/**
 * Component that registers global keybinding handlers.
 *
 * Must be rendered inside KeybindingSetup to have access to the keybinding context.
 * This component renders nothing - it just registers the keybinding handlers.
 */
import { feature } from 'bun:bundle';
import { useCallback } from 'react';
import { instances } from '@anthropic/ink';
import { useKeybinding } from '../keybindings/useKeybinding.js';
import type { Screen } from '../screens/REPL.js';
import { getFeatureValue_CACHED_MAY_BE_STALE } from '../services/analytics/growthbook.js';
import {
  type AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
  logEvent,
} from '../services/analytics/index.js';
import { useAppState, useSetAppState } from '../state/AppState.js';
import { count } from '../utils/array.js';
import { getTerminalPanel } from '../utils/terminalPanel.js';

type Props = {
  screen: Screen;
  setScreen: React.Dispatch<React.SetStateAction<Screen>>;
  showAllInTranscript: boolean;
  setShowAllInTranscript: React.Dispatch<React.SetStateAction<boolean>>;
  messageCount: number;
  onEnterTranscript?: () => void;
  onExitTranscript?: () => void;
  virtualScrollActive?: boolean;
  searchBarOpen?: boolean;
};

/**
 * Registers global keybinding handlers for:
 * - ctrl+t: Toggle todo list
 * - ctrl+o: Toggle transcript mode
 * - ctrl+e: Toggle showing all messages in transcript
 * - ctrl+c/escape: Exit transcript mode
 */
export function GlobalKeybindingHandlers({
  screen,
  setScreen,
  showAllInTranscript,
  setShowAllInTranscript,
  messageCount,
  onEnterTranscript,
  onExitTranscript,
  virtualScrollActive,
  searchBarOpen = false,
}: Props): null {
  const expandedView = useAppState(s => s.expandedView);
  const setAppState = useSetAppState();

  // Toggle todo list (ctrl+t) - cycles through views
  const handleToggleTodos = useCallback(() => {
    logEvent('tengu_toggle_todos', {
      is_expanded: expandedView === 'tasks',
    });
    setAppState(prev => {
      const { getAllInProcessTeammateTasks } =
        // eslint-disable-next-line @typescript-eslint/no-require-imports
        require('../tasks/InProcessTeammateTask/InProcessTeammateTask.js') as typeof import('../tasks/InProcessTeammateTask/InProcessTeammateTask.js');
      const hasTeammates = count(getAllInProcessTeammateTasks(prev.tasks), t => t.status === 'running') > 0;

      if (hasTeammates) {
        // Both exist: none → tasks → teammates → none
        switch (prev.expandedView) {
          case 'none':
            return { ...prev, expandedView: 'tasks' as const };
          case 'tasks':
            return { ...prev, expandedView: 'teammates' as const };
          case 'teammates':
            return { ...prev, expandedView: 'none' as const };
        }
      }
      // Only tasks: none ↔ tasks
      return {
        ...prev,
        expandedView: prev.expandedView === 'tasks' ? ('none' as const) : ('tasks' as const),
      };
    });
  }, [expandedView, setAppState]);

  // Toggle transcript mode (ctrl+o). Two-way prompt ↔ transcript.
  // Brief view has its own dedicated toggle on ctrl+shift+b.
  const isBriefOnlyState = useAppState(s => s.isBriefOnly);
  const handleToggleTranscript = useCallback(() => {
    if (feature('KAIROS') || feature('KAIROS_BRIEF')) {
      // Escape hatch: GB kill-switch while defaultView=chat was persisted
      // can leave isBriefOnly stuck on, showing a blank filterForBriefTool
      // view. Users will reach for ctrl+o — clear the stuck state first.
      // Only needed in the prompt screen — transcript mode already ignores
      // isBriefOnly (Messages.tsx filter is gated on !isTranscriptMode).
      /* eslint-disable @typescript-eslint/no-require-imports */
      const { isBriefEnabled } =
        require('@claude-code-best/builtin-tools/tools/BriefTool/BriefTool.js') as typeof import('@claude-code-best/builtin-tools/tools/BriefTool/BriefTool.js');
      /* eslint-enable @typescript-eslint/no-require-imports */
      if (!isBriefEnabled() && isBriefOnlyState && screen !== 'transcript') {
        setAppState(prev => {
          if (!prev.isBriefOnly) return prev;
          return { ...prev, isBriefOnly: false };
        });
        return;
      }
    }

    const isEnteringTranscript = screen !== 'transcript';
    logEvent('tengu_toggle_transcript', {
      is_entering: isEnteringTranscript,
      show_all: showAllInTranscript,
      message_count: messageCount,
    });
    setScreen(s => (s === 'transcript' ? 'prompt' : 'transcript'));
    setShowAllInTranscript(false);
    if (isEnteringTranscript && onEnterTranscript) {
      onEnterTranscript();
    }
    if (!isEnteringTranscript && onExitTranscript) {
      onExitTranscript();
    }
  }, [
    screen,
    setScreen,
    isBriefOnlyState,
    showAllInTranscript,
    setShowAllInTranscript,
    messageCount,
    setAppState,
    onEnterTranscript,
    onExitTranscript,
  ]);

  // Toggle showing all messages in transcript mode (ctrl+e)
  const handleToggleShowAll = useCallback(() => {
    logEvent('tengu_transcript_toggle_show_all', {
      is_expanding: !showAllInTranscript,
      message_count: messageCount,
    });
    setShowAllInTranscript(prev => !prev);
  }, [showAllInTranscript, setShowAllInTranscript, messageCount]);

  // Exit transcript mode (ctrl+c or escape)
  const handleExitTranscript = useCallback(() => {
    logEvent('tengu_transcript_exit', {
      show_all: showAllInTranscript,
      message_count: messageCount,
    });
    setScreen('prompt');
    setShowAllInTranscript(false);
    if (onExitTranscript) {
      onExitTranscript();
    }
  }, [setScreen, showAllInTranscript, setShowAllInTranscript, messageCount, onExitTranscript]);

  // Toggle brief-only view (ctrl+shift+b). Pure display filter toggle —
  // does not touch opt-in state. Asymmetric gate (mirrors /brief): OFF
  // transition always allowed so the same key that got you in gets you
  // out even if the GB kill-switch fires mid-session.
  const handleToggleBrief = useCallback(() => {
    if (feature('KAIROS') || feature('KAIROS_BRIEF')) {
      /* eslint-disable @typescript-eslint/no-require-imports */
      const { isBriefEnabled } =
        require('@claude-code-best/builtin-tools/tools/BriefTool/BriefTool.js') as typeof import('@claude-code-best/builtin-tools/tools/BriefTool/BriefTool.js');
      /* eslint-enable @typescript-eslint/no-require-imports */
      if (!isBriefEnabled() && !isBriefOnlyState) return;
      const next = !isBriefOnlyState;
      logEvent('tengu_brief_mode_toggled', {
        enabled: next,
        gated: false,
        source: 'keybinding' as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
      });
      setAppState(prev => {
        if (prev.isBriefOnly === next) return prev;
        return { ...prev, isBriefOnly: next };
      });
    }
  }, [isBriefOnlyState, setAppState]);

  // Register keybinding handlers
  useKeybinding('app:toggleTodos', handleToggleTodos, {
    context: 'Global',
  });
  useKeybinding('app:toggleTranscript', handleToggleTranscript, {
    context: 'Global',
  });
  useKeybinding('app:toggleBrief', handleToggleBrief, {
    context: 'Global',
    isActive: feature('KAIROS') ? true : feature('KAIROS_BRIEF') ? true : false,
  });

  // Register teammate keybinding
  useKeybinding(
    'app:toggleTeammatePreview',
    () => {
      setAppState(prev => ({
        ...prev,
        showTeammateMessagePreview: !prev.showTeammateMessagePreview,
      }));
    },
    {
      context: 'Global',
    },
  );

  // Toggle built-in terminal panel (meta+j).
  // toggle() blocks in spawnSync until the user detaches from tmux.
  const handleToggleTerminal = useCallback(() => {
    if (feature('TERMINAL_PANEL')) {
      if (!getFeatureValue_CACHED_MAY_BE_STALE('tengu_terminal_panel', false)) {
        return;
      }
      getTerminalPanel().toggle();
    }
  }, []);
  useKeybinding('app:toggleTerminal', handleToggleTerminal, {
    context: 'Global',
  });

  // Clear screen and force full redraw (ctrl+l). Recovery path when the
  // terminal was cleared externally (macOS Cmd+K) and Ink's diff engine
  // thinks unchanged cells don't need repainting.
  const handleRedraw = useCallback(() => {
    instances.get(process.stdout)?.forceRedraw();
  }, []);
  useKeybinding('app:redraw', handleRedraw, { context: 'Global' });

  // Transcript-specific bindings (only active when in transcript mode)
  const isInTranscript = screen === 'transcript';
  useKeybinding('transcript:toggleShowAll', handleToggleShowAll, {
    context: 'Transcript',
    isActive: isInTranscript && !virtualScrollActive,
  });
  useKeybinding('transcript:exit', handleExitTranscript, {
    context: 'Transcript',
    // Bar-open is a mode (owns keystrokes). Navigating (highlights
    // visible, n/N active, bar closed) is NOT — Esc exits transcript
    // directly, same as less q. useSearchInput doesn't stopPropagation,
    // so without this gate its onCancel AND this handler would both
    // fire on one Esc (child registers first, fires first, bubbles).
    isActive: isInTranscript && !searchBarOpen,
  });

  return null;
}