import * as React from 'react';
import { render } from 'react-dom';

import useTrie, { Trie } from '@cshooks/usetrie';
import styled, { createGlobalStyle } from 'styled-components';

import './styles.css';

const log = console.log;

const ContentContainer = styled.section`
  display: grid;
  grid: 1fr / 2fr 3fr;
  margin-top: 2rem;
`;

function reducer(state, action) {
  switch (action.type) {
    case 'SET_WORD':
      return { ...state, word: action.word };
    case 'ADD_WORD':
      // Mutating the trie returns a new instance
      state.trie.add(action.word);
      return { ...state, words: [...state.words, action.word] };
    case 'REMOVE_WORD':
      const removed = state.words.filter(word => word !== action.word);
      // Mutating the trie returns a new instance
      state.trie.remove(action.word);
      return { ...state, words: [...removed] };
    case 'SET_TERM':
      return { ...state, term: action.term };
    case 'SET_ISEXACT': {
      return { ...state, isExact: action.isExact };
    }
    default:
      return state;
  }
}

function App() {
  // prettier-ignore
  const initialWords = [
    "abcd", "abce", "ABC", "THE", "their",
    "there", "hel", "hell", "hello", "help",
    "helping", "helps"
  ];
  const isCaseInsensitive = false;
  const trie = useTrie(initialWords, isCaseInsensitive);

  const initialState = {
    words: initialWords,
    word: '',
    term: '',
    isExact: true,
    trie,
  };
  const [state, dispatch] = React.useReducer(reducer, initialState);

  const checkIfTermExists = e =>
    dispatch({ type: 'SET_TERM', term: e.target.value });

  const removeWord = React.useCallback(
    (word: string) => {
      log(`removing "${word}"`);
      trie.remove(word);
      dispatch({ type: 'REMOVE_WORD', word });
    },
    [trie]
  );

  const AvailableWords = React.useMemo(
    () =>
      state.words.map(word => {
        return (
          <li key={word}>
            <button key={word} onClick={() => removeWord(word)}>
              ❌
            </button>{' '}
            {word}
          </li>
        );
      }),
    [state.words]
  );

  const setWord = React.useCallback(
    e => dispatch({ type: 'SET_WORD', word: e.target.value }),
    [state.word]
  );

  const addWord = React.useCallback(
    e => {
      e.preventDefault();

      dispatch({ type: 'ADD_WORD', word: state.word });
    },
    [state.word]
  );

  const getMatches = React.useCallback(() => {
    return trie.search(state.term).map(word => <li key={word}>{word}</li>);
  }, [trie]);

  return (
    <React.Fragment>
      <header>
        <h1>Case Insensitive search</h1>
      </header>
      <section>
        <form onSubmit={addWord}>
          <input
            placeholder="Add a new word"
            onChange={setWord}
            value={state.word}
          />
          <button type="submit">Add</button>
        </form>
      </section>
      <ContentContainer>
        <section>
          <h2>Available for search</h2>
          <ol>{AvailableWords}</ol>
        </section>
        <section>
          <article>
            <div>
              <input
                placeholder="Search"
                type="text"
                value={state.term}
                onChange={checkIfTermExists}
              />
            </div>
            <label>
              Exact match?
              <input
                type="checkbox"
                checked={state.isExact}
                onChange={e =>
                  dispatch({ type: 'SET_ISEXACT', isExact: e.target.checked })
                }
              />
            </label>
          </article>
          <article>
            The term "{state.term}"{' '}
            {trie.has(state.term, state.isExact) ? 'exists' : 'does not exist!'}
          </article>
          <article>
            <h2>Possible Matches</h2>
            <ol>{getMatches()}</ol>
          </article>{' '}
        </section>
      </ContentContainer>
    </React.Fragment>
  );
}

const GlobalStyle = createGlobalStyle({
  boxSizing: 'border-box',
});

const rootElement = document.getElementById('root');
render(
  <React.Fragment>
    <GlobalStyle />
    <App />
  </React.Fragment>,
  rootElement
);