/* ###
 * IP: GHIDRA
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*******************************************************************************
 * fetchDependencies.gradle                                                    *
 *                                                                             *
 * Fetches/downloads required dependencies that aren't available in the        *
 * standard online repositories (eg: maven) and configures a flat              *
 * directory-style respository that points to them. This should be run         *
 * immediately after cloning the Ghidra repository before any other gradle     *
 * tasks are run.                                                              *
 *                                                                             *
 * usage: from the command line in the main ghidra repository directory, run   *
 *        the following:                                                       *
 *                                                                             *
 *        gradle -I gradle/support/fetchDependencies.gradle init               *
 *                                                                             *
 * Note: When running the script, files will only be downloaded if             *
 *       necessary (eg: they are not already in the dependencies/downloads/    *
 *       directory).                                                           *
 *                                                                             *
 *******************************************************************************/

import java.util.zip.*;
import java.nio.file.*;
import java.security.MessageDigest;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.filefilter.WildcardFileFilter;

initscript {
	repositories { mavenCentral() }
	dependencies { classpath 'commons-io:commons-io:2.11.0' }
}

ext.NUM_RETRIES = 3 // # of times to try to download a file before failing
ext.REPO_DIR = ((Script)this).buildscript.getSourceFile().getParentFile().getParentFile().getParentFile()
ext.DEPS_DIR = file("${REPO_DIR}/dependencies")
ext.DOWNLOADS_DIR = file("${DEPS_DIR}/downloads")
ext.FID_DIR = file("${DEPS_DIR}/fidb")
ext.FLAT_REPO_DIR = file("${DEPS_DIR}/flatRepo")

file("${REPO_DIR}/Ghidra/application.properties").withReader { reader ->
	def ghidraProps = new Properties()
	ghidraProps.load(reader)
	ext.RELEASE_VERSION = ghidraProps.getProperty('application.version')
}

ext.deps = [
	[
		name: "dex-tools-2.0.zip",
		url: "https://github.com/pxb1988/dex2jar/releases/download/2.0/dex-tools-2.0.zip",
		sha256: "7907eb4d6e9280b6e17ddce7ee0507eae2ef161ee29f70a10dbc6944fdca75bc",
		destination: {
			unzip(DOWNLOADS_DIR, DOWNLOADS_DIR, "dex-tools-2.0.zip")
			FileUtils.copyDirectory(new File(DOWNLOADS_DIR, "dex2jar-2.0/lib/"), FLAT_REPO_DIR, new WildcardFileFilter("dex-*"));
		}
	],
	[
		name: "AXMLPrinter2.jar",
		url: "https://storage.googleapis.com/google-code-archive-downloads/v2/code.google.com/android4me/AXMLPrinter2.jar",
		sha256: "00ed038eb6abaf6ddec8d202a3ed7a81b521458f4cd459948115cfd02ff59d6d",
		destination: FLAT_REPO_DIR
	],
	[
		name: "yajsw-beta-13.01.zip",
		url: "https://sourceforge.net/projects/yajsw/files/yajsw/yajsw-beta-13.01/yajsw-beta-13.01.zip",
		sha256: "430fb7901bd0fd52a5b90bd0cbd89e9d334077eb72a9b26896f465de1e593a99",
		destination: file("${DEPS_DIR}/GhidraServer")
	],
	[
		name: "PyDev 6.3.1.zip",
		url: "https://sourceforge.net/projects/pydev/files/pydev/PyDev%206.3.1/PyDev%206.3.1.zip",
		sha256: "4d81fe9d8afe7665b8ea20844d3f5107f446742927c59973eade4f29809b0699",
		destination: file("${DEPS_DIR}/GhidraDev")
	],
	[
		name: "cdt-8.6.0.zip",
		url: "https://archive.eclipse.org/tools/cdt/releases/8.6/cdt-8.6.0.zip",
		sha256: "81b7d19d57c4a3009f4761699a72e8d642b5e1d9251d2bb98df438b1e28f8ba9",
		destination: file("${DEPS_DIR}/GhidraDev")
	],
	[
		name: "vs2012_x64.fidb",
		url: "https://github.com/NationalSecurityAgency/ghidra-data/raw/Ghidra_${RELEASE_VERSION}/FunctionID/vs2012_x64.fidb",
		sha256: "80d1c31c636b1775dd06001747dfb7e2ff60ff716299a8fcc232b8d2faa53a21",
		destination: FID_DIR
	],
	[
		name: "vs2012_x86.fidb",
		url: "https://github.com/NationalSecurityAgency/ghidra-data/raw/Ghidra_${RELEASE_VERSION}/FunctionID/vs2012_x86.fidb",
		sha256: "8fc7ea9451b3a201ac3623b4a0924427cbb6bba410bdf9ebba4f2dfe8e77dfad",
		destination: FID_DIR
	],
	[
		name: "vs2015_x64.fidb",
		url: "https://github.com/NationalSecurityAgency/ghidra-data/raw/Ghidra_${RELEASE_VERSION}/FunctionID/vs2015_x64.fidb",
		sha256: "c3c16d23517c233d6950d5d43e34cdfa1b15c1ee2e066c8e9a53b4f75a907a87",
		destination: FID_DIR
	],
	[
		name: "vs2015_x86.fidb",
		url: "https://github.com/NationalSecurityAgency/ghidra-data/raw/Ghidra_${RELEASE_VERSION}/FunctionID/vs2015_x86.fidb",
		sha256: "6fc0a61e935a0060ab33bd6406c9ca5f215ac3dff655f83c18f3d144ad389fe5",
		destination: FID_DIR
	],
	[
		name: "vs2017_x64.fidb",
		url: "https://github.com/NationalSecurityAgency/ghidra-data/raw/Ghidra_${RELEASE_VERSION}/FunctionID/vs2017_x64.fidb",
		sha256: "5b0f8b8dee110d8c54fc27ed808ea28c2c675e95f3809e33eb99f03672741833",
		destination: FID_DIR
	],
	[
		name: "vs2017_x86.fidb",
		url: "https://github.com/NationalSecurityAgency/ghidra-data/raw/Ghidra_${RELEASE_VERSION}/FunctionID/vs2017_x86.fidb",
		sha256: "2a81615d588aa80043f7bc3a35db04580c990c90398e77399fcffc66f053e5ac",
		destination: FID_DIR
	],
	[
		name: "vs2019_x64.fidb",
		url: "https://github.com/NationalSecurityAgency/ghidra-data/raw/Ghidra_${RELEASE_VERSION}/FunctionID/vs2019_x64.fidb",
		sha256: "80413b57ae20fc1850d15a401d1cec87ac61b1809a1dafc2fa4403bf2029ec94",
		destination: FID_DIR
	],
	[
		name: "vs2019_x86.fidb",
		url: "https://github.com/NationalSecurityAgency/ghidra-data/raw/Ghidra_${RELEASE_VERSION}/FunctionID/vs2019_x86.fidb",
		sha256: "68b96a4e13ee2c157517636aa1c7841f750fbfc0026188f6123af017f3fa3117",
		destination: FID_DIR
	],
	[
		name: "vsOlder_x64.fidb",
		url: "https://github.com/NationalSecurityAgency/ghidra-data/raw/Ghidra_${RELEASE_VERSION}/FunctionID/vsOlder_x64.fidb",
		sha256: "2466595f6e74d9599e16095cc61c6de769461c935c20a442db1d2dfd2d7bde9b",
		destination: FID_DIR
	],
	[
		name: "vsOlder_x86.fidb",
		url: "https://github.com/NationalSecurityAgency/ghidra-data/raw/Ghidra_${RELEASE_VERSION}/FunctionID/vsOlder_x86.fidb",
		sha256: "5b97f786eaebc785aaa365f17eb7cc9a1dd2b5a15b277a5229157ea76945fdc1",
		destination: FID_DIR
	]
]

// Download dependencies (if necessary) and verify their hashes
DOWNLOADS_DIR.mkdirs()
deps.each {
	File file = new File(DOWNLOADS_DIR, it.name)
	if (!it.sha256.equals(generateHash(file))) {
		download(it.url, file.path)
		assert(it.sha256.equals(generateHash(file)));
	}
}

// Copies the downloaded dependencies to their required destination. 
// Some downloads require pre-processing before their relevant pieces can be copied.
deps.each {
	if (it.destination instanceof File) {
		println("Copying " + it.name + " to " + it.destination)
		it.destination.mkdirs()
		FileUtils.copyFile(new File(DOWNLOADS_DIR, it.name), new File(it.destination, it.name));
	}
	else if (it.destination instanceof Closure) {
		println("Processing " + it.name)
		it.destination()
	}
	else {
		throw new GradleException("Unexpected destination type: " + it.destination)
	}
}
//-------------------------------------Helper methods----------------------------------------------

/**
 * Downloads a file from a URL. The download attempt will be tried NUM_RETRIES times before failing.
 *
 * Progress is shown on the command line in the form of the number of bytes downloaded and a 
 * percentage of the total. 
 *
 * Note: We do not validate that the number of bytes downloaded matches the expected total here; any
 * discrepencies will be caught when checking the SHA-256s later on.
 *
 * @param url the file to download
 * @param filename the local file to create for the download
 */
def download(url, filename) {

	println("URL: " + url)
	def(InputStream istream, size) = establishConnection(url, NUM_RETRIES);
	assert istream != null : "   ***CONNECTION FAILURE***\n   max attempts exceeded; exiting\n"

	FileOutputStream ostream = new FileOutputStream(filename);
	def dataBuffer = new byte[1024];
	int bytesRead;
	int totalRead;
	while ((bytesRead = istream.read(dataBuffer, 0, 1024)) != -1) { 
		ostream.write(dataBuffer, 0, bytesRead);
		totalRead += bytesRead
		print("\r")
		print("   Downloading: " + totalRead + " of " + size)
		if (!size.equals("???")) {
			int pctComplete = (totalRead / size) * 100
			print(" (" + pctComplete + "%)")
		}
		print("                                               ") // overwrite gradle timer output
		System.out.flush()
	}
	println()
	istream.close();
	ostream.close();
}

/**
 * Attempts to establish a connection to the given URL 
 *
 * @param url the URL to connect to
 * @param retries the number of times to attempt to connect if there are failures
 * @return the InputStream for the URL, and the size of the download in bytes as a string
 */
def establishConnection(url, retries) {
	for (int i = 0; i < retries; i++) {
		try {
			if (i == 0) {
				println("   Connecting...")
			}
			else {
				println("   Connecting (" + (i+1) + "/" + retries + ")...")
			}
			URLConnection conn = new URL(url).openConnection();
			conn.setRequestMethod("HEAD");
			def size = conn.getContentLengthLong();
			if (size == -1) {
				size = "???" 
			}
			return [new BufferedInputStream(new URL(url).openStream()), size]; 
		}
		catch (Exception e) {
			println("   Connection error! " + e)
		}
	}
}

/**
 * Unzips a file to a directory
 *
 * @param sourceDir the directory where the zip file resides
 * @param targetDir the directory where the unzipped files should be placed
 * @param zipFileName the name of the file to unpack
 */
def unzip(sourceDir, targetDir, zipFileName) {
	def zip = new ZipFile(new File(sourceDir, zipFileName))
	zip.entries().findAll { !it.directory }.each { e ->
		(e.name as File).with { f -> 
			if (f.parentFile != null) {
				File destPath = new File(targetDir.path, f.parentFile.path)
				destPath.mkdirs()
				File targetFile = new File(destPath.path, f.name)
				targetFile.withOutputStream { w -> 
					w << zip.getInputStream(e)
				}
			}
		}
	}
	zip.close()
}

/**
 * Generates the SHA-256 hash for the given file
 *
 * @param file the file to generate the SHA-256 hash for
 * @return the generated SHA-256 hash, or null if the file does not exist
 */
def generateHash(file) {
	if (!file.exists()) {
		return null
	}
	MessageDigest md = MessageDigest.getInstance("SHA-256");
	md.update(Files.readAllBytes(Paths.get(file.path)));
	byte[] digest = md.digest();
	StringBuilder sb = new StringBuilder();
	for (byte b : digest) {
		sb.append(String.format("%02x", b));
	}
	return sb.toString();
}