Alert

'use client';

import { useRef, useState } from 'react';
import { cn, prefersReducedMotion, useInView, useTexts } from '@/lib/kit';
import { Icon, type IconName } from '@/components/ui/icon';

const TEXTS = { en: { dismiss: 'Dismiss' }, de: { dismiss: 'Ausblenden' } };

/* The icon pops in once the alert is in view */
const CSS =
  '.kitfx-alert[data-in] .kitfx-alert-icon{animation:kitfx-alert-icon .6s cubic-bezier(.34,1.56,.64,1) .12s both}@keyframes kitfx-alert-icon{from{opacity:0;transform:scale(.5)}}' +
  '@media (prefers-reduced-motion:reduce){.kitfx-alert .kitfx-alert-icon{animation:none}}';

export type AlertTone = 'neutral' | 'info' | 'success' | 'warning' | 'error';

/* One color per tone, everything else is mixed from it, so both modes and every accent stay in tune */
const TONE: Record<AlertTone, { color: string; icon: IconName }> = {
  neutral: { color: 'var(--muted-foreground)', icon: 'info' },
  info: { color: 'var(--info)', icon: 'info' },
  success: { color: 'var(--success)', icon: 'check-circle' },
  warning: { color: 'var(--warning)', icon: 'alert' },
  error: { color: 'var(--destructive)', icon: 'alert-circle' },
};

export interface AlertProps {
  tone?: AlertTone;
  title?: React.ReactNode;
  children?: React.ReactNode;
  /** Override the tone icon */
  icon?: IconName;
  /** Buttons or links under the text (or at the end in the inline layout) */
  actions?: React.ReactNode;
  /** Shows a dismiss button. The alert hides itself and calls onDismiss. */
  dismissible?: boolean;
  onDismiss?: () => void;
  /** soft: tinted surface (default). outline: card with a colored icon. accent: a bar on the start edge. inline: one compact line. */
  variant?: 'soft' | 'outline' | 'accent' | 'inline';
  labels?: Partial<(typeof TEXTS)['en']>;
  className?: string;
}

/**
 * A message in the flow of the page: info, success, warning or error. Always text and icon, never color alone.
 * Errors and warnings use role="alert", the others role="status".
 *   <Alert tone="warning" title="Your trial ends in 3 days">Add a payment method to keep your projects.</Alert>
 */
export function Alert({ tone = 'info', title, children, icon, actions, dismissible, onDismiss, variant = 'soft', labels, className }: AlertProps) {
  const t = useTexts(TEXTS, labels);
  const [open, setOpen] = useState(true);
  const [ref, inView] = useInView<HTMLDivElement>();
  const leaving = useRef(false);
  if (!open) return null;
  const c = TONE[tone];
  const urgent = tone === 'error' || tone === 'warning';
  const ink = `color-mix(in oklab, ${c.color} 78%, var(--foreground))`;

  const surface = {
    soft: 'border border-[color-mix(in_oklab,var(--tone)_28%,var(--border))] bg-[color-mix(in_oklab,var(--tone)_8%,var(--background))]',
    outline: 'border border-border bg-card shadow-[var(--highlight),var(--shadow-sm)]',
    accent: 'border border-border border-s-[3px] border-s-[var(--tone)] bg-card shadow-[var(--shadow-sm)]',
    inline: 'border border-[color-mix(in_oklab,var(--tone)_24%,var(--border))] bg-[color-mix(in_oklab,var(--tone)_7%,var(--background))]',
  }[variant];

  const dismiss = dismissible && (
    <button
      type="button"
      aria-label={t.dismiss}
      onClick={() => {
        const el = ref.current;
        const done = () => {
          setOpen(false);
          onDismiss?.();
        };
        if (!el || prefersReducedMotion()) return done();
        if (leaving.current) return;
        leaving.current = true;
        // Out first, then the space closes, so the content below glides up instead of jumping
        const h = el.offsetHeight;
        el.style.pointerEvents = 'none';
        el.style.overflow = 'hidden';
        el.animate([{ opacity: 1, transform: 'none' }, { opacity: 0, transform: 'translateX(12px) scale(0.98)' }], { duration: 220, easing: 'cubic-bezier(0.4, 0, 0.9, 0.6)', fill: 'forwards' })
          .finished.then(() => el.animate([{ height: `${h}px`, marginBlock: getComputedStyle(el).marginBlock }, { height: '0px', marginBlock: '0px', paddingBlock: '0px', borderWidth: '0px' }], { duration: 240, easing: 'cubic-bezier(0.2, 0.7, 0.2, 1)', fill: 'forwards' }).finished)
          .then(done, done);
      }}
      className={cn('group/close grid size-8 shrink-0 place-items-center rounded-md text-muted-foreground transition-colors hover:bg-[color-mix(in_oklab,var(--tone)_12%,transparent)] hover:text-foreground', variant !== 'inline' && '-me-1.5 -mt-1.5')}
    >
      <Icon name="x" size={15} className="transition-transform duration-300 ease-[var(--ease-kit)] group-hover/close:rotate-90 motion-reduce:transition-none" />
    </button>
  );

  // Rises into place when it scrolls into view, the icon pops
  const motion = cn('kitfx-alert transition-[opacity,translate] duration-700 ease-[var(--ease-kit)] motion-reduce:transition-none', !inView && 'translate-y-3 opacity-0');
  const style = <style href="kitfx-alert" precedence="default">{CSS}</style>;

  if (variant === 'inline') {
    return (
      <div ref={ref} data-in={inView || undefined} role={urgent ? 'alert' : 'status'} className={cn('flex min-h-11 items-center gap-2.5 rounded-lg px-3 py-2 text-sm', surface, motion, className)} style={{ '--tone': c.color } as React.CSSProperties}>
        {style}
        <Icon name={icon ?? c.icon} size={16} className="kitfx-alert-icon shrink-0" style={{ color: ink }} />
        <p className="min-w-0 flex-1 text-pretty text-foreground">
          {title && <span className="font-medium">{title} </span>}
          <span className="text-muted-foreground">{children}</span>
        </p>
        {actions && <div className="flex shrink-0 items-center gap-2 text-[13px] font-medium">{actions}</div>}
        {dismiss}
      </div>
    );
  }

  return (
    <div ref={ref} data-in={inView || undefined} role={urgent ? 'alert' : 'status'} className={cn('relative flex gap-3 rounded-xl p-4', surface, motion, className)} style={{ '--tone': c.color } as React.CSSProperties}>
      {style}
      <span
        className={cn('kitfx-alert-icon grid shrink-0 place-items-center', variant === 'outline' ? 'size-8 rounded-lg bg-[color-mix(in_oklab,var(--tone)_12%,transparent)]' : 'size-5 mt-px')}
        style={{ color: ink }}
      >
        <Icon name={icon ?? c.icon} size={variant === 'outline' ? 17 : 18} />
      </span>
      <div className={cn('min-w-0 flex-1', variant === 'outline' && 'pt-[5px]')}>
        {title && <p className="text-sm font-semibold leading-5 text-foreground">{title}</p>}
        {children && <div className={cn('text-pretty text-sm leading-relaxed text-muted-foreground', title && 'mt-1')}>{children}</div>}
        {actions && <div className="mt-3 flex flex-wrap items-center gap-x-4 gap-y-2 text-[13px] font-medium">{actions}</div>}
      </div>
      {dismiss}
    </div>
  );
}

/** A text link styled for alert actions */
export function AlertLink({ href, onClick, children }: { href?: string; onClick?: () => void; children: React.ReactNode }) {
  const cls = 'inline-flex items-center gap-1 text-foreground underline decoration-[color-mix(in_oklab,var(--tone,var(--foreground))_45%,transparent)] underline-offset-4 transition-[text-decoration-color] duration-200 hover:decoration-current';
  return href ? (
    <a href={href} className={cls}>
      {children}
    </a>
  ) : (
    <button type="button" onClick={onClick} className={cls}>
      {children}
    </button>
  );
}