import React from 'react';
import PropTypes from 'prop-types';
import { GlobalHotKeys } from 'react-hotkeys';

export default class HotkeysDetector extends React.Component {

  constructor(props) {
    super(props);
    this.hotkeyList = this.props.hotkeyList;
    this.state = {
      userCommand: [],
    };
    this.processingCommands = [];
    this.check = this.check.bind(this);
  }

  check(event) {
    const target = event.target;
    // ignore when target dom is input
    const inputPattern = /^input|textinput|textarea$/i;
    if (inputPattern.test(target.tagName) || target.isContentEditable) {
      return;
    }

    // don't fire when not needed
    if (!event.ctrlKey && !event.metaKey && !event.altKey && !event.shiftKey) {
      console.log(event.key);
      this.setState({
        userCommand: this.state.userCommand.concat(event.key),
      });

      // filters the corresponding hotkeys(keys) that the user has pressed so far
      const tempUserCommand = this.state.userCommand;
      this.processingCommands = this.hotkeyList.filter((value) => {
        return value.slice(0, tempUserCommand.length).toString() === tempUserCommand.toString();
      });

      // executes if there were keymap that matches what the user pressed fully.
      if ((this.processingCommands.length === 1) && (this.hotkeyList.find(ary => ary.toString() === this.state.userCommand.toString()))) {
        this.props.onDetected(this.processingCommands[0]);
        this.setState({
          userCommand: [],
        });
      }
      else if (this.processingCommands.toString() === [].toString()) {
        this.setState({
          userCommand: [],
        });
      }
    }
    return null;

  }

  render() {
    const keyMap = { check: this.props.keymap };
    const handlers = { check: (event) => { return this.check(event) } };
    return (
      <GlobalHotKeys keyMap={keyMap} handlers={handlers}>
      </GlobalHotKeys>
    );
  }

}

HotkeysDetector.propTypes = {
  onDetected: PropTypes.func.isRequired,
  keymap: PropTypes.array.isRequired,
  hotkeyList: PropTypes.array.isRequired,
};