/**
 * @license
 * Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
 * This code may only be used under the BSD style license found at
 * http://polymer.github.io/LICENSE.txt
 * The complete set of authors may be found at
 * http://polymer.github.io/AUTHORS.txt
 * The complete set of contributors may be found at
 * http://polymer.github.io/CONTRIBUTORS.txt
 * Code distributed by Google as part of the polymer project is also
 * subject to an additional IP rights grant found at
 * http://polymer.github.io/PATENTS.txt
 */

/**
 * @module lit-html
 */

import {reparentNodes} from './dom.js';
import {TemplateProcessor} from './template-processor.js';
import {boundAttributeSuffix, lastAttributeNameRegex, marker, nodeMarker} from './template.js';

/**
 * The return type of `html`, which holds a Template and the values from
 * interpolated expressions.
 */
export class TemplateResult {
  strings: TemplateStringsArray;
  values: unknown[];
  type: string;
  processor: TemplateProcessor;

  constructor(
      strings: TemplateStringsArray, values: unknown[], type: string,
      processor: TemplateProcessor) {
    this.strings = strings;
    this.values = values;
    this.type = type;
    this.processor = processor;
  }

  /**
   * Returns a string of HTML used to create a `<template>` element.
   */
  getHTML(): string {
    const endIndex = this.strings.length - 1;
    let html = '';
    for (let i = 0; i < endIndex; i++) {
      const s = this.strings[i];
      // This exec() call does two things:
      // 1) Appends a suffix to the bound attribute name to opt out of special
      // attribute value parsing that IE11 and Edge do, like for style and
      // many SVG attributes. The Template class also appends the same suffix
      // when looking up attributes to create Parts.
      // 2) Adds an unquoted-attribute-safe marker for the first expression in
      // an attribute. Subsequent attribute expressions will use node markers,
      // and this is safe since attributes with multiple expressions are
      // guaranteed to be quoted.
      const match = lastAttributeNameRegex.exec(s);
      if (match) {
        // We're starting a new bound attribute.
        // Add the safe attribute suffix, and use unquoted-attribute-safe
        // marker.
        html += s.substr(0, match.index) + match[1] + match[2] +
            boundAttributeSuffix + match[3] + marker;
      } else {
        // We're either in a bound node, or trailing bound attribute.
        // Either way, nodeMarker is safe to use.
        html += s + nodeMarker;
      }
    }
    return html + this.strings[endIndex];
  }

  getTemplateElement(): HTMLTemplateElement {
    const template = document.createElement('template');
    template.innerHTML = this.getHTML();
    return template;
  }
}

/**
 * A TemplateResult for SVG fragments.
 *
 * This class wraps HTMl in an `<svg>` tag in order to parse its contents in the
 * SVG namespace, then modifies the template to remove the `<svg>` tag so that
 * clones only container the original fragment.
 */
export class SVGTemplateResult extends TemplateResult {
  getHTML(): string {
    return `<svg>${super.getHTML()}</svg>`;
  }

  getTemplateElement(): HTMLTemplateElement {
    const template = super.getTemplateElement();
    const content = template.content;
    const svgElement = content.firstChild!;
    content.removeChild(svgElement);
    reparentNodes(content, svgElement.firstChild);
    return template;
  }
}