import React from 'react';
import PropTypes from 'prop-types';
import classNames from 'classnames';
import classNamesBind from 'classnames/bind';
import ThemeContext from 'terra-theme-context';
import IconCritical from 'terra-icon/lib/icon/IconCritical';
import IconHigh from 'terra-icon/lib/icon/IconHigh';
import IconLow from 'terra-icon/lib/icon/IconLow';
import IconAbnormal from 'terra-icon/lib/icon/IconAbnormal';
import { injectIntl } from 'react-intl';
import interpretationPropType from '../../proptypes/interpretationPropTypes';
import valueQuantityPropType from '../../proptypes/valuePropTypes';
import ResultError from '../other/_ResultError';
import styles from './Observation.module.scss';

const cx = classNamesBind.bind(styles);

const propTypes = {
  /**
   *  Event ID
   */
  eventId: PropTypes.string,
  /**
   *  Value and optional Unit of Measure for the Observation Result
   */
  result: valueQuantityPropType,
  /**
   * Interpretation of the Result, indicates Criticality
   */
  interpretation: interpretationPropType,
  /**
   * If Result has not been verified
   */
  isUnverified: PropTypes.bool,
  /**
   * Visually hides the unit of measure when presented in a series of side-by-side columns of the same unit.
   */
  hideUnit: PropTypes.bool,
  /**
  * Internationalization object with translation APIs. Provided by `injectIntl`.
  */
  intl: PropTypes.shape({ formatMessage: PropTypes.func }),
};

const interpretationTextClassMap = {
  critical: 'critical',
  'critical-high': 'critical',
  'critical-low': 'critical',
  positive: 'positive',
  abnormal: 'abnormal',
  high: 'high',
  low: 'low',
};

const Observation = (props) => {
  const {
    eventId,
    result,
    interpretation,
    isUnverified,
    hideUnit,
    intl,
    ...customProps
  } = props;

  const interpretationIndicatorMap = {
    critical: <IconCritical className={cx('icon-interpretation')} a11yLabel={intl.formatMessage({ id: 'Terra.clinicalResult.interpretationCritical' })} role="img" focusable="true" />,
    'critical-high': <IconCritical className={cx('icon-interpretation')} a11yLabel={intl.formatMessage({ id: 'Terra.clinicalResult.interpretationCriticalHigh' })} role="img" focusable="true" />,
    'critical-low': <IconCritical className={cx('icon-interpretation')} a11yLabel={intl.formatMessage({ id: 'Terra.clinicalResult.interpretationCriticalLow' })} role="img" focusable="true" />,
    positive: <IconCritical className={cx('icon-interpretation')} a11yLabel={intl.formatMessage({ id: 'Terra.clinicalResult.interpretationPositive' })} role="img" focusable="true" />,
    abnormal: <IconAbnormal className={cx('icon-interpretation')} a11yLabel={intl.formatMessage({ id: 'Terra.clinicalResult.interpretationAbnormal' })} role="img" focusable="true" />,
    high: <IconHigh className={cx('icon-interpretation')} a11yLabel={intl.formatMessage({ id: 'Terra.clinicalResult.interpretationOutOfRangeHigh' })} role="img" focusable="true" />,
    low: <IconLow className={cx('icon-interpretation')} a11yLabel={intl.formatMessage({ id: 'Terra.clinicalResult.interpretationOutOfRangeLow' })} role="img" focusable="true" />,
  };

  const isValidValue = result && result.value && (!Array.isArray(result.value) || result.value.length !== 0);

  const theme = React.useContext(ThemeContext);
  const valueTextClasses = classNames(
    cx(
      'value',
      !isUnverified && interpretationTextClassMap[interpretation],
      { unverified: isUnverified },
      theme.className,
    ),
    customProps.className,
  );

  const unitClassNames = cx([
    'unit',
    { 'unit-hidden': hideUnit },
    theme.className,
  ]);

  const observationDisplay = () => {
    if (isValidValue) {
      return (
        <React.Fragment>
          <span
            {...customProps}
            className={valueTextClasses}
          >
            {interpretation && !isUnverified && interpretationIndicatorMap[interpretation]}
            {result.value}
          </span>
          {result.unit ? (<span className={unitClassNames}>{result.unit}</span>) : null}
        </React.Fragment>
      );
    }
    return (<ResultError />);
  };

  return observationDisplay();
};

Observation.propTypes = propTypes;

export default injectIntl(Observation);