hsifananab/frontend-project-lvl2

import _ from 'lodash';

const stringify = (value) => {
  if (_.isObject(value) && value !== null) {
    return '[complex value]';
  }
  if (_.isString(value)) return `'${value}'`;
  return String(value);
};

const plain = (data) => {
  const format = (tree, parent) => tree
    .filter((node) => node.type !== 'unchanged')
    .map((node) => {
      const property = parent ? `${parent}.${node.key}` : `${node.key}`;
      switch (node.type) {
        case 'removed':
          return `Property '${property}' was ${node.type}`;
        case 'added':
          return `Property '${property}' was ${
            node.type
          } with value: ${stringify(node.value)}`;
        case 'updated':
          return `Property '${property}' was updated. From ${stringify(
            node.removedValue,
          )} to ${stringify(node.addedValue)}`;
        case 'children':
          return `${format(node.children, property)}`;
        default:
          throw new Error(`${node.type} does not exist`);
      }
    })
    .join('\n');
  return format(data, 0);
};

export default plain;