import fitz  # PyMuPDF
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.metrics.pairwise import cosine_similarity

import os
import requests
from functools import wraps
from flask import request, jsonify


def extract_text_from_pdf(file_storage):
    with fitz.open(stream=file_storage.read(), filetype="pdf") as doc:
        return " ".join([page.get_text() for page in doc])

def rank_resumes_by_similarity(resume_files, job_description):
    resume_texts = [extract_text_from_pdf(f) for f in resume_files]
    documents = [job_description] + resume_texts

    vectorizer = TfidfVectorizer(stop_words='english')
    tfidf_matrix = vectorizer.fit_transform(documents)

    job_vector = tfidf_matrix[0]
    resume_vectors = tfidf_matrix[1:]

    similarities = cosine_similarity(job_vector, resume_vectors).flatten()
    ranked = sorted(zip(resume_files, similarities), key=lambda x: x[1], reverse=True)

    return [
        {"filename": file.filename, "score": round(score, 4)}
        for file, score in ranked
    ]


SUPABASE_URL = os.getenv("SUPABASE_URL")
SUPABASE_API_KEY = os.getenv("SUPABASE_API_KEY")

def require_api_key(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        auth_header = request.headers.get('Authorization')

        if not auth_header or not auth_header.startswith('Bearer '):
            return jsonify({"error": "Missing or invalid Authorization header."}), 401

        token = auth_header.split("Bearer ")[1].strip()

        # Call Supabase REST API to validate token
        headers = {
            "apikey": SUPABASE_API_KEY,
            "Authorization": f"Bearer {SUPABASE_API_KEY}",  # service role
            "Content-Type": "application/json"
        }

        url = f"{SUPABASE_URL}/rest/v1/users?api_key=eq.{token}"

        response = requests.get(url, headers=headers)

        if response.status_code != 200:
            return jsonify({"error": "Failed to contact Supabase"}), 500

        user_data = response.json()

        if not user_data:
            return jsonify({"error": "Invalid or revoked API key."}), 403

        # Optionally attach user to request (like before)
        request.user = user_data[0]

        return f(*args, **kwargs)
    return decorated_function