// The prayer journal: what you are praying about (and for whom), the verses tied to each request, the days you
// prayed, and the answers when they come.
import { useEffect, useMemo, useRef, useState } from 'react';
import { useApp } from '../context/AppContext.js';
import PageShell from '../components/study/PageShell.jsx';
import { useToast } from '../components/Toasts.jsx';
import { STATUSES, filterPrayers, daysToAnswer, labelFor, live, parsePrayerImport, parseVerses, pinned as pinnedList, prayersToJson, prayersToMarkdown } from '../utils/prayers.js';
import { localDateString } from '../utils/readingPlans.js';

const field = 'rounded-xl border border-[var(--r-line)] bg-[var(--r-bg)] px-3 py-2 text-sm text-[var(--r-text)] focus:outline-none focus:ring-2 focus:ring-[var(--r-line)]';
const small = 'rounded-lg border border-[var(--r-line)] px-2.5 py-1 text-xs hover:bg-black/5';
const tabBtn = (on) => `rounded-full border px-3 py-1 text-xs font-medium ${on ? 'border-[var(--r-text)] bg-[var(--r-text)] text-[var(--r-bg)]' : 'border-[var(--r-line)] text-[var(--r-sub)] hover:bg-black/5'}`;

function VerseChips({ verses, onOpen }) {
  if (!verses?.length) return null;
  return (
    <span className="mt-1 flex flex-wrap gap-1.5">
      {verses.map((v, i) => (
        <button key={`${v.book}${v.chapter}${v.verse}${i}`} type="button" onClick={() => onOpen(v.book, v.chapter, v.verse ?? 1)}
          className="rounded-full border border-[var(--r-line)] px-2 py-0.5 text-[11px] text-[var(--r-accent)] hover:bg-black/5" title="Read it in the Bible">{labelFor(v)}</button>
      ))}
    </span>
  );
}

function PrayerCard({ prayer, today, actions, onOpenVerse, pinPos }) {
  const [mode, setMode] = useState(null); // null | 'edit' | 'answer' | 'partial'
  const [text, setText] = useState('');
  const [note, setNote] = useState('');
  const prayedToday = prayer.prayedOn.includes(today);
  const isPinned = !!pinPos;
  const days = daysToAnswer(prayer);
  return (
    <li className="rounded-2xl border border-[var(--r-line)] bg-[var(--r-bar)] p-4">
      {mode === 'edit' ? (
        <div>
          <textarea aria-label="Edit prayer" value={text} onChange={(e) => setText(e.target.value)} rows={3} maxLength={2000} className={`${field} w-full`} />
          <div className="mt-2 flex gap-3 text-xs">
            <button type="button" onClick={() => { if (text.trim()) actions.edit(prayer.id, { text: text.trim() }); setMode(null); }} className="font-medium text-[var(--r-accent)] hover:underline">Save</button>
            <button type="button" onClick={() => setMode(null)} className="text-[var(--r-sub)] hover:underline">Cancel</button>
          </div>
        </div>
      ) : (
        <div>
          {(prayer.forWhom || isPinned || prayer.status) && (
            <p className="flex flex-wrap items-center gap-2 text-xs font-medium uppercase tracking-wide text-[var(--r-sub)]">
              {isPinned && <span className="text-[var(--r-accent)]">Pinned</span>}
              {prayer.status && <span className="rounded-full border border-[var(--r-line)] px-2 py-0.5 normal-case tracking-normal">{STATUSES[prayer.status]}</span>}
              {prayer.forWhom && <span>For {prayer.forWhom}</span>}
            </p>
          )}
          <p className="whitespace-pre-wrap text-[15px] leading-relaxed">{prayer.text}</p>
          <VerseChips verses={prayer.verses} onOpen={onOpenVerse} />
        </div>
      )}
      {prayer.status === 'partial' && prayer.answerNote && mode !== 'partial' && (
        <div className="mt-3 rounded-xl bg-[var(--r-bg)] px-3 py-2 text-sm" role="note">
          <p className="text-xs font-medium text-[var(--r-accent)]">Partly answered</p>
          <p className="mt-0.5 whitespace-pre-wrap">{prayer.answerNote}</p>
        </div>
      )}
      {prayer.answeredAt && (
        <div className="mt-3 rounded-xl bg-[var(--r-bg)] px-3 py-2 text-sm" role="note">
          <p className="text-xs font-medium text-[var(--r-accent)]">Answered {new Date(prayer.answeredAt).toLocaleDateString()}{days != null ? ` · after ${days} day${days === 1 ? '' : 's'}` : ''}</p>
          {prayer.answerNote && <p className="mt-0.5 whitespace-pre-wrap">{prayer.answerNote}</p>}
        </div>
      )}
      {mode === 'answer' && (
        <div className="mt-3">
          <textarea aria-label="How was it answered?" autoFocus value={note} onChange={(e) => setNote(e.target.value)} rows={2} maxLength={1000} placeholder="How was it answered? (optional)" className={`${field} w-full`} />
          <div className="mt-2 flex gap-3 text-xs">
            <button type="button" onClick={() => { actions.answer(prayer.id, note); setMode(null); }} className="font-medium text-[var(--r-accent)] hover:underline">Mark answered</button>
            <button type="button" onClick={() => setMode(null)} className="text-[var(--r-sub)] hover:underline">Cancel</button>
          </div>
        </div>
      )}
      {mode === 'partial' && (
        <div className="mt-3">
          <textarea aria-label="What has been answered so far?" autoFocus value={note} onChange={(e) => setNote(e.target.value)} rows={2} maxLength={1000} placeholder="What has been answered so far? (optional)" className={`${field} w-full`} />
          <div className="mt-2 flex gap-3 text-xs">
            <button type="button" onClick={() => { actions.status(prayer.id, 'partial', note); setMode(null); }} className="font-medium text-[var(--r-accent)] hover:underline">Save</button>
            <button type="button" onClick={() => setMode(null)} className="text-[var(--r-sub)] hover:underline">Cancel</button>
          </div>
        </div>
      )}
      <div className="mt-3 flex flex-wrap items-center gap-2">
        {!prayer.answeredAt && (
          <button type="button" onClick={() => actions.toggle(prayer.id)} aria-pressed={prayedToday} className={`${small} ${prayedToday ? 'border-[var(--r-accent)] text-[var(--r-accent)]' : ''}`}>
            {prayedToday ? '✓ Prayed today' : 'I prayed'}
          </button>
        )}
        {prayer.prayedOn.length > 0 && <span className="text-xs text-[var(--r-sub)]">Prayed on {prayer.prayedOn.length} day{prayer.prayedOn.length === 1 ? '' : 's'}</span>}
        <span className="ml-auto flex flex-wrap gap-2">
          {!prayer.answeredAt && isPinned && (
            <>
              <button type="button" onClick={() => actions.move(prayer.id, -1)} disabled={pinPos.index === 0} aria-label="Move up" title="Move up" className={`${small} disabled:opacity-40`}>↑</button>
              <button type="button" onClick={() => actions.move(prayer.id, 1)} disabled={pinPos.index === pinPos.count - 1} aria-label="Move down" title="Move down" className={`${small} disabled:opacity-40`}>↓</button>
            </>
          )}
          {!prayer.answeredAt && <button type="button" onClick={() => actions.pin(prayer.id, !isPinned)} aria-pressed={isPinned} className={`${small} ${isPinned ? 'border-[var(--r-accent)] text-[var(--r-accent)]' : ''}`}>{isPinned ? 'Unpin' : 'Pin'}</button>}
          {!prayer.answeredAt && (
            <>
              <button type="button" onClick={() => actions.status(prayer.id, prayer.status === 'waiting' ? '' : 'waiting')} aria-pressed={prayer.status === 'waiting'} className={`${small} ${prayer.status === 'waiting' ? 'border-[var(--r-accent)] text-[var(--r-accent)]' : ''}`}>Waiting</button>
              <button type="button" onClick={() => { setNote(prayer.status === 'partial' ? prayer.answerNote : ''); setMode('partial'); }} aria-pressed={prayer.status === 'partial'} className={`${small} ${prayer.status === 'partial' ? 'border-[var(--r-accent)] text-[var(--r-accent)]' : ''}`}>Partly answered</button>
            </>
          )}
          {prayer.answeredAt
            ? <button type="button" onClick={() => actions.reopen(prayer.id)} className={small}>Pray again</button>
            : <button type="button" onClick={() => { setNote(''); setMode('answer'); }} className={small}>Answered</button>}
          <button type="button" onClick={() => { setText(prayer.text); setMode('edit'); }} className={small}>Edit</button>
          <button type="button" onClick={() => actions.remove(prayer.id)} className={`${small} text-[var(--r-danger,#b42318)]`}>Delete</button>
        </span>
      </div>
    </li>
  );
}

export default function PrayerPage() {
  const { prayers, addPrayer, editPrayer, togglePrayed, answerPrayer, reopenPrayer, deletePrayer, pinPrayer, movePrayer, setPrayerStatus, importPrayers, prayerDraft, clearPrayerDraft, jumpToReaderVerse, openBibleReader } = useApp();
  const { toast } = useToast();
  const [tab, setTab] = useState('open');
  const [query, setQuery] = useState('');
  const [form, setForm] = useState({ text: '', forWhom: '', verses: '' });
  const today = localDateString();
  const fileRef = useRef(null);

  // "Pray about this verse" from the Reader arrives with the verse filled in
  useEffect(() => {
    if (prayerDraft) { setForm((f) => ({ ...f, verses: prayerDraft.label })); clearPrayerDraft(); }
  }, [prayerDraft, clearPrayerDraft]);

  const parsed = useMemo(() => parseVerses(form.verses), [form.verses]);
  const shown = filterPrayers(prayers, { tab, query });
  const counts = { open: filterPrayers(prayers, { tab: 'open' }).length, answered: filterPrayers(prayers, { tab: 'answered' }).length };

  const add = (e) => {
    e.preventDefault();
    if (!form.text.trim()) return;
    addPrayer({ text: form.text, forWhom: form.forWhom, verses: parsed.verses });
    setForm({ text: '', forWhom: '', verses: '' });
    setTab('open');
  };
  const actions = {
    edit: editPrayer, toggle: togglePrayed, reopen: reopenPrayer, pin: pinPrayer, move: movePrayer, status: setPrayerStatus,
    answer: (id, note) => { answerPrayer(id, note); toast('Marked answered. Thank God for it.'); },
    remove: (id) => { const undo = deletePrayer(id); toast('Prayer deleted', { action: { label: 'Undo', onClick: undo } }); },
  };
  const openVerse = (book, chapter, verse) => { jumpToReaderVerse(book, chapter, verse); openBibleReader(); };
  const pinOrder = useMemo(() => pinnedList(prayers).map((p) => p.id), [prayers]);
  const download = (json = false) => {
    const url = URL.createObjectURL(new Blob([json ? prayersToJson(prayers) : prayersToMarkdown(prayers)], { type: json ? 'application/json' : 'text/markdown;charset=utf-8' }));
    const a = document.createElement('a');
    a.href = url; a.download = json ? 'prayer-journal.json' : 'prayer-journal.md';
    document.body.appendChild(a); a.click(); a.remove();
    setTimeout(() => URL.revokeObjectURL(url), 1000);
  };

  const onImportFile = async (e) => {
    const file = e.target.files?.[0];
    e.target.value = '';
    if (!file) return;
    let result;
    try { result = parsePrayerImport(await file.text(), prayers); } catch { result = { prayers: [], skipped: 0, error: 'Couldn’t read that file.' }; }
    if (result.error) { toast(result.error); return; }
    if (result.prayers.length) importPrayers(result.prayers);
    toast(`Imported ${result.prayers.length} prayer${result.prayers.length === 1 ? '' : 's'}${result.skipped ? ` (${result.skipped} already here or skipped)` : ''}`);
  };

  return (
    <PageShell title="Prayer journal" active="prayer" maxWidth="max-w-3xl">
      <main className="mx-auto max-w-3xl space-y-5 px-4 py-6">
        <form onSubmit={add} className="rounded-2xl border border-[var(--r-line)] bg-[var(--r-bar)] p-4" aria-label="Add a prayer">
          <label className="block text-sm font-medium">What are you praying about?
            <textarea value={form.text} onChange={(e) => setForm((f) => ({ ...f, text: e.target.value }))} rows={3} maxLength={2000} className={`${field} mt-1 w-full`} placeholder="A request, a thanks, someone to keep in prayer…" />
          </label>
          <div className="mt-3 grid gap-3 sm:grid-cols-2">
            <label className="block text-xs text-[var(--r-sub)]">For (optional)
              <input type="text" value={form.forWhom} onChange={(e) => setForm((f) => ({ ...f, forWhom: e.target.value }))} maxLength={80} placeholder="e.g. Sam, my church" className={`${field} mt-1 w-full`} />
            </label>
            <label className="block text-xs text-[var(--r-sub)]">Verses (optional)
              <input type="text" value={form.verses} onChange={(e) => setForm((f) => ({ ...f, verses: e.target.value }))} placeholder="e.g. Philippians 4:6, Psalm 23" className={`${field} mt-1 w-full`} />
            </label>
          </div>
          {(parsed.verses.length > 0 || parsed.unknown.length > 0) && (
            <p className="mt-2 text-xs text-[var(--r-sub)]">
              {parsed.verses.length > 0 && <>Linked: {parsed.verses.map(labelFor).join(' · ')}. </>}
              {parsed.unknown.length > 0 && <span className="text-[var(--r-danger,#b42318)]">Couldn’t read: {parsed.unknown.join(', ')}.</span>}
            </p>
          )}
          <button type="submit" disabled={!form.text.trim()} className="mt-3 rounded-xl bg-[var(--r-accent)] px-4 py-2 text-sm font-medium text-[var(--r-on)] hover:opacity-90 disabled:opacity-50">Add to my journal</button>
        </form>

        <div className="flex flex-wrap items-center gap-2">
          <div role="tablist" aria-label="Which prayers" className="flex gap-1.5">
            <button type="button" role="tab" aria-selected={tab === 'open'} onClick={() => setTab('open')} className={tabBtn(tab === 'open')}>Praying ({counts.open})</button>
            <button type="button" role="tab" aria-selected={tab === 'answered'} onClick={() => setTab('answered')} className={tabBtn(tab === 'answered')}>Answered ({counts.answered})</button>
            <button type="button" role="tab" aria-selected={tab === 'all'} onClick={() => setTab('all')} className={tabBtn(tab === 'all')}>All</button>
          </div>
          <input type="search" value={query} onChange={(e) => setQuery(e.target.value)} placeholder="Search prayers…" aria-label="Search prayers" className={`${field} ml-auto w-48 py-1.5`} />
          <button type="button" onClick={() => fileRef.current?.click()} className={small}>Import</button>
          <input ref={fileRef} type="file" accept=".json,.md,.txt,text/markdown,application/json,text/plain" onChange={onImportFile} className="hidden" aria-label="Import prayers file" />
          {live(prayers).length > 0 && (
            <>
              <button type="button" onClick={() => download(false)} className={small}>Download</button>
              <button type="button" onClick={() => download(true)} className={small} title="Keeps every detail, including the days you prayed">Download JSON</button>
            </>
          )}
        </div>

        {shown.length === 0 ? (
          <p className="rounded-2xl border border-dashed border-[var(--r-line)] p-8 text-center text-sm text-[var(--r-sub)]">
            {live(prayers).length === 0 ? 'Nothing here yet. Write down something you’re praying about, and come back to mark how God answers.'
              : query ? 'No prayers match that search.' : tab === 'answered' ? 'No answered prayers yet.' : 'Nothing open right now.'}
          </p>
        ) : (
          <ul className="space-y-3" aria-label="Prayers">
            {shown.map((p) => <PrayerCard key={p.id} prayer={p} today={today} actions={actions} onOpenVerse={openVerse} pinPos={pinOrder.includes(p.id) ? { index: pinOrder.indexOf(p.id), count: pinOrder.length } : null} />)}
          </ul>
        )}
      </main>
    </PageShell>
  );
}