utils.ts

import fs from 'node:fs/promises'
import path from 'node:path'

import type { NavItem } from '@rspress/shared'
import { loadFrontMatter } from '@rspress/shared/node-utils'
import { logger } from 'rspress/core'

import { extractTextAndId } from '../../shared/index.js'
import { pathExists } from '../../utils/index.js'

import type { DoomSidebar } from './walk.js'

export async function detectFilePath(rawPath: string, extensions: string[]) {
  // The params doesn't have extension name, so we need to try to find the file with the extension name.
  let realPath: string | undefined = rawPath
  const fileExtname = path.extname(rawPath)

  // pathname may contain .json, see issue: https://github.com/web-infra-dev/rspress/issues/951
  if (!extensions.includes(fileExtname)) {
    const pathWithExtension = extensions.map((ext) => `${rawPath}${ext}`)
    const pathExistInfo = await Promise.all(
      pathWithExtension.map((p) => pathExists(p)),
    )
    const findPath = pathWithExtension.find((_, i) => pathExistInfo[i])
    // file may be public resource, see issue: https://github.com/web-infra-dev/rspress/issues/1052
    if (!fileExtname || findPath) {
      realPath = findPath
    }
  }

  return realPath
}

export async function extractInfoFromFrontmatter(
  filePath: string,
  rootDir: string,
  extensions: string[],
): Promise<{
  realPath: string | undefined
  title: string
  overviewHeaders: number[] | undefined
  context: string | undefined
  weight?: number
}> {
  const realPath = await detectFilePath(filePath, extensions)
  if (!realPath) {
    logger.warn(
      `Can't find the file: ${filePath}, please check it in "${path.join(
        path.dirname(filePath),
        '_meta.json',
      )}".`,
    )
    return {
      realPath,
      title: '',
      overviewHeaders: undefined,
      context: undefined,
    }
  }
  const content = await fs.readFile(realPath, 'utf-8')
  const fileNameWithoutExt = path.basename(realPath, path.extname(realPath))
  // eslint-disable-next-line regexp/no-super-linear-backtracking
  const h1RegExp = /^#\s+(.*)$/m
  const match = content.match(h1RegExp)
  let contentTitle = match?.[1]?.trim()
  if (contentTitle) {
    contentTitle =
      contentTitle.match(
        /\{\s*useI18n\s*\(\s*\)\s*\(\s*(['"])([^'"]+)\1\s*\)\s*\}/,
      )?.[2] ?? contentTitle
  }
  const { frontmatter } = loadFrontMatter<{
    title?: string
    overviewHeaders?: number[]
    context?: string
    weight?: number
  }>(content, filePath, rootDir)

  return {
    realPath,
    title: extractTextAndId(
      frontmatter.title || contentTitle || fileNameWithoutExt,
    )[0],
    overviewHeaders: frontmatter.overviewHeaders,
    context: frontmatter.context,
    weight: frontmatter.weight,
  }
}

export function combineWalkResult(
  walks: { nav: NavItem[]; sidebar: Record<string, DoomSidebar[]> }[],
  versions: string[],
) {
  return walks.reduce(
    (acc, cur, curIndex) => ({
      nav: { ...acc.nav, [versions[curIndex] || 'default']: cur.nav },
      sidebar: { ...acc.sidebar, ...cur.sidebar },
    }),
    { nav: {}, sidebar: {} },
  )
}