/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

export enum TagContentType {
  RAW_TEXT,
  ESCAPABLE_RAW_TEXT,
  PARSABLE_DATA
}

export interface TagDefinition {
  closedByParent: boolean;
  implicitNamespacePrefix: string|null;
  isVoid: boolean;
  ignoreFirstLf: boolean;
  canSelfClose: boolean;
  preventNamespaceInheritance: boolean;

  isClosedByChild(name: string): boolean;
  getContentType(prefix?: string): TagContentType;
}

export function splitNsName(elementName: string): [string|null, string] {
  if (elementName[0] != ':') {
    return [null, elementName];
  }

  const colonIndex = elementName.indexOf(':', 1);

  if (colonIndex === -1) {
    throw new Error(`Unsupported format "${elementName}" expecting ":namespace:name"`);
  }

  return [elementName.slice(1, colonIndex), elementName.slice(colonIndex + 1)];
}

// `<ng-container>` tags work the same regardless the namespace
export function isNgContainer(tagName: string): boolean {
  return splitNsName(tagName)[1] === 'ng-container';
}

// `<ng-content>` tags work the same regardless the namespace
export function isNgContent(tagName: string): boolean {
  return splitNsName(tagName)[1] === 'ng-content';
}

// `<ng-template>` tags work the same regardless the namespace
export function isNgTemplate(tagName: string): boolean {
  return splitNsName(tagName)[1] === 'ng-template';
}

export function getNsPrefix(fullName: string): string;
export function getNsPrefix(fullName: null): null;
export function getNsPrefix(fullName: string|null): string|null {
  return fullName === null ? null : splitNsName(fullName)[0];
}

export function mergeNsAndName(prefix: string, localName: string): string {
  return prefix ? `:${prefix}:${localName}` : localName;
}