import type { PageRef } from '../pdf/pdfTypes';

export interface WorkspaceCommandState {
  pages: PageRef[];
  selectedPageIds: string[];
  lastSelectedVisualIndex: number | null;
}

export interface WorkspaceCommandPayload {
  before: WorkspaceCommandState;
  after: WorkspaceCommandState;
  details?: Record<string, unknown>;
}

export interface WorkspaceCommandRecord {
  id: string;
  type: string;
  label: string;
  timestamp: string;
  payload: WorkspaceCommandPayload;
}

export interface WorkspaceCommand extends WorkspaceCommandRecord {
  do: (state: WorkspaceCommandState) => WorkspaceCommandState;
  undo: (state: WorkspaceCommandState) => WorkspaceCommandState;
}

export function cloneCommandState(
  state: WorkspaceCommandState
): WorkspaceCommandState {
  return {
    pages: state.pages.map((page) => ({ ...page })),
    selectedPageIds: [...state.selectedPageIds],
    lastSelectedVisualIndex: state.lastSelectedVisualIndex,
  };
}

export function createSnapshotCommand(params: {
  id: string;
  type: string;
  label: string;
  timestamp?: string;
  before: WorkspaceCommandState;
  after: WorkspaceCommandState;
  details?: Record<string, unknown>;
}): WorkspaceCommand {
  return reviveWorkspaceCommand({
    id: params.id,
    type: params.type,
    label: params.label,
    timestamp: params.timestamp ?? new Date().toISOString(),
    payload: {
      before: cloneCommandState(params.before),
      after: cloneCommandState(params.after),
      details: params.details,
    },
  });
}

export function reviveWorkspaceCommand(
  record: WorkspaceCommandRecord
): WorkspaceCommand {
  return {
    ...record,
    do: () => cloneCommandState(record.payload.after),
    undo: () => cloneCommandState(record.payload.before),
  };
}

export function toWorkspaceCommandRecord(
  command: WorkspaceCommand
): WorkspaceCommandRecord {
  return {
    id: command.id,
    type: command.type,
    label: command.label,
    timestamp: command.timestamp,
    payload: {
      before: cloneCommandState(command.payload.before),
      after: cloneCommandState(command.payload.after),
      details: command.payload.details,
    },
  };
}