import fs from 'fs'
import path from 'path'
import sharp from 'sharp'
import FacialRecognition from './libs/FacialRecognition'
import FileHelpers from './libs/FileHelpers'
import ImageHelpers from './libs/ImageHelpers'

export default function FaceReplace(facePicPathOrUrl: string) {
  return {
    faceReplacePath: facePicPathOrUrl,
    tmpPath: path.join(__dirname, '..', 'tmp'),

    setFacePicture(pathOrUrl: string) {
      this.faceReplacePath = pathOrUrl
    },

    async replace(sourceImgPathOrUrl: string) {
      const img = ImageHelpers()

      await FileHelpers.checkAndCreateDirectory(this.tmpPath)
      await this.confirmFacePathIsSet()

      let imgPath = sourceImgPathOrUrl
      if (this.isStringValidUrl(imgPath))
        imgPath = await this.getFileAndStoreLocally(imgPath)

      let imgBuffer = await fs.promises.readFile(imgPath, { encoding: null })
      await img.open(imgPath)
      const [detections] = await FacialRecognition.drawFaceOutlines(imgBuffer)
      const compositeAry: sharp.OverlayOptions[] = await Promise.all(
        detections.map(async ({ detection }: any) => {
          const localFaceImg = ImageHelpers()
          await localFaceImg.open(this.faceReplacePath)
          localFaceImg.cover(
            parseInt(detection._box._width),
            parseInt(detection._box._height)
          )

          return {
            input: await localFaceImg.image.toBuffer(),
            left: parseInt(detection._box._x),
            top: parseInt(detection._box._y),
          }
        })
      )

      img.composite(compositeAry)
      return await img.toBuffer()
    },

    async getFileAndStoreLocally(imgUrl: string) {
      const splitUrl = imgUrl.split('/')
      const localFilename = splitUrl[splitUrl.length - 1]
      const imgBuff = await FileHelpers.getUrlBuffer(imgUrl)

      const fullPath = path.join(this.tmpPath, localFilename)
      await fs.promises.writeFile(fullPath, imgBuff)
      return fullPath
    },

    async confirmFacePathIsSet() {
      if (!this.faceReplacePath)
        throw new Error(`Make sure a face replacement picture is set`)

      if (this.isStringValidUrl(this.faceReplacePath))
        return (this.faceReplacePath = await this.getFileAndStoreLocally(
          this.faceReplacePath
        ))

      return this.faceReplacePath
    },

    isStringValidUrl(str: string) {
      return /^https*\:\/\//.test(str)
    },
  }
}