import { FindContainerById, MakeDFSIterator } from './itertools';
import { IEditorState } from '../Interfaces/IEditorState';
import { IHistoryState } from '../Interfaces/IHistoryState';

/**
 * Revive the Editor state
 * by setting the containers references to their parent
 * @param editorState Editor state
 */
export function Revive(editorState: IEditorState): void {
  const history = editorState.history;

  // restore last step
  editorState.historyCurrentStep = history.length - 1;

  // restore the parents and the selected container
  ReviveHistory(history);
}

export function ReviveHistory(history: IHistoryState[]): void {
  for (const state of history) {
    ReviveState(state);
  }
}

export function ReviveState(state: IHistoryState): void {
  if (state.mainContainer === null || state.mainContainer === undefined) {
    return;
  }

  state.symbols = new Map(state.symbols);
  for (const symbol of state.symbols.values()) {
    symbol.linkedContainers = new Set(symbol.linkedContainers);
  }

  const it = MakeDFSIterator(state.mainContainer);
  for (const container of it) {
    const parentId = container.properties.parentId;
    if (parentId === null) {
      container.parent = null;
      continue;
    }
    const parent = FindContainerById(state.mainContainer, parentId);
    if (parent === undefined) {
      continue;
    }
    container.parent = parent;
  }
}

export function GetCircularReplacer(): (key: any, value: object | Map<string, any> | null) => object | null | undefined {
  return (key: any, value: object | null) => {
    if (key === 'parent') {
      return;
    }

    if (key === 'symbols') {
      return Array.from((value as Map<string, any>).entries());
    }

    if (key === 'linkedContainers') {
      return Array.from(value as Set<string>);
    }

    return value;
  };
}

export function GetCircularReplacerKeepDataStructure(): (key: any, value: object | Map<string, any> | null) => object | null | undefined {
  return (key: any, value: object | null) => {
    if (key === 'parent') {
      return;
    }

    return value;
  };
}