/* eslint-disable @typescript-eslint/no-shadow */
import { S3Client, DeleteObjectCommand, ObjectCannedACL } from '@aws-sdk/client-s3'
import { Upload } from '@aws-sdk/lib-storage'

import type { FileUploadCallback, FileDeleteCallback } from './types'
import type { S3Config } from '@config/index'

let cachedClient: S3Client | null = null
let cachedConfig: S3Config | null = null

const getS3Client = (config: S3Config): S3Client => {
  if (cachedClient) {
    if (
      cachedConfig?.AWS_ENDPOINT !== config.AWS_ENDPOINT ||
      cachedConfig?.AWS_ACCESS_KEY_ID !== config.AWS_ACCESS_KEY_ID ||
      cachedConfig?.AWS_SECRET_ACCESS_KEY !== config.AWS_SECRET_ACCESS_KEY
    ) {
      throw new Error('S3Client singleton was created with different credentials')
    }
    return cachedClient
  }
  const { AWS_ENDPOINT, AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY } = config
  cachedClient = new S3Client({
    credentials: {
      accessKeyId: AWS_ACCESS_KEY_ID,
      secretAccessKey: AWS_SECRET_ACCESS_KEY,
    },
    endpoint: AWS_ENDPOINT,
    forcePathStyle: true,
  })
  cachedConfig = config
  return cachedClient
}

export const s3Service = (config: S3Config, prefix: string) => {
  const { AWS_BUCKET: Bucket } = config
  const s3 = getS3Client(config)

  const uploadFile: FileUploadCallback = async ({ createReadStream, uniqueFilename, mimetype }) => {
    const s3Location = prefix.length > 0 ? `${prefix}/${uniqueFilename}` : uniqueFilename

    const params = {
      Bucket,
      Key: s3Location,
      ACL: ObjectCannedACL.public_read,
      CacheControl: 'public, max-age=604800',
      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
      ContentType: mimetype,
      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-call
      Body: createReadStream(),
    }
    const command = new Upload({ client: s3, params })
    const data = await command.done()
    let { Location: location } = data
    if (!location) {
      throw new Error('File upload did not return `Location`')
    }

    if (!location.startsWith('https://') && !location.startsWith('http://')) {
      // Ensure the location has a protocol. Hetzner sometimes does not return a protocol in the location.
      location = `https://${location}`
    }

    return location
  }

  const deleteFile: FileDeleteCallback = async (url) => {
    let { pathname } = new URL(url, 'http://example.org') // dummy domain to avoid invalid URL error
    pathname = pathname.substring(1) // remove first character '/'
    const prefix = `${Bucket}/`
    if (pathname.startsWith(prefix)) {
      pathname = pathname.slice(prefix.length)
    }
    const params = {
      Bucket,
      Key: pathname,
    }
    await s3.send(new DeleteObjectCommand(params))
  }

  return {
    uploadFile,
    deleteFile,
  }
}