'use client';

import { useEffect, useState, type CSSProperties } from 'react';
import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
import { faPlay } from '@fortawesome/free-solid-svg-icons';
import {
	DONATION_AMOUNT_MIN, DONATION_AMOUNT_MAX, DONATION_AMOUNT_STEP, DONATION_AMOUNT_DEFAULT
} from '@/constants/donation';
import type { FormState } from '../types';

type Props = {
	form: FormState;
};

export default function GoalPreviewPanel({ form }: Props) {
	const [previewAmount, setPreviewAmount] = useState(DONATION_AMOUNT_DEFAULT);
	const [simulatedAmount, setSimulatedAmount] = useState(0);

	// form.startAmount가 변경되면 시뮬레이션 누적값 초기화
	useEffect(() => {
		setSimulatedAmount(0);
	}, [form.startAmount]);

	const currentAmount = form.startAmount + simulatedAmount;
	const percent = form.targetAmount > 0 ? Math.min((currentAmount / form.targetAmount) * 100, 100) : 0;

	const titleStyle = {
		'--title-font': form.titleFontFamily || 'inherit',
		'--title-size': `${form.titleFontSizePx}px`,
		'--title-color': form.titleFontColor
	} as CSSProperties;

	const barWrapStyle = {
		'--bar-height': `${form.barHeightPx}px`,
		'--bar-bg': form.barBackgroundColor
	} as CSSProperties;

	const barFillStyle = {
		'--bar-percent': `${percent}%`,
		'--bar-color': form.barColor
	} as CSSProperties;

	const amountStyle = {
		'--amount-font': form.amountFontFamily || 'inherit',
		'--amount-size': `${form.amountFontSizePx}px`,
		'--amount-color': form.amountFontColor
	} as CSSProperties;

	const handlePreview = () => {
		setSimulatedAmount(prev => prev + (previewAmount || DONATION_AMOUNT_DEFAULT));
	};

	const handleReset = () => {
		setSimulatedAmount(0);
	};

	return (
		<aside className="goal-config__preview-panel">
			<div className="goal-config__widget">
				<div className="goal-config__widget-label">미리보기</div>
				<div className="goal-config__widget-body">
					<div className="goal-preview">
						<div className="goal-preview__title" style={titleStyle}>
							{form.title || '후원 목표'}
						</div>
						<div className="goal-preview__bar-wrap" style={barWrapStyle}>
							<div className="goal-preview__bar-fill" style={barFillStyle} />
							<div className="goal-preview__amount" style={amountStyle}>
								{currentAmount.toLocaleString()}원 / {form.targetAmount.toLocaleString()}원
								{form.isShowPercent && (
									<span className="goal-preview__percent">
										{' '}({Math.round(percent)}%)
									</span>
								)}
							</div>
						</div>
					</div>
				</div>
			</div>

			<fieldset className="goal-config__fieldset">
				<legend className="goal-config__legend">미리보기</legend>
				<div className="goal-config__preview-form">
					<div className="goal-config__field">
						<label htmlFor="goal-preview-amount" className="goal-config__field-label">후원 금액 (원)</label>
						<input
							id="goal-preview-amount"
							type="number"
							className="goal-config__input"
							min={DONATION_AMOUNT_MIN}
							max={DONATION_AMOUNT_MAX}
							step={DONATION_AMOUNT_STEP}
							value={previewAmount}
							onChange={e => setPreviewAmount(parseInt(e.target.value) || DONATION_AMOUNT_DEFAULT)}
						/>
					</div>
					<div className="goal-config__preview-actions">
						<button
							type="button"
							className="goal-config__btn goal-config__btn--primary goal-config__preview-btn"
							onClick={handlePreview}
						>
							<FontAwesomeIcon icon={faPlay} />
							미리보기
						</button>
						<button
							type="button"
							className="goal-config__btn"
							onClick={handleReset}
							disabled={simulatedAmount === 0}
						>
							초기화
						</button>
					</div>
					{simulatedAmount > 0 && (
						<p className="goal-config__field-hint">누적: +{simulatedAmount.toLocaleString()}원</p>
					)}
				</div>
			</fieldset>
		</aside>
	);
}