/*
 * This file is part of fabric-loom, licensed under the MIT License (MIT).
 *
 * Copyright (c) 2016, 2017, 2018 FabricMC
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package net.fabricmc.loom.providers;

import com.google.gson.Gson;
import net.fabricmc.loom.LoomGradleExtension;
import net.fabricmc.loom.util.Checksum;
import net.fabricmc.loom.util.Constants;
import net.fabricmc.loom.util.DownloadUtil;
import net.fabricmc.loom.util.MinecraftVersionInfo;
import net.fabricmc.loom.util.assets.AssetIndex;
import net.fabricmc.loom.util.assets.AssetObject;
import net.fabricmc.loom.util.progress.ProgressLogger;

import org.gradle.api.GradleException;
import org.gradle.api.Project;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.net.URL;
import java.util.Map;

public class MinecraftAssetsProvider {
	public static void provide(MinecraftProvider minecraftProvider, Project project) throws IOException {
		LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);
		boolean offline = project.getGradle().getStartParameter().isOffline();

		MinecraftVersionInfo versionInfo = minecraftProvider.versionInfo;
		MinecraftVersionInfo.AssetIndex assetIndex = versionInfo.assetIndex;

		// get existing cache files
		File assets = new File(extension.getUserCache(), "assets");
		if (!assets.exists()) {
			assets.mkdirs();
		}

		File assetsInfo = new File(assets, "indexes" + File.separator + assetIndex.getFabricId(minecraftProvider.minecraftVersion) + ".json");
		if (!assetsInfo.exists() || !Checksum.equals(assetsInfo, assetIndex.sha1)) {
			project.getLogger().lifecycle(":downloading asset index");
			if (offline) {
				if (assetsInfo.exists()) {
					//We know it's outdated but can't do anything about it, oh well
					project.getLogger().warn("Asset index outdated");
				} else {
					//We don't know what assets we need, just that we don't have any
					throw new GradleException("Asset index not found at " + assetsInfo.getAbsolutePath());
				}
			} else {
				DownloadUtil.downloadIfChanged(new URL(assetIndex.url), assetsInfo, project.getLogger());
			}
		}

		ProgressLogger progressLogger = ProgressLogger.getProgressFactory(project, MinecraftAssetsProvider.class.getName());
		progressLogger.start("Downloading assets...", "assets");
		AssetIndex index;
		try (FileReader fileReader = new FileReader(assetsInfo)) {
			index = new Gson().fromJson(fileReader, AssetIndex.class);
		}
		Map<String, AssetObject> parent = index.getFileMap();
		final int totalSize = parent.size();
		int position = 0;
		project.getLogger().lifecycle(":downloading assets...");
		for (Map.Entry<String, AssetObject> entry : parent.entrySet()) {
			AssetObject object = entry.getValue();
			String sha1 = object.getHash();
			String filename = "objects" + File.separator + sha1.substring(0, 2) + File.separator + sha1;
			File file = new File(assets, filename);

			if (!file.exists() || !Checksum.equals(file, sha1)) {
				if (offline) {
					if (file.exists()) {
						project.getLogger().warn("Outdated asset " + entry.getKey());
					} else {
						throw new GradleException("Asset " + entry.getKey() + " not found at " + file.getAbsolutePath());
					}
				} else {
					project.getLogger().debug(":downloading asset " + entry.getKey());
					DownloadUtil.downloadIfChanged(new URL(Constants.RESOURCES_BASE + sha1.substring(0, 2) + "/" + sha1), file, project.getLogger(), true);
				}
			}
			String assetName = entry.getKey();
			int end = assetName.lastIndexOf("/") + 1;
			if (end > 0) {
				assetName = assetName.substring(end);
			}
			progressLogger.progress(assetName + " - " + position + "/" + totalSize + " (" + (int) ((position / (double) totalSize) * 100) + "%) assets downloaded");
			position++;
		}

		progressLogger.completed();
	}
}