feat(auth): improve otp delivery and verification flow

src/pages/auth/AuthOtpInput.tsx

@@ -0,0 +1,132 @@
+import { useEffect, useMemo, useRef } from "react"
+
+const OTP_LENGTH = 5
+
+const normalizeDigits = (value: string) =>
+  value
+    .replace(/[۰-۹]/g, (digit) => String("۰۱۲۳۴۵۶۷۸۹".indexOf(digit)))
+    .replace(/[٠-٩]/g, (digit) => String("٠١٢٣٤٥٦٧٨٩".indexOf(digit)))
+
+const sanitizeOtp = (value: string) => normalizeDigits(value).replace(/\D/g, "").slice(0, OTP_LENGTH)
+
+export function AuthOtpInput({
+  id,
+  value,
+  disabled,
+  onChange,
+  onComplete,
+}: {
+  id: string
+  value: string
+  disabled?: boolean
+  onChange: (value: string) => void
+  onComplete?: (value: string) => void
+}) {
+  const inputRefs = useRef<Array<HTMLInputElement | null>>([])
+  const lastCompletedValueRef = useRef("")
+  const normalizedValue = useMemo(() => sanitizeOtp(value), [value])
+  const digits = useMemo(
+    () => Array.from({ length: OTP_LENGTH }, (_, index) => normalizedValue[index] ?? ""),
+    [normalizedValue],
+  )
+
+  useEffect(() => {
+    if (normalizedValue.length !== OTP_LENGTH) {
+      lastCompletedValueRef.current = ""
+      return
+    }
+
+    if (normalizedValue !== lastCompletedValueRef.current) {
+      lastCompletedValueRef.current = normalizedValue
+      onComplete?.(normalizedValue)
+    }
+  }, [normalizedValue, onComplete])
+
+  const focusIndex = (index: number) => {
+    inputRefs.current[index]?.focus()
+    inputRefs.current[index]?.select()
+  }
+
+  const handleSlotChange = (index: number, nextRawValue: string) => {
+    const nextValue = sanitizeOtp(nextRawValue)
+    if (!nextValue) {
+      const updated = digits.slice()
+      updated[index] = ""
+      onChange(updated.join(""))
+      return
+    }
+
+    if (nextValue.length > 1) {
+      onChange(nextValue)
+      const focusTarget = Math.min(nextValue.length, OTP_LENGTH - 1)
+      focusIndex(focusTarget)
+      return
+    }
+
+    const updated = digits.slice()
+    updated[index] = nextValue
+    const combined = updated.join("")
+    onChange(combined)
+
+    if (index < OTP_LENGTH - 1) {
+      focusIndex(index + 1)
+    }
+  }
+
+  const handleKeyDown = (index: number, event: React.KeyboardEvent<HTMLInputElement>) => {
+    if (event.key === "Backspace" && !digits[index] && index > 0) {
+      const updated = digits.slice()
+      updated[index - 1] = ""
+      onChange(updated.join(""))
+      focusIndex(index - 1)
+      event.preventDefault()
+      return
+    }
+
+    if (event.key === "ArrowLeft" && index > 0) {
+      focusIndex(index - 1)
+      event.preventDefault()
+      return
+    }
+
+    if (event.key === "ArrowRight" && index < OTP_LENGTH - 1) {
+      focusIndex(index + 1)
+      event.preventDefault()
+    }
+  }
+
+  const handlePaste = (event: React.ClipboardEvent<HTMLInputElement>) => {
+    event.preventDefault()
+    const pasted = sanitizeOtp(event.clipboardData.getData("text"))
+    if (!pasted) {
+      return
+    }
+    onChange(pasted)
+    focusIndex(Math.min(pasted.length, OTP_LENGTH - 1))
+  }
+
+  return (
+    <div className="flex items-center justify-center gap-2 sm:gap-3" dir="ltr">
+      {digits.map((digit, index) => (
+        <input
+          key={`${id}-${index}`}
+          ref={(element) => {
+            inputRefs.current[index] = element
+          }}
+          id={index === 0 ? id : undefined}
+          type="text"
+          inputMode="numeric"
+          autoComplete="one-time-code"
+          pattern="[0-9]*"
+          maxLength={OTP_LENGTH}
+          disabled={disabled}
+          value={digit}
+          onChange={(event) => handleSlotChange(index, event.target.value)}
+          onKeyDown={(event) => handleKeyDown(index, event)}
+          onPaste={handlePaste}
+          className="h-12 w-12 rounded-2xl border border-slate-200 bg-white text-center text-lg font-semibold tracking-[0.18em] text-slate-900 outline-none transition focus:border-sky-500 focus:ring-2 focus:ring-sky-200 dark:border-slate-700 dark:bg-slate-900 dark:text-white dark:focus:ring-sky-500/20 sm:h-14 sm:w-14"
+        />
+      ))}
+    </div>
+  )
+}