import { useEffect, useLayoutEffect, useState } from 'react';
import type { ThemeMode } from './components/AppSettingsWindow';
import CanvasStudio from './pages/CanvasStudio';
import FindPage from './pages/FindPage';
import HelpPage from './pages/HelpPage';
import OrdersPage from './pages/OrdersPage';
import TemplateHome from './pages/TemplateHome';
import TestWorkbench from './pages/TestWorkbench';
import { CanvasDocument, WordcloudReplaceSession, WordcloudStickerPayload } from './types';
import { createDefaultDocument } from './lib/canvasDocument';

type AppPage = 'home' | 'canvas' | 'wordcloud' | 'orders' | 'find' | 'help';

const getStoredTheme = (): ThemeMode => {
  const stored = window.localStorage.getItem('wordcloud-theme');
  return stored === 'light' || stored === 'dark' || stored === 'system' ? stored : 'system';
};

const getSystemTheme = () =>
  window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';

export default function App() {
  const [page, setPage] = useState<AppPage>('home');
  const [themeMode, setThemeMode] = useState<ThemeMode>(getStoredTheme);
  const [systemTheme, setSystemTheme] = useState<'light' | 'dark'>(getSystemTheme);
  const [initialDocument, setInitialDocument] = useState<CanvasDocument | null>(null);
  const [pendingWordcloudSticker, setPendingWordcloudSticker] = useState<WordcloudStickerPayload | null>(null);
  const [pendingReplaceSession, setPendingReplaceSession] = useState<WordcloudReplaceSession | null>(null);

  const openHelp = () => setPage('help');

  useLayoutEffect(() => {
    const resolvedTheme = themeMode === 'system' ? systemTheme : themeMode;
    document.documentElement.dataset.theme = resolvedTheme;
    document.documentElement.dataset.themeMode = themeMode;
    document.documentElement.style.colorScheme = resolvedTheme;
    window.localStorage.setItem('wordcloud-theme', themeMode);
  }, [themeMode, systemTheme]);

  useEffect(() => {
    const media = window.matchMedia('(prefers-color-scheme: dark)');
    const handleChange = (event: MediaQueryListEvent) => {
      setSystemTheme(event.matches ? 'dark' : 'light');
    };

    setSystemTheme(media.matches ? 'dark' : 'light');
    media.addEventListener('change', handleChange);
    return () => media.removeEventListener('change', handleChange);
  }, []);

  if (page === 'wordcloud') {
    return (
      <TestWorkbench
        themeMode={themeMode}
        systemTheme={systemTheme}
        onThemeModeChange={setThemeMode}
        onOpenCanvas={() => setPage('canvas')}
        onOpenHome={() => setPage('home')}
        onOpenHelp={openHelp}
        replaceSession={pendingReplaceSession}
        onConsumeReplaceSession={() => setPendingReplaceSession(null)}
        onImportWordcloudSticker={(payload) => {
          setPendingWordcloudSticker(payload);
          setPendingReplaceSession(null);
          setPage('canvas');
        }}
      />
    );
  }

  if (page === 'canvas') {
    return (
      <CanvasStudio
        themeMode={themeMode}
        systemTheme={systemTheme}
        onThemeModeChange={setThemeMode}
        onOpenHome={() => setPage('home')}
        onOpenWordcloud={() => {
          setPendingReplaceSession(null);
          setPage('wordcloud');
        }}
        onOpenHelp={openHelp}
        onReplaceWordcloudNames={(session) => {
          setPendingReplaceSession(session);
          setPage('wordcloud');
        }}
        initialDocument={initialDocument}
        onConsumeInitialDocument={() => setInitialDocument(null)}
        pendingWordcloudSticker={pendingWordcloudSticker}
        onConsumeWordcloudSticker={() => setPendingWordcloudSticker(null)}
      />
    );
  }

  if (page === 'help') {
    return (
      <HelpPage
        themeMode={themeMode}
        systemTheme={systemTheme}
        onThemeModeChange={setThemeMode}
        onOpenHome={() => setPage('home')}
        onOpenCanvas={() => setPage('canvas')}
        onOpenWordcloud={() => setPage('wordcloud')}
        onOpenOrders={() => setPage('orders')}
        onOpenFind={() => setPage('find')}
      />
    );
  }

  if (page === 'orders') {
    return (
      <OrdersPage
        themeMode={themeMode}
        systemTheme={systemTheme}
        onThemeModeChange={setThemeMode}
        onOpenHome={() => setPage('home')}
      />
    );
  }

  if (page === 'find') {
    return (
      <FindPage
        themeMode={themeMode}
        systemTheme={systemTheme}
        onThemeModeChange={setThemeMode}
        onOpenHome={() => setPage('home')}
      />
    );
  }

  return (
    <TemplateHome
      themeMode={themeMode}
      systemTheme={systemTheme}
      onThemeModeChange={setThemeMode}
      onCreateBlank={() => {
        setInitialDocument(createDefaultDocument());
        setPage('canvas');
      }}
      onUseTemplate={(template) => {
        setInitialDocument(template.document);
        setPage('canvas');
      }}
      onOpenOrders={() => setPage('orders')}
      onOpenFind={() => setPage('find')}
      onOpenHelp={openHelp}
    />
  );
}