/* global React, ReactDOM */
// ==============================================================
// app.jsx — main controller + Tweaks
// ==============================================================

var { useState, useEffect, useCallback } = React;

const TWEAKS = /*EDITMODE-BEGIN*/{
  "theme": "light",
  "fontSize": "medium",
  "questionLayout": "standard",
  "feedbackMode": "auto"
}/*EDITMODE-END*/;

const App = () => {
  const [screen, setScreen] = useState('landing'); // landing | exam | results | review
  const [exam, setExam] = useState(null);
  const [state, setState] = useState(null);
  const [history, setHistory] = useState(() => window.loadHistory());
  const [tweaks, setTweaks] = useState(TWEAKS);
  const [tweaksOpen, setTweaksOpen] = useState(false);

  // Apply theme/font tweaks
  useEffect(() => {
    document.documentElement.dataset.theme = tweaks.theme;
    const map = { small: '14px', medium: '15px', large: '17px' };
    document.body.style.fontSize = map[tweaks.fontSize] || '15px';
    document.documentElement.dataset.layout = tweaks.questionLayout;
  }, [tweaks]);

  // Persist state on change during exam
  useEffect(() => {
    if (screen === 'exam' && exam && state) {
      window.saveState({ exam, state });
    }
  }, [exam, state, screen]);

  // Edit mode protocol
  useEffect(() => {
    const handler = (e) => {
      if (e.data?.type === '__activate_edit_mode') setTweaksOpen(true);
      if (e.data?.type === '__deactivate_edit_mode') setTweaksOpen(false);
    };
    window.addEventListener('message', handler);
    window.parent.postMessage({ type: '__edit_mode_available' }, '*');
    return () => window.removeEventListener('message', handler);
  }, []);

  const updateTweak = (key, value) => {
    setTweaks((t) => {
      const next = { ...t, [key]: value };
      window.parent.postMessage({ type: '__edit_mode_set_keys', edits: { [key]: value } }, '*');
      return next;
    });
  };

  const loadExam = (data) => {
    const finalFeedbackMode = tweaks.feedbackMode === 'auto' ? (data.feedbackMode || 'end') : tweaks.feedbackMode;
    const initialState = {
      currentIdx: 0,
      answers: {},
      flags: {},
      revealed: {},
      startedAt: Date.now(),
      feedbackMode: finalFeedbackMode,
    };
    setExam(data);
    setState(initialState);
    setScreen('exam');
  };

  const resume = () => {
    const saved = window.loadState();
    if (saved?.exam && saved?.state) {
      setExam(saved.exam);
      setState(saved.state);
      setScreen('exam');
    }
  };

  const submit = useCallback(() => {
    if (!exam || !state) return;
    const completedAt = Date.now();
    const elapsedMs = completedAt - state.startedAt;
    const graded = exam.questions.map((q) => window.gradeQuestion(q, state.answers[q.id]));
    const gradedCount = graded.filter((r) => r.status !== 'ungraded').length;
    const correctCount = graded.filter((r) => r.correct).length;
    const totalPoints = exam.questions.reduce((a, q) => a + (q.points || 1), 0);
    const scorePoints = graded.reduce((a, r) => a + r.points, 0);
    const historyEntry = {
      id: `${Date.now()}-${Math.random().toString(36).slice(2, 7)}`,
      title: exam.title,
      completedAt,
      elapsedMs,
      gradedCount,
      correctCount,
      totalPoints,
      scorePoints,
      passingScore: exam.passingScore || 60,
      exam, // full snapshot so we can re-review
      state: { ...state, completedAt },
    };
    window.appendHistory(historyEntry);
    setHistory(window.loadHistory());
    window.clearState();
    setState((s) => ({ ...s, completedAt }));
    setScreen('results');
  }, [exam, state]);

  const exit = () => {
    setScreen('landing');
    setExam(null);
    setState(null);
  };

  const restart = () => {
    if (!exam) return;
    loadExam(exam);
  };

  // Replay a past attempt
  window.__replayAttempt = (entry) => {
    setExam(entry.exam);
    setState(entry.state);
    setScreen('review');
  };

  const clearAllHistory = () => {
    if (confirm('Clear all past attempts?')) {
      window.clearHistory();
      setHistory([]);
    }
  };

  return (
    <div className="shell">
      <header className="topbar">
        <div className="brand">
          <span className="brand-mark" />
          <span>BrainWave</span>
          <span className="faint mono" style={{ fontSize: 11, marginLeft: 4 }}>/ practice</span>
        </div>
        <div className="topbar-meta">
          {screen === 'exam' && exam && (
            <>
              <span className="mono" style={{ fontSize: 12 }}>{exam.title}</span>
              <button className="btn btn-ghost btn-sm" onClick={exit}>Exit</button>
            </>
          )}
        </div>
      </header>

      {screen === 'landing' && (
        <Landing
          onLoadExam={loadExam}
          history={history}
          onResume={resume}
          onClearHistory={clearAllHistory}
        />
      )}
      {screen === 'exam' && exam && state && (
        <ExamRunner
          exam={exam}
          state={state}
          setState={setState}
          onSubmit={submit}
          onExit={exit}
        />
      )}
      {(screen === 'results' || screen === 'review') && exam && state && (
        <Results
          exam={exam}
          state={state}
          onRestart={restart}
          onExit={exit}
          reviewOnly={screen === 'review'}
        />
      )}

      {tweaksOpen && <TweaksPanel tweaks={tweaks} update={updateTweak} onClose={() => setTweaksOpen(false)} />}
    </div>
  );
};

// ---------- Tweaks Panel ----------
const TweaksPanel = ({ tweaks, update, onClose }) => {
  const Seg = ({ tkey, options }) => (
    <div className="tweak-control">
      {options.map((opt) => (
        <button
          key={opt.value}
          className={`tweak-seg ${tweaks[tkey] === opt.value ? 'active' : ''}`}
          onClick={() => update(tkey, opt.value)}
        >
          {opt.label}
        </button>
      ))}
    </div>
  );
  return (
    <div className="tweaks-panel">
      <div className="tweaks-header">
        <span>Tweaks</span>
        <button className="btn btn-ghost btn-sm" onClick={onClose} style={{ padding: '2px 6px' }}>×</button>
      </div>
      <div className="tweaks-body">
        <div className="tweak-row">
          <div className="tweak-label">Theme</div>
          <Seg tkey="theme" options={[{ value: 'light', label: 'Light' }, { value: 'dark', label: 'Dark' }]} />
        </div>
        <div className="tweak-row">
          <div className="tweak-label">Text size</div>
          <Seg tkey="fontSize" options={[{ value: 'small', label: 'S' }, { value: 'medium', label: 'M' }, { value: 'large', label: 'L' }]} />
        </div>
        <div className="tweak-row">
          <div className="tweak-label">Feedback</div>
          <Seg tkey="feedbackMode" options={[
            { value: 'auto', label: 'Auto' },
            { value: 'immediate', label: 'Immediate' },
            { value: 'end', label: 'End' },
          ]} />
        </div>
      </div>
    </div>
  );
};

ReactDOM.createRoot(document.getElementById('root')).render(<App />);