import { makeReducer } from "../../libraries/reducer.ts";
import { EventStoreFactory } from "./events.ts";

export const userPostReducer = makeReducer<EventStoreFactory, UserPostState>(
  (state, event) => {
    switch (event.type) {
      case "post:created": {
        state.posts.push({ id: event.stream, author: event.meta.auditor });
        state.count += 1;
        break;
      }
      case "post:removed": {
        state.posts = state.posts.filter(({ id }) => id !== event.stream);
        state.count -= 1;
        break;
      }
    }
    return state;
  },
  () => ({
    posts: [],
    count: 0,
  }),
);

type UserPostState = {
  posts: {
    id: string;
    author: string;
  }[];
  count: number;
};