// Home: how your weekly recalls have gone — the last eight weeks at a glance, then every recall you've written.
import { useMemo, useState } from 'react';
import { useApp } from '../context/AppContext.js';
import { loadProjectById } from '../utils/projectStorage.js';
import { recallHistory, recallSummary } from '../utils/recall.js';

const LABEL = { solid: 'Had it', partly: 'Partly', forgot: 'Slipped' };
const DOT = { solid: 'bg-[var(--r-accent)] border-[var(--r-accent)]', partly: 'bg-[var(--r-hl)] border-[var(--r-accent)]', forgot: 'border-[var(--r-sub)]' };

export default function RecallHistory() {
  const { projectIndex, openStudyChunk } = useApp();
  const [open, setOpen] = useState(false);
  const history = useMemo(() => recallHistory(projectIndex.map((e) => loadProjectById(e.id)).filter(Boolean)), [projectIndex]);
  if (history.length === 0) return null;
  const { counts, total, recent } = recallSummary(history);

  return (
    <section aria-label="Recall history" className="mb-4 rounded-xl border border-[var(--r-line)] bg-[var(--r-bar)] px-4 py-3 text-sm">
      <button type="button" onClick={() => setOpen((o) => !o)} aria-expanded={open} className="flex w-full flex-wrap items-center justify-between gap-3 text-left">
        <span><span className="font-medium">Recall history</span> <span className="text-xs text-[var(--r-sub)]">{total} recall{total === 1 ? '' : 's'} · {counts.solid} had it · {counts.partly} partly · {counts.forgot} slipped</span></span>
        <span className="flex items-center gap-1" aria-label="Last eight weeks">
          {recent.map((w) => (
            <span key={w.start} title={w.rating ? LABEL[w.rating] : 'No recall that week'}
              className={`h-3 w-3 rounded-full border ${w.rating ? DOT[w.rating] : 'border-[var(--r-line)]'}`} />
          ))}
          <span className="ml-1 text-xs text-[var(--r-sub)]">{open ? '▾' : '▸'}</span>
        </span>
      </button>
      {open && (
        <ul className="mt-3 space-y-2.5">
          {history.map((h) => (
            <li key={`${h.chunkId}-${h.at}`} className="rounded-lg border border-[var(--r-line)] bg-[var(--r-bg)] p-3">
              <div className="flex flex-wrap items-center justify-between gap-2 text-xs">
                <span><span className="font-medium text-sm">{h.reference}</span> <span className="text-[var(--r-sub)]">· {h.projectTitle} · {new Date(h.at).toLocaleDateString()}</span></span>
                <span className="flex items-center gap-2">
                  <span className="rounded-full border border-[var(--r-line)] px-2 py-0.5">{LABEL[h.rating] ?? '—'}</span>
                  <button type="button" onClick={() => openStudyChunk(h.projectId, h.chunkId)} className="text-[var(--r-accent)] hover:underline">Open</button>
                </span>
              </div>
              {h.text && <p className="mt-1.5 line-clamp-3 whitespace-pre-line font-serif text-[13px] leading-relaxed text-[var(--r-sub)]">{h.text}</p>}
            </li>
          ))}
        </ul>
      )}
    </section>
  );
}