'use strict';

const isKey = (x, k) => !!x && k in x;
const mapFalsyToUndefined = (obj) => Object.fromEntries(
  Object.entries(obj).map(([key, value]) => [key, value || void 0])
);

function sva(config) {
  const {
    base = {},
    variants = {},
    compoundVariants = [],
    defaultVariants = {}
  } = config;
  return (variantProps) => {
    const { styles = {}, ...props } = variantProps || {};
    const resolvedStyles = { ...base, ...styles };
    for (const variant of Object.keys(defaultVariants)) {
      const variantValue = defaultVariants[variant];
      if (variantValue && variants[variant]) {
        Object.assign(resolvedStyles, variants[variant][variantValue]);
      }
    }
    for (const variant of Object.keys(props)) {
      if (!isKey(variants, variant))
        continue;
      const variantValue = props[variant];
      if (variantValue && variants[variant]) {
        Object.assign(resolvedStyles, variants[variant][variantValue]);
      }
    }
    for (const compound of compoundVariants) {
      const matches = Object.keys(compound).every((key) => {
        if (key === "styles" || compound[key] === "*")
          return true;
        return isKey(props, key) && props[key] === compound[key];
      });
      if (matches) {
        Object.assign(resolvedStyles, compound.styles);
      }
    }
    return JSON.parse(
      JSON.stringify(mapFalsyToUndefined(resolvedStyles))
    );
  };
}

exports.sva = sva;