/* ---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/
// Some code copied and modified from https://github.com/microsoft/vscode/blob/1.44.0/src/vs/base/common/linkedText.ts

import { memoize } from './decorators';

export interface ILink {
  readonly label: string;
  readonly href: string;
  readonly title?: string;
}

export type LinkedTextNode = string | ILink;

export class LinkedText {
  constructor(readonly nodes: LinkedTextNode[]) {}

  @memoize
  toString(): string {
    return this.nodes.map((node) => (typeof node === 'string' ? node : node.label)).join('');
  }
}

const LINK_REGEX = /\[([^\]]+)\]\(((?:https?:\/\/|command:)[^\)\s]+)(?: ("|')([^\x03]+)(\3))?\)/gi;

export function parseLinkedText(text: string): LinkedText {
  const result: LinkedTextNode[] = [];

  let index = 0;
  let match: RegExpExecArray | null;

  while ((match = LINK_REGEX.exec(text))) {
    if (match.index - index > 0) {
      result.push(text.substring(index, match.index));
    }

    const [, label, href, , title] = match;

    if (title) {
      result.push({ label, href, title });
    } else {
      result.push({ label, href });
    }

    index = match.index + match[0].length;
  }

  if (index < text.length) {
    result.push(text.substring(index));
  }

  return new LinkedText(result);
}
