from flask import Blueprint, render_template, redirect, url_for, flash, request, jsonify
from flask_login import login_user, logout_user, login_required, current_user
from werkzeug.utils import secure_filename
import os
import json
from datetime import datetime

from backend.form.AuthForms import LoginForm, SignupForm
from backend.models.user import User
from backend.models.database import db

auth_bp = Blueprint('auth', __name__)


def handle_resume_upload(file):
    """
    Handle a resume upload by saving the file to a temporary location and
    returning an empty feature dictionary.  This function no longer attempts
    to parse the resume contents; it simply stores the file so that it can
    be referenced later (e.g. for downloading or inspection) and returns
    a placeholder features object.  A tuple of (features_dict, error_message,
    filepath) is returned.  If an error occurs, ``features_dict`` will be
    ``None`` and ``error_message`` will contain a description of the error.
    """
    # Validate that a file was provided
    if not file or file.filename == '':
        return None, "No file uploaded", None

    try:
        # Generate a safe filename and determine the target directory.  Use
        # ``/tmp/resumes`` so that the directory is writable within Hugging
        # Face Spaces.  Creating the directory with ``exist_ok=True`` ensures
        # that it is available without raising an error if it already exists.
        filename = secure_filename(file.filename)
        temp_dir = os.path.join('/tmp', 'resumes')
        os.makedirs(temp_dir, exist_ok=True)
        filepath = os.path.join(temp_dir, filename)

        # Save the uploaded file to the temporary location.  If this fails
        # (e.g. due to permissions issues) the exception will be caught below.
        file.save(filepath)

        # Resume parsing has been removed from this project.  To maintain
        # compatibility with the rest of the application, return an empty
        # dictionary of features.  Downstream code will interpret an empty
        # dictionary as "no extracted features", which still allows the
        # interview flow to proceed.
        features = {}
        return features, None, filepath
    except Exception as e:
        # Log the error and propagate it to the caller.  Returning None for
        # ``features`` signals that the upload failed.
        print(f"Error in handle_resume_upload: {e}")
        return None, str(e), None


@auth_bp.route('/login', methods=['GET', 'POST'])
def login():
    form = LoginForm()
    # When the form is submitted and passes validation, attempt to authenticate
    # the user.  If the email/password pair is valid, log them in and provide
    # a success flash message so the user has feedback. Without this message
    # the application silently redirects to the home page, which can be
    # confusing.  If authentication fails, flash an error message.
    if form.validate_on_submit():
        user = User.query.filter_by(email=form.email.data).first()
        if user and user.check_password(form.password.data):
            login_user(user)
            # ✅ Provide a success message so users know the login worked
            flash('You have been logged in successfully!', 'success')
            return redirect(url_for('index'))
        else:
            flash('Invalid credentials', 'danger')
    return render_template('login.html', form=form)


@auth_bp.route('/signup', methods=['GET', 'POST'])
def signup():
    form = SignupForm()
    if form.validate_on_submit():
        existing_user = User.query.filter_by(email=form.email.data).first()
        if existing_user:
            flash('Email already registered.', 'warning')
        else:
            user = User(
                username=form.username.data,
                email=form.email.data,
                role=form.role.data
            )
            user.set_password(form.password.data)
            db.session.add(user)
            db.session.commit()

            # Log the user in and redirect to profile completion
            login_user(user)
            flash('Account created successfully! Welcome to Codingo.', 'success')
            return redirect(url_for('index')) 
    return render_template('signup.html', form=form)


@auth_bp.route('/logout')
@login_required
def logout():
    logout_user()
    flash('You have been logged out successfully.', 'info')
    return redirect(url_for('auth.login'))