package xyz.maxwellj.mapm

import fuel.Fuel
import fuel.get
import java.io.File
import java.math.BigInteger
import java.security.MessageDigest
import kotlin.system.exitProcess
import org.tukaani.xz.XZInputStream
import java.io.*
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream
import java.io.BufferedInputStream
import java.io.FileInputStream
import java.nio.file.Files
import java.nio.file.Paths
import kotlin.collections.listOf as listOf


fun uncompressXZFile(inputFile: String, outputFile: String) {
    XZInputStream(FileInputStream(inputFile)).use { input ->
        FileOutputStream(outputFile).use { output ->
            input.copyTo(output)
        }
    }
}

fun unarchiveTarFile(tarFilePath: String, outputDirectoryPath: String) {
    val tarFile = File(tarFilePath)
    val outputDir = File(outputDirectoryPath)

    if (!outputDir.exists()) {
        outputDir.mkdirs()
    }

    TarArchiveInputStream(BufferedInputStream(FileInputStream(tarFile))).use { tarIn ->
        var entry = tarIn.nextTarEntry
        while (entry != null) {
            val outputFile = File(outputDir, entry.name)
            if (entry.isDirectory) {
                outputFile.mkdirs()
            } else {
                outputFile.parentFile.mkdirs()
                Files.copy(tarIn, Paths.get(outputFile.absolutePath))
            }
            entry = tarIn.nextTarEntry
        }
    }
}

// hurrah for https://stackoverflow.com/questions/64171624/how-to-generate-an-md5-hash-in-kotlin!
fun md5(input:String): String {
    val md = MessageDigest.getInstance("MD5")
    return BigInteger(1, md.digest(input.toByteArray())).toString(16).padStart(32, '0')
}

suspend fun main(args: Array<String>) {
    var userInput: String = args[0]
    println(userInput)
    if (userInput == "g") {
        val userInput: String = args[1]
        val linkToUse = "https://git.maxwellj.xyz/mapm/stable/raw/branch/main/$userInput"
        val dingus = Fuel.get(linkToUse).body.string()
        println("Package $userInput found at $dingus")
	// val packageList = listOf($userInput)
	println("Downloading package $userInput")
        println("Is this okay?")
	val userInputInteractive: String = readln()
	if (userInputInteractive != "y") {
	    println("Confirmation not given. Exiting...")
	    exitProcess(0)
	}
	val file = File("/usr/mapm/tmp/$userInput.tar.xz")
        val fileBytes = Fuel.get(dingus).body.bytes()
        file.writeBytes(fileBytes)
        val fileChecksum = Fuel.get("https://git.maxwellj.xyz/mapm/stable/raw/branch/main/$userInput.hash").body.string()
        if (fileChecksum == md5(file.readText())) {
            println("Checksum matches!")
            uncompressXZFile(inputFile = "/usr/mapm/tmp/${userInput}.tar.xz", outputFile = "/usr/mapm/tmp/${userInput}.tar")
            unarchiveTarFile(tarFilePath = "/usr/mapm/tmp/${userInput}.tar", outputDirectoryPath = "/usr/mapm/")
            Runtime.getRuntime().exec("chmod +x /usr/mapm/${userInput}")
            println("Finished!")
            exitProcess(0)
        } else {
            println("Checksum doesn't match! Aborting...")
            println("Please tell Max or your app's developer to use mapm to generate a new checksum. If the checksum is right, check your internet connection security.")
            exitProcess(1)
        }
    } else if (userInput == "r") {
	val executable = File("/usr/mapm/${args[1]}")
	println("Deleting package ${args[1]}")
	println("Is this okay? (y/n)")
	var userInput = readln()
	if (userInput != "y") {
	    executable.delete()
	}
    } else if (userInput == "c") {
        val userInput = args[1] 
        val file = File(userInput)
        println("Checksum of that file is ${md5(file.readText())}")
    } else {
	println("mapm - Max's Package Manager")
	println("Version 0.0.2")
	println("(C) Maxwell Jeffress 2024, licensed under the GNU GPL V3")
	println("")
	println("---Help---")
	println("Arguments that can be run")
	println("g  Grab a package from the internet")
	println("r  Remove a package")
	println("c  Generate a checksum for a package")
	println("")
	println("More info at the following links:")
	println("https://maxwellj.xyz/mapm")
	println("https://git.maxwellj.xyz/max/mapm")
    }
}