from flask import Blueprint, request, session, redirect, flash
import json, bcrypt
from auth import require_level

bp = Blueprint('action_change_password', __name__)

DATA_DIR      = '/data'
ACCOUNTS_FILE = f'{DATA_DIR}/authorized_accounts.json'


def _load_accounts():
    try:
        with open(ACCOUNTS_FILE) as f:
            return json.load(f)
    except Exception:
        return {'accounts': []}

def _save_accounts(data):
    with open(ACCOUNTS_FILE, 'w') as f:
        json.dump(data, f, indent=2)


@bp.route('/action/change_password', methods=['POST'])
@require_level('viewer')
def change_password():
    current_password = request.form.get('current_password', '')
    new_password     = request.form.get('new_password', '')
    confirm_password = request.form.get('confirm_password', '')

    if not current_password or not new_password or not confirm_password:
        flash('All fields are required.', 'error')
        return redirect('/view/view_preferences')

    if new_password != confirm_password:
        flash('New passwords do not match.', 'error')
        return redirect('/view/view_preferences')

    if len(new_password) < 8:
        flash('New password must be at least 8 characters.', 'error')
        return redirect('/view/view_preferences')

    email    = session.get('email_address', '').lower()
    data     = _load_accounts()
    accounts = data.get('accounts', [])
    account  = next((a for a in accounts if a.get('email_address', '').lower() == email), None)

    if account is None:
        flash('Account not found. Please log in again.', 'error')
        return redirect('/view/view_log_in')

    stored_hash = account.get('hashed_password', '').encode('utf-8')
    if not bcrypt.checkpw(current_password.encode('utf-8'), stored_hash):
        flash('Current password is incorrect.', 'error')
        return redirect('/view/view_preferences')

    salt   = bcrypt.gensalt()
    hashed = bcrypt.hashpw(new_password.encode('utf-8'), salt)

    account['hashed_password'] = hashed.decode('utf-8')
    account['salt']            = salt.decode('utf-8')
    _save_accounts(data)

    flash('Password changed successfully.', 'success')
    return redirect('/view/view_preferences')