import fs from 'fs'
import { join, relative } from 'path'

import { PAGES_MANIFEST, BUILD_ID_FILE } from '../shared/lib/constants'
import { PagesManifest } from '../build/webpack/plugins/pages-manifest-plugin'
import type { Route } from './router'
import { recursiveReadDirSync } from './lib/recursive-readdir-sync'
import { route } from './router'

import BaseServer from './base-server'
export * from './base-server'

export default class NextNodeServer extends BaseServer {
  protected getHasStaticDir(): boolean {
    return fs.existsSync(join(this.dir, 'static'))
  }

  protected getPagesManifest(): PagesManifest | undefined {
    const pagesManifestPath = join(this.serverBuildDir, PAGES_MANIFEST)
    return require(pagesManifestPath)
  }

  protected getBuildId(): string {
    const buildIdFile = join(this.distDir, BUILD_ID_FILE)
    try {
      return fs.readFileSync(buildIdFile, 'utf8').trim()
    } catch (err) {
      if (!fs.existsSync(buildIdFile)) {
        throw new Error(
          `Could not find a production build in the '${this.distDir}' directory. Try building your app with 'next build' before starting the production server. https://nextjs.org/docs/messages/production-start-no-build-id`
        )
      }

      throw err
    }
  }

  protected generatePublicRoutes(): Route[] {
    if (!fs.existsSync(this.publicDir)) return []

    const publicFiles = new Set(
      recursiveReadDirSync(this.publicDir).map((p) =>
        encodeURI(p.replace(/\\/g, '/'))
      )
    )

    return [
      {
        match: route('/:path*'),
        name: 'public folder catchall',
        fn: async (req, res, params, parsedUrl) => {
          const pathParts: string[] = params.path || []
          const { basePath } = this.nextConfig

          // if basePath is defined require it be present
          if (basePath) {
            const basePathParts = basePath.split('/')
            // remove first empty value
            basePathParts.shift()

            if (
              !basePathParts.every((part: string, idx: number) => {
                return part === pathParts[idx]
              })
            ) {
              return { finished: false }
            }

            pathParts.splice(0, basePathParts.length)
          }

          let path = `/${pathParts.join('/')}`

          if (!publicFiles.has(path)) {
            // In `next-dev-server.ts`, we ensure encoded paths match
            // decoded paths on the filesystem. So we need do the
            // opposite here: make sure decoded paths match encoded.
            path = encodeURI(path)
          }

          if (publicFiles.has(path)) {
            await this.serveStatic(
              req,
              res,
              join(this.publicDir, ...pathParts),
              parsedUrl
            )
            return {
              finished: true,
            }
          }
          return {
            finished: false,
          }
        },
      } as Route,
    ]
  }

  private _validFilesystemPathSet: Set<string> | null = null
  protected getFilesystemPaths(): Set<string> {
    if (this._validFilesystemPathSet) {
      return this._validFilesystemPathSet
    }

    const pathUserFilesStatic = join(this.dir, 'static')
    let userFilesStatic: string[] = []
    if (this.hasStaticDir && fs.existsSync(pathUserFilesStatic)) {
      userFilesStatic = recursiveReadDirSync(pathUserFilesStatic).map((f) =>
        join('.', 'static', f)
      )
    }

    let userFilesPublic: string[] = []
    if (this.publicDir && fs.existsSync(this.publicDir)) {
      userFilesPublic = recursiveReadDirSync(this.publicDir).map((f) =>
        join('.', 'public', f)
      )
    }

    let nextFilesStatic: string[] = []

    nextFilesStatic =
      !this.minimalMode && fs.existsSync(join(this.distDir, 'static'))
        ? recursiveReadDirSync(join(this.distDir, 'static')).map((f) =>
            join('.', relative(this.dir, this.distDir), 'static', f)
          )
        : []

    return (this._validFilesystemPathSet = new Set<string>([
      ...nextFilesStatic,
      ...userFilesPublic,
      ...userFilesStatic,
    ]))
  }
}