import { createSlice } from '@reduxjs/toolkit';

export const postsSlice = createSlice({
    name: 'post',
    initialState: {
        lastID: 0,
        posts: [],
        authors: []
    },
    reducers: {
        createPost: (state, action) => {
            state.posts.push({
                id: ++state.lastID,
                author: action.payload.author,
                text: action.payload.text
            });
            if(!state.authors.includes(action.payload.author))
                state.authors.push(action.payload.author);
        }
    }
});

export const { createPost } = postsSlice.actions;

export const selectPosts = (state) => state.post.posts;
export const selectAuthors = (state) => state.post.authors;

export const selectPostsByAuthor = postAuthor => state => {
    return state.post.posts.filter(({ author }) => postAuthor === author).length;
};

export default postsSlice.reducer;