import type { AppState } from "@editor/state";
import type { CommandContext } from "./command";
import type { CommandRegistry } from "./registry";

export type Dispatch = <TPayload>(commandId: string, payload: TPayload) => AppState;

export type CommandDispatcher = {
  dispatch: Dispatch;
};

export function createCommandDispatcher(options: {
  registry: CommandRegistry;
  getState: () => AppState;
  setState: (state: AppState) => void;
}): CommandDispatcher {
  return {
    dispatch(commandId, payload) {
      const command = options.registry.get(commandId);
      if (!command) {
        throw new Error(`Unknown command: ${commandId}`);
      }

      const context: CommandContext = { state: options.getState() };
      const nextState = command.execute(context, payload);
      options.setState(nextState);
      return nextState;
    },
  };
}