import type { App, Page } from 'vuepress/core'
import { createFilter } from 'create-filter'
import { removeLeadingSlash } from '@vuepress/helper'
import { logger, normalizePath, resolveContent, writeTemp } from '../utils/index.js'
import type {
  PlumeThemeBlogPostData,
  PlumeThemeBlogPostItem,
  PlumeThemeEncrypt,
  PlumeThemeLocaleOptions,
  PlumeThemePageData,
  PlumeThemePostFrontmatter,
} from '../../shared/index.js'
import { resolveNotesOptions } from '../config/index.js'
import { isEncryptPage } from './prepareEncrypt.js'

const HEADING_RE = /<h(\d)[^>]*>.*?<\/h\1>/gi
const EXCERPT_SPLIT = '<!-- more -->'

function getTimestamp(time: Date): number {
  return new Date(time).getTime()
}

export async function preparedBlogData(
  app: App,
  localeOptions: PlumeThemeLocaleOptions,
  encrypt?: PlumeThemeEncrypt,
): Promise<void> {
  const start = performance.now()

  const blog = localeOptions.blog || {}
  const notesList = resolveNotesOptions(localeOptions)
  const notesDirList = notesList
    .map(notes => removeLeadingSlash(normalizePath(`${notes.dir}/**`)))
    .filter(Boolean)

  const filter = createFilter(
    blog.include ?? ['**/*.md'],
    [
      '**/{README,readme,index}.md',
      '.vuepress/',
      'node_modules/',
      ...(blog.exclude ?? []),
      ...notesDirList,
    ].filter(Boolean),
    { resolve: false },
  )

  const pages = app.pages.filter(page =>
    page.filePathRelative
    && filter(page.filePathRelative)
    && page.frontmatter.draft !== true,
  ).sort((prev, next) =>
    getTimestamp((prev.frontmatter.createTime as Date) || prev.date)
    < getTimestamp(next.frontmatter.createTime as Date || next.date)
      ? 1
      : -1,
  ) as Page<PlumeThemePageData, PlumeThemePostFrontmatter>[]

  const blogData: PlumeThemeBlogPostData = pages.map((page) => {
    const tags = page.frontmatter.tags
    const data: PlumeThemeBlogPostItem = {
      path: page.path,
      title: page.title,
      categoryList: page.data.categoryList,
      tags,
      sticky: page.frontmatter.sticky,
      createTime: page.data.frontmatter.createTime! || page.date?.replaceAll('-', '/') || '',
      lang: page.lang,
      excerpt: '',
    }

    isEncryptPage(page, encrypt) && (data.encrypt = true)

    if (page.contentRendered.includes(EXCERPT_SPLIT)) {
      const contents = page.contentRendered.split(EXCERPT_SPLIT)
      let excerpt = contents[0]
      // 删除摘要中的标题
      excerpt = excerpt.replace(HEADING_RE, '')
      data.excerpt = excerpt
    }

    return data
  })

  const content = resolveContent(app, { name: 'blogPostData', content: blogData })
  await writeTemp(app, 'internal/blogData.js', content)

  if (app.env.isDebug)
    logger.info(`prepare blog data time spent: ${(performance.now() - start).toFixed(2)}ms`)
}