import { useId, useLayoutEffect, useRef, useState, type ReactNode } from 'react';
import { useI18n } from '../lib/i18n';
import { CATEGORY_ICON } from '../lib/categoryIcon';
import type { Confidence, Fact, PlaceCategory, SourceKind, Status, Verdict, VetState } from '../lib/types';

const SPRITE = `${import.meta.env.BASE_URL}uswds/sprite.svg`;

export function Icon({ name, size = 3, className = '' }: { name: string; size?: 2 | 3 | 4 | 5; className?: string }) {
  return (
    <svg className={`usa-icon usa-icon--size-${size} ${className}`} aria-hidden="true" focusable="false" role="img">
      <use href={`${SPRITE}#${name}`} />
    </svg>
  );
}

/** Category pictogram in a soft square; decorative, the category name is always written next to it. */
export function CategoryIcon({ cat, size = 'md' }: { cat: PlaceCategory; size?: 'sm' | 'md' }) {
  return (
    <span className={`kbb-cat kbb-cat--${size}`} aria-hidden="true">
      <Icon name={CATEGORY_ICON[cat]} size={size === 'sm' ? 2 : 3} />
    </span>
  );
}

export const VERDICT_STYLE: Record<Verdict, { icon: string; tag: string; alert: string; hex: string }> = {
  match: { icon: 'check_circle', tag: 'bg-success-dark text-white', alert: 'usa-alert--success', hex: '#00a91c' },
  partial: { icon: 'warning', tag: 'bg-warning text-ink', alert: 'usa-alert--warning', hex: '#ffbe2e' },
  conflict: { icon: 'report', tag: 'bg-accent-warm-darker text-white', alert: 'usa-alert--warning', hex: '#a2461c' },
  incomplete: { icon: 'help', tag: 'bg-base-lighter text-ink', alert: 'usa-alert--info', hex: '#ffffff' },
  fail: { icon: 'error', tag: 'bg-error-dark text-white', alert: 'usa-alert--error', hex: '#b50909' },
};

export function VerdictTag({ verdict }: { verdict: Verdict }) {
  const { t } = useI18n();
  const s = VERDICT_STYLE[verdict];
  return (
    <span className={`usa-tag display-inline-flex flex-align-center ${s.tag}`}>
      <Icon name={s.icon} size={2} className="margin-right-05" />
      {t(`verdict.${verdict}`)}
    </span>
  );
}

const STATUS_STYLE: Record<Status, { icon: string; text: string }> = {
  ok: { icon: 'check_circle', text: 'text-success-dark' },
  warn: { icon: 'warning', text: 'text-warning-darker' },
  fail: { icon: 'error', text: 'text-error-dark' },
  unknown: { icon: 'help', text: 'text-base-dark' },
  conflict: { icon: 'report', text: 'text-accent-warm-darker' },
};

export function StatusLabel({ status }: { status: Status }) {
  const { t } = useI18n();
  const s = STATUS_STYLE[status];
  return (
    <span className={`display-inline-flex flex-align-center text-bold ${s.text}`}>
      <Icon name={s.icon} size={3} className="margin-right-05" />
      {t(`status.${status}`)}
    </span>
  );
}

const CONF_STYLE: Record<Confidence, string> = {
  verified: 'bg-success-dark text-white',
  mapped: 'bg-primary text-white',
  stale: 'bg-warning text-ink',
  inferred: 'bg-base-dark text-white',
  user: 'bg-accent-warm-darker text-white',
  none: 'bg-base-lighter text-ink',
};
const CONF_ICON: Record<Confidence, string> = {
  verified: 'verified', mapped: 'check', stale: 'update', inferred: 'info_outline', user: 'edit', none: 'help_outline',
};

export function ConfidenceTag({ confidence }: { confidence: Confidence }) {
  const { t } = useI18n();
  return (
    <span className={`usa-tag display-inline-flex flex-align-center ${CONF_STYLE[confidence]}`} title={t(`conf.${confidence}.help`)}>
      <Icon name={CONF_ICON[confidence]} size={2} className="margin-right-05" />
      {t(`conf.${confidence}`)}
    </span>
  );
}

export function SourceLine({ source, confidence, date }: { source: SourceKind; confidence: Confidence; date: string | null }) {
  const { t, date: fmt } = useI18n();
  return (
    <dl className="kbb-source font-sans-3xs margin-top-1 margin-bottom-0">
      <div>
        <dt className="text-base-dark">{t('src.label')}</dt>
        <dd>{t(`src.${source}`)}</dd>
      </div>
      <div>
        <dt className="text-base-dark">{t('fact.updated')}</dt>
        <dd>{date ? fmt(date) : t('fact.dateUnknown')}</dd>
      </div>
      <div>
        <dt className="text-base-dark">{t('fact.confidence')}</dt>
        <dd><ConfidenceTag confidence={confidence} /></dd>
      </div>
    </dl>
  );
}

export function FactCard({ fact, onReport }: { fact: Fact; onReport?: (() => void) | undefined }) {
  const { t, tm } = useI18n();
  const canReport = onReport && ['entrance', 'steps', 'width', 'toilet', 'ramp'].includes(fact.key);
  return (
    <li className="border-1px border-base-lighter radius-md padding-2 margin-bottom-2 bg-white">
      <div className="display-flex flex-justify flex-wrap flex-align-center">
        <h4 className="margin-0 font-sans-md">{t(`fact.title.${fact.key}`)}</h4>
        <StatusLabel status={fact.status} />
      </div>
      <p className="margin-top-1 margin-bottom-0">{tm(fact.headline)}</p>
      {fact.detail && <p className="margin-top-05 margin-bottom-0 text-base-dark font-sans-xs">{tm(fact.detail)}</p>}
      <SourceLine source={fact.source} confidence={fact.confidence} date={fact.date} />
      {fact.alt && (
        <div className="usa-alert usa-alert--warning usa-alert--slim margin-top-2">
          <div className="usa-alert__body">
            <p className="usa-alert__text">
              <strong>{t('fact.otherSource')}:</strong> {tm(fact.alt.headline)}
            </p>
            <SourceLine source={fact.alt.source} confidence={fact.alt.confidence} date={fact.alt.date} />
          </div>
        </div>
      )}
      <div className="display-flex flex-wrap flex-align-center margin-top-1">
        {fact.required && <span className="font-sans-3xs text-base-dark margin-right-2">{t('fact.required')}</span>}
        {canReport && (
          <button type="button" className="usa-button usa-button--unstyled font-sans-xs" onClick={onReport}>
            {t('fact.report')}
          </button>
        )}
      </div>
    </li>
  );
}

export function Alert({ kind, heading, children, slim = false, role }: { kind: 'info' | 'warning' | 'error' | 'success'; heading?: string; children: ReactNode; slim?: boolean; role?: 'alert' | 'status' }) {
  return (
    <div className={`usa-alert usa-alert--${kind} ${slim ? 'usa-alert--slim' : ''}`} role={role}>
      <div className="usa-alert__body">
        {heading && <h4 className="usa-alert__heading">{heading}</h4>}
        <div className="usa-alert__text">{children}</div>
      </div>
    </div>
  );
}

/** Accessible help bubble: hover, focus or click opens it; Escape or blur closes it (WCAG 1.4.13). */
export function InfoTip({ topic, text }: { topic: string; text: string }) {
  const { t } = useI18n();
  const [open, setOpen] = useState(false);
  const [hover, setHover] = useState(false);
  const id = useId();
  const show = open || hover;
  const bubble = useRef<HTMLSpanElement>(null);
  const [shift, setShift] = useState(0);
  useLayoutEffect(() => {
    const el = bubble.current;
    if (!show || !el) return;
    el.style.transform = '';
    const r = el.getBoundingClientRect();
    const over = r.right - (window.innerWidth - 8);
    setShift(over > 0 ? -Math.min(over, r.left - 8) : 0);
  }, [show]);
  return (
    <span className="kbb-tip" onMouseEnter={() => setHover(true)} onMouseLeave={() => setHover(false)}>
      <button
        type="button" className="kbb-tip__btn" aria-expanded={show} aria-controls={id} aria-label={t('tip.label', { topic })}
        onClick={() => setOpen((o) => !o)}
        onBlur={() => setOpen(false)}
        onKeyDown={(e) => { if (e.key === 'Escape') { setOpen(false); setHover(false); } }}
      >
        <Icon name="help_outline" size={3} />
      </button>
      <span id={id} ref={bubble} role="tooltip" className="kbb-tip__bubble" hidden={!show} style={{ transform: `translateX(${shift}px)` }}>{text}</span>
    </span>
  );
}

const TRIAGE_STYLE = { 'fast-track': 'bg-primary-dark text-white', review: 'bg-base-lighter text-ink', 'likely-reject': 'bg-base-dark text-white' } as const;
const SEVERITY_STYLE = { critical: 'bg-error-dark text-white', major: 'bg-accent-warm-darker text-white', minor: 'bg-warning text-ink', none: 'bg-base-lighter text-ink' } as const;

/** Automatic first assessment of a report. Always framed as advisory. */
export function VettingSummary({ v, detailed = false }: { v: VetState | undefined; detailed?: boolean }) {
  const { t, tm } = useI18n();
  if (!v) return null;
  if (v.state === 'running') return <p className="font-sans-xs margin-y-05" role="status"><Icon name="update" size={2} className="margin-right-05" />{t('vet.running')}</p>;
  if (v.state === 'failed') {
    return <p className="font-sans-xs margin-y-05 text-error-dark" role="status"><Icon name="error_outline" size={2} className="margin-right-05" />{t(v.reason === 'no-credits' ? 'vet.noCredits' : v.reason === 'skipped' ? 'vet.skipped' : 'vet.error')}</p>;
  }
  const r = v.result;
  return (
    <div className="margin-y-05">
      <p className="margin-y-05 display-flex flex-wrap flex-align-center">
        <span className={`usa-tag margin-right-05 ${TRIAGE_STYLE[r.triage]}`}>{t(`vet.triage.${r.triage}`)}</span>
        <span className={`usa-tag margin-right-05 ${SEVERITY_STYLE[r.severity]}`}>{t('vet.severityLabel')}: {t(`vet.severity.${r.severity}`)}</span>
        <span className="usa-tag bg-base-lighter text-ink margin-right-05">{t(`vet.validity.${r.validity}`)}</span>
        {r.flags.map((f) => <span key={f} className="usa-tag bg-warning text-ink margin-right-05">{t(`vet.flag.${f}`)}</span>)}
      </p>
      {detailed && (
        <>
          <p className="font-sans-xs margin-y-05">
            {t('vet.classLabel')}: <strong>{t(`vet.class.${r.accessibilityClass}`)}</strong> · {t(`vet.consistency.${r.consistency}`)} · {t('vet.confidence', { pct: Math.round(r.confidence * 100) })}
          </p>
          <details className="font-sans-xs">
            <summary>{t('dash.queue.reasons')}</summary>
            <ul className="usa-list">
              {r.reasons.map((m, i) => <li key={i}>{tm(m)}</li>)}
            </ul>
            <p className="text-base-dark margin-y-05">{t('vet.provider', { name: r.provider })}</p>
          </details>
          <p className="font-sans-3xs text-base-dark margin-y-05">{t('vet.disclaimer')}</p>
        </>
      )}
    </div>
  );
}