// @ts-check

import { getInnerText } from '@redocly/realm/dist/server/plugins/markdown/markdoc/helpers/get-inner-text.js'

import { dirname, relative, join as joinPath } from 'path'
import markdoc from '@markdoc/markdoc'
import moment from 'moment'

export function blogPosts() {
  /** @type {import("@redocly/realm/dist/server/plugins/types").PluginInstance } */
  const instance = {
    processContent: async (actions, { fs, cache }) => {
      try {
        const posts = []

        const allFiles = await fs.scan()
        const markdownFiles = allFiles.filter((file) => file.relativePath.match(/^blog[\/\\]([^\\\/]*)[\/\\].*\.md$/))

        for (const { relativePath } of markdownFiles) {
          const {
            data: { ast },
          } = await cache.load(relativePath, 'markdown-ast')
          const {
            data: { frontmatter },
          } = await cache.load(relativePath, 'markdown-frontmatter')

          const dirPath = dirname(relativePath)
          const title = extractFirstHeading(ast) || ''
          const category = extractCategory(frontmatter.labels)
          const year = `${relativePath.split('/')[1]}`

          posts.push({
            path: dirPath,
            author: frontmatter.author || '',
            title: title || toTitleCase(dirname(dirPath)),
            description: getInnerText([ast.children[1]]).replace(title, '').trim(),
            year: year,
            date: frontmatter.date ? moment(frontmatter.date).format('YYYY-MM-DD') : moment(year).format('YYYY-MM-DD'),
            category: category || 'General',
            category_id: category ? category.toLowerCase().replace(/ /g, '_') : 'general',
            link: `${relativePath.replace('blog/', '').replace('.md', '')}`,
          })
        }

        const sortedPosts = sortBlogPostsByDate(posts)

        actions.createSharedData('blog-posts', { blogPosts: sortedPosts })
        actions.addRouteSharedData('/blog/', 'blog-posts', 'blog-posts')
        actions.addRouteSharedData('/ja/blog/', 'blog-posts', 'blog-posts')
        actions.addRouteSharedData('/es-es/blog/', 'blog-posts', 'blog-posts')
      } catch (e) {
        console.log(e)
      }
    },
  }
  return instance
}

function extractCategory(labelsFrontmatter) {
  const categories = []
  for (const i in labelsFrontmatter) {
    if (labelsFrontmatter[i].includes('Release')) {
      labelsFrontmatter[i] = 'Release Notes'
    }
    categories.push(labelsFrontmatter[i])
  }
  // We only need the first category from the frontmatter.
  return categories[0]
}

function sortBlogPostsByDate(posts) {
  const sortedItems = posts.sort((a, b) => {
    let dateA = new Date(a.date)
    let dateB = new Date(b.date)

    // Sort in descending order
    return dateB.getTime() - dateA.getTime()
  })
  return sortedItems
}

const WORDS_TO_CAPS = ['xrp']

function toTitleCase(s) {
  const words = s.split(/_|[^\w']/)
  return words
    .filter((word) => word)
    .map((word) => (WORDS_TO_CAPS.includes(word) ? word.toUpperCase() : word.charAt(0).toUpperCase() + word.slice(1)))
    .join(' ')
    .replace("'S", "'s")
    .replace(' A ', ' a ')
}

function unique(array) {
  return Array.from(new Set(array))
}

function extractFirstHeading(ast) {
  let heading

  visit(ast, (node) => {
    if (!isNode(node)) {
      return
    }

    if (node.type === 'heading') {
      heading = getInnerText([node])
      return EXIT
    }
  })

  return heading
}

function isNode(value) {
  return !!(value?.$$mdtype === 'Node')
}

const EXIT = Symbol('Exit visitor')
function visit(node, visitor) {
  if (!node) return

  const res = visitor(node)
  if (res === EXIT) return res

  for (const child of node.children) {
    if (!child || typeof child === 'string') {
      continue
    }
    const res = visit(child, visitor)
    if (res === EXIT) return res
  }
}