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 os
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]:
    upload_url = f"https://api.docparser.com/v1/document/upload/{parser_id}"
    auth = (api_key, '')  # Use HTTP Basic Auth with the API key
    files = {'file': file}
    try:
        # Upload the document
        response = requests.post(upload_url, auth=auth, files=files)
        response.raise_for_status()
        document_id = response.json().get('id')

        # Ensure document ID is valid
        if not document_id:
            st.error("Failed to retrieve document ID from Docparser.")
            return None

        # Fetch parsed data
        result_url = f"https://api.docparser.com/v1/results/{parser_id}/{document_id}"
        result_response = requests.get(result_url, auth=auth)
        result_response.raise_for_status()
        data = result_response.json()

        # Check if the response is a list and handle accordingly
        if isinstance(data, list) and len(data) > 0:
            data = data[0]  # Assuming you want the first result

        return data
    except requests.exceptions.HTTPError as http_err:
        st.error(f"HTTP error occurred: {http_err}")
    except Exception as e:
        st.error(f"Error fetching data from Docparser: {e}")
    return None

def get_openai_data(file_path: str, openai_key: str) -> Optional[dict]:
    openai.api_key = openai_key
    try:
        with open(file_path, 'rb') as file:
            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(folder_path, 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):
    if not os.path.isdir(folder_path):
        st.error("Invalid folder path")
        return []

    scores = []
    processed_count = 0

    try:
        pdf_files = [f for f in os.listdir(folder_path) if f.lower().endswith('.pdf')]

        if not pdf_files:
            st.warning("No PDF files found in the folder")
            return []

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

        for index, filename in enumerate(pdf_files):
            file_path = os.path.join(folder_path, filename)
            with open(file_path, 'rb') as file:
                result = process_resume(file, job_description, filename, 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  # Assuming projects are part of the summary or add a separate field if needed
            })
        
        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():
            st.write(f"**{row['S.No']}. {row['Name']}**")
            st.write(f"Score: {row['Score']}%")
            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']}")

            col1, col2 = st.columns([1, 1])
            with col1:
                if st.button(f"View Detailed Analysis ({row['Name']})", key=f"view_{index}"):
                    st.write(f"## Analysis Report for {row['Name']}")
                    st.write(f"### Score: {row['Score']}%")
                    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("### Projects:")
                    st.text(row['Projects'])
            with col2:
                if st.button(f"Delete {row['Name']}", key=f"delete_{index}"):
                    # Find the resume in the database and delete it
                    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']} from the database.")
                        st.experimental_set_query_params(refresh=True)  # Use query params to trigger a rerun

        # Display best-fit resumes
        if not best_fits.empty:
            st.subheader("Best Fit Resumes")
            for index, row in best_fits.iterrows():
                st.write(f"**{row['S.No']}. {row['Name']}**")
                st.write(f"Score: {row['Score']}%")
                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']}")

                col1, col2 = st.columns([1, 1])
                with col1:
                    if st.button(f"View Detailed Analysis ({row['Name']})", key=f"view_best_{index}"):
                        st.write(f"## Analysis Report for {row['Name']}")
                        st.write(f"### Score: {row['Score']}%")
                        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("### Projects:")
                        st.text(row['Projects'])
                with col2:
                    if st.button(f"Delete {row['Name']}", key=f"delete_best_{index}"):
                        # Find the resume in the database and delete it
                        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']} from the database.")
                            st.experimental_set_query_params(refresh=True)  # Use query params to trigger a rerun
    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":
            folder_path = st.text_input("Resume folder path:", placeholder="e.g. C:/Users/username/resumes")

            if st.button("Analyze Resumes"):
                if not folder_path:
                    st.error("Please enter the folder path containing resumes")
                    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(folder_path, 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 enter the path to a folder containing resumes.
            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()