/**
 * Block Handle — Notion-style drag handle and context menu
 *
 * Pure logic module: handle state, context menu actions, and turn-into items.
 * No DOM dependencies — rendering is handled in main.js.
 */
import type { BlockHandlePosition, BlockHandleAction, TurnIntoItem, BlockHandleMode } from './types.js';

// ============================================================
// Icons
// ============================================================

/** 6-dot grip icon for the drag handle */
export const BLOCK_HANDLE_ICON = '\u2807';

/** Plus icon for the add-block button */
export const BLOCK_HANDLE_ADD_ICON = '+';

// ============================================================
// Context Menu Actions
// ============================================================

export const BLOCK_HANDLE_ACTIONS: BlockHandleAction[] = [
  { id: 'turnInto',  label: 'Turn into...',  icon: '\u21C4' },
  { id: 'delete',    label: 'Delete',        icon: '\uD83D\uDDD1' },
  { id: 'duplicate', label: 'Duplicate',     icon: '\u2398' },
  { id: 'moveUp',    label: 'Move up',       icon: '\u2191' },
  { id: 'moveDown',  label: 'Move down',     icon: '\u2193' },
];

// ============================================================
// Turn Into Items (block type conversion targets)
// ============================================================

export const TURN_INTO_ITEMS: TurnIntoItem[] = [
  { id: 'paragraph',    name: 'Paragraph',     icon: '\u00B6' },
  { id: 'heading1',     name: 'Heading 1',     icon: 'H1' },
  { id: 'heading2',     name: 'Heading 2',     icon: 'H2' },
  { id: 'heading3',     name: 'Heading 3',     icon: 'H3' },
  { id: 'bulletList',   name: 'Bullet List',   icon: '\u2022' },
  { id: 'numberedList', name: 'Numbered List', icon: '1.' },
  { id: 'taskList',     name: 'Task List',     icon: '\u2611' },
  { id: 'blockquote',   name: 'Blockquote',    icon: '\u201C' },
  { id: 'codeBlock',    name: 'Code Block',    icon: '</>' },
];

/**
 * Filter turn-into items by a search query.
 */
export function filterTurnIntoItems(query: string): TurnIntoItem[] {
  const q = (query || '').trim().toLowerCase();
  if (!q) return [...TURN_INTO_ITEMS];
  return TURN_INTO_ITEMS.filter(item => item.name.toLowerCase().includes(q));
}

// ============================================================
// Block Handle State
// ============================================================

/**
 * Manages the state of the block drag handle and its context menus.
 * Pure state object — no DOM coupling.
 */
export class BlockHandleState {
  visible: boolean;
  position: BlockHandlePosition | null;
  blockPos: number | null;
  contextMenuOpen: boolean;
  turnIntoMenuOpen: boolean;

  constructor() {
    this.visible = false;
    this.position = null;
    this.blockPos = null;
    this.contextMenuOpen = false;
    this.turnIntoMenuOpen = false;
  }

  /**
   * Show the handle at a position, associated with a block at the given
   * ProseMirror document position.
   */
  show(position: BlockHandlePosition, blockPos: number): void {
    this.visible = true;
    this.position = { ...position };
    this.blockPos = blockPos;
  }

  hide(): void {
    this.visible = false;
    this.position = null;
    this.blockPos = null;
    this.contextMenuOpen = false;
    this.turnIntoMenuOpen = false;
  }

  updatePosition(position: BlockHandlePosition): void {
    this.position = { ...position };
  }

  openContextMenu(): void {
    this.contextMenuOpen = true;
  }

  closeContextMenu(): void {
    this.contextMenuOpen = false;
    this.turnIntoMenuOpen = false;
  }

  openTurnIntoMenu(): void {
    this.turnIntoMenuOpen = true;
  }

  closeTurnIntoMenu(): void {
    this.turnIntoMenuOpen = false;
  }

  /**
   * Determine if the handle should be hidden in a given mode.
   */
  isHiddenInMode(mode: BlockHandleMode): boolean {
    return mode === 'zen' || mode === 'print';
  }
}