import React, { Component } from 'react';
import PropTypes from 'prop-types';
import { connect } from 'react-redux';
import { checkError, readJSON, jsonString, progress, resetTutorial } from '../../../actions/tutorialBuilderActions';

import { saveAs } from 'file-saver';

import { detectWhitespacesAndReturnReadableResult } from '../../../helpers/whitespace';

import Breadcrumbs from '../../Breadcrumbs';
import Textfield from './Textfield';
import Step from './Step';
import Dialog from '../../Dialog';
import Snackbar from '../../Snackbar';

import { withStyles } from '@material-ui/core/styles';
import Button from '@material-ui/core/Button';
import Backdrop from '@material-ui/core/Backdrop';
import CircularProgress from '@material-ui/core/CircularProgress';
import Divider from '@material-ui/core/Divider';
import FormHelperText from '@material-ui/core/FormHelperText';

const styles = (theme) => ({
  backdrop: {
    zIndex: theme.zIndex.drawer + 1,
    color: '#fff',
  },
  errorColor: {
    color: theme.palette.error.dark
  }
});

class Builder extends Component {

  constructor(props) {
    super(props);
    this.state = {
      open: false,
      title: '',
      content: '',
      string: false,
      snackbar: false,
      key: '',
      message: ''
    };
    this.inputRef = React.createRef();
  }

  componentWillUnmount() {
    this.reset();
  }

  submit = () => {
    if (this.props.id === null) {
      var randomID = Date.now();
    } else {
      randomID = this.props.id;
    }

    var isError = this.props.checkError();
    if (isError) {
      this.setState({ snackbar: true, key: Date.now(), message: `Die Angaben für das Tutorial sind nicht vollständig.`, type: 'error' });
      window.scrollTo(0, 0);
    }
    else {
      // export steps without attribute 'url'
      var steps = this.props.steps.map(step => {
        if (step.url) {
          delete step.url;
        }
        return step;
      });
      var tutorial = {
        id: randomID,
        title: this.props.title,
        steps: steps
      }
      var blob = new Blob([JSON.stringify(tutorial)], { type: 'text/json' });
      saveAs(blob, `${detectWhitespacesAndReturnReadableResult(tutorial.title)}.json`);
    }
  }

  reset = () => {
    this.props.resetTutorial();
    this.setState({ snackbar: true, key: Date.now(), message: `Das Tutorial wurde erfolgreich zurückgesetzt.`, type: 'success' });
    window.scrollTo(0, 0);
  }

  uploadJsonFile = (jsonFile) => {
    this.props.progress(true);
    if (jsonFile.type !== 'application/json') {
      this.props.progress(false);
      this.setState({ open: true, string: false, title: 'Unzulässiger Dateityp', content: 'Die übergebene Datei entspricht nicht dem geforderten Format. Es sind nur JSON-Dateien zulässig.' });
    }
    else {
      var reader = new FileReader();
      reader.readAsText(jsonFile);
      reader.onloadend = () => {
        this.readJson(reader.result, true);
      };
    }
  }

  uploadJsonString = () => {
    this.setState({ open: true, string: true, title: 'JSON-String einfügen', content: '' });
  }

  readJson = (jsonString, isFile) => {
    try {
      var result = JSON.parse(jsonString);
      if (!this.checkSteps(result.steps)) {
        result.steps = [{}];
      }
      this.props.readJSON(result);
      this.setState({ snackbar: true, key: Date.now(), message: `${isFile ? 'Die übergebene JSON-Datei' : 'Der übergebene JSON-String'} wurde erfolgreich übernommen.`, type: 'success' });
    } catch (err) {
      this.props.progress(false);
      this.props.jsonString('');
      this.setState({ open: true, string: false, title: 'Ungültiges JSON-Format', content: `${isFile ? 'Die übergebene Datei' : 'Der übergebene String'} enthält nicht valides JSON. Bitte überprüfe ${isFile ? 'die JSON-Datei' : 'den JSON-String'} und versuche es erneut.` });
    }
  }

  checkSteps = (steps) => {
    if (!(steps && steps.length > 0)) {
      return false;
    }
    return true;
  }

  toggle = () => {
    this.setState({ open: !this.state });
  }


  render() {
    return (
      <div>
        <Breadcrumbs content={[{ link: '/tutorial', title: 'Tutorial' }, { link: '/tutorial/builder', title: 'Builder' }]} />

        <h1>Tutorial-Builder</h1>

        {/*upload JSON*/}
        <div ref={this.inputRef}>
          <input
            style={{ display: 'none' }}
            accept="application/json"
            onChange={(e) => { this.uploadJsonFile(e.target.files[0]) }}
            id="open-json"
            type="file"
          />
          <label htmlFor="open-json">
            <Button component="span" style={{ marginRight: '10px', marginBottom: '10px' }} variant='contained' color='primary'>Datei laden</Button>
          </label>
          <Button style={{ marginRight: '10px', marginBottom: '10px' }} variant='contained' color='primary' onClick={() => this.uploadJsonString()}>String laden</Button>
        </div>
        <Divider variant='fullWidth' style={{ margin: '10px 0 15px 0' }} />

        {/*Tutorial-Builder-Form*/}
        {this.props.error.type ?
          <FormHelperText style={{ lineHeight: 'initial' }} className={this.props.classes.errorColor}>{`Ein Tutorial muss mindestens jeweils eine Instruktion und eine Aufgabe enthalten.`}</FormHelperText>
          : null}
        {/* <Id error={this.props.error.id} value={this.props.id} /> */}
        <Textfield value={this.props.title} property={'title'} label={'Titel'} error={this.props.error.title} />

        {this.props.steps.map((step, i) =>
          <Step step={step} index={i} key={i} />
        )}

        {/*submit or reset*/}
        <Divider variant='fullWidth' style={{ margin: '30px 0 10px 0' }} />
        <Button style={{ marginRight: '10px', marginTop: '10px' }} variant='contained' color='primary' onClick={() => this.submit()}>Tutorial-Vorlage erstellen</Button>
        <Button style={{ marginTop: '10px' }} variant='contained' onClick={() => this.reset()}>Zurücksetzen</Button>

        <Backdrop className={this.props.classes.backdrop} open={this.props.isProgress}>
          <CircularProgress color="inherit" />
        </Backdrop>

        <Dialog
          open={this.state.open}
          maxWidth={this.state.string ? 'md' : 'sm'}
          fullWidth={this.state.string}
          title={this.state.title}
          content={this.state.content}
          onClose={this.toggle}
          onClick={this.toggle}
          button={'Schließen'}
          actions={
            this.state.string ?
              <div>
                <Button disabled={this.props.error.json || this.props.json === ''} variant='contained' onClick={() => { this.toggle(); this.props.progress(true); this.readJson(this.props.json, false); }} color="primary">Bestätigen</Button>
                <Button onClick={() => { this.toggle(); this.props.jsonString(''); }} color="primary">Abbrechen</Button>
              </div>
              : null
          }
        >
          {this.state.string ?
            <Textfield value={this.props.json} property={'json'} label={'JSON'} multiline error={this.props.error.json} />
            : null}
        </Dialog>

        <Snackbar
          open={this.state.snackbar}
          message={this.state.message}
          type={this.state.type}
          key={this.state.key}
        />

      </div>
    );
  };
}

Builder.propTypes = {
  checkError: PropTypes.func.isRequired,
  readJSON: PropTypes.func.isRequired,
  jsonString: PropTypes.func.isRequired,
  progress: PropTypes.func.isRequired,
  resetTutorial: PropTypes.func.isRequired,
  title: PropTypes.string.isRequired,
  steps: PropTypes.array.isRequired,
  change: PropTypes.number.isRequired,
  error: PropTypes.object.isRequired,
  json: PropTypes.string.isRequired,
  isProgress: PropTypes.bool.isRequired
};

const mapStateToProps = state => ({
  title: state.builder.title,
  id: state.builder.id,
  steps: state.builder.steps,
  change: state.builder.change,
  error: state.builder.error,
  json: state.builder.json,
  isProgress: state.builder.progress
});

export default connect(mapStateToProps, { checkError, readJSON, jsonString, progress, resetTutorial })(withStyles(styles, { withTheme: true })(Builder));