Progress

'use client';

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

export type ProgressTone = 'accent' | 'success' | 'warning' | 'destructive' | 'neutral';

const FILL: Record<ProgressTone, string> = {
  accent: 'bg-primary',
  success: 'bg-success',
  warning: 'bg-warning',
  destructive: 'bg-destructive',
  neutral: 'bg-foreground',
};
const STROKE: Record<ProgressTone, string> = {
  accent: 'var(--primary)',
  success: 'var(--success)',
  warning: 'var(--warning)',
  destructive: 'var(--destructive)',
  neutral: 'var(--foreground)',
};
/** Graded accent tones for stacked segments, strongest first */
const SEGMENT = [100, 62, 38, 22, 12];

const TEXTS = {
  en: { progress: 'Progress', loading: 'Loading', step: 'Step', of: 'of', done: 'done', current: 'current' },
  de: { progress: 'Fortschritt', loading: 'Lädt', step: 'Schritt', of: 'von', done: 'erledigt', current: 'aktuell' },
};
type ProgressTexts = (typeof TEXTS)['en'];

const clamp = (v: number, max: number) => Math.min(Math.max(v / (max || 1), 0), 1);

function usePercent() {
  const locale = useLocale();
  const nf = new Intl.NumberFormat(locale === 'de' ? 'de-DE' : 'en-US', { style: 'percent', maximumFractionDigits: 0 });
  return (share: number) => nf.format(share);
}

const KEYFRAMES = `@keyframes kitdd-indeterminate{0%{transform:translateX(-100%)}100%{transform:translateX(250%)}}`;

/* Steps pop in one after another, a check that arrives springs a little */
const STYLES =
  '.kitfx-pr-in .kitfx-pr-step{animation:kitfx-pr-step .55s cubic-bezier(.34,1.45,.64,1) both;animation-delay:calc(var(--i,0) * 110ms)}' +
  '@keyframes kitfx-pr-step{from{opacity:0;transform:scale(.6)}}' +
  '@media (prefers-reduced-motion:reduce){.kitfx-pr-in .kitfx-pr-step{animation:none}}';

/** Entrance only for elements that were below the fold, so nothing above it blinks on load */
function useEntrance<T extends Element>() {
  const [ref, inView] = useInView<T>();
  const waited = useRef(false);
  if (!inView) waited.current = true;
  return [ref, inView, inView && waited.current] as const;
}

/** A number that runs from 0 to its value once `run` turns true. Starts at the value for the server and reduced motion. */
function useCount(value: number, run: boolean, ms = 1000) {
  const [n, setN] = useState(value);
  const done = useRef(false);
  useEffect(() => {
    if (!run || done.current || prefersReducedMotion()) return;
    done.current = true;
    let raf = 0;
    const start = performance.now();
    const tick = (now: number) => {
      const t = Math.min(1, (now - start) / ms);
      setN(value * (1 - Math.pow(1 - t, 3)));
      if (t < 1) raf = requestAnimationFrame(tick);
    };
    raf = requestAnimationFrame(tick);
    return () => cancelAnimationFrame(raf);
  }, [run, value, ms]);
  return done.current || run ? n : value;
}

/* ------------------------------------------------------------------ */

export interface ProgressBarProps {
  value?: number;
  max?: number;
  /** Text above the bar, e.g. the file name */
  label?: React.ReactNode;
  /** Shown right of the label. Defaults to the percentage when showValue is set. */
  valueText?: React.ReactNode;
  showValue?: boolean;
  size?: 'sm' | 'md' | 'lg';
  tone?: ProgressTone;
  /** Unknown duration: a light runs through the track */
  indeterminate?: boolean;
  /** Several parts in one bar, e.g. storage by type. Values share max. */
  segments?: { value: number; label: string }[];
  labels?: Partial<ProgressTexts>;
  className?: string;
}

const HEIGHT = { sm: 'h-1', md: 'h-1.5', lg: 'h-2.5' };

/** A horizontal bar. Fills up when it scrolls into view, the percentage counts along. */
export function ProgressBar({ value = 0, max = 100, label, valueText, showValue, size = 'md', tone = 'accent', indeterminate, segments, labels, className }: ProgressBarProps) {
  const t = useTexts(TEXTS, labels);
  const pct = usePercent();
  const [ref, inView, entering] = useEntrance<HTMLDivElement>();
  const share = clamp(segments ? segments.reduce((s, x) => s + x.value, 0) : value, max);
  const counted = useCount(share, entering, 1000);
  const shown = valueText ?? (showValue && !indeterminate ? pct(entering ? counted : share) : null);
  const name = typeof label === 'string' ? label : t.progress;

  return (
    <div ref={ref} className={cn('w-full', className)}>
      {(label || shown) && (
        <div className="mb-2 flex items-baseline justify-between gap-3 text-[13px]">
          {label && <span className="min-w-0 truncate font-medium text-foreground">{label}</span>}
          {shown && <span className="shrink-0 tabular-nums text-muted-foreground">{shown}</span>}
        </div>
      )}
      <div
        role="progressbar"
        aria-label={name}
        aria-valuemin={0}
        aria-valuemax={indeterminate ? undefined : 100}
        aria-valuenow={indeterminate ? undefined : round(share * 100, 0)}
        aria-valuetext={indeterminate ? t.loading : undefined}
        className={cn('relative w-full overflow-hidden rounded-full bg-[color-mix(in_oklab,var(--foreground)_8%,transparent)]', HEIGHT[size])}
      >
        {indeterminate ? (
          <>
            <style>{KEYFRAMES}</style>
            <span className={cn('absolute inset-y-0 left-0 w-2/5 rounded-full animate-[kitdd-indeterminate_1.6s_var(--ease-kit)_infinite] motion-reduce:left-[30%] motion-reduce:animate-none motion-reduce:opacity-60', FILL[tone])} />
          </>
        ) : segments ? (
          // The parts keep their widths, a clip opens over them from the start
          <span className="flex h-full gap-[2px] transition-[clip-path] duration-[1200ms] ease-[var(--ease-kit)] motion-reduce:transition-none" style={{ clipPath: `inset(0 ${inView ? 0 : 100}% 0 0)` }}>
            {segments.map((sgm, i) => (
              <span
                key={sgm.label}
                className="h-full first:rounded-l-full last:rounded-r-full"
                style={{ width: `${round(clamp(sgm.value, max) * 100)}%`, background: `color-mix(in oklab, ${STROKE[tone]} ${SEGMENT[i % SEGMENT.length]}%, var(--background))` }}
              />
            ))}
          </span>
        ) : (
          // The fill is full width and slides in from the start, so its rounded end keeps its shape
          <span
            data-clip-ok
            className={cn('absolute inset-0 rounded-full transition-transform duration-1000 ease-[var(--ease-kit)] motion-reduce:transition-none', FILL[tone])}
            style={{ transform: `translateX(${inView ? round((share - 1) * 100) : -100}%)` }}
          />
        )}
      </div>
      {segments && (
        <ul className="mt-3 flex flex-wrap gap-x-5 gap-y-1.5 text-[12px] text-muted-foreground">
          {segments.map((sgm, i) => (
            <li key={sgm.label} className="flex items-center gap-1.5">
              <span className="size-2 rounded-full" style={{ background: `color-mix(in oklab, ${STROKE[tone]} ${SEGMENT[i % SEGMENT.length]}%, var(--background))` }} aria-hidden />
              {sgm.label}
              <span className="tabular-nums text-subtle-foreground">{pct(clamp(sgm.value, max))}</span>
            </li>
          ))}
        </ul>
      )}
    </div>
  );
}

/* ------------------------------------------------------------------ */

export interface ProgressRingProps {
  value: number;
  max?: number;
  /** Diameter in px */
  size?: number;
  /** Stroke width in px */
  thickness?: number;
  tone?: ProgressTone;
  /** Accessible name, e.g. "Monthly goal" */
  label?: string;
  /** Content in the middle. Defaults to the percentage. */
  children?: React.ReactNode;
  className?: string;
}

/** A ring that fills clockwise from the top when it scrolls into view, the percentage counts along. */
export function ProgressRing({ value, max = 100, size = 96, thickness = 8, tone = 'accent', label, children, className }: ProgressRingProps) {
  const t = useTexts(TEXTS);
  const pct = usePercent();
  const [ref, inView, entering] = useEntrance<HTMLDivElement>();
  const share = clamp(value, max);
  const counted = useCount(share, entering, 1200);
  const r = (size - thickness) / 2;
  const c = 2 * Math.PI * r;
  return (
    <div
      ref={ref}
      role="progressbar"
      aria-label={label ?? t.progress}
      aria-valuemin={0}
      aria-valuemax={100}
      aria-valuenow={round(share * 100, 0)}
      className={cn('relative inline-grid shrink-0 place-items-center', className)}
      style={{ width: size, height: size }}
    >
      <svg width={size} height={size} viewBox={`0 0 ${size} ${size}`} className="-rotate-90" aria-hidden>
        <circle cx={size / 2} cy={size / 2} r={round(r)} fill="none" strokeWidth={thickness} style={{ stroke: 'color-mix(in oklab, var(--foreground) 8%, transparent)' }} />
        <circle
          cx={size / 2}
          cy={size / 2}
          r={round(r)}
          fill="none"
          strokeWidth={thickness}
          strokeLinecap="round"
          strokeDasharray={round(c)}
          strokeDashoffset={round(inView ? c * (1 - share) : c)}
          className="transition-[stroke-dashoffset] duration-[1200ms] ease-[var(--ease-kit)] motion-reduce:transition-none"
          style={{ stroke: STROKE[tone] }}
        />
      </svg>
      <span className="absolute inset-0 grid place-items-center text-center">
        {children ?? (
          <span className="font-semibold tabular-nums tracking-tight text-foreground" style={{ fontSize: round(Math.max(9, size * 0.16)) }}>
            {pct(entering ? counted : share)}
          </span>
        )}
      </span>
    </div>
  );
}

/* ------------------------------------------------------------------ */

export interface ProgressStepsProps {
  steps: string[];
  /** Index of the current step, steps before it count as done */
  current: number;
  variant?: 'numbered' | 'bars' | 'dots';
  labels?: Partial<ProgressTexts>;
  className?: string;
}

/** Steps of a flow: numbered with connectors, bars or dots. They fill one after another when they scroll into view. */
export function ProgressSteps({ steps, current, variant = 'numbered', labels, className }: ProgressStepsProps) {
  const t = useTexts(TEXTS, labels);
  const [ref, inView, entering] = useEntrance<HTMLDivElement & HTMLOListElement>();
  const lag = (i: number) => ({ transitionDelay: entering ? `${i * 160}ms` : undefined });
  const style = (
    <style href="kitfx-pr" precedence="default">
      {STYLES}
    </style>
  );
  const state = (i: number) => (i < current ? 'done' : i === current ? 'current' : 'upcoming');
  const summary = `${t.step} ${current + 1} ${t.of} ${steps.length}`;

  if (variant === 'dots') {
    return (
      <div ref={ref} className={cn('flex items-center gap-3', !inView && '[&_.kitfx-pr-step]:opacity-0', entering && 'kitfx-pr-in', className)}>
        {style}
        <ol className="flex items-center gap-1.5" aria-label={summary}>
          {steps.map((s, i) => (
            <li
              key={s}
              aria-current={i === current ? 'step' : undefined}
              style={{ '--i': i } as React.CSSProperties}
              className={cn('kitfx-pr-step h-1.5 rounded-full transition-colors duration-500 ease-[var(--ease-kit)] motion-reduce:transition-none', i === current ? 'w-6 bg-primary' : i < current ? 'w-1.5 bg-[color-mix(in_oklab,var(--primary)_55%,var(--background))]' : 'w-1.5 bg-border-strong')}
            >
              <span data-clip-ok className="sr-only">
                {s}, {state(i) === 'done' ? t.done : state(i) === 'current' ? t.current : ''}
              </span>
            </li>
          ))}
        </ol>
        <span className="text-[13px] tabular-nums text-muted-foreground">{summary}</span>
      </div>
    );
  }

  if (variant === 'bars') {
    return (
      <div ref={ref} className={cn('w-full', className)}>
        <div className="mb-3 flex items-baseline justify-between gap-3 text-[13px] sm:hidden">
          <span className="font-medium text-foreground">{steps[current]}</span>
          <span className="tabular-nums text-muted-foreground">{summary}</span>
        </div>
        <ol className="grid gap-2" style={{ gridTemplateColumns: `repeat(${steps.length}, minmax(0, 1fr))` }} aria-label={summary}>
          {steps.map((s, i) => (
            <li key={s} aria-current={i === current ? 'step' : undefined}>
              <span className="block h-1.5 overflow-hidden rounded-full bg-[color-mix(in_oklab,var(--foreground)_8%,transparent)]">
                <span
                  data-clip-ok
                  className="block h-full w-full rounded-full bg-primary transition-transform duration-700 ease-[var(--ease-kit)] motion-reduce:transition-none"
                  style={{ transform: `translateX(${inView ? (i < current ? 0 : i === current ? -50 : -100) : -100}%)`, ...lag(i) }}
                />
              </span>
              <span className={cn('mt-2.5 hidden truncate text-[13px] sm:block', i <= current ? 'font-medium text-foreground' : 'text-muted-foreground')}>{s}</span>
              <span data-clip-ok className="sr-only sm:hidden">{s}</span>
            </li>
          ))}
        </ol>
      </div>
    );
  }

  return (
    <ol ref={ref} className={cn('flex w-full items-start', !inView && '[&_.kitfx-pr-step]:opacity-0', entering && 'kitfx-pr-in', className)} aria-label={summary}>
      {style}
      {steps.map((s, i) => {
        const st = state(i);
        return (
          <li key={s} aria-current={st === 'current' ? 'step' : undefined} className={cn('relative flex min-w-0 flex-1 flex-col items-center text-center')}>
            {i < steps.length - 1 && (
              <span aria-hidden className="absolute left-[calc(50%+1.25rem)] right-[calc(-50%+1.25rem)] top-4 h-px overflow-hidden bg-border-strong">
                <span
                  className={cn('block h-full w-full origin-left bg-primary transition-transform duration-500 ease-[var(--ease-kit)] motion-reduce:transition-none', st === 'done' && inView ? 'scale-x-100' : 'scale-x-0')}
                  style={{ transitionDelay: entering ? `${i * 110 + 160}ms` : undefined }}
                />
              </span>
            )}
            <span
              style={{ '--i': i } as React.CSSProperties}
              className={cn(
                'kitfx-pr-step relative grid size-8 place-items-center rounded-full text-[13px] font-semibold tabular-nums transition-colors',
                st === 'done' && 'bg-primary text-primary-foreground',
                st === 'current' && 'bg-background text-foreground shadow-[inset_0_0_0_1.5px_var(--primary),0_0_0_4px_color-mix(in_oklab,var(--primary)_14%,transparent)]',
                st === 'upcoming' && 'bg-background text-muted-foreground shadow-[inset_0_0_0_1px_var(--border-strong)]',
              )}
            >
              {st === 'done' ? <Icon name="check" size={15} strokeWidth={2.2} /> : i + 1}
            </span>
            <span className={cn('mt-2.5 max-w-full truncate px-1 text-[12px] sm:text-[13px]', st === 'upcoming' ? 'text-muted-foreground' : 'font-medium text-foreground', st !== 'current' && 'max-sm:sr-only')}>
              {s}
              <span data-clip-ok className="sr-only">, {st === 'done' ? t.done : st === 'current' ? t.current : ''}</span>
            </span>
          </li>
        );
      })}
    </ol>
  );
}