Change .packages file use to package config file (flutter#5993)

* Change .packages file use to package config file

* Restore deprecated methods to build for 2020.3

Author: stevemessick

bin/plugin

@@ -1,5 +1,5 @@
 #!/bin/bash
 
-# TODO(devoncarew): Warn if tool/plugin/.packages does not exist.
+# TODO: Warn if 'pub get' needs to be done.
 
 dart tool/plugin/bin/main.dart "$@"

flutter-idea/src/io/flutter/FlutterInitializer.java

@@ -173,7 +173,7 @@ public void moduleAdded(@NotNull Project project, @NotNull Module module) {
     // Watch save actions for format on save.
     FlutterSaveActionsManager.init(project);
 
-    // Start watching for project structure and .packages file changes.
+    // Start watching for project structure changes.
     final FlutterPluginsLibraryManager libraryManager = new FlutterPluginsLibraryManager(project);
     libraryManager.startWatching();
 

flutter-idea/src/io/flutter/run/MainFile.java

@@ -58,7 +58,7 @@ public VirtualFile getFile() {
   }
 
   /**
-   * Returns the closest ancestor directory containing a pubspec.yaml, BUILD, or .packages file.
+   * Returns the closest ancestor directory containing a pubspec.yaml, BUILD, or packages meta-data file.
    */
   @NotNull
   public VirtualFile getAppDir() {
@@ -137,6 +137,7 @@ private static boolean isAppDir(@NotNull VirtualFile dir, @NotNull Project proje
     assert(!WorkspaceCache.getInstance(project).isBazel());
     return dir.isDirectory() && (
       dir.findChild("pubspec.yaml") != null ||
+      dir.findChild(".dart_tool") != null ||
       dir.findChild(".packages") != null
     );
   }

flutter-idea/src/io/flutter/sdk/FlutterPluginsLibraryManager.java

@@ -5,6 +5,9 @@
  */
 package io.flutter.sdk;
 
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
 import com.intellij.ProjectTopics;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.application.ModalityState;
@@ -13,16 +16,21 @@
 import com.intellij.openapi.roots.ModuleRootEvent;
 import com.intellij.openapi.roots.ModuleRootListener;
 import com.intellij.openapi.roots.libraries.PersistentLibraryKind;
+import com.intellij.openapi.util.SystemInfo;
+import com.intellij.openapi.util.io.FileUtil;
+import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.*;
+import com.intellij.util.io.URLUtil;
 import com.jetbrains.lang.dart.util.DotPackagesFileUtil;
 import io.flutter.pub.PubRoot;
 import io.flutter.pub.PubRoots;
+import io.flutter.utils.JsonUtils;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.*;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import static com.jetbrains.lang.dart.util.PubspecYamlUtil.PUBSPEC_YAML;
@@ -123,15 +131,23 @@ private static Set<String> getFlutterPluginPaths(List<PubRoot> roots) {
     final Set<String> paths = new HashSet<>();
 
     for (PubRoot pubRoot : roots) {
+
+      final Map<String, String> map;
       if (pubRoot.getPackagesFile() == null) {
-        continue;
+        @Nullable VirtualFile configFile = pubRoot.getPackageConfigFile();
+        if (configFile == null) {
+          continue;
+        }
+        // TODO(messick) Use the code in the Dart plugin when available.
+        // This is just a backup in case we need it. It does not have a proper cache, but the Dart plugin does.
+        map = loadPackagesMap(configFile);
       }
-
-      final Map<String, String> map = DotPackagesFileUtil.getPackagesMap(pubRoot.getPackagesFile());
-      if (map == null) {
-        continue;
+      else {
+        map = DotPackagesFileUtil.getPackagesMap(pubRoot.getPackagesFile());
+        if (map == null) {
+          continue;
+        }
       }
-
       for (String packagePath : map.values()) {
         final VirtualFile libFolder = LocalFileSystem.getInstance().findFileByPath(packagePath);
         if (libFolder == null) {
@@ -150,4 +166,53 @@ private static Set<String> getFlutterPluginPaths(List<PubRoot> roots) {
 
     return paths;
   }
+
+  private static Map<String, String> loadPackagesMap(@NotNull VirtualFile root) {
+    Map<String, String> result = new HashMap<>();
+    try {
+      JsonElement element = JsonUtils.parseString(new String(root.contentsToByteArray(), StandardCharsets.UTF_8));
+      if (element != null) {
+        JsonElement packages = element.getAsJsonObject().get("packages");
+        if (packages != null) {
+          JsonArray array = packages.getAsJsonArray();
+          for (int i = 0; i < array.size(); i++) {
+            JsonObject pkg = array.get(i).getAsJsonObject();
+            String name = pkg.get("name").getAsString();
+            String rootUri = pkg.get("rootUri").getAsString();
+            if (name != null && rootUri != null) {
+              // need to protect '+' chars because URLDecoder.decode replaces '+' with space
+              final String encodedUriWithoutPluses = StringUtil.replace(rootUri, "+", "%2B");
+              final String uri = URLUtil.decode(encodedUriWithoutPluses);
+              final String packageUri = getAbsolutePackageRootPath(root.getParent().getParent(), uri);
+              result.put(name, packageUri);
+            }
+          }
+        }
+      }
+    }
+    catch (IOException ignored) {
+    }
+    return result;
+  }
+
+  @Nullable
+  private static String getAbsolutePackageRootPath(@NotNull final VirtualFile baseDir, @NotNull final String uri) {
+    // Copied from the Dart plugin.
+    if (uri.startsWith("file:/")) {
+      final String pathAfterSlashes = StringUtil.trimEnd(StringUtil.trimLeading(StringUtil.trimStart(uri, "file:/"), '/'), "/");
+      if (SystemInfo.isWindows && !ApplicationManager.getApplication().isUnitTestMode()) {
+        if (pathAfterSlashes.length() > 2 && Character.isLetter(pathAfterSlashes.charAt(0)) && ':' == pathAfterSlashes.charAt(1)) {
+          return pathAfterSlashes;
+        }
+      }
+      else {
+        return "/" + pathAfterSlashes;
+      }
+    }
+    else {
+      return FileUtil.toCanonicalPath(baseDir.getPath() + "/" + uri);
+    }
+
+    return null;
+  }
 }

flutter-idea/src/io/flutter/sdk/FlutterSdk.java

@@ -467,7 +467,7 @@ public Process startPubGet(@NotNull PubRoot root, @NotNull Project project) {
     if (module == null) return null;
     // Ensure pubspec is saved.
     FileDocumentManager.getInstance().saveAllDocuments();
-    // Refresh afterwards to ensure Dart Plugin sees .packages and doesn't mistakenly nag to run pub.
+    // Refresh afterwards to ensure Dart Plugin doesn't mistakenly nag to run pub.
     return flutterPackagesGet(root).startInModuleConsole(module, root::refresh, null);
   }
 

flutter-idea/src/io/flutter/sdk/FlutterSdkUtil.java

@@ -254,7 +254,7 @@ public static void enableDartSdk(@NotNull final Project project) {
   }
 
   /**
-   * Parse any .packages file and infer the location of the Flutter SDK from that.
+   * Parse packages meta-data file and infer the location of the Flutter SDK from that.
    */
   @Nullable
   public static String guessFlutterSdkFromPackagesFile(@NotNull Module module) {