feat: implement credentials login

implements the credentials login functionality

src/lib/validation/user.ts

@@ -0,0 +1,67 @@
+import zod from 'zod';
+
+export const loginSchema = zod.object({
+  email: zod
+    .string()
+    .email('Invalid email address')
+    .min(3, 'Email is required')
+    .or(
+      zod
+        .string()
+        .min(3, 'Username is required')
+        .max(32, 'Username must be at most 32 characters long')
+        .regex(
+          /^[a-zA-Z0-9_]+$/,
+          'Username can only contain letters, numbers, and underscores',
+        ),
+    ),
+  password: zod.string().min(1, 'Password is required'),
+});
+
+export const registerSchema = zod
+  .object({
+    firstName: zod
+      .string()
+      .min(1, 'First name is required')
+      .max(32, 'First name must be at most 32 characters long'),
+    lastName: zod
+      .string()
+      .min(1, 'Last name is required')
+      .max(32, 'Last name must be at most 32 characters long'),
+    email: zod
+      .string()
+      .email('Invalid email address')
+      .min(3, 'Email is required'),
+    password: zod
+      .string()
+      .min(8, 'Password must be at least 8 characters long')
+      .max(128, 'Password must be at most 128 characters long'),
+    confirmPassword: zod
+      .string()
+      .min(8, 'Password must be at least 8 characters long')
+      .max(128, 'Password must be at most 128 characters long'),
+    username: zod
+      .string()
+      .min(3, 'Username is required')
+      .max(32, 'Username must be at most 32 characters long')
+      .regex(
+        /^[a-zA-Z0-9_]+$/,
+        'Username can only contain letters, numbers, and underscores',
+      ),
+  })
+  .refine((data) => data.password === data.confirmPassword, {
+    message: 'Passwords do not match',
+    path: ['confirmPassword'],
+  })
+  .refine(
+    (data) =>
+      !data.password.includes(data.firstName) &&
+      !data.password.includes(data.lastName) &&
+      !data.password.includes(data.email) &&
+      !data.password.includes(data.username),
+    {
+      message:
+        'Password cannot contain your first name, last name, email, or username',
+      path: ['password'],
+    },
+  );