Choonster · May 12, 2017 14:53 · May 12, 2017
diff --git a/ExtractMinecraftAssets.lua b/ExtractMinecraftAssets.lua
@@ -0,0 +1,120 @@
+-- Extracts Minecraft's assets from the repository format used by the Mojang launcher and ForgeGradle into regular directories.
+-- Requires Lua 5.2+/LuaJIT, LuaJSON, Penlight and LuaFileSystem
+
+---------------------
+-- Start of Config --
+---------------------
+
+-- The location of the index JSON file
+local INDEX_FILE = [[C:\Users\USER\.gradle\caches\minecraft\assets\indexes\1.11.json]]
+
+-- The directory to extract the assets to
+local OUTPUT_DIR = [[C:\Users\USER\Documents\Minecraft\Mods\TestMod3\TestMod3_1.11.2\vanilla_assets]]
+
+-------------------
+-- End of Config --
+-------------------
+
+local json = require("json")
+local path = require("pl.path")
+local file = require("pl.file")
+local pretty = require("pl.pretty")
+
+--- Calls string.format and prints the result.
+local function printf(formatStr, ...)
+	print(formatStr:format(...))
+end
+
+--- Formats a number with thousands comma separators.
+local function formatNumber(number)
+	return pretty.number(number, "T")
+end
+
+--- Creates a directory, also creating any intermediate directories if they don't exist.
+-- @return true on success or nil, the directory that couldn't be created and an error message on failure
+local function mkdirs(directoryPath)
+	local baseDirectory, thisDir = path.splitpath(directoryPath)
+
+	if not path.isdir(baseDirectory) then -- If the base directory doesn't exist, try to create it
+		local success, failedDirectory, errorMessage = mkdirs(baseDirectory)
+		if not success then -- If creating the base directory fails, we can't create this directory
+			return nil, failedDirectory, errorMessage
+		end
+	end
+
+	local success, errorMessage = path.mkdir(directoryPath)
+	if success then
+		return true
+	else
+		return nil, directoryPath, errorMessage
+	end
+end
+
+local function extractRepository(indexFilePath, outputDirPath)
+	print("Extracting files from repository")
+	printf("Index file: %s", indexFilePath)
+	printf("Output dir: %s", outputDirPath)
+	print("\n")
+
+	local numSucceeded, numFailed, numSkipped = 0, 0, 0
+
+	local function succeeded(...)
+		numSucceeded = numSucceeded + 1
+		printf(...)
+	end
+
+	local function failed(...)
+		numFailed = numFailed + 1
+		printf(...)
+	end
+
+	local function skipped(...)
+		numSkipped = numSkipped + 1
+		printf(...)
+	end
+
+	local index = json.decode(file.read(indexFilePath))
+
+	local indexesDirPath = path.splitpath(indexFilePath)
+	local objectsDirPath = path.join(indexesDirPath, "../objects")
+
+	for filePath, fileData in pairs(index.objects) do
+		local hash = fileData.hash
+		local repositoryFilePath = path.join(hash:sub(1, 2), hash)
+		local fullRepositoryFilePath = path.join(objectsDirPath, repositoryFilePath)
+
+		filePath = path.normpath(filePath)
+		local outputFilePath = path.join(outputDirPath, filePath)
+		local outputSubDirPath = path.join(outputDirPath, (path.splitpath(filePath)))
+
+		printf("Copying %s to %s...", repositoryFilePath, filePath)
+
+		if not path.isdir(outputSubDirPath) then
+			local success, failedDirectory, errorMessage = mkdirs(outputSubDirPath)
+			if not success then
+				failed("Failed to create directory %s: %s", failedDirectory, errorMessage)
+				goto continue
+			end
+		end
+
+		if path.exists(outputFilePath) then
+			skipped("Skipping file as it already exists")
+		else
+			local success, errorMessage = file.copy(fullRepositoryFilePath, outputFilePath)
+			if success then
+				succeeded("Successfully copied file")
+			else
+				failed("Failed to copy file: %s", errorMessage)
+			end
+		end
+
+		::continue::
+
+		print()
+	end
+
+	print()
+	printf("Finished extracting %s files with %s successes, %s failures and %s skipped",  formatNumber(numSucceeded + numFailed + numSkipped), formatNumber(numSucceeded), formatNumber(numFailed), formatNumber(numSkipped))
+end
+
+extractRepository(INDEX_FILE, OUTPUT_DIR)