// src/layout/command-palette/useCommandPalette.ts
import { useState, useCallback, useRef } from 'react'
import type { RegisteredCommand } from '../../plugin/commands'
import type { App } from '../../plugin/app'

/**
 * Hook to manage command palette state.
 * 
 * Features:
 * - Open/close state management
 * - Available command filtering from registry
 * - Centralized command execution with error isolation
 * 
 * Note: The Cmd/Ctrl+P keyboard shortcut is registered by LayoutCommandsPlugin,
 * not handled here. This avoids duplicate keyboard handlers and allows the
 * shortcut to be customizable.
 */
export function useCommandPalette(app: App) {
  const [isOpen, setIsOpen] = useState(false)
  // Cache to prevent re-renders when commands haven't changed
  const commandsRef = useRef<RegisteredCommand[]>([])

  const open = useCallback(() => setIsOpen(true), [])
  const close = useCallback(() => setIsOpen(false), [])
  const toggle = useCallback(() => setIsOpen(prev => !prev), [])

  // Get available commands (filters by checkCallback, etc.)
  // Uses cached array if content is the same to prevent unnecessary re-renders
  const getCommands = useCallback((editorContext: { editor: unknown; view: unknown } | null = null): RegisteredCommand[] => {
    const commands = app.commands.getAvailableCommands(editorContext)
    
    // Check if commands have changed by comparing IDs
    const currentIds = commands.map(c => c.id).join(',')
    const cachedIds = commandsRef.current.map(c => c.id).join(',')
    
    if (currentIds !== cachedIds) {
      commandsRef.current = commands
    }
    
    return commandsRef.current
  }, [app.commands])

  // Search commands via centralized registry method (includes availability filtering + scoring)
  const searchCommands = useCallback((query: string, editorContext: { editor: unknown; view: unknown } | null = null): RegisteredCommand[] => {
    return app.commands.searchCommands(query, editorContext)
  }, [app.commands])

  // Execute command via centralized registry method
  const executeCommand = useCallback((command: RegisteredCommand, editorContext: { editor: unknown; view: unknown } | null = null): void => {
    app.commands.executeCommand(command, editorContext)
  }, [app.commands])

  return {
    isOpen,
    open,
    close,
    toggle,
    getCommands,
    searchCommands,
    executeCommand,
  }
}