From 3c1030aaeb6a4c3f4035c202e87ae85076e992a0 Mon Sep 17 00:00:00 2001
From: Jonni Liljamo <jonni@liljamo.com>
Date: Tue, 22 Aug 2023 17:13:16 +0300
Subject: [PATCH] feat: create user in db on login

---
 go.mod           |  1 +
 go.sum           |  3 +++
 handlers/auth.go | 38 ++++++++++++++++++++++++++++++++++++--
 3 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/go.mod b/go.mod
index 6d681de..9b89cbd 100644
--- a/go.mod
+++ b/go.mod
@@ -30,6 +30,7 @@ require (
 	github.com/mattn/go-isatty v0.0.19 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/oklog/ulid/v2 v2.1.0 // indirect
 	github.com/pelletier/go-toml/v2 v2.0.8 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.2.11 // indirect
diff --git a/go.sum b/go.sum
index ebdd88e..fb3f935 100644
--- a/go.sum
+++ b/go.sum
@@ -61,6 +61,9 @@ github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9Gz0M=
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
+github.com/oklog/ulid/v2 v2.1.0 h1:+9lhoxAP56we25tyYETBBY1YLA2SaoLvUFgrP2miPJU=
+github.com/oklog/ulid/v2 v2.1.0/go.mod h1:rcEKHmBBKfef9DhnvX7y1HZBYxjXb0cP5ExxNsTT1QQ=
+github.com/pborman/getopt v0.0.0-20170112200414-7148bc3a4c30/go.mod h1:85jBQOZwpVEaDAr341tbn15RS4fCAsIst0qp7i8ex1o=
 github.com/pelletier/go-toml/v2 v2.0.8 h1:0ctb6s9mE31h0/lhu+J6OPmVeDxJn+kYnJc2jZR9tGQ=
 github.com/pelletier/go-toml/v2 v2.0.8/go.mod h1:vuYfssBdrU2XDZ9bYydBu6t+6a6PYNcZljzZR9VXg+4=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
diff --git a/handlers/auth.go b/handlers/auth.go
index d76e37a..d68f167 100644
--- a/handlers/auth.go
+++ b/handlers/auth.go
@@ -1,11 +1,16 @@
 package handlers
 
 import (
+	"context"
+	"log"
 	"net/http"
 	"tixe/auth"
+	"tixe/db"
 
 	"github.com/gin-contrib/sessions"
 	"github.com/gin-gonic/gin"
+	"github.com/jackc/pgx/v5"
+	"github.com/oklog/ulid/v2"
 )
 
 func AuthCallback(auth *auth.Auth) gin.HandlerFunc {
@@ -30,14 +35,43 @@ func AuthCallback(auth *auth.Auth) gin.HandlerFunc {
 
 		var profile map[string]interface{}
 		if err := idToken.Claims(&profile); err != nil {
-			c.String(http.StatusInternalServerError, err.Error())
+			log.Printf("[tixe/auth] ERROR: Failed to get claims")
+			c.String(http.StatusInternalServerError, "Failed to get claims!")
 			return
 		}
 
+		// Try to get the relevant details of the user
+		var userId string
+		// idToken.Subject should be unique and should not change.
+		// I think. Maybe. Possibly. Hopefully.
+		scanErr := db.PgPool.QueryRow(context.Background(),
+			"SELECT id FROM users WHERE oidc_subject = $1", idToken.Subject).Scan(&userId)
+		if scanErr == pgx.ErrNoRows {
+			log.Printf("[tixe/auth] New user detected logging in, creating entry in database")
+			// The user does not exist in the db, create it
+			userId = ulid.Make().String()
+			_, err = db.PgPool.Exec(context.Background(),
+				"INSERT INTO users(id, display_name, oidc_subject) VALUES($1, $2, $3)",
+				userId, profile["name"].(string), idToken.Subject)
+			if err != nil {
+				log.Printf("[tixe/auth] ERROR: Could not create database entry for oidc user")
+				c.String(http.StatusInternalServerError, "Could not create database entry for oidc user")
+				return
+			}
+		} else if scanErr != nil {
+			// scanErr was some other error than ErrNoRows
+			log.Printf("[tixe/auth] ERROR: Could not query database for oidc user: %v", scanErr)
+			c.String(http.StatusInternalServerError, "Could not query database for oidc user")
+			return
+		}
+
+		// The user_id field is read in other requests to read user data from the db
+		session.Set("user_id", userId)
 		session.Set("access_token", token.AccessToken)
 		session.Set("profile", profile)
 		if err := session.Save(); err != nil {
-			c.String(http.StatusInternalServerError, err.Error())
+			log.Printf("[tixe/auth] ERROR: Failed to save session")
+			c.String(http.StatusInternalServerError, "Failed to save session!")
 			return
 		}
 
-- 
2.44.1