de.comhix.commons.updater.Updater.kt Maven / Gradle / Ivy

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package de.comhix.commons.updater

import com.google.gson.GsonBuilder
import okhttp3.OkHttpClient.Builder
import okhttp3.Request
import okio.Okio
import java.io.*
import java.util.zip.ZipInputStream

/**
 * @author Benjamin Beeker
 */
class Updater> private constructor(
        private val url: String,
        private val currentVersion: Info,
        private val updateUrlProvider: (Info) -> String,
        private val versionProvider: (Info) -> Version) {
    private val info: Info by lazy {
        GsonBuilder().create().fromJson(InputStreamReader(loadInfo()), currentVersion::class.java as Class)
    }

    @Throws(IOException::class)
    fun loadInfo(): InputStream {
        val client = Builder().build()
        val response = client.newCall(Request.Builder().url(url).build()).execute()
        return response.body()!!.byteStream()
    }

    @Throws(IOException::class)
    fun hasUpdate(): Boolean {
        return versionProvider.invoke(currentVersion) < versionProvider.invoke(info)
    }

    @Throws(IOException::class)
    fun doUpdate() {
        val client = Builder().build()
        val response = client.newCall(Request.Builder().url(updateUrlProvider.invoke(info)).build()).execute()
        Okio.buffer(Okio.sink(File("update.zip"))).use { output -> output.writeAll(Okio.source(response.body()!!.byteStream())) }
        val buffer = ByteArray(1024)
        val zis = ZipInputStream(FileInputStream("update.zip"))
        var zipEntry = zis.nextEntry
        while (zipEntry != null) {
            val fileName = zipEntry.name
            val newFile = File(fileName)
            val fos = FileOutputStream(newFile)
            var len: Int
            while (zis.read(buffer).also { len = it } > 0) {
                fos.write(buffer, 0, len)
            }
            fos.close()
            zipEntry = zis.nextEntry
        }
        zis.closeEntry()
        zis.close()
        File("update.zip").deleteOnExit()
    }

    companion object {
        fun > create(url: String,
                                                               currentVersion: Info,
                                                               updateUrlProvider: (Info) -> String,
                                                               versionProvider: (Info) -> Version): Updater {
            return Updater(url, currentVersion, updateUrlProvider, versionProvider)
        }
    }
}