import { useState, useRef, useId } from 'react'
import { useChatStore } from '@/features/chat/stores/useChatStore'

// 단위(원/%) 오버레이 + 전송 버튼이 붙은 값 입력 (Percent / Price 공용)
function InputWithUnit({
  value,
  onChange,
  onSubmit,
  placeholder,
  unit,
  error,
  inputRef,
  ariaLabel,
}: {
  value: string
  onChange: (e: React.ChangeEvent<HTMLInputElement>) => void
  onSubmit: () => void
  placeholder: string
  unit: string
  error: string
  inputRef: React.RefObject<HTMLInputElement | null>
  ariaLabel: string
}) {
  const errorId = useId()
  return (
    <div className="relative flex flex-col gap-3">
      <div className="relative flex items-center min-w-[480px] max-[1350px]:min-w-[420px] max-[1180px]:min-w-[320px]">
        <input
          ref={inputRef}
          type="text"
          inputMode="decimal"
          value={value}
          onChange={onChange}
          onKeyDown={(e) => e.key === 'Enter' && onSubmit()}
          className="h-[50px] flex-1 bg-white border-none rounded-[999px] outline-none ring-1 ring-primary headline-3 text-negative placeholder:text-neutral-60 pl-[32px]"
          placeholder={placeholder}
          aria-label={ariaLabel}
          aria-invalid={!!error}
          aria-describedby={error ? errorId : undefined}
        />
        <div className="absolute left-[32px] headline-3 text-neutral-70 pointer-events-none">
          <span className="opacity-0">{value}</span>
          {value && <span className="ml-1">{unit}</span>}
        </div>
        <button
          type="button"
          onClick={onSubmit}
          className="absolute right-0 flex items-center justify-center min-w-[120px] h-[50px] px-[32px] bg-primary hover:brightness-[0.97] rounded-[999px] title-2 text-primary-foreground cursor-pointer whitespace-nowrap transition-colors duration-200"
          aria-label="전송"
        >
          전송
        </button>
      </div>
      {error && (
        <div id={errorId} role="alert" className="absolute top-[62px] left-1/2 -translate-x-1/2 title-2 text-negative w-full text-center">
          {error}
        </div>
      )}
    </div>
  )
}

export function Percent() {
  const [percent, setPercent] = useState('')
  const [error, setError] = useState('')
  const inputRef = useRef<HTMLInputElement>(null)
  const sendMessage = useChatStore((s) => s.sendMessage)

  const handleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
    const value = e.target.value
    if (value === '') {
      setPercent('')
      setError('')
      return
    }
    if (!/^\d*\.?\d*$/.test(value)) return
    if (value.includes('.')) {
      const parts = value.split('.')
      if (parts[1] && parts[1].length > 1) return
    } else if (value.length > 2) {
      return
    }
    if (parseFloat(value) > 80) return
    setPercent(value)
    setError('')
  }

  const handleSubmit = () => {
    if (!percent || percent === '.') {
      setError('숫자를 입력해주세요')
      return
    }
    sendMessage(`${parseFloat(percent).toString()}%`, 'percent')
    setError('')
  }

  return (
    <InputWithUnit
      value={percent}
      onChange={handleChange}
      onSubmit={handleSubmit}
      placeholder="할인율(%) 소수점 첫째 자리까지"
      unit="%"
      error={error}
      inputRef={inputRef}
      ariaLabel="할인율 입력"
    />
  )
}

export function Price({ priceErrorMessage }: { priceErrorMessage?: string }) {
  const [inputValue, setInputValue] = useState('')
  const [error, setError] = useState('')
  const inputRef = useRef<HTMLInputElement>(null)
  const sendMessage = useChatStore((s) => s.sendMessage)
  const setPriceErrorMessage = useChatStore((s) => s.setPriceErrorMessage)

  const displayError = priceErrorMessage || error

  const handleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
    const value = e.target.value
    if (priceErrorMessage) setPriceErrorMessage('')
    if (value === '') {
      setInputValue('')
      setError('')
      return
    }
    const numberOnly = value.replace(/,/g, '')
    if (!/^\d*$/.test(numberOnly)) return
    if (parseInt(numberOnly) > 999999999999) return
    setInputValue(numberOnly.replace(/\B(?=(\d{3})+(?!\d))/g, ','))
    setError('')
  }

  const handleSubmit = () => {
    if (!inputValue) {
      if (priceErrorMessage) setPriceErrorMessage('')
      setError('가격을 입력해주세요')
      return
    }
    sendMessage(`${inputValue}원`, 'price')
    setError('')
  }

  return (
    <InputWithUnit
      value={inputValue}
      onChange={handleChange}
      onSubmit={handleSubmit}
      placeholder="가격(원)을 입력해주세요"
      unit="원"
      error={displayError}
      inputRef={inputRef}
      ariaLabel="가격 입력"
    />
  )
}