ligun and sogup

src/pages/SignupPage.tsx

@@ -1,9 +1,10 @@
 import { useParams } from 'react-router'
-import { useEffect, useRef, useState } from 'react'
+import { useEffect, useRef, useState, FormEvent, useCallback, Ref } from 'react'
 import SingleColumnLayout from '../layouts/SingleColumnLayout.tsx'
 import TextInput from '../components/TextInput.tsx'
 import PrimaryButton from '../components/PrimaryButton.tsx'
 import PrimaryLinkButton from '../components/PrimaryLinkButton.tsx'
+import { invalid, valid, Validation } from '../utils/validation.ts'
 
 const SignupCodeKey = 'signupCode'
 
@@ -12,9 +13,17 @@ export default function SignupPage() {
   const [signupCode, setSignupCode] = useState<string | null>(null)
   const [isSubmitting, setIsSubmitting] = useState(false)
 
-  const [username, setUsername] = useState('')
-  const [email, setEmail] = useState('')
-  const [password, setPassword] = useState('')
+  const [username, setUsername, usernameError, validateUsername] =
+    useValidatedInput(isValidUsername)
+
+  const [email, setEmail, emailError, validateEmail] = useValidatedInput(isValidEmail)
+
+  const [password, setPassword, passwordError, validatePassword] =
+    useValidatedInput(isValidPassword)
+
+  const userNameInputRef = useRef<HTMLInputElement | null>(null)
+  const emailInputRef = useRef<HTMLInputElement | null>(null)
+  const passwordInputRef = useRef<HTMLInputElement | null>(null)
 
   const dialogRef = useRef<HTMLDialogElement | null>(null)
 
@@ -35,8 +44,29 @@ export default function SignupPage() {
     }
   }, [code, signupCode])
 
-  const onSubmit = async (e: React.FormEvent<HTMLFormElement>) => {
+  const onSubmit = async (e: FormEvent<HTMLFormElement>) => {
     e.preventDefault()
+
+    const isUsernameValid = validateUsername()
+    const isEmailValid = validateEmail()
+    const isPasswordValid = validatePassword()
+
+    if (!isPasswordValid) {
+      passwordInputRef.current?.focus()
+    }
+
+    if (!isEmailValid) {
+      emailInputRef.current?.focus()
+    }
+
+    if (!isUsernameValid) {
+      userNameInputRef.current?.focus()
+    }
+
+    if (!isUsernameValid || !isEmailValid || !isPasswordValid) {
+      return
+    }
+
     setIsSubmitting(true)
 
     try {
@@ -51,34 +81,33 @@ export default function SignupPage() {
       <main className="w-full mx-auto p-4">
         <div className="mt-12">
           <form className="flex flex-col gap-4 max-w-md" onSubmit={onSubmit}>
-            <div className="flex flex-col gap-2">
-              <label htmlFor="username" className="text-sm text-gray-600">
-                username
-              </label>
-              <TextInput id="username" value={username} onInput={setUsername} required />
-            </div>
-
-            <div className="flex flex-col gap-2">
-              <label htmlFor="email" className="text-sm text-gray-600">
-                email (optional)
-              </label>
-              <TextInput id="email" value={email} onInput={setEmail} required />
-            </div>
-
-            <div className="flex flex-col gap-2">
-              <label htmlFor="password" className="text-sm text-gray-600">
-                password
-              </label>
-              <TextInput
-                id="password"
-                type="password"
-                value={password}
-                onInput={setPassword}
-                required
-              />
-            </div>
-
-            <PrimaryButton className="mt-4" disabled={isSubmitting} type="submit">
+            <FormInput
+              id="username"
+              value={username}
+              onInput={setUsername}
+              error={usernameError}
+              ref={userNameInputRef}
+            />
+            <FormInput
+              id="email"
+              value={email}
+              onInput={setEmail}
+              error={emailError}
+              ref={emailInputRef}
+            />
+            <FormInput
+              id="password"
+              value={password}
+              onInput={setPassword}
+              error={passwordError}
+              type="password"
+              ref={passwordInputRef}
+            />
+            <PrimaryButton
+              className="mt-4"
+              disabled={isSubmitting || !!usernameError || !!passwordError}
+              type="submit"
+            >
               {isSubmitting ? 'wait...' : 'give me an account pls'}
             </PrimaryButton>
           </form>
@@ -109,3 +138,87 @@ export default function SignupPage() {
     </SingleColumnLayout>
   )
 }
+
+interface FormInputProps {
+  id: string
+  value: string
+  onInput: (value: string) => void
+  error: string | null
+  type?: 'text' | 'password'
+  ref: Ref<HTMLInputElement>
+}
+
+function FormInput({ id, value, onInput, error, type = 'text', ref }: FormInputProps) {
+  return (
+    <div className="flex flex-col gap-1">
+      <label htmlFor={id} className="text-sm text-gray-600">
+        {id}
+      </label>
+      <TextInput ref={ref} type={type} id={id} value={value} onInput={onInput} />
+      <span className="text-xs h-3 text-red-500">{error}</span>
+    </div>
+  )
+}
+
+type UseValidateInputReturn = [string, (value: string) => void, string | null, () => boolean]
+
+function useValidatedInput(validator: (value: string) => Validation): UseValidateInputReturn {
+  const [value, setValue] = useState<string>('')
+  const [error, setError] = useState<string | null>(null)
+  const [keepValidating, setKeepValidating] = useState(false)
+
+  const validate = useCallback(() => {
+    const { isValid, error } = validator(value)
+    if (isValid) {
+      setError(null)
+    } else {
+      // We only want to validate on input after they have invalidly submitted once.
+      // It's annoying if we set error messages before they've even finished typing.
+      setKeepValidating(true)
+      setError(error)
+    }
+
+    return isValid
+  }, [validator, value])
+
+  useEffect(() => {
+    if (keepValidating) {
+      validate()
+    }
+  }, [keepValidating, validate])
+
+  return [value, setValue, error, validate]
+}
+
+function isValidUsername(username: string): Validation {
+  if (!username) return invalid('you need to enter a username :/')
+
+  if (username.length < 3) {
+    return invalid('not long enough :(')
+  }
+
+  const usernameRegex = /^[a-zA-Z0-9_-]+$/
+  if (usernameRegex.test(username)) {
+    return valid()
+  } else {
+    return invalid("that's not a good username :'(")
+  }
+}
+
+function isValidEmail(email: string): Validation {
+  if (!email) return valid()
+  const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/
+  if (emailRegex.test(email)) {
+    return valid()
+  } else {
+    return invalid("um sorry but that doesn't look like an email 🤔")
+  }
+}
+
+function isValidPassword(password: string): Validation {
+  if (password.length >= 10) {
+    return valid()
+  } else {
+    return invalid("that isn't a good password :/")
+  }
+}