function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }

var path = _interopDefault(require('path'));
var postcss = _interopDefault(require('postcss'));
var cssImportResolve = require('css-import-resolve');

/** Enhance the composes behavior in CSS Modules. */

var index = postcss.plugin('postcss-plugin-composes', function initializer(opts) {
  opts = Object(opts);
  opts.resolveImports = Boolean('resolveImports' in opts ? opts.resolveImports : true);
  opts.transformAtRules = Boolean('transformAtRules' in opts ? opts.transformAtRules : true);
  opts.extensions = [].concat('extensions' in opts ? opts.extensions : 'module.css');
  opts.indexes = [].concat('indexes' in opts ? opts.indexes : 'index.module.css');
  opts.packageProps = [].concat('packageProps' in opts ? opts.packageProps : ['exports.icss.import', 'exports.icss.default', 'exports.icss']);
  return function transformer(css) {
    /** Directory of the current CSS file. */
    const cwd = path.dirname(css.source.input.file);
    css.walk(node => {
      // replace any "@composes" at-rule with a "composes" declaration
      if (opts.transformAtRules) {
        if (node.type === 'atrule' && node.name === 'composes') {
          node.replaceWith(node = postcss.decl({
            prop: node.name,
            value: node.params
          }));
        }
      } // ignore any non-"composes" declaration


      if (!opts.resolveImports || node.type !== 'decl' || node.prop !== 'composes') return;
      /** Matches of any declarations */

      const matches = node.value.match(matchImports);

      if (matches) {
        /** Whether this is a global "composes" value, which will be ignored. */
        const [,,,,, global] = matches; // resolve the path of any non-global "composes"

        if (!global) {
          const originalValue = node.value;
          const modifiedValue = getModifiedValue(originalValue, cwd, opts);

          if (originalValue !== modifiedValue) {
            node.value = modifiedValue;
          }
        }
      }
    });
  };
});
/** RegExp used to match imports (from https://github.com/css-modules/postcss-modules-extract-imports/blob/2.0.0/src/index.js#L6) */

const matchImports = /^(.+?)(\s+from\s+)(?:"([^"]+)"|'([^']+)'|(global))$/;
/**
 * Return the value of a composes declaration with any import paths resolved.
 * @arg {string} value
 * @arg {string} cwd
 * @arg {{ [key: string]: any }} opts
 */

function getModifiedValue(value, cwd, opts) {
  return value.replace(matchImports, ($0, symbols, fromPart, doubleQuotePath, singleQuotePath) => {
    const originalPath = doubleQuotePath || singleQuotePath;
    const modifiedPath = cssResolve(originalPath, cwd, opts);
    const exportedPath = modifiedPath === originalPath ? originalPath : path.relative(cwd, modifiedPath);
    const quote = doubleQuotePath ? '"' : "'";
    return symbols + fromPart + quote + exportedPath + quote;
  });
}
/**
 * Return a css-resolved path or the original path.
 * @arg {string} file
 * @arg {string} cwd
 * @arg {{ [key: string]: any }} opts
 */


function cssResolve(file, cwd, opts) {
  return (// use the node-resolve-able path
    cssImportResolve.resolveSync(withoutTilde(file), cwd, opts) || file
  );
}
/**
 * Return the filename without the starting tilde.
 * @arg {string} file
 */


function withoutTilde(file) {
  return file.replace(/^~/, '');
}

module.exports = index;