From e24c6b3ef31e6a7a65502efaf1218916968f6604 Mon Sep 17 00:00:00 2001
From: Alexander Zhylin <zheiling@hotmail.com>
Date: Thu, 19 Feb 2026 14:46:08 +0200
Subject: [PATCH] improves registration

---
 TODO.md    |  2 +-
 src/db.c   | 33 +++++++++++++++++++++++++++++++--
 src/user.c | 18 +++++++++++++-----
 3 files changed, 45 insertions(+), 8 deletions(-)

diff --git a/TODO.md b/TODO.md
index 9803114..99f5b21 100644
--- a/TODO.md
+++ b/TODO.md
@@ -7,7 +7,7 @@
 - [x] Get files in FS by their hash
 - [x] Registration
 - [x] Encrypt passwords in DB
-- [ ] Registration: Error when username or email is already used
+- [x] Registration: Error when username or email is already used
 - [ ] Check correctness of email
 - [ ] Message to admin
 - [x] Advanced folder structure in the storage
diff --git a/src/db.c b/src/db.c
index 3f68fcc..4dcb2e6 100644
--- a/src/db.c
+++ b/src/db.c
@@ -147,22 +147,51 @@ int32_t db_user_auth(i_auth_t *c, o_auth_t *r) {
 
 int32_t db_user_create(i_db_user_create *args) {
   const char *paramValues[3];
+  int32_t paramLengths[3];
   char passHashed[SHA256_DIGEST_LENGTH * 2];
   paramValues[0] = args->uname;
   paramValues[2] = args->email;
+
+  paramLengths[0] = strlen(args->uname);
+  paramLengths[2] = strlen(args->email);
   uint32_t ret_value;
 
   string_to_SHA256(args->pass, passHashed);
   paramValues[1] = passHashed;
+  paramLengths[1] = 64;
+
+  /* Check username */
+  res = PQexecParams(conn, "SELECT id FROM users WHERE username=$1", 1, NULL,
+                     paramValues, paramLengths, NULL, TEXT);
+
+  if (PQresultStatus(res) != PGRES_TUPLES_OK && !PQntuples(res))
+    return exit_query_2(-1);
+
+  if (PQntuples(res) > 0) {
+    return exit_query_2(-2);
+  }
+
+  /* Check email */
+  res = PQexecParams(conn, "SELECT id FROM users WHERE email=$1", 1, NULL,
+                     paramValues+2, paramLengths+2, NULL, TEXT);
+
+  if (PQresultStatus(res) != PGRES_TUPLES_OK && !PQntuples(res))
+    return exit_query_2(-1);
+
+  if (PQntuples(res) > 0) {
+    return exit_query_2(-3);
+  }
+
+  clearRes();
 
   res = PQexecParams(conn,
                      "INSERT INTO users (username, password, email, "
                      "privileges, created_at, last_login)"
                      " VALUES ($1, $2, $3, 1, NOW(), NOW()) RETURNING id",
-                     3, NULL, paramValues, NULL, NULL, TEXT);
+                     3, NULL, paramValues, paramLengths, NULL, TEXT);
 
   if (PQresultStatus(res) != PGRES_TUPLES_OK && !PQntuples(res))
-    return exit_query(-1);
+    return exit_query(-4);
 
   ret_value = atoi(PQgetvalue(res, 0, 0));
   clearRes();
diff --git a/src/user.c b/src/user.c
index 55b0cd0..47cf595 100644
--- a/src/user.c
+++ b/src/user.c
@@ -9,16 +9,23 @@
 int32_t create_user(session *sess, char *line) {
   i_db_user_create p;
   uint32_t privileges;
-  uint32_t res;
+  int32_t res;
   if (sscanf(line, "register %s %s", p.uname, p.pass) == 2) {
+    sprintf(p.email, "%s@mail.net", p.uname); /* TODO: return back email */
     res = db_user_create(&p);
-    if (res) {
+    if (res > 0) {
       sess->state = OP_WAIT;
       sess->uname = malloc(strlen(p.uname));
       strcpy(sess->uname, p.uname);
       sess->uid = res;
-      sess->privileges = 1; // by default
-      session_send_string(sess, "ok");
+      sess->privileges = 1; /* by default */
+      session_send_string(sess, "ok\n");
+    } else if (res == -2) {
+      session_send_string(sess, "User with such name already exists\n");
+    } else if (res == -3) {
+      session_send_string(sess, "User with such email already exists\n");
+    } else {
+      session_send_string(sess, "Error creating the user\n");
     }
     return res;
   };
@@ -85,7 +92,8 @@ int process_error(session *sess) {
       return 1;
       break;
     case LOGIN:
-      session_send_string(sess, "Can't find the user with such credentials\04\n");
+      session_send_string(sess,
+                          "Can't find the user with such credentials\04\n");
       sess->state = OP_LOGIN_USR;
       sess->reason = NO_REASON;
       session_send_string(sess, "login_again> ");