Add login function

- Handles logins from Discord OAuth2 API
- If the discord email changes, it should notice this and then ipdate it
(untested due to time)
- Saves majority of the data Discord OAuth2 sends back, much of this can
be used for quality of life things like profile pictures later.

src/discord_auth.py

@@ -51,7 +51,7 @@ def discord_oauth_login():
     return redirect(discord_oauth.gen_auth_url())
 
 
-@discord_blueprint.route("/discord/oauth_callback", methods=["GET","POST"])
+@discord_blueprint.route("/discord/oauth_callback", methods=["GET", "POST"])
 @ratelimit(method="POST", limit=10, interval=5)
 def discord_oauth_callback():
     """
@@ -64,10 +64,52 @@ def discord_oauth_callback():
     log.debug("OAuth Response Code: [{}]".format(request.args.get("code")))
     global discord_oauth
     token = discord_oauth.get_access_token(request.args.get("code"))
-    log.debug("token= {}".format(token))
+    log.debug("token=[{}]".format(token))
     user_json = discord_oauth.get_user_info(token)
+    log.debug("User data: [{}]".format(str(user_json)))
     # process user info/login/etc
-    return "userdata: " + str(user_json)
+    if user_json:
+        # lookup by email
+        user = Users.query.filter_by(email=user_json["email"]).first()
+        if user is None:
+            # Check if user changed email
+            discord_user = DiscordUser.query.filter_by(id=user_json["id"]).first()
+            if discord_user:
+                user = Users.query.filter_by(email=discord_user.email)
+                if user:
+                    user.email = user_json["email"]
+                    discord_user.email = user_json["email"]
+                    db.session.commit()
+                else:
+                    log.error("Login failed: user[{user}], discord_user[{d_user}], \
+                        oauth[{user_json}]".format(user=user, d_user=discord_user,
+                                                   user_json=user_json))
+                    return "Error logging in via Discord Oauth2"
+            else:
+                # Create new user
+                user = Users(
+                    name=user_json["username"],
+                    email=user_json["email"],
+                    oauth_id=user_json["id"],
+                    verified=user_json["verified"]
+                )
+                discord_user = DiscordUser(
+                    id=user_json["id"],
+                    username=user_json["username"],
+                    discriminator=user_json["discriminator"],
+                    avatar_hash=user_json["avatar"],
+                    mfa_enabled=user_json["mfa_enabled"],
+                    verified=user_json["verified"],
+                    email=user_json["email"]
+                )
+                db.session.add(user)
+                db.session.add(discord_user)
+                db.session.commit()
+        # Login
+        login_user(user)
+    else:
+        return "Error logging in via Discord OAuth2"
+    return redirect('/challenges')
 
 
 def check_debug_mode(debug: bool):
@@ -119,13 +161,13 @@ def setup_oauth(config):
     global discord_oauth
     global plugin_name
     discord_oauth = Discord_Oauth(
-            client_id=config["client_id"],
-            client_secret=config["client_secret"],
-            scope=config["scope"],
-            redirect_uri="https://{}/discord/oauth_callback".format(config["domain"]),
-            discord_api_url=config["base_discord_api_url"],
-            plugin_name=plugin_name
-            )
+        client_id=config["client_id"],
+        client_secret=config["client_secret"],
+        scope=config["scope"],
+        redirect_uri="https://{}/discord/oauth_callback".format(config["domain"]),
+        discord_api_url=config["base_discord_api_url"],
+        plugin_name=plugin_name
+    )
 
 
 # Load plugin into CTFd