rb") as f:
                                pdf_bytes = f.read()
                            
                            st.success("PDF generated successfully!")
                            st.download_button(
                                label="📥 Download PDF",
                                data=pdf_bytes,
                                file_name="resume.pdf",
                                mime="application/pdf"
                            )
                        else:
                            st.error("Failed to generate PDF")
                except Exception as e:
                    st.error(f"Error generating PDF: {str(e)}")
                    st.text(str(e))