/* eslint max-nested-callbacks: ["error", 4] */

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */

// @flow
import { toPairs } from "lodash";

import type { NamedValue } from "./types";
import type { BindingContents, ScopeBindings } from "../../../types";

// VarAndBindingsPair actually is [name: string, contents: BindingContents]
type VarAndBindingsPair = [string, any];
type VarAndBindingsPairs = Array<VarAndBindingsPair>;

// Scope's bindings field which holds variables and arguments
type ScopeBindingsWrapper = {
  variables: ScopeBindings,
  arguments: BindingContents[]
};

// Create the tree nodes representing all the variables and arguments
// for the bindings from a scope.
export function getBindingVariables(
  bindings: ?ScopeBindingsWrapper,
  parentName: string
): NamedValue[] {
  if (!bindings) {
    return [];
  }

  const args: VarAndBindingsPairs = bindings.arguments.map(
    arg => toPairs(arg)[0]
  );

  const variables: VarAndBindingsPairs = toPairs(bindings.variables);

  return args.concat(variables).map(binding => {
    const name = binding[0];
    const contents = binding[1];
    return {
      name,
      path: `${parentName}/${name}`,
      contents
    };
  });
}