/**
 * Main App component for the XO Wallet CLI.
 * Uses Ink for terminal rendering with React components.
 */

import React, { useEffect, useState } from 'react';
import { Box, Text, useApp } from 'ink';
import { NavigationProvider, useNavigation } from './hooks/useNavigation.js';
import { AppProvider, useAppContext, useDialog, useStatus } from './hooks/useAppContext.js';
import { InputLayerProvider, useBlockableInput } from './hooks/useInputLayer.js';
import type { AppConfig } from '../app.js';
import type {
  GitUpdateService,
  UpdateCheck,
  UpdateLaunchRequest,
} from '../updater/git-update-service.js';
import { colors, logoSmall } from './theme.js';

// Screen imports
import { SeedInputScreen } from './screens/SeedInput.js';
import { WalletStateScreen } from './screens/WalletState.js';
import { TemplateListScreen } from './screens/TemplateList.js';
import { ActionWizardScreen } from './screens/action-wizard/ActionWizardScreen.js';
import { InvitationScreen } from './screens/invitations/InvitationScreen.js';

import { ConfirmDialog, MessageDialog } from './components/Dialog.js';

/**
 * Props for the App component.
 */
interface AppProps {
  config: AppConfig;
  updater: GitUpdateService;
  onUpdateAndRestart: (request: UpdateLaunchRequest) => void;
}

/**
 * Router component that renders the current screen.
 */
function Router(): React.ReactElement {
  const { screen } = useNavigation();

  switch (screen) {
    case 'seed-input':
      return <SeedInputScreen />;
    case 'wallet':
      return <WalletStateScreen />;
    case 'templates':
      return <TemplateListScreen />;
    case 'wizard':
      return <ActionWizardScreen />;
    case 'invitations':
      return <InvitationScreen />;
    default:
      return <Text color={colors.error}>Unknown screen: {screen}</Text>;
  }
}

/**
 * Status bar component shown at the bottom of the screen.
 */
function StatusBar({ update }: { update: UpdateCheck | null }): React.ReactElement {
  const { status } = useStatus();
  const { screen, canGoBack } = useNavigation();

  return (
    <Box 
      borderStyle="single" 
      borderColor={colors.border}
      paddingX={1}
      justifyContent="space-between"
    >
      <Text color={colors.primary} bold>{logoSmall}</Text>
      <Text color={update?.status === 'available' ? colors.warning : colors.textMuted}>
        {update?.status === 'available' ? 'Update available · press U' : status}
      </Text>
      <Text color={colors.textMuted}>
        {canGoBack ? 'ESC: Back | ' : ''}q: Quit
      </Text>
    </Box>
  );
}

/**
 * Dialog overlay component for modals.
 */
function DialogOverlay(): React.ReactElement | null {
  const { dialog } = useDialog();

  if (!dialog?.visible) return null;

  const contents = dialog.type === 'confirm' ? (
    <ConfirmDialog
      title={dialog.title ?? "Confirm"}
      message={dialog.message}
      onConfirm={dialog.onConfirm ?? (() => {})}
      onCancel={dialog.onCancel ?? (() => {})}
      confirmLabel={dialog.confirmLabel}
      cancelLabel={dialog.cancelLabel}
    />
  ) : (
    <MessageDialog
      title={dialog.type === 'error' ? 'Error' : 'Info'}
      message={dialog.message}
      onClose={dialog.onCancel ?? (() => {})}
      type={dialog.type}
    />
  );

  return (
    <Box
      position="absolute"
      flexDirection="column"
      alignItems="center"
      justifyContent="center"
      width="100%"
      height="100%"
    >
      {contents}
    </Box>
  );
}

/**
 * Main content wrapper with global keybindings.
 */
function MainContent({
  updater,
  onUpdateAndRestart,
}: Pick<AppProps, 'updater' | 'onUpdateAndRestart'>): React.ReactElement {
  const { goBack, canGoBack } = useNavigation();
  const { screen } = useNavigation();
  const appContext = useAppContext();
  const [update, setUpdate] = useState<UpdateCheck | null>(null);

  useEffect(() => {
    let active = true;
    updater.check().then((result) => {
      if (active) setUpdate(result);
    }).catch(() => {
      // Update checks are advisory and must never prevent wallet use.
    });
    return () => {
      active = false;
    };
  }, [updater]);

  // Global keybindings — auto-blocked when any dialog/overlay is capturing input.
  useBlockableInput((input, key) => {
    // Quit on Ctrl+C
    if (key.ctrl && input === 'c') {
      void appContext.exit();
      return;
    }

    if ((input === 'u' || input === 'U') && update?.status === 'available') {
      if (!update.canApply) {
        appContext.showError(update.blockReason ?? 'This update cannot be applied automatically.');
        return;
      }

      void appContext.confirm(
        `Branch: ${update.branch}\nInstalled: ${update.currentCommit.slice(0, 7)}\nAvailable: ${update.targetCommit.slice(0, 7)}\n\n${update.summary}`,
        {
          title: 'XO update available',
          confirmLabel: 'Update and restart',
          cancelLabel: 'Later',
        },
      ).then(async (confirmed) => {
        if (!confirmed) return;
        onUpdateAndRestart(update);
        await appContext.exit();
      });
      return;
    }

    // Go back on Escape
    if (key.escape && canGoBack) {
      goBack();

      // If we went back to the seed input screen, remove the current engine
      // TODO: This was to support going back to seed input then re-opening your seed, but there is a bug in the engine which prevents it from closing the current
      // storage instance, giving us an error about the database already being opened.
      if (screen === 'seed-input') {
        appContext.appService?.engine.stop();
        appContext.appService = null;
      }
    }
  });

  return (
    <Box flexDirection="column" height="100%">
      {/* Main content area */}
      <Box flexDirection="column" flexGrow={1}>
        <Router />
      </Box>
      
      {/* Status bar */}
      <StatusBar update={update} />
      
      {/* Dialog overlay */}
      <DialogOverlay />
    </Box>
  );
}

/**
 * Main App component.
 * Sets up providers and renders the main content.
 */
export function App({ config, updater, onUpdateAndRestart }: AppProps): React.ReactElement {
  const { exit } = useApp();

  // Cleanup will be handled by React when components unmount
  const handleExit = () => {
    exit();
  };

  return (
    <AppProvider
      config={config}
      onExit={handleExit}
    >
      <InputLayerProvider>
        <NavigationProvider initialScreen="seed-input">
          <MainContent updater={updater} onUpdateAndRestart={onUpdateAndRestart} />
        </NavigationProvider>
      </InputLayerProvider>
    </AppProvider>
  );
}