import streamlit as st
import PyPDF2
import re
import nltk
from nltk.tokenize import word_tokenize
from nltk.corpus import wordnet
import requests
from typing import Optional
import pandas as pd
from sqlalchemy import create_engine, Column, Integer, String, Float
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
import json
import openai  # Import OpenAI

# Initialize NLTK resources
def download_nltk_resources():
    resources = {
        'punkt': 'tokenizers/punkt',
        'averaged_perceptron_tagger': 'taggers/averaged_perceptron_tagger',
        'wordnet': 'corpora/wordnet',
        'stopwords': 'corpora/stopwords'
    }
    for package, resource in resources.items():
        try:
            nltk.data.find(resource)
        except LookupError:
            nltk.download(package)

download_nltk_resources()

# Ensure spaCy model is downloaded
import spacy
try:
    nlp = spacy.load("en_core_web_sm")
except OSError:
    spacy.cli.download("en_core_web_sm")
    nlp = spacy.load("en_core_web_sm")

# Database setup
Base = declarative_base()

class ResumeScore(Base):
    __tablename__ = 'resume_scores'
    id = Column(Integer, primary_key=True)
    resume_name = Column(String)
    score = Column(Float)
    skills = Column(String)
    certifications = Column(String)
    experience_years = Column(Float)
    education_level = Column(String)
    summary = Column(String)

# Create engine and session
engine = create_engine('sqlite:///resumes.db')
Base.metadata.create_all(engine)
Session = sessionmaker(bind=engine)
session = Session()

# Custom CSS to enhance UI
def set_custom_css():
    st.markdown("""
    <style>
        .stProgress .st-bo {
            background-color: #f0f2f6;
        }
        .stProgress .st-bp {
            background: linear-gradient(to right, #4CAF50, #8BC34A);
        }
        .skill-tag {
            display: inline-block;
            padding: 5px 10px;
        }
    </style>
    """, unsafe_allow_html=True)

def get_docparser_data(file, api_key, parser_id) -> Optional[dict]:
    try:
        # First, upload the document
        upload_url = f"https://api.docparser.com/v1/document/upload/{parser_id}"
        
        # Create proper headers with base64 encoded API key
        import base64
        auth_string = base64.b64encode(f"{api_key}:".encode()).decode()
        headers = {
            'Authorization': f'Basic {auth_string}'
        }
        
        # Prepare the file for upload
        files = {
            'file': (file.name, file, 'application/pdf')
        }
        
        # Upload document
        upload_response = requests.post(
            upload_url,
            headers=headers,
            files=files
        )
        upload_response.raise_for_status()
        
        # Get document ID from upload response
        upload_data = upload_response.json()
        
        # Extract document ID from the correct response format
        document_id = upload_data.get('id')
        if not document_id:
            st.error("Failed to get document ID from upload response")
            return None

        # Wait a moment for processing
        import time
        time.sleep(3)  # Increased wait time to ensure document is processed

        # Get parsed results
        results_url = f"https://api.docparser.com/v1/results/{parser_id}/{document_id}"
        results_response = requests.get(
            results_url,
            headers=headers
        )
        results_response.raise_for_status()
        
        # Handle results
        results_data = results_response.json()
        
        if isinstance(results_data, list) and len(results_data) > 0:
            # Map the fields according to your Docparser parser configuration
            result = results_data[0]  # Get the first result
            parsed_data = {
                'name': result.get('name', result.get('full_name', 'Unknown')),
                'email': result.get('email', 'Unknown'),
                'phone': result.get('phone', result.get('phone_number', 'Unknown')),
                'skills': result.get('skills', []),
                'certifications': result.get('certifications', []),
                'experience_years': float(result.get('experience_years', 0)),
                'degree': result.get('degree', result.get('education_degree', 'Not specified')),
                'institution': result.get('institution', result.get('university', 'Not specified')),
                'year': result.get('year', result.get('graduation_year', 'Not specified')),
                'summary': result.get('summary', result.get('profile_summary', 'No summary available')),
                'projects': result.get('projects', [])
            }
            
            # Convert skills from string to list if needed
            if isinstance(parsed_data['skills'], str):
                parsed_data['skills'] = [skill.strip() for skill in parsed_data['skills'].split(',')]
            
            # Convert certifications from string to list if needed
            if isinstance(parsed_data['certifications'], str):
                parsed_data['certifications'] = [cert.strip() for cert in parsed_data['certifications'].split(',')]
            
            return parsed_data
        else:
            st.error(f"No parsed data received from Docparser: {results_data}")
            return None

    except requests.exceptions.HTTPError as http_err:
        st.error(f"HTTP error occurred: {http_err}")
        if hasattr(http_err, 'response') and http_err.response is not None:
            st.error(f"Response content: {http_err.response.content}")
    except json.JSONDecodeError as json_err:
        st.error(f"JSON decode error: {json_err}")
        st.error("Raw response content: " + str(upload_response.content if 'upload_response' in locals() else 'No response'))
    except Exception as e:
        st.error(f"Error fetching data from Docparser: {e}")
        st.error(f"Upload data: {upload_data if 'upload_data' in locals() else 'No upload data'}")
        st.error(f"Results data: {results_data if 'results_data' in locals() else 'No results data'}")
    return None

def get_openai_data(file, openai_key: str) -> Optional[dict]:
    openai.api_key = openai_key
    try:
        file_content = file.read()
        response = openai.Completion.create(
            engine="text-davinci-003",
            prompt=f"Extract and analyze the resume content: {file_content}",
            max_tokens=1500
        )
        return response.choices[0].text
    except Exception as e:
        st.error(f"Error fetching data from OpenAI: {e}")
        return None

def calculate_weighted_score(skills, certifications, experience_years, education_level, projects, skill_weight, certification_weight, experience_weight, education_weight, project_weight):
    skill_score = min(len(skills) * 15, 100)
    certification_score = min(len(certifications) * 20, 100)
    experience_score = min(experience_years * 15, 100)
    education_score = 100 if education_level else 0
    project_score = min(len(projects) * 10, 100)  # Assuming each project contributes 10 points

    total_score = (
        skill_score * skill_weight +
        certification_score * certification_weight +
        experience_score * experience_weight +
        education_score * education_weight +
        project_score * project_weight
    )

    return round(min(total_score, 100), 2)

def process_resume(file, job_description, filename, parser_choice, openai_key=None, api_key=None, parser_id=None, skill_weight=0.9, certification_weight=0.05, experience_weight=0.03, education_weight=0.02, project_weight=0.1):
    try:
        if parser_choice == "Docparser":
            data = get_docparser_data(file, api_key, parser_id)
        elif parser_choice == "OpenAI":
            data = get_openai_data(file, openai_key)
        else:
            st.error("Invalid parser choice")
            return None

        if not data:
            st.warning(f"Failed to extract data from the resume {filename}")
            return None

        # Extract fields from the response
        personal_details = {
            'name': data.get('name', 'Unknown'),
            'email': data.get('email', 'Unknown'),
            'phone': data.get('phone', 'Unknown')
        }
        education = {
            'degree': data.get('degree', 'Not specified'),
            'institution': data.get('institution', 'Not specified'),
            'year': data.get('year', 'Not specified')
        }
        experience_years = data.get('experience_years', 0)
        
        # Ensure certifications, skills, and projects are lists of strings
        certifications = [cert if isinstance(cert, str) else str(cert) for cert in data.get('certifications', [])]
        skills = [skill if isinstance(skill, str) else str(skill) for skill in data.get('skills', [])]
        projects = [project if isinstance(project, str) else str(project) for project in data.get('projects', [])]  # Assuming 'projects' is a key in the data
        summary = data.get('summary', 'No summary available')

        # Calculate weighted score
        weighted_score = calculate_weighted_score(
            skills, certifications, experience_years, education.get('degree', 'Not specified'), projects,
            skill_weight, certification_weight, experience_weight, education_weight, project_weight
        )

        resume_name = filename or personal_details.get('name', 'Unknown')
        skills_str = ', '.join(skills)
        certifications_str = ', '.join(certifications)
        projects_str = ', '.join(projects)

        resume_score = ResumeScore(
            resume_name=resume_name,
            score=weighted_score,
            skills=skills_str,
            certifications=certifications_str,
            experience_years=experience_years,
            education_level=education.get('degree', 'Not specified'),
            summary=summary
        )
        session.add(resume_score)
        session.commit()

        result = {
            'name': resume_name,
            'score': weighted_score,
            'personal_details': personal_details,
            'education': education,
            'experience': {'total_years': experience_years},
            'certifications': certifications,
            'skills': skills,
            'projects': projects,  # Include projects in the result
            'summary': summary
        }

        return result
    except Exception as e:
        st.error(f"Error processing the resume {filename}: {e}")
        session.rollback()
        return None

def process_resumes(files, job_description, parser_choice, openai_key=None, api_key=None, parser_id=None, skill_weight=0.9, certification_weight=0.05, experience_weight=0.03, education_weight=0.02, project_weight=0.1):
    scores = []
    processed_count = 0

    try:
        if not files:
            st.warning("No PDF files uploaded")
            return []

        total_files = len(files)
        progress_bar = st.progress(0)

        for index, file in enumerate(files):
            result = process_resume(file, job_description, file.name, parser_choice, openai_key, api_key, parser_id, skill_weight, certification_weight, experience_weight, education_weight, project_weight)
            if result:
                scores.append(result)
                processed_count += 1

            progress = (index + 1) / total_files
            progress_bar.progress(progress)

        st.success(f"Successfully processed {processed_count} resumes")
        return scores

    except Exception as e:
        st.error(f"Error processing resumes: {e}")
        session.rollback()
        return []

def display_results(result):
    with st.expander(f"📄 {result.get('name', 'Unknown')} - Match: {result['score']}%"):
        st.write(f"### Overall Match Score: {result['score']}%")
        st.write("### Skills Found:")
        if result['skills']:
            for skill in result['skills']:
                st.markdown(f"- {skill}")
        else:
            st.markdown("No skills found.")

        st.write("### Certifications:")
        if result['certifications']:
            for cert in result['certifications']:
                st.markdown(f"- {cert}")
        else:
            st.markdown("No certifications found.")

        st.write(f"### Total Years of Experience: {result['experience'].get('total_years', 0)}")
        st.write("### Education:")
        degree = result['education'].get('degree', 'Not specified')
        st.markdown(f"- Degree: {degree}")

        if st.button(f"View Detailed Analysis ({result.get('name', 'Unknown')})", key=f"view_{result.get('name', 'default')}"):
            st.write("#### Resume Summary:")
            st.text(result['summary'])

def view_scores():
    st.header("Stored Resume Scores")
    resumes = session.query(ResumeScore).order_by(ResumeScore.score.desc()).all()
    
    if resumes:
        data = []
        for idx, resume in enumerate(resumes, start=1):
            try:
                # Attempt to parse skills and certifications as JSON
                skills = json.loads(resume.skills)
                certifications = json.loads(resume.certifications)
                
                # Extract values if they are in JSON format
                skills_str = ', '.join([skill['key_0'] for skill in skills]) if isinstance(skills, list) else resume.skills
                certifications_str = ', '.join([cert['key_0'] for cert in certifications]) if isinstance(certifications, list) else resume.certifications
            except json.JSONDecodeError:
                # If parsing fails, treat them as plain strings
                skills_str = resume.skills
                certifications_str = resume.certifications

            data.append({
                'S.No': idx,
                'Name': resume.resume_name,
                'Score': resume.score,
                'Skills': skills_str,
                'Certifications': certifications_str,
                'Experience (Years)': resume.experience_years,
                'Education': resume.education_level,
                'Projects': resume.summary
            })
        
        df = pd.DataFrame(data)
        df_display = df[['S.No', 'Name', 'Score', 'Skills', 'Certifications', 'Experience (Years)', 'Education', 'Projects']]

        # Define a threshold for best-fit resumes
        threshold = 50
        best_fits = df[df['Score'] >= threshold]

        # Display all resumes
        st.subheader("All Resumes")
        for index, row in df_display.iterrows():
            with st.container():
                col1, col2, col3 = st.columns([3, 1, 1])
                with col1:
                    st.write(f"**{row['Name']}** (Score: {row['Score']}%)")
                    st.write(f"Skills: {row['Skills']}")
                    st.write(f"Experience: {row['Experience (Years)']} years")
                with col2:
                    if st.button(f"View Details", key=f"view_{index}"):
                        st.write(f"### Analysis Report")
                        st.write(f"Skills: {row['Skills']}")
                        st.write(f"Certifications: {row['Certifications']}")
                        st.write(f"Experience: {row['Experience (Years)']} years")
                        st.write(f"Education: {row['Education']}")
                        st.write(f"Projects: {row['Projects']}")
                with col3:
                    if st.button(f"Delete", key=f"delete_{index}"):
                        resume_to_delete = session.query(ResumeScore).filter_by(resume_name=row['Name']).first()
                        if resume_to_delete:
                            session.delete(resume_to_delete)
                            session.commit()
                            st.success(f"Deleted {row['Name']}")
                            st.rerun()  # Use st.rerun() instead of experimental_set_query_params

        # Display best-fit resumes
        if not best_fits.empty:
            st.subheader("Best Fit Resumes")
            for index, row in best_fits.iterrows():
                with st.container():
                    col1, col2, col3 = st.columns([3, 1, 1])
                    with col1:
                        st.write(f"**{row['Name']}** (Score: {row['Score']}%)")
                        st.write(f"Skills: {row['Skills']}")
                        st.write(f"Experience: {row['Experience (Years)']} years")
                    with col2:
                        if st.button(f"View Details", key=f"view_best_{index}"):
                            st.write(f"### Analysis Report")
                            st.write(f"Skills: {row['Skills']}")
                            st.write(f"Certifications: {row['Certifications']}")
                            st.write(f"Experience: {row['Experience (Years)']} years")
                            st.write(f"Education: {row['Education']}")
                            st.write(f"Projects: {row['Projects']}")
                    with col3:
                        if st.button(f"Delete", key=f"delete_best_{index}"):
                            resume_to_delete = session.query(ResumeScore).filter_by(resume_name=row['Name']).first()
                            if resume_to_delete:
                                session.delete(resume_to_delete)
                                session.commit()
                                st.success(f"Deleted {row['Name']}")
                                st.rerun()  # Use st.rerun() instead of experimental_set_query_params
    else:
        st.write("No resume scores available.")

def main():
    st.title("Resume Analyzer")
    set_custom_css()

    menu = ["Home", "View Scores"]
    choice = st.sidebar.selectbox("Menu", menu)

    if choice == "Home":
        analysis_type = st.selectbox("Select Analysis Type:", ["Single Resume", "Folder Upload"])
        method_choice = st.selectbox("Select Method:", ["Use LLM", "Use Field Extraction"])

        openai_key = None  # Initialize openai_key
        if method_choice == "Use LLM":
            openai_key = st.text_input("Enter OpenAI API Key:", type="password")
            parser_choice = "OpenAI"
        else:
            parser_choice = "Docparser"  # Only Docparser is available for field extraction
            api_key = st.text_input("Enter Docparser API Key:", type="password")
            parser_id = st.text_input("Enter Docparser Parser ID:")

        job_description = st.text_area("Enter job description:", height=150, placeholder="Paste job description here...", key="job_desc")

        # Configure weights
        st.sidebar.header("Configure Weights")
        skill_weight = st.sidebar.slider("Skill Weight", 0.0, 1.0, 0.9)
        certification_weight = st.sidebar.slider("Certification Weight", 0.0, 1.0, 0.05)
        experience_weight = st.sidebar.slider("Experience Weight", 0.0, 1.0, 0.03)
        education_weight = st.sidebar.slider("Education Weight", 0.0, 1.0, 0.02)
        project_weight = st.sidebar.slider("Project Weight", 0.0, 1.0, 0.1)  # New slider for project weight

        if analysis_type == "Single Resume":
            uploaded_file = st.file_uploader("Upload a resume PDF file", type="pdf")

            if st.button("Analyze Resume"):
                if not uploaded_file:
                    st.error("Please upload a resume PDF file")
                    return
                if not job_description:
                    st.error("Please enter a job description")
                    return
                if method_choice == "Use LLM" and not openai_key:
                    st.error("Please enter the OpenAI API key")
                    return
                if method_choice == "Use Field Extraction" and (not api_key or not parser_id):
                    st.error("Please enter the Docparser API key and Parser ID")
                    return
                with st.spinner("Processing resume..."):
                    result = process_resume(uploaded_file, job_description, uploaded_file.name, parser_choice, openai_key, api_key, parser_id, skill_weight, certification_weight, experience_weight, education_weight, project_weight)
                    if result:
                        st.success("Analysis complete!")
                        display_results(result)
                    else:
                        st.warning("Failed to process the resume.")

        elif analysis_type == "Folder Upload":
            uploaded_files = st.file_uploader("Upload multiple resume PDF files", type="pdf", accept_multiple_files=True)

            if st.button("Analyze Resumes"):
                if not uploaded_files:
                    st.error("Please upload resume PDF files")
                    return
                if not job_description:
                    st.error("Please enter a job description")
                    return
                if method_choice == "Use LLM" and not openai_key:
                    st.error("Please enter the OpenAI API key")
                    return
                if method_choice == "Use Field Extraction" and (not api_key or not parser_id):
                    st.error("Please enter the Docparser API key and Parser ID")
                    return
                with st.spinner("Processing resumes..."):
                    scores = process_resumes(uploaded_files, job_description, parser_choice, openai_key, api_key, parser_id, skill_weight, certification_weight, experience_weight, education_weight, project_weight)
                    if scores:
                        st.success("Analysis complete!")
                        for result in scores:
                            display_results(result)
                    else:
                        st.warning("No valid resumes found to process")

        with st.expander("ℹ️ How to use"):
            st.markdown("""
            1. Select the analysis type: Single Resume or Folder Upload.
            2. Choose the method: Use LLM or Use Field Extraction.
            3. If using LLM, enter the OpenAI API key.
            4. If using Field Extraction, enter the Docparser API key and Parser ID.
            5. Upload a resume PDF file or multiple files.
            6. Paste the job description.
            7. Configure the weights for skills, certifications, experience, education, and projects.
            8. Click 'Analyze' to start processing.
            9. View the match score and extracted information.
            10. Click 'View Detailed Analysis' to see the summary and more details.
            """)

    elif choice == "View Scores":
        view_scores()

if __name__ == "__main__":
    main()