import Rule from './Rule.js'
import { extensionFilter, getContent } from '../helpers.js'
import { getTitle } from '../parser.js'

export default class TitleUnique extends Rule {
  initialize() {
    this.filenames = extensionFilter(this.filenames, 'html');
  }

  report() {
    return {
      ...super.report(),
      ...{
        issueTitle: `The <title> should be unique for every page, ${this.issueCount} pages are concerned.`,
        issueDescription: `You should change title on:`,
        issueReferences: ['https://moz.com/learn/seo/title-tag']
      }
    }
  }

  check() {
    let titles = {}
    for (const filename of this.filenames) {
      const content = getContent(filename);
      const title = getTitle(content)
      titles[title] = titles[title] ? [...titles[title], ...[filename]] : [filename]
    }

    for (const title in titles) {
      if (titles[title].length > 1) {
        this.issueCount += titles[title].length
        const issue = {
            title: title,
            url: titles[title]
        }
        this.issues = [...this.issues, ...[issue]]
      }
    }

    return this.report()
  }
}