package expo.modules.filesystem.next

import android.net.Uri
import android.util.Base64
import android.webkit.MimeTypeMap
import expo.modules.interfaces.filesystem.Permission
import expo.modules.kotlin.apifeatures.EitherType
import expo.modules.kotlin.typedarray.TypedArray
import java.io.File
import java.io.FileOutputStream
import java.security.MessageDigest

@OptIn(EitherType::class)
class FileSystemFile(file: File) : FileSystemPath(file) {
  // Kept empty for now, but can be used to validate if the uri is a valid file uri. // TODO: Move to the constructor once also moved on iOS
  fun validatePath() {
  }

  // This makes sure that if a file already exists at a location, it is the correct type so that all available operations perform as expected.
  // After calling this function, we can use the `isDirectory` and `isFile` functions safely as they will match the shared class used.
  override fun validateType() {
    validatePermission(Permission.READ)
    if (file.exists() && file.isDirectory) {
      throw InvalidTypeFileException()
    }
  }

  val exists: Boolean get() {
    validatePermission(Permission.READ)
    return file.isFile
  }

  fun create() {
    validateType()
    validatePermission(Permission.WRITE)
    file.createNewFile()
  }

  fun write(content: String) {
    validateType()
    validatePermission(Permission.WRITE)
    if (!exists) {
      create()
    }
    FileOutputStream(file).use {
      it.write(content.toByteArray())
    }
  }

  fun write(content: TypedArray) {
    validateType()
    validatePermission(Permission.WRITE)
    if (!exists) {
      create()
    }
    FileOutputStream(file).use {
      it.channel.write(content.toDirectBuffer())
    }
  }

  fun asString(): String {
    val uriString = Uri.fromFile(file).toString()
    return if (uriString.endsWith("/")) uriString.dropLast(1) else uriString
  }

  fun text(): String {
    validateType()
    validatePermission(Permission.READ)
    return file.readText()
  }

  fun base64(): String {
    validateType()
    validatePermission(Permission.READ)
    return Base64.encodeToString(file.readBytes(), Base64.NO_WRAP)
  }

  fun bytes(): ByteArray {
    validateType()
    validatePermission(Permission.READ)
    return file.readBytes()
  }

  @OptIn(ExperimentalStdlibApi::class)
  val md5: String get() {
    validatePermission(Permission.READ)
    val md = MessageDigest.getInstance("MD5")
    val digest = md.digest(file.readBytes())
    return digest.toHexString()
  }

  val size: Long? get() {
    return if (file.exists()) {
      file.length()
    } else {
      null
    }
  }

  val type: String? get() {
    return MimeTypeMap.getFileExtensionFromUrl(file.path)
      ?.run { MimeTypeMap.getSingleton().getMimeTypeFromExtension(lowercase()) }
  }
}