import { useState, useRef, useEffect } from 'react';
import { Toaster } from 'react-hot-toast';
import { ThemeProvider } from './context/ThemeContext';
import { AuthProvider, useAuth } from './context/AuthContext';
import { FormProvider, useForm } from './context/FormContext';
import { fetchTemplateData, hydrateTemplateData } from './data/templateData';
import LoginPage from './components/auth/LoginPage';
import Navbar from './components/layout/Navbar';
import Sidebar from './components/layout/Sidebar';
import PatientHeader from './components/sections/PatientHeader';
import SectionRenderer from './components/sections/SectionRenderer';
import AbbreviationPanel from './components/reference/AbbreviationPanel';
import SmartPhrasesPanel from './components/reference/SmartPhrasesPanel';
import AIGeneratorPanel from './components/ai/AIGeneratorPanel';
import PreviewPanel from './components/preview/PreviewPanel';
import AddSectionModal from './components/modals/AddSectionModal';
import './index.css';

function AppContent({ templateSections }) {
  const [activeSection, setActiveSection] = useState('_header');
  const [showPreview, setShowPreview] = useState(false);
  const [showGenerator, setShowGenerator] = useState(false);
  const [showAddSection, setShowAddSection] = useState(false);
  const [sidebarOpen, setSidebarOpen] = useState(() => window.innerWidth > 1024);
  const mainRef = useRef(null);
  const { addCustomSection, formState } = useForm();

  const isMobile = () => window.innerWidth <= 1024;

  const handleSectionClick = (sectionId) => {
    setActiveSection(sectionId);
    const el = document.getElementById(`section-${sectionId}`);
    if (el) {
      el.scrollIntoView({ behavior: 'smooth', block: 'start' });
    }
    // Auto-close sidebar on mobile after clicking a section
    if (isMobile()) {
      setSidebarOpen(false);
    }
  };

  const handleAddSection = (title) => {
    addCustomSection(title);
  };

  return (
    <>
      <Navbar
        onPreview={() => setShowPreview(true)}
        onGenerate={() => setShowGenerator(true)}
        onToggleSidebar={() => setSidebarOpen(!sidebarOpen)}
      />

      <div className="app-layout">
        {/* Backdrop overlay for mobile sidebar */}
        {sidebarOpen && isMobile() && (
          <div
            className="sidebar-backdrop"
            onClick={() => setSidebarOpen(false)}
          />
        )}

        <Sidebar
          activeSection={activeSection}
          onSectionClick={handleSectionClick}
          onAddSection={() => setShowAddSection(true)}
          isOpen={sidebarOpen}
        />

        <main className="main-content" ref={mainRef}>
          <div id="section-_header">
            <PatientHeader />
          </div>

          <div id="section-_abbreviations">
            <AbbreviationPanel />
          </div>

          <div id="section-_smart_phrases">
            <SmartPhrasesPanel />
          </div>

          {templateSections.map(section => (
            <SectionRenderer key={section.id} section={section} />
          ))}

          {formState.customSections.map(cs => (
            <div key={cs.id} id={`section-${cs.id}`} className="section">
              <div className="section__header">
                <div className="section__header-icon" style={{ background: 'linear-gradient(135deg, var(--accent-500), var(--accent-700))' }}>
                  <span style={{ color: 'white', fontWeight: 700, fontSize: 'var(--font-sm)' }}>C</span>
                </div>
                <h2 className="section__title">{cs.title}</h2>
              </div>
              <div className="subsection">
                <div className="subsection__title">
                  <span className="subsection__title-dot" />
                  Custom Content
                </div>
                <p style={{ color: 'var(--text-secondary)', fontSize: 'var(--font-sm)' }}>
                  This custom section will be included in AI generation. Add relevant notes below.
                </p>
                <div style={{ marginTop: 'var(--space-3)' }}>
                  <textarea
                    className="text-input__field"
                    placeholder="Enter custom notes, observations, or selections for this section..."
                    rows={4}
                    style={{ resize: 'vertical', width: '100%' }}
                  />
                </div>
              </div>
            </div>
          ))}

          <div style={{ height: 80 }} />
        </main>
      </div>

      <PreviewPanel isOpen={showPreview} onClose={() => setShowPreview(false)} />
      <AIGeneratorPanel isOpen={showGenerator} onClose={() => setShowGenerator(false)} />
      <AddSectionModal
        isOpen={showAddSection}
        onClose={() => setShowAddSection(false)}
        onAdd={handleAddSection}
      />

      <Toaster
        position="bottom-right"
        toastOptions={{
          style: {
            background: 'var(--surface-card)',
            color: 'var(--text-primary)',
            border: '1px solid var(--border-primary)',
            fontFamily: 'var(--font-family)',
            fontSize: 'var(--font-sm)',
          },
        }}
      />
    </>
  );
}

function AuthGate() {
  const { isAuthenticated, loading, token } = useAuth();
  const [templateLoaded, setTemplateLoaded] = useState(false);
  const [templateSections, setTemplateSections] = useState([]);
  const [templateError, setTemplateError] = useState('');

  // Fetch template data once authenticated
  useEffect(() => {
    if (isAuthenticated && token && !templateLoaded) {
      fetchTemplateData(token)
        .then(data => {
          const hydrated = hydrateTemplateData(data);
          setTemplateSections(hydrated.TEMPLATE_SECTIONS);
          setTemplateLoaded(true);
        })
        .catch(err => {
          setTemplateError(err.message);
        });
    }
  }, [isAuthenticated, token, templateLoaded]);

  // Checking stored token
  if (loading) {
    return (
      <div className="login-page">
        <div className="loading-container">
          <div className="loading-spinner" />
          <p className="loading-text">Verifying session...</p>
        </div>
      </div>
    );
  }

  // Not authenticated
  if (!isAuthenticated) {
    return <LoginPage />;
  }

  // Authenticated but template not yet loaded
  if (!templateLoaded) {
    return (
      <div className="login-page">
        <div className="loading-container">
          <div className="loading-spinner" />
          <p className="loading-text">
            {templateError || 'Loading clinical template...'}
          </p>
          {templateError && (
            <button
              className="navbar__btn navbar__btn--primary"
              onClick={() => { setTemplateError(''); setTemplateLoaded(false); }}
              style={{ marginTop: 'var(--space-4)' }}
            >
              Retry
            </button>
          )}
        </div>
      </div>
    );
  }

  // Fully ready
  return (
    <FormProvider>
      <AppContent templateSections={templateSections} />
    </FormProvider>
  );
}

export default function App() {
  return (
    <ThemeProvider>
      <AuthProvider>
        <AuthGate />
      </AuthProvider>
    </ThemeProvider>
  );
}