Significant rewrite to use 4koma, OkHttp, PackwizPath; fixing several issues

Github release plugin, Kotlin, Okio and OkHttp updated
Toml4j removed and replaced with 4koma - improves null safety, immutability, TOML compliance
kotlin-result removed (I don't think it was used anyway)
SpaceSafeURI replaced with PackwizPath which handles special characters much better (fixes #5)
Fixed directory traversal issues
Hashing system rewritten for better type safety and cleaner code
Download mode changed to use an enum
Request system completely rewritten; now uses OkHttp for HTTP requests (fixes #36, fixes #5)
Added request interceptor which retries requests (fixes #4)
Removed: support for extracting packs from zip files (and Github zipballs)
Cleaner exceptions; more improvements pending (in particular showing request failure causes)
Improved speed of cancelling in-progress downloads
Better support for installing from local files (no file: URI required; though it is still supported)
Various code cleanup changes

src/main/kotlin/link/infra/packwiz/installer/metadata/DownloadMode.kt

@@ -0,0 +1,19 @@
+package link.infra.packwiz.installer.metadata
+
+import cc.ekblad.toml.model.TomlValue
+import cc.ekblad.toml.tomlMapper
+
+enum class DownloadMode {
+	URL,
+	CURSEFORGE;
+
+	companion object {
+		fun mapper() = tomlMapper {
+			decoder { it: TomlValue.String -> when (it.value) {
+				"", "url" -> URL
+				"metadata:curseforge" -> CURSEFORGE
+				else -> throw Exception("Unsupported download mode ${it.value}")
+			} }
+		}
+	}
+}

src/main/kotlin/link/infra/packwiz/installer/metadata/EfficientBooleanAdapter.kt

@@ -17,7 +17,7 @@ class EfficientBooleanAdapter : TypeAdapter<Boolean?>() {
 	}
 
 	@Throws(IOException::class)
-	override fun read(reader: JsonReader): Boolean? {
+	override fun read(reader: JsonReader): Boolean {
 		if (reader.peek() == JsonToken.NULL) {
 			reader.nextNull()
 			return false

src/main/kotlin/link/infra/packwiz/installer/metadata/IndexFile.kt

@@ -1,100 +1,97 @@
 package link.infra.packwiz.installer.metadata
 
-import com.google.gson.annotations.SerializedName
-import com.moandjiezana.toml.Toml
+import cc.ekblad.toml.decode
+import cc.ekblad.toml.tomlMapper
 import link.infra.packwiz.installer.metadata.hash.Hash
-import link.infra.packwiz.installer.metadata.hash.HashUtils.getHash
-import link.infra.packwiz.installer.metadata.hash.HashUtils.getHasher
-import link.infra.packwiz.installer.request.HandlerManager.getFileSource
-import link.infra.packwiz.installer.request.HandlerManager.getNewLoc
+import link.infra.packwiz.installer.metadata.hash.HashFormat
+import link.infra.packwiz.installer.target.ClientHolder
+import link.infra.packwiz.installer.target.path.PackwizPath
+import link.infra.packwiz.installer.util.delegateTransitive
 import okio.Source
 import okio.buffer
-import java.io.InputStreamReader
-import java.nio.file.Paths
 
-class IndexFile {
-	@SerializedName("hash-format")
-	var hashFormat: String = "sha-256"
-	var files: MutableList<File> = ArrayList()
-
-	class File {
-		var file: SpaceSafeURI? = null
-		@SerializedName("hash-format")
-		var hashFormat: String? = null
-		var hash: String? = null
-		var alias: SpaceSafeURI? = null
-		var metafile = false
-		var preserve = false
-
-		@Transient
+data class IndexFile(
+	val hashFormat: HashFormat<*>,
+	val files: List<File> = listOf()
+) {
+	data class File(
+		val file: PackwizPath<*>,
+		private val hashFormat: HashFormat<*>? = null,
+		val hash: String,
+		val alias: PackwizPath<*>?,
+		val metafile: Boolean = false,
+		val preserve: Boolean = false,
+	) {
 		var linkedFile: ModFile? = null
-		@Transient
-		var linkedFileURI: SpaceSafeURI? = null
+
+		fun hashFormat(index: IndexFile) = hashFormat ?: index.hashFormat
+		@Throws(Exception::class)
+		fun getHashObj(index: IndexFile): Hash<*> {
+			// TODO: more specific exceptions?
+			return hashFormat(index).fromString(hash)
+		}
 
 		@Throws(Exception::class)
-		fun downloadMeta(parentIndexFile: IndexFile, indexUri: SpaceSafeURI?) {
+		fun downloadMeta(index: IndexFile, clientHolder: ClientHolder) {
 			if (!metafile) {
 				return
 			}
-			if (hashFormat?.length ?: 0 == 0) {
-				hashFormat = parentIndexFile.hashFormat
-			}
-			// TODO: throw a proper exception instead of allowing NPE?
-			val fileHash = getHash(hashFormat!!, hash!!)
-			linkedFileURI = getNewLoc(indexUri, file)
-			val src = getFileSource(linkedFileURI!!)
-			val fileStream = getHasher(hashFormat!!).getHashingSource(src)
-			linkedFile = Toml().read(InputStreamReader(fileStream.buffer().inputStream(), "UTF-8")).to(ModFile::class.java)
-			if (!fileStream.hashIsEqual(fileHash)) {
+			val fileHash = getHashObj(index)
+			val src = file.source(clientHolder)
+			val fileStream = hashFormat(index).source(src)
+			linkedFile = ModFile.mapper(file).decode<ModFile>(fileStream.buffer().inputStream())
+			if (fileHash != fileStream.hash) {
+				// TODO: propagate details about hash, and show better error!
 				throw Exception("Invalid mod file hash")
 			}
 		}
 
 		@Throws(Exception::class)
-		fun getSource(indexUri: SpaceSafeURI?): Source {
+		fun getSource(clientHolder: ClientHolder): Source {
 			return if (metafile) {
 				if (linkedFile == null) {
 					throw Exception("Linked file doesn't exist!")
 				}
-				linkedFile!!.getSource(linkedFileURI)
+				linkedFile!!.getSource(clientHolder)
 			} else {
-				val newLoc = getNewLoc(indexUri, file) ?: throw Exception("Index file URI is invalid")
-				getFileSource(newLoc)
+				file.source(clientHolder)
 			}
 		}
 
-		@Throws(Exception::class)
-		fun getHashObj(): Hash {
-			if (hash == null) { // TODO: should these be more specific exceptions (e.g. IndexFileException?!)
-				throw Exception("Index file doesn't have a hash")
-			}
-			if (hashFormat == null) {
-				throw Exception("Index file doesn't have a hash format")
-			}
-			return getHash(hashFormat!!, hash!!)
-		}
-
-		// TODO: throw some kind of exception?
 		val name: String
 			get() {
 				if (metafile) {
-					return linkedFile?.name ?: linkedFile?.filename ?:
-					file?.run { Paths.get(path ?: return "Invalid file").fileName.toString() } ?: "Invalid file"
+					return linkedFile?.name ?: file.filename
 				}
-				return file?.run { Paths.get(path ?: return "Invalid file").fileName.toString() } ?: "Invalid file"
+				return file.filename
 			}
 
-		// TODO: URIs are bad
-		val destURI: SpaceSafeURI?
+		val destURI: PackwizPath<*>
 			get() {
 				if (alias != null) {
 					return alias
 				}
-				return if (metafile && linkedFile != null) {
-					linkedFile?.filename?.let { file?.resolve(it) }
+				return if (metafile) {
+					linkedFile!!.filename
 				} else {
 					file
 				}
 			}
+
+		companion object {
+			fun mapper(base: PackwizPath<*>) = tomlMapper {
+				mapping<File>("hash-format" to "hashFormat")
+				delegateTransitive<HashFormat<*>>(HashFormat.mapper())
+				delegateTransitive<PackwizPath<*>>(PackwizPath.mapperRelativeTo(base))
+			}
+		}
+	}
+
+	companion object {
+		fun mapper(base: PackwizPath<*>) = tomlMapper {
+			mapping<IndexFile>("hash-format" to "hashFormat")
+			delegateTransitive<HashFormat<*>>(HashFormat.mapper())
+			delegateTransitive<File>(File.mapper(base))
+		}
 	}
 }

src/main/kotlin/link/infra/packwiz/installer/metadata/ManifestFile.kt

@@ -3,23 +3,23 @@ package link.infra.packwiz.installer.metadata
 import com.google.gson.annotations.JsonAdapter
 import link.infra.packwiz.installer.metadata.hash.Hash
 import link.infra.packwiz.installer.target.Side
+import link.infra.packwiz.installer.target.path.PackwizFilePath
 
 class ManifestFile {
-	var packFileHash: Hash? = null
-	var indexFileHash: Hash? = null
-	var cachedFiles: MutableMap<SpaceSafeURI, File> = HashMap()
+	var packFileHash: Hash<*>? = null
+	var indexFileHash: Hash<*>? = null
+	var cachedFiles: MutableMap<PackwizFilePath, File> = HashMap()
 	// If the side changes, EVERYTHING invalidates. FUN!!!
 	var cachedSide = Side.CLIENT
 
-	// TODO: switch to Kotlin-friendly JSON/TOML libs?
 	class File {
 		@Transient
 		var revert: File? = null
 			private set
 
-		var hash: Hash? = null
-		var linkedFileHash: Hash? = null
-		var cachedLocation: String? = null
+		var hash: Hash<*>? = null
+		var linkedFileHash: Hash<*>? = null
+		var cachedLocation: PackwizFilePath? = null
 
 		@JsonAdapter(EfficientBooleanAdapter::class)
 		var isOptional = false

src/main/kotlin/link/infra/packwiz/installer/metadata/ModFile.kt

@@ -1,74 +1,96 @@
 package link.infra.packwiz.installer.metadata
 
-import com.google.gson.annotations.JsonAdapter
-import com.google.gson.annotations.SerializedName
+import cc.ekblad.toml.delegate
+import cc.ekblad.toml.model.TomlValue
+import cc.ekblad.toml.tomlMapper
 import link.infra.packwiz.installer.metadata.curseforge.UpdateData
-import link.infra.packwiz.installer.metadata.curseforge.UpdateDeserializer
 import link.infra.packwiz.installer.metadata.hash.Hash
-import link.infra.packwiz.installer.metadata.hash.HashUtils.getHash
-import link.infra.packwiz.installer.request.HandlerManager.getFileSource
-import link.infra.packwiz.installer.request.HandlerManager.getNewLoc
+import link.infra.packwiz.installer.metadata.hash.HashFormat
+import link.infra.packwiz.installer.target.ClientHolder
 import link.infra.packwiz.installer.target.Side
+import link.infra.packwiz.installer.target.path.HttpUrlPath
+import link.infra.packwiz.installer.target.path.PackwizPath
+import link.infra.packwiz.installer.util.delegateTransitive
+import okhttp3.HttpUrl.Companion.toHttpUrl
 import okio.Source
+import kotlin.reflect.KType
 
-class ModFile {
-	var name: String? = null
-	var filename: String? = null
-	var side: Side? = null
-	var download: Download? = null
+data class ModFile(
+	val name: String,
+	val filename: PackwizPath<*>,
+	val side: Side = Side.BOTH,
+	val download: Download,
+	val update: Map<String, UpdateData> = mapOf(),
+	val option: Option = Option(false)
+) {
+	data class Download(
+		val url: PackwizPath<*>?,
+		val hashFormat: HashFormat<*>,
+		val hash: String,
+		val mode: DownloadMode = DownloadMode.URL
+	) {
+		companion object {
+			fun mapper() = tomlMapper {
+				decoder<TomlValue.String, PackwizPath<*>> { it -> HttpUrlPath(it.value.toHttpUrl()) }
+				mapping<Download>("hash-format" to "hashFormat")
 
-	class Download {
-		var url: SpaceSafeURI? = null
-		@SerializedName("hash-format")
-		var hashFormat: String? = null
-		var hash: String? = null
-		var mode: String? = null
+				delegateTransitive<HashFormat<*>>(HashFormat.mapper())
+				delegate<DownloadMode>(DownloadMode.mapper())
+			}
+		}
 	}
 
-	@JsonAdapter(UpdateDeserializer::class)
-	var update: Map<String, UpdateData>? = null
-	var option: Option? = null
-
 	@Transient
-	val resolvedUpdateData = mutableMapOf<String, SpaceSafeURI>()
+	val resolvedUpdateData = mutableMapOf<String, PackwizPath<*>>()
 
-	class Option {
-		var optional = false
-		var description: String? = null
-		@SerializedName("default")
-		var defaultValue = false
+	data class Option(
+		val optional: Boolean,
+		val description: String = "",
+		val defaultValue: Boolean = false
+	) {
+		companion object {
+			fun mapper() = tomlMapper {
+				mapping<Option>("default" to "defaultValue")
+			}
+		}
 	}
 
 	@Throws(Exception::class)
-	fun getSource(baseLoc: SpaceSafeURI?): Source {
-		download?.let {
-			if (it.mode == null || it.mode == "" || it.mode == "url") {
-				if (it.url == null) {
-					throw Exception("Metadata file doesn't have a download URI")
-				}
-				val newLoc = getNewLoc(baseLoc, it.url) ?: throw Exception("Metadata file URI is invalid")
-				return getFileSource(newLoc)
-			} else if (it.mode == "metadata:curseforge") {
+	fun getSource(clientHolder: ClientHolder): Source {
+		return when (download.mode) {
+			DownloadMode.URL -> {
+				(download.url ?: throw Exception("No download URL provided")).source(clientHolder)
+			}
+			DownloadMode.CURSEFORGE -> {
 				if (!resolvedUpdateData.contains("curseforge")) {
 					throw Exception("Metadata file specifies CurseForge mode, but is missing metadata")
 				}
-				return getFileSource(resolvedUpdateData["curseforge"]!!)
-			} else {
-				throw Exception("Unsupported download mode " + it.mode)
+				return resolvedUpdateData["curseforge"]!!.source(clientHolder)
 			}
-		} ?: throw Exception("Metadata file doesn't have download")
+		}
 	}
 
 	@get:Throws(Exception::class)
-	val hash: Hash
-		get() {
-			download?.let {
-				return getHash(
-						it.hashFormat ?: throw Exception("Metadata file doesn't have a hash format"),
-						it.hash ?: throw Exception("Metadata file doesn't have a hash")
-				)
-			} ?: throw Exception("Metadata file doesn't have download")
-		}
+	val hash: Hash<*>
+		get() = download.hashFormat.fromString(download.hash)
 
-	val isOptional: Boolean get() = option?.optional ?: false
+	companion object {
+		fun mapper(base: PackwizPath<*>) = tomlMapper {
+			delegateTransitive<PackwizPath<*>>(PackwizPath.mapperRelativeTo(base))
+
+			delegateTransitive<Option>(Option.mapper())
+			delegateTransitive<Download>(Download.mapper())
+
+			delegateTransitive<Side>(Side.mapper())
+
+			val updateDataMapper = UpdateData.mapper()
+			decoder { type: KType, it: TomlValue.Map ->
+				if (type.arguments[1].type?.classifier == UpdateData::class) {
+					updateDataMapper.decode<Map<String, UpdateData>>(it)
+				} else {
+					pass()
+				}
+			}
+		}
+	}
 }

src/main/kotlin/link/infra/packwiz/installer/metadata/PackFile.kt

@@ -1,17 +1,37 @@
 package link.infra.packwiz.installer.metadata
 
-import com.google.gson.annotations.SerializedName
+import cc.ekblad.toml.model.TomlValue
+import cc.ekblad.toml.tomlMapper
+import link.infra.packwiz.installer.metadata.hash.HashFormat
+import link.infra.packwiz.installer.target.path.PackwizPath
+import link.infra.packwiz.installer.util.delegateTransitive
 
-class PackFile {
-	var name: String? = null
-	var index: IndexFileLoc? = null
-
-	class IndexFileLoc {
-		var file: SpaceSafeURI? = null
-		@SerializedName("hash-format")
-		var hashFormat: String? = null
-		var hash: String? = null
+data class PackFile(
+	val name: String,
+	val packFormat: PackFormat = PackFormat.DEFAULT,
+	val index: IndexFileLoc,
+	val versions: Map<String, String> = mapOf()
+) {
+	data class IndexFileLoc(
+		val file: PackwizPath<*>,
+		val hashFormat: HashFormat<*>,
+		val hash: String,
+	) {
+		companion object {
+			fun mapper(base: PackwizPath<*>) = tomlMapper {
+				mapping<IndexFileLoc>("hash-format" to "hashFormat")
+				delegateTransitive<PackwizPath<*>>(PackwizPath.mapperRelativeTo(base))
+				delegateTransitive<HashFormat<*>>(HashFormat.mapper())
+			}
+		}
 	}
 
-	var versions: Map<String, String>? = null
+	companion object {
+		fun mapper(base: PackwizPath<*>) = tomlMapper {
+			mapping<PackFile>("pack-format" to "packFormat")
+			decoder { it: TomlValue.String -> PackFormat(it.value) }
+			encoder { it: PackFormat -> TomlValue.String(it.format) }
+			delegateTransitive<IndexFileLoc>(IndexFileLoc.mapper(base))
+		}
+	}
 }

src/main/kotlin/link/infra/packwiz/installer/metadata/PackFormat.kt

@@ -0,0 +1,10 @@
+package link.infra.packwiz.installer.metadata
+
+@JvmInline
+value class PackFormat(val format: String) {
+	companion object {
+		val DEFAULT = PackFormat("packwiz:1.0.0")
+	}
+
+	// TODO: implement validation, errors for too new / invalid versions
+}

src/main/kotlin/link/infra/packwiz/installer/metadata/SpaceSafeURI.kt

@@ -1,61 +0,0 @@
-package link.infra.packwiz.installer.metadata
-
-import com.google.gson.annotations.JsonAdapter
-import java.io.Serializable
-import java.net.MalformedURLException
-import java.net.URI
-import java.net.URISyntaxException
-import java.net.URL
-
-// The world's worst URI wrapper
-@JsonAdapter(SpaceSafeURIParser::class)
-class SpaceSafeURI : Comparable<SpaceSafeURI>, Serializable {
-	private val u: URI
-
-	@Throws(URISyntaxException::class)
-	constructor(str: String) {
-		u = URI(str.replace(" ", "%20"))
-	}
-
-	constructor(uri: URI) {
-		u = uri
-	}
-
-	@Throws(URISyntaxException::class)
-	constructor(scheme: String?, authority: String?, path: String?, query: String?, fragment: String?) { // TODO: do all components need to be replaced?
-		u = URI(
-				scheme?.replace(" ", "%20"),
-				authority?.replace(" ", "%20"),
-				path?.replace(" ", "%20"),
-				query?.replace(" ", "%20"),
-				fragment?.replace(" ", "%20")
-		)
-	}
-
-	val path: String? get() = u.path?.replace("%20", " ")
-
-	override fun toString(): String = u.toString().replace("%20", " ")
-
-	fun resolve(path: String): SpaceSafeURI = SpaceSafeURI(u.resolve(path.replace(" ", "%20")))
-
-	fun resolve(loc: SpaceSafeURI): SpaceSafeURI = SpaceSafeURI(u.resolve(loc.u))
-
-	fun relativize(loc: SpaceSafeURI): SpaceSafeURI = SpaceSafeURI(u.relativize(loc.u))
-
-	override fun equals(other: Any?): Boolean {
-		return if (other is SpaceSafeURI) {
-			u == other.u
-		} else false
-	}
-
-	override fun hashCode() = u.hashCode()
-
-	override fun compareTo(other: SpaceSafeURI): Int = u.compareTo(other.u)
-
-	val scheme: String? get() = u.scheme
-	val authority: String? get() = u.authority
-	val host: String? get() = u.host
-
-	@Throws(MalformedURLException::class)
-	fun toURL(): URL = u.toURL()
-}

src/main/kotlin/link/infra/packwiz/installer/metadata/SpaceSafeURIParser.kt

@@ -1,25 +0,0 @@
-package link.infra.packwiz.installer.metadata
-
-import com.google.gson.JsonDeserializationContext
-import com.google.gson.JsonDeserializer
-import com.google.gson.JsonElement
-import com.google.gson.JsonParseException
-import java.lang.reflect.Type
-import java.net.URISyntaxException
-
-/**
- * This class encodes spaces before parsing the URI, so the URI can actually be
- * parsed.
- */
-internal class SpaceSafeURIParser : JsonDeserializer<SpaceSafeURI> {
-	@Throws(JsonParseException::class)
-	override fun deserialize(json: JsonElement, typeOfT: Type, context: JsonDeserializationContext): SpaceSafeURI {
-		return try {
-			SpaceSafeURI(json.asString)
-		} catch (e: URISyntaxException) {
-			throw JsonParseException("Failed to parse URI", e)
-		}
-	}
-
-	// TODO: replace this with a better solution?
-}

src/main/kotlin/link/infra/packwiz/installer/metadata/curseforge/CurseForgeSourcer.kt

@@ -4,15 +4,18 @@ import com.google.gson.Gson
 import com.google.gson.JsonIOException
 import com.google.gson.JsonSyntaxException
 import link.infra.packwiz.installer.metadata.IndexFile
-import link.infra.packwiz.installer.metadata.SpaceSafeURI
 import link.infra.packwiz.installer.target.ClientHolder
+import link.infra.packwiz.installer.target.path.HttpUrlPath
+import link.infra.packwiz.installer.target.path.PackwizFilePath
 import link.infra.packwiz.installer.ui.data.ExceptionDetails
+import okhttp3.HttpUrl.Companion.toHttpUrl
 import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.Request
 import okhttp3.RequestBody.Companion.toRequestBody
 import okhttp3.internal.closeQuietly
 import okio.ByteString.Companion.decodeBase64
 import java.nio.charset.StandardCharsets
+import kotlin.io.path.absolute
 
 private class GetFilesRequest(val fileIds: List<Int>)
 private class GetModsRequest(val modIds: List<Int>)
@@ -21,7 +24,7 @@ private class GetFilesResponse {
 	class CfFile {
 		var id = 0
 		var modId = 0
-		var downloadUrl: SpaceSafeURI? = null
+		var downloadUrl: String? = null
 	}
 	val data = mutableListOf<CfFile>()
 }
@@ -43,25 +46,17 @@ private const val APIServer = "api.curseforge.com"
 private val APIKey = "JDJhJDEwJHNBWVhqblU1N0EzSmpzcmJYM3JVdk92UWk2NHBLS3BnQ2VpbGc1TUM1UGNKL0RYTmlGWWxh".decodeBase64()!!
 	.string(StandardCharsets.UTF_8)
 
-private val clientHolder = ClientHolder()
-
-// TODO: switch to PackwizPath stuff and OkHttp in old code
-
 @Throws(JsonSyntaxException::class, JsonIOException::class)
-fun resolveCfMetadata(mods: List<IndexFile.File>): List<ExceptionDetails> {
+fun resolveCfMetadata(mods: List<IndexFile.File>, packFolder: PackwizFilePath, clientHolder: ClientHolder): List<ExceptionDetails> {
 	val failures = mutableListOf<ExceptionDetails>()
 	val fileIdMap = mutableMapOf<Int, IndexFile.File>()
 
 	for (mod in mods) {
-		if (mod.linkedFile!!.update == null) {
-			failures.add(ExceptionDetails(mod.linkedFile!!.name ?: mod.linkedFile!!.filename!!, Exception("Failed to resolve CurseForge metadata: no update section")))
+		if (!mod.linkedFile!!.update.contains("curseforge")) {
+			failures.add(ExceptionDetails(mod.linkedFile!!.name, Exception("Failed to resolve CurseForge metadata: no CurseForge update section")))
 			continue
 		}
-		if (!mod.linkedFile!!.update!!.contains("curseforge")) {
-			failures.add(ExceptionDetails(mod.linkedFile!!.name ?: mod.linkedFile!!.filename!!, Exception("Failed to resolve CurseForge metadata: no CurseForge update section")))
-			continue
-		}
-		fileIdMap[(mod.linkedFile!!.update!!["curseforge"] as CurseForgeUpdateData).fileId] = mod
+		fileIdMap[(mod.linkedFile!!.update["curseforge"] as CurseForgeUpdateData).fileId] = mod
 	}
 
 	val reqData = GetFilesRequest(fileIdMap.keys.toList())
@@ -93,7 +88,13 @@ fun resolveCfMetadata(mods: List<IndexFile.File>): List<ExceptionDetails> {
 			manualDownloadMods[file.modId] = Pair(fileIdMap[file.id]!!, file.id)
 			continue
 		}
-		fileIdMap[file.id]!!.linkedFile!!.resolvedUpdateData["curseforge"] = file.downloadUrl!!
+		try {
+			fileIdMap[file.id]!!.linkedFile!!.resolvedUpdateData["curseforge"] =
+				HttpUrlPath(file.downloadUrl!!.toHttpUrl())
+		} catch (e: IllegalArgumentException) {
+			failures.add(ExceptionDetails(file.id.toString(),
+				Exception("Failed to parse URL: ${file.downloadUrl} for ID ${file.id}, Project ID ${file.modId}", e)))
+		}
 	}
 
 	if (manualDownloadMods.isNotEmpty()) {
@@ -124,7 +125,7 @@ fun resolveCfMetadata(mods: List<IndexFile.File>): List<ExceptionDetails> {
 
 			val modFile = manualDownloadMods[mod.id]!!
 			failures.add(ExceptionDetails(mod.name, Exception("This mod is excluded from the CurseForge API and must be downloaded manually.\n" +
-				"Please go to ${mod.links?.websiteUrl}/files/${modFile.second} and save this file to ${modFile.first.destURI}")))
+				"Please go to ${mod.links?.websiteUrl}/files/${modFile.second} and save this file to ${modFile.first.destURI.rebase(packFolder).nioPath.absolute()}")))
 		}
 	}
 

src/main/kotlin/link/infra/packwiz/installer/metadata/curseforge/CurseForgeUpdateData.kt

@@ -1,10 +1,14 @@
 package link.infra.packwiz.installer.metadata.curseforge
 
-import com.google.gson.annotations.SerializedName
+import cc.ekblad.toml.tomlMapper
 
-class CurseForgeUpdateData: UpdateData {
-	@SerializedName("file-id")
-	var fileId = 0
-	@SerializedName("project-id")
-	var projectId = 0
+data class CurseForgeUpdateData(
+	val fileId: Int,
+	val projectId: Int,
+): UpdateData {
+	companion object {
+		fun mapper() = tomlMapper {
+			mapping<CurseForgeUpdateData>("file-id" to "fileId", "project-id" to "projectId")
+		}
+	}
 }

src/main/kotlin/link/infra/packwiz/installer/metadata/curseforge/UpdateData.kt

@@ -1,3 +1,17 @@
 package link.infra.packwiz.installer.metadata.curseforge
 
-interface UpdateData
+import cc.ekblad.toml.model.TomlValue
+import cc.ekblad.toml.tomlMapper
+
+interface UpdateData {
+	companion object {
+		fun mapper() = tomlMapper {
+			val cfMapper = CurseForgeUpdateData.mapper()
+			decoder { it: TomlValue.Map ->
+				if (it.properties.contains("curseforge")) {
+					mapOf("curseforge" to cfMapper.decode<CurseForgeUpdateData>(it.properties["curseforge"]!!))
+				} else { mapOf() }
+			}
+		}
+	}
+}

src/main/kotlin/link/infra/packwiz/installer/metadata/hash/GeneralHashingSource.kt

@@ -1,10 +0,0 @@
-package link.infra.packwiz.installer.metadata.hash
-
-import okio.ForwardingSource
-import okio.Source
-
-abstract class GeneralHashingSource(delegate: Source) : ForwardingSource(delegate) {
-	abstract val hash: Hash
-
-	fun hashIsEqual(compareTo: Any) = compareTo == hash
-}

src/main/kotlin/link/infra/packwiz/installer/metadata/hash/Hash.kt

@@ -1,20 +1,55 @@
 package link.infra.packwiz.installer.metadata.hash
 
 import com.google.gson.*
+import link.infra.packwiz.installer.metadata.hash.Hash.SourceProvider
+import okio.ByteString
+import okio.ByteString.Companion.decodeHex
+import okio.ForwardingSource
+import okio.HashingSource
+import okio.Source
 import java.lang.reflect.Type
 
-abstract class Hash {
-	protected abstract val stringValue: String
-	protected abstract val type: String
+data class Hash<T>(val type: HashFormat<T>, val value: T) {
+	interface Encoding<T> {
+		fun encodeToString(value: T): String
+		fun decodeFromString(str: String): T
 
-	class TypeHandler : JsonDeserializer<Hash>, JsonSerializer<Hash> {
-		override fun serialize(src: Hash, typeOfSrc: Type, context: JsonSerializationContext): JsonElement = JsonObject().apply {
-			add("type", JsonPrimitive(src.type))
-			add("value", JsonPrimitive(src.stringValue))
+		object Hex: Encoding<ByteString> {
+			override fun encodeToString(value: ByteString) = value.hex()
+			override fun decodeFromString(str: String) = str.decodeHex()
+		}
+
+		object UInt: Encoding<kotlin.UInt> {
+			override fun encodeToString(value: kotlin.UInt) = value.toString()
+			override fun decodeFromString(str: String) = str.toUInt()
+		}
+	}
+
+	fun interface SourceProvider<T> {
+		fun source(type: HashFormat<T>, delegate: Source): HasherSource<T>
+
+		companion object {
+			fun fromOkio(provider: ((Source) -> HashingSource)): SourceProvider<ByteString> {
+				return SourceProvider { type, delegate ->
+					val delegateHashing = provider.invoke(delegate)
+					object : ForwardingSource(delegateHashing), HasherSource<ByteString> {
+						override val hash: Hash<ByteString> by lazy(LazyThreadSafetyMode.NONE) { Hash(type, delegateHashing.hash) }
+					}
+				}
+			}
+		}
+	}
+
+	class TypeHandler : JsonDeserializer<Hash<*>>, JsonSerializer<Hash<*>> {
+		override fun serialize(src: Hash<*>, typeOfSrc: Type, context: JsonSerializationContext): JsonElement = JsonObject().apply {
+			add("type", JsonPrimitive(src.type.formatName))
+			// Local function for generics
+			fun <T> addValue(src: Hash<T>) = add("value", JsonPrimitive(src.type.encodeToString(src.value)))
+			addValue(src)
 		}
 
 		@Throws(JsonParseException::class)
-		override fun deserialize(json: JsonElement, typeOfT: Type, context: JsonDeserializationContext): Hash {
+		override fun deserialize(json: JsonElement, typeOfT: Type, context: JsonDeserializationContext): Hash<*> {
 			val obj = json.asJsonObject
 			val type: String
 			val value: String
@@ -25,7 +60,7 @@ abstract class Hash {
 				throw JsonParseException("Invalid hash JSON data")
 			}
 			return try {
-				HashUtils.getHash(type, value)
+				(HashFormat.fromName(type) ?: throw JsonParseException("Unknown hash type $type")).fromString(value)
 			} catch (e: Exception) {
 				throw JsonParseException("Failed to create hash object", e)
 			}

src/main/kotlin/link/infra/packwiz/installer/metadata/hash/HashFormat.kt

@@ -0,0 +1,39 @@
+package link.infra.packwiz.installer.metadata.hash
+
+import cc.ekblad.toml.model.TomlValue
+import cc.ekblad.toml.tomlMapper
+import link.infra.packwiz.installer.metadata.hash.Hash.Encoding
+import link.infra.packwiz.installer.metadata.hash.Hash.SourceProvider
+import link.infra.packwiz.installer.metadata.hash.Hash.SourceProvider.Companion.fromOkio
+import okio.ByteString
+import okio.Source
+import okio.HashingSource.Companion as OkHashes
+
+sealed class HashFormat<T>(val formatName: String): Encoding<T>, SourceProvider<T> {
+	object SHA1: HashFormat<ByteString>("sha1"),
+		Encoding<ByteString> by Encoding.Hex, SourceProvider<ByteString> by fromOkio(OkHashes::sha1)
+	object SHA256: HashFormat<ByteString>("sha256"),
+		Encoding<ByteString> by Encoding.Hex, SourceProvider<ByteString> by fromOkio(OkHashes::sha256)
+	object SHA512: HashFormat<ByteString>("sha512"),
+		Encoding<ByteString> by Encoding.Hex, SourceProvider<ByteString> by fromOkio(OkHashes::sha512)
+	object MD5: HashFormat<ByteString>("md5"),
+		Encoding<ByteString> by Encoding.Hex, SourceProvider<ByteString> by fromOkio(OkHashes::md5)
+	object MURMUR2: HashFormat<UInt>("murmur2"),
+		Encoding<UInt> by Encoding.UInt, SourceProvider<UInt> by SourceProvider(::Murmur2HasherSource)
+
+	fun source(delegate: Source): HasherSource<T> = source(this, delegate)
+	fun fromString(str: String) = Hash(this, decodeFromString(str))
+	override fun toString() = formatName
+
+	companion object {
+		// lazy used to prevent initialisation issues!
+		private val values by lazy { listOf(SHA1, SHA256, SHA512, MD5, MURMUR2) }
+		fun fromName(formatName: String) = values.find { formatName == it.formatName }
+
+		fun mapper() = tomlMapper {
+			// TODO: better exception?
+			decoder { it: TomlValue.String -> fromName(it.value) ?: throw Exception("Hash format ${it.value} not supported") }
+			encoder { it: HashFormat<*> -> TomlValue.String(it.formatName) }
+		}
+	}
+}

src/main/kotlin/link/infra/packwiz/installer/metadata/hash/HashUtils.kt

@@ -1,22 +0,0 @@
-package link.infra.packwiz.installer.metadata.hash
-
-object HashUtils {
-	private val hashTypeConversion: Map<String, IHasher> = mapOf(
-			"sha256" to HashingSourceHasher("sha256"),
-			"sha512" to HashingSourceHasher("sha512"),
-			"murmur2" to Murmur2Hasher(),
-			"sha1" to HashingSourceHasher("sha1")
-	)
-
-	@JvmStatic
-	@Throws(Exception::class)
-	fun getHasher(type: String): IHasher {
-		return hashTypeConversion[type] ?: throw Exception("Hash type not supported: $type")
-	}
-
-	@JvmStatic
-	@Throws(Exception::class)
-	fun getHash(type: String, value: String): Hash {
-		return hashTypeConversion[type]?.getHash(value) ?: throw Exception("Hash type not supported: $type")
-	}
-}

src/main/kotlin/link/infra/packwiz/installer/metadata/hash/HasherSource.kt

@@ -0,0 +1,7 @@
+package link.infra.packwiz.installer.metadata.hash
+
+import okio.Source
+
+interface HasherSource<T>: Source {
+	val hash: Hash<T>
+}

src/main/kotlin/link/infra/packwiz/installer/metadata/hash/HashingSourceHasher.kt

@@ -1,46 +0,0 @@
-package link.infra.packwiz.installer.metadata.hash
-
-import okio.HashingSource
-import okio.Source
-
-class HashingSourceHasher internal constructor(private val type: String) : IHasher {
-	// i love naming things
-	private inner class HashingSourceGeneralHashingSource(val delegateHashing: HashingSource) : GeneralHashingSource(delegateHashing) {
-		override val hash: Hash by lazy(LazyThreadSafetyMode.NONE) {
-			HashingSourceHash(delegateHashing.hash.hex())
-		}
-	}
-
-	// this some funky inner class stuff
-	// each of these classes is specific to the instance of the HasherHashingSource
-	// therefore HashingSourceHashes from different parent instances will be not instanceof each other
-	private inner class HashingSourceHash(val value: String) : Hash() {
-		override val stringValue get() = value
-
-		override fun equals(other: Any?): Boolean {
-			if (other !is HashingSourceHash) {
-				return false
-			}
-			return stringValue.equals(other.stringValue, ignoreCase = true)
-		}
-
-		override fun toString(): String = "$type: $stringValue"
-		override fun hashCode(): Int = value.hashCode()
-
-		override val type: String get() = this@HashingSourceHasher.type
-	}
-
-	override fun getHashingSource(delegate: Source): GeneralHashingSource {
-		when (type) {
-			"md5" -> return HashingSourceGeneralHashingSource(HashingSource.md5(delegate))
-			"sha256" -> return HashingSourceGeneralHashingSource(HashingSource.sha256(delegate))
-			"sha512" -> return HashingSourceGeneralHashingSource(HashingSource.sha512(delegate))
-			"sha1" -> return HashingSourceGeneralHashingSource(HashingSource.sha1(delegate))
-		}
-		throw RuntimeException("Invalid hash type provided")
-	}
-
-	override fun getHash(value: String): Hash {
-		return HashingSourceHash(value)
-	}
-}

src/main/kotlin/link/infra/packwiz/installer/metadata/hash/IHasher.kt

@@ -1,8 +0,0 @@
-package link.infra.packwiz.installer.metadata.hash
-
-import okio.Source
-
-interface IHasher {
-	fun getHashingSource(delegate: Source): GeneralHashingSource
-	fun getHash(value: String): Hash
-}

src/main/kotlin/link/infra/packwiz/installer/metadata/hash/Murmur2Hasher.kt

@@ -1,91 +0,0 @@
-package link.infra.packwiz.installer.metadata.hash
-
-import okio.Buffer
-import okio.Source
-import java.io.IOException
-
-class Murmur2Hasher : IHasher {
-	private inner class Murmur2GeneralHashingSource(delegate: Source) : GeneralHashingSource(delegate) {
-		val internalBuffer = Buffer()
-		val tempBuffer = Buffer()
-
-		override val hash: Hash by lazy(LazyThreadSafetyMode.NONE) {
-			val data = internalBuffer.readByteArray()
-			Murmur2Hash(Murmur2Lib.hash32(data, data.size, 1))
-		}
-
-		@Throws(IOException::class)
-		override fun read(sink: Buffer, byteCount: Long): Long {
-			val out = delegate.read(tempBuffer, byteCount)
-			if (out > -1) {
-				sink.write(tempBuffer.clone(), out)
-				computeNormalizedBufferFaster(tempBuffer, internalBuffer)
-			}
-			return out
-		}
-
-		// Credit to https://github.com/modmuss50/CAV2/blob/master/murmur.go
-//		private fun computeNormalizedArray(input: ByteArray): ByteArray {
-//			val output = ByteArray(input.size)
-//			var index = 0
-//			for (b in input) {
-//				when (b) {
-//					9.toByte(), 10.toByte(), 13.toByte(), 32.toByte() -> {}
-//					else -> {
-//						output[index] = b
-//						index++
-//					}
-//				}
-//			}
-//			val outputTrimmed = ByteArray(index)
-//			System.arraycopy(output, 0, outputTrimmed, 0, index)
-//			return outputTrimmed
-//		}
-
-		private fun computeNormalizedBufferFaster(input: Buffer, output: Buffer) {
-			var index = 0
-			val arr = input.readByteArray()
-			for (b in arr) {
-				when (b) {
-					9.toByte(), 10.toByte(), 13.toByte(), 32.toByte() -> {}
-					else -> {
-						arr[index] = b
-						index++
-					}
-				}
-			}
-			output.write(arr, 0, index)
-		}
-
-	}
-
-	private class Murmur2Hash : Hash {
-		val value: Int
-
-		constructor(value: String) {
-			// Parsing as long then casting to int converts values gt int max value but lt uint max value
-			// into negatives. I presume this is how the murmur2 code handles this.
-			this.value = value.toLong().toInt()
-		}
-
-		constructor(value: Int) {
-			this.value = value
-		}
-
-		override val stringValue get() = value.toString()
-		override val type get() = "murmur2"
-
-		override fun equals(other: Any?): Boolean {
-			if (other !is Murmur2Hash) {
-				return false
-			}
-			return value == other.value
-		}
-
-		override fun toString(): String = "murmur2: $value"
-		override fun hashCode(): Int = value
-	}
-
-	override fun getHashingSource(delegate: Source): GeneralHashingSource = Murmur2GeneralHashingSource(delegate)
-	override fun getHash(value: String): Hash = Murmur2Hash(value)
-}

src/main/kotlin/link/infra/packwiz/installer/metadata/hash/Murmur2HasherSource.kt

@@ -0,0 +1,43 @@
+package link.infra.packwiz.installer.metadata.hash
+
+import okio.Buffer
+import okio.ForwardingSource
+import okio.Source
+import java.io.IOException
+
+class Murmur2HasherSource(type: HashFormat<UInt>, delegate: Source) : ForwardingSource(delegate), HasherSource<UInt> {
+	private val internalBuffer = Buffer()
+	private val tempBuffer = Buffer()
+
+	override val hash: Hash<UInt> by lazy(LazyThreadSafetyMode.NONE) {
+		// TODO: remove internal buffering?
+		val data = internalBuffer.readByteArray()
+		Hash(type, Murmur2Lib.hash32(data, data.size, 1).toUInt())
+	}
+
+	@Throws(IOException::class)
+	override fun read(sink: Buffer, byteCount: Long): Long {
+		val out = delegate.read(tempBuffer, byteCount)
+		if (out > -1) {
+			sink.write(tempBuffer.clone(), out)
+			computeNormalizedBufferFaster(tempBuffer, internalBuffer)
+		}
+		return out
+	}
+
+	// Credit to https://github.com/modmuss50/CAV2/blob/master/murmur.go
+	private fun computeNormalizedBufferFaster(input: Buffer, output: Buffer) {
+		var index = 0
+		val arr = input.readByteArray()
+		for (b in arr) {
+			when (b) {
+				9.toByte(), 10.toByte(), 13.toByte(), 32.toByte() -> {}
+				else -> {
+					arr[index] = b
+					index++
+				}
+			}
+		}
+		output.write(arr, 0, index)
+	}
+}