# -*- coding: utf-8 -*-
"""Similarity_score_refined (2).ipynb

Automatically generated by Colab.

Original file is located at
    https://colab.research.google.com/drive/1c8mlCBnLbduLsI8rUGFEOYDuyBqdz2JJ
"""

# !pip install sentence_transformers
# !pip install openai==0.28
# !pip install docx2txt PyPDF2 transformers

# from google.colab import drive,userdata
# drive.mount("/content/drive")
# print("Google Drive mounted.")

import re
from sklearn.feature_extraction.text import TfidfVectorizer
from nltk.corpus import stopwords
from nltk.stem import WordNetLemmatizer
import os

# Ensure you have downloaded stopwords and wordnet
import nltk
nltk.download('stopwords')
nltk.download('wordnet')

def extract_text(file_path):
    import docx2txt
    import PyPDF2
    if file_path.endswith(".docx"):
        # Extract text from DOCX file
        return docx2txt.process(file_path)

    elif file_path.endswith(".pdf"):
        # Extract text from PDF file
        text = ""
        with open(file_path, 'rb') as file:
            reader = PyPDF2.PdfReader(file)
            for page_num in range(len(reader.pages)):
                text += reader.pages[page_num].extract_text()
        return text

    else:
        raise ValueError("Unsupported file type")

def preprocess(text):
    # Lowercase the text
    text = text.lower()

    # Remove special characters and numbers
    text = re.sub(r'[^a-z\s]', '', text)

    # Tokenize the text by splitting on whitespace
    words = text.split()

    # Remove stop words
    stop_words = set(stopwords.words('english'))
    words = [word for word in words if word not in stop_words]

    # Lemmatize the words (to get root form)
    lemmatizer = WordNetLemmatizer()
    words = [lemmatizer.lemmatize(word) for word in words]

    # Join words back into a single string
    return ' '.join(words)

def calculate_tfidf(doc):
    vectorizer = TfidfVectorizer()
    tfidf_matrix = vectorizer.fit_transform([doc])  # Only fit on the individual document
    feature_names = vectorizer.get_feature_names_out()
    dense_tfidf_matrix = tfidf_matrix.todense()

    # Extract important terms from the document with a threshold
    important_terms = [feature_names[i] for i in range(len(feature_names)) if dense_tfidf_matrix[0, i] > 0.2]

    return ' '.join(important_terms)

def call_chatgpt_api(prompt, api_key,model="gpt-3.5-turbo"):
    import openai
    openai.api_key = api_key
    response = openai.ChatCompletion.create(
        model="gpt-3.5-turbo",
        messages=[
            {"role": "system", "content": "You are a helpful assistant."},
            {"role": "user", "content": prompt}
        ],
        max_tokens=500,
        temperature= 0,
        top_p=1,
        frequency_penalty= 0,
        presence_penalty= 0
    )
    return response['choices'][0]['message']['content'].strip()

def calculate_similarity(resume, job_desc, model_name="sentence-transformers/all-MiniLM-L6-v2"):
    from sentence_transformers import SentenceTransformer, util
    model = SentenceTransformer(model_name)

    # Convert texts to embeddings
    embeddings1 = model.encode(resume, convert_to_tensor=True)
    embeddings2 = model.encode(job_desc, convert_to_tensor=True)

    # Calculate cosine similarity
    similarity_score = util.pytorch_cos_sim(embeddings1, embeddings2)
    return similarity_score.item()  # return as a scalar

def similarity_main(resume_path,job_description_path):

    # Extract text from files (replace with actual file paths)
    Resume_text = extract_text(resume_path)
    job_des = extract_text(job_description_path)
    api_key=os.environ.get('OPENAI_KEY')


    prompt=f"Extract the skills or competencies section from the resume. Avoid using name of the candidate:\n\n{Resume_text}"
    resume_skills = call_chatgpt_api(prompt,api_key)
    experience_prompt = f"Extract the experience of the candidate from the resume. Avoid using name of the candidate:\n\n{Resume_text}"
    resume_experience = call_chatgpt_api(experience_prompt,api_key)

    # Extract sections from job description (JD)
    jd_skills_prompt = f"Extract the skills section from the job description:\n\n{job_des}"
    jd_skills = call_chatgpt_api(jd_skills_prompt,api_key)

    jd_experience_prompt = f"Extract the experience section from the job description:\n\n{job_des}"
    jd_experience = call_chatgpt_api(jd_experience_prompt,api_key)

    resume_skills_clean = preprocess(resume_skills)
    jd_skills_clean = preprocess(jd_skills)

    resume_experience_clean = preprocess(resume_experience)
    jd_experience_clean = preprocess(jd_experience)

    filtered_resume = calculate_tfidf(resume_skills_clean)
    filtered_jd = calculate_tfidf(jd_skills_clean)
    similarity_skills=calculate_similarity(filtered_resume,filtered_jd)

    filtered_resume_ex = calculate_tfidf(resume_experience_clean)
    filtered_jd_ex = calculate_tfidf(jd_experience_clean)
    similarity_ex=calculate_similarity(filtered_resume_ex,filtered_jd_ex)

    Average_Score=(similarity_skills+similarity_ex)/2
    percentage= f"{Average_Score * 100:.2f}%"
    return percentage