import os
import re
from datetime import datetime
import PyPDF2
import torch
from transformers import AutoTokenizer, AutoModelForSequenceClassification
from sentence_transformers import SentenceTransformer, util
from groq import Groq
import gradio as gr

# Set your API key for Groq
os.environ["GROQ_API_KEY"] = "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"
client = Groq(api_key=os.environ.get("GROQ_API_KEY"))

# --- PDF/Text Extraction Functions --- #
def extract_text_from_file(file_path):
    """Extracts text from PDF or TXT files based on file extension."""
    if file_path.endswith('.pdf'):
        return extract_text_from_pdf(file_path)
    elif file_path.endswith('.txt'):
        return extract_text_from_txt(file_path)
    else:
        raise ValueError("Unsupported file type. Only PDF and TXT files are accepted.")

def extract_text_from_pdf(pdf_file_path):
    """Extracts text from a PDF file."""
    with open(pdf_file_path, 'rb') as pdf_file:
        pdf_reader = PyPDF2.PdfReader(pdf_file)
        text = ''.join(page.extract_text() for page in pdf_reader.pages if page.extract_text())
    return text

def extract_text_from_txt(txt_file_path):
    """Extracts text from a .txt file."""
    with open(txt_file_path, 'r', encoding='utf-8') as txt_file:
        return txt_file.read()

# --- Skill Extraction with Llama Model --- #
def extract_skills_llama(text):
    """Extracts skills from the text using the Llama model via Groq API."""
    try:
        response = client.chat.completions.create(
            messages=[{"role": "user", "content": f"Extract skills from the following text: {text}"}],
            model="llama3-70b-8192",
        )
        skills = response.choices[0].message.content.split(', ')  # Expecting a comma-separated list
        return skills
    except Exception as e:
        raise RuntimeError(f"Error during skill extraction: {e}")

# --- Job Description Processing Function --- #
def process_job_description(text):
    """Extracts skills or relevant keywords from the job description."""
    return extract_skills_llama(text)

# --- Qualification and Experience Extraction --- #
def extract_qualifications(text):
    """Extracts qualifications from text (e.g., degrees, certifications)."""
    qualifications = re.findall(r'(bachelor|master|phd|certified|degree)', text, re.IGNORECASE)
    return qualifications if qualifications else ['No specific qualifications found']

def extract_experience(text):
    """Extracts years of experience from the text."""
    experience_years = re.findall(r'(\d+)\s*(years|year) of experience', text, re.IGNORECASE)
    job_titles = re.findall(r'\b(software engineer|developer|manager|analyst)\b', text, re.IGNORECASE)
    experience_years = [int(year[0]) for year in experience_years]
    return experience_years, job_titles

# --- Updated Resume Analysis Function --- #
def analyze_resume(resume_file, job_description_file):
    if not resume_file or not job_description_file:
        return "", "", "", "Please upload both files."

    # Load and preprocess resume and job description
    resume_text = extract_text_from_file(resume_file)
    job_description_text = extract_text_from_file(job_description_file)

    # Extract skills, qualifications, and experience from the resume
    resume_skills = extract_skills_llama(resume_text)
    resume_qualifications = extract_qualifications(resume_text)
    resume_experience, _ = extract_experience(resume_text)
    total_experience = sum(resume_experience)  # Assuming this returns a list of experiences

    # Extract required skills, qualifications, and experience from the job description
    job_description_skills = process_job_description(job_description_text)
    job_description_qualifications = extract_qualifications(job_description_text)
    job_description_experience, _ = extract_experience(job_description_text)
    required_experience = sum(job_description_experience)  # Assuming total years required

    # Calculate similarity scores
    skills_similarity = len(set(resume_skills).intersection(set(job_description_skills))) / len(job_description_skills) * 100 if job_description_skills else 0
    qualifications_similarity = len(set(resume_qualifications).intersection(set(job_description_qualifications))) / len(job_description_qualifications) * 100 if job_description_qualifications else 0
    experience_similarity = 1.0 if total_experience >= required_experience else 0.0

    # Fit assessment logic
    fit_score = 0
    if total_experience >= required_experience:
        fit_score += 1
    if skills_similarity > 50:  # Define a threshold for skills match
        fit_score += 1
    if qualifications_similarity > 50:  # Define a threshold for qualifications match
        fit_score += 1

    # Determine fit
    if fit_score == 3:
        fit_assessment = "Strong fit"
    elif fit_score == 2:
        fit_assessment = "Moderate fit"
    else:
        fit_assessment = "Not a fit"

    # Prepare output messages for tab display
    summary_message = (
        f"### Summary of Analysis\n"
        f"- **Skills Similarity**: {skills_similarity:.2f}%\n"
        f"- **Qualifications Similarity**: {qualifications_similarity:.2f}%\n"
        f"- **Experience Similarity**: {experience_similarity * 100:.2f}%\n"
        f"- **Candidate Experience**: {total_experience} years\n"
        f"- **Fit Assessment**: {fit_assessment}\n"
    )

    skills_message = (
        f"### Skills Overview\n"
        f"- **Resume Skills:**\n" + "\n".join(f"  - {skill}" for skill in resume_skills) + "\n"
        f"- **Job Description Skills:**\n" + "\n".join(f"  - {skill}" for skill in job_description_skills) + "\n"
    )

    qualifications_message = (
        f"### Qualifications Overview\n"
        f"- **Resume Qualifications:** " + ", ".join(resume_qualifications) + "\n" +
        f"- **Job Description Qualifications:** " + ", ".join(job_description_qualifications) + "\n"
    )

    experience_message = (
        f"### Experience Overview\n"
        f"- **Total Experience:** {total_experience} years\n"
        f"- **Required Experience:** {required_experience} years\n"
    )

    return summary_message, skills_message, qualifications_message, experience_message


# --- Gradio Interface --- #
def run_gradio_interface():
    with gr.Blocks() as demo:
        gr.Markdown("## Resume and Job Description Analyzer")
        resume_file = gr.File(label="Upload Resume")
        job_description_file = gr.File(label="Upload Job Description")

        # Create placeholders for output messages
        summary_output = gr.Textbox(label="Summary of Analysis", interactive=False, lines=10)
        skills_output = gr.Textbox(label="Skills Overview", interactive=False, lines=10)
        qualifications_output = gr.Textbox(label="Qualifications Overview", interactive=False, lines=10)
        experience_output = gr.Textbox(label="Experience Overview", interactive=False, lines=10)

        # Create tabs for output sections
        with gr.Tab("Analysis Summary"):
            gr.Markdown("### Summary of Analysis")
            summary_output  # This automatically renders the output box

        with gr.Tab("Skills Overview"):
            gr.Markdown("### Skills Overview")
            skills_output  # This automatically renders the output box

        with gr.Tab("Qualifications Overview"):
            gr.Markdown("### Qualifications Overview")
            qualifications_output  # This automatically renders the output box

        with gr.Tab("Experience Overview"):
            gr.Markdown("### Experience Overview")
            experience_output  # This automatically renders the output box

        analyze_button = gr.Button("Analyze")

        # Button action
        analyze_button.click(analyze, inputs=[resume_file, job_description_file], outputs=[summary_output, skills_output, qualifications_output, experience_output])

    demo.launch()

def analyze(resume, job_desc):
    # Always ensure the correct number of return values
    summary, skills, qualifications, experience = analyze_resume(resume, job_desc)
    return summary, skills, qualifications, experience

if __name__ == "__main__":
    run_gradio_interface()