add user signup flow

app/routes/users.py

@@ -1,8 +1,10 @@
 from flask import Blueprint, redirect, url_for, render_template, request, session
 from functools import wraps
+import time
 
-from ..auth import digest, verify, create_session, is_logged_in
+from ..auth import digest, verify, create_session, is_logged_in, parse_username, is_password_valid
 from ..models import Users
+from ..constants import PermissionLevel
 
 bp = Blueprint('users', __name__, url_prefix='/users/')
 
@@ -39,10 +41,53 @@ def log_in_post():
         session.permanent = True
     return redirect(request.form.get('return_to', default=url_for('topics.all_topics')))
 
-@bp.get('/sign-up')
+@bp.get('/sign-up/')
 @redirect_if_logged_in()
 def sign_up():
-    return 'stub'
+    return render_template('users/sign_up.html')
+
+@bp.post('/sign-up/')
+@redirect_if_logged_in()
+def sign_up_post():
+    generic_error_page = redirect(url_for('.sign_up', error='The username or password you entered is invalid.'))
+    user_exists_error_page = redirect(url_for('.sign_up', error='This username is already taken. Please pick another.'))
+    passwords_error_page = redirect(url_for('.sign_up', error='The passwords do not match.'))
+    username = request.form.get('username', default='')
+    if not username:
+        return generic_error_page
+    if request.form.get('password', default=None) is None:
+        return generic_error_page
+    if len(request.form.getlist('password')) != 2:
+        return passwords_error_page
+    username_pair = parse_username(username)
+    potential_user = Users.find({'username': username})
+    if potential_user:
+        return user_exists_error_page
+
+    if request.form.getlist('password')[0] != request.form.getlist('password')[1]:
+        return passwords_error_page
+
+    password_hash = digest(request.form.get('password'))
+
+    user = Users.create({
+        'username': username_pair[0],
+        'password_hash': password_hash,
+        'permission': PermissionLevel.GUEST.value,
+        'created_at': int(time.time()),
+    })
+
+    if username_pair[0] != username_pair[1]:
+        user.update({
+            'display_name': username_pair[1]
+        })
+
+    session['remember'] = request.form.get('remember') == 'on'
+    sess = create_session(user.id, not session['remember'])
+    session['pyrom_session_key'] = sess.key
+    if session['remember']:
+        session.permanent = True
+
+    return redirect(url_for('topics.all_topics'))
 
 @bp.get('/<username>')
 def user_page(username):