app/bin/main/xyz/brysonsteck/serverfordummies/downloadFile.kt


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37

import java.net.http.HttpClient
import kotlinx.coroutines.flow

sealed class DownloadStatus {

    object Success : DownloadStatus()

    data class Error(val message: String) : DownloadStatus()

    data class Progress(val progress: Int): DownloadStatus()
  
}

// function from https://gist.githubusercontent.com/SG-K/63e379efcc3d1cd3ce4fb56ee0e29c42/raw/cd9a4a016401b7c54ec01303415b5871ffa26066/downloadFile.kt
suspend fun HttpClient.downloadFile(file: File, url: String): Flow<DownloadStatus> {
    return flow {
        val response = call {
            url(url)
            method = HttpMethod.Get
        }.response
        val byteArray = ByteArray(response.contentLength()!!.toInt())
        var offset = 0
        do {
            val currentRead = response.content.readAvailable(byteArray, offset, byteArray.size)
            offset += currentRead
            val progress = (offset * 100f / byteArray.size).roundToInt()
            emit(DownloadStatus.Progress(progress))
        } while (currentRead > 0)
        response.close()
        if (response.status.isSuccess()) {
            file.writeBytes(byteArray)
            emit(DownloadStatus.Success)
        } else {
            emit(DownloadStatus.Error("File not downloaded"))
        }
    }
}