import type { SerializedProjectCommand } from "./project-command.model.js";
import {
  assertDistributionBoardSubtreeSnapshot,
  type DistributionBoardSubtreeSnapshot,
} from "./distribution-board-subtree-snapshot.model.js";

export const distributionBoardInsertSubtreeCommandType =
  "distribution-board.insert-subtree" as const;
export const distributionBoardDeleteSubtreeCommandType =
  "distribution-board.delete-subtree" as const;
export const distributionBoardSubtreeCommandSchemaVersion = 1 as const;

interface Payload {
  snapshot: DistributionBoardSubtreeSnapshot;
}

export interface DistributionBoardInsertSubtreeProjectCommand
  extends SerializedProjectCommand<Payload> {
  schemaVersion: typeof distributionBoardSubtreeCommandSchemaVersion;
  type: typeof distributionBoardInsertSubtreeCommandType;
}

export interface DistributionBoardDeleteSubtreeProjectCommand
  extends SerializedProjectCommand<Payload> {
  schemaVersion: typeof distributionBoardSubtreeCommandSchemaVersion;
  type: typeof distributionBoardDeleteSubtreeCommandType;
}

export type DistributionBoardSubtreeProjectCommand =
  | DistributionBoardInsertSubtreeProjectCommand
  | DistributionBoardDeleteSubtreeProjectCommand;

export function createDistributionBoardInsertSubtreeProjectCommand(
  snapshot: DistributionBoardSubtreeSnapshot
): DistributionBoardInsertSubtreeProjectCommand {
  const command: DistributionBoardInsertSubtreeProjectCommand = {
    schemaVersion: distributionBoardSubtreeCommandSchemaVersion,
    type: distributionBoardInsertSubtreeCommandType,
    payload: { snapshot },
  };
  assertDistributionBoardInsertSubtreeProjectCommand(command);
  return command;
}

export function createDistributionBoardDeleteSubtreeProjectCommand(
  snapshot: DistributionBoardSubtreeSnapshot
): DistributionBoardDeleteSubtreeProjectCommand {
  const command: DistributionBoardDeleteSubtreeProjectCommand = {
    schemaVersion: distributionBoardSubtreeCommandSchemaVersion,
    type: distributionBoardDeleteSubtreeCommandType,
    payload: { snapshot },
  };
  assertDistributionBoardDeleteSubtreeProjectCommand(command);
  return command;
}

export function assertDistributionBoardInsertSubtreeProjectCommand(
  command: SerializedProjectCommand<unknown>
): asserts command is DistributionBoardInsertSubtreeProjectCommand {
  assertCommand(command, distributionBoardInsertSubtreeCommandType);
}

export function assertDistributionBoardDeleteSubtreeProjectCommand(
  command: SerializedProjectCommand<unknown>
): asserts command is DistributionBoardDeleteSubtreeProjectCommand {
  assertCommand(command, distributionBoardDeleteSubtreeCommandType);
}

function assertCommand(
  command: SerializedProjectCommand<unknown>,
  type: DistributionBoardSubtreeProjectCommand["type"]
) {
  if (
    command.schemaVersion !== distributionBoardSubtreeCommandSchemaVersion ||
    command.type !== type ||
    !isPlainObject(command.payload) ||
    Object.keys(command.payload).length !== 1
  ) {
    throw new Error("Unsupported distribution-board subtree command.");
  }
  assertDistributionBoardSubtreeSnapshot(command.payload.snapshot);
}

function isPlainObject(value: unknown): value is Record<string, unknown> {
  return value !== null && typeof value === "object" && !Array.isArray(value);
}