import { supportedKeyframes, supportedValue, supportedProperty } from 'css-vendor';
import { toCssValue } from 'jss';

/**
 * Add vendor prefix to a property name when needed.
 *
 * @api public
 */

function jssVendorPrefixer() {
  function onProcessRule(rule) {
    if (rule.type === 'keyframes') {
      var atRule = rule;
      atRule.at = supportedKeyframes(atRule.at);
    }
  }

  function prefixStyle(style) {
    for (var prop in style) {
      var value = style[prop];

      if (prop === 'fallbacks' && Array.isArray(value)) {
        style[prop] = value.map(prefixStyle);
        continue;
      }

      var changeProp = false;
      var supportedProp = supportedProperty(prop);
      if (supportedProp && supportedProp !== prop) changeProp = true;
      var changeValue = false;
      var supportedValue$1 = supportedValue(supportedProp, toCssValue(value));
      if (supportedValue$1 && supportedValue$1 !== value) changeValue = true;

      if (changeProp || changeValue) {
        if (changeProp) delete style[prop];
        style[supportedProp || prop] = supportedValue$1 || value;
      }
    }

    return style;
  }

  function onProcessStyle(style, rule) {
    if (rule.type !== 'style') return style;
    return prefixStyle(style);
  }

  function onChangeValue(value, prop) {
    return supportedValue(prop, toCssValue(value)) || value;
  }

  return {
    onProcessRule: onProcessRule,
    onProcessStyle: onProcessStyle,
    onChangeValue: onChangeValue
  };
}

export default jssVendorPrefixer;