Added library-dependency resolver

arduino-core/src/cc/arduino/contributions/libraries/LibrariesIndex.java

@@ -29,6 +29,7 @@
 
 package cc.arduino.contributions.libraries;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
@@ -98,4 +99,74 @@ public abstract class LibrariesIndex {
     ContributedLibraryReleases rel = new ContributedLibraryReleases(find(name));
     return rel.getInstalled();
   }
+
+  public List<ContributedLibrary> resolveDependeciesOf(ContributedLibrary library) {
+    List<ContributedLibrary> solution = new ArrayList<>();
+    solution.add(library);
+    if (resolveDependeciesOf(solution, library)) {
+      return solution;
+    } else {
+      return null;
+    }
+  }
+
+  public boolean resolveDependeciesOf(List<ContributedLibrary> solution,
+                                      ContributedLibrary library) {
+    List<ContributedLibraryDependency> requirements = library.getRequires();
+    if (requirements == null) {
+      // No deps for this library, great!
+      return true;
+    }
+
+    for (ContributedLibraryDependency dep : requirements) {
+
+      // If the current solution already contains this dependency, skip over
+      boolean alreadyInSolution = false;
+      for (ContributedLibrary c : solution) {
+        if (c.getName().equals(dep.getName()))
+          alreadyInSolution = true;
+      }
+      if (alreadyInSolution)
+        continue;
+
+      // Generate possible matching dependencies
+      List<ContributedLibrary> possibleDeps = findMatchingDependencies(dep);
+
+      // If there are no dependencies available add as "missing" lib
+      if (possibleDeps.isEmpty()) {
+        solution.add(new UnavailableContributedLibrary(dep));
+        continue;
+      }
+
+      // Pick the latest version among possible deps
+      ContributedLibrary last = possibleDeps.stream()
+          .reduce((a, b) -> b.isBefore(a) ? a : b).get();
+
+      // Add dependecy to the solution and process recursively
+      solution.add(last);
+      if (!resolveDependeciesOf(solution, last)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  private List<ContributedLibrary> findMatchingDependencies(ContributedLibraryDependency dep) {
+    List<ContributedLibrary> available = find(dep.getName());
+    if (dep.getVersionRequired() == null || dep.getVersionRequired().isEmpty())
+      return available;
+
+    // XXX: The following part is actually never reached. The use of version
+    // constraints requires a much complex backtracking algorithm, the following
+    // is just a draft placeholder.
+
+//    List<ContributedLibrary> match = available.stream()
+//        // TODO: add more complex version comparators (> >= < <= ~ 1.0.* 1.*...)
+//        .filter(candidate -> candidate.getParsedVersion()
+//            .equals(dep.getVersionRequired()))
+//        .collect(Collectors.toList());
+//    return match;
+
+    return available;
+  }
 }

arduino-core/src/cc/arduino/contributions/libraries/UnavailableContributedLibrary.java

@@ -0,0 +1,142 @@
+/*
+ * This file is part of Arduino.
+ *
+ * Copyright 2017 Arduino LLC (http://www.arduino.cc/)
+ *
+ * Arduino is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ */
+
+package cc.arduino.contributions.libraries;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class UnavailableContributedLibrary extends ContributedLibrary {
+
+  private String name;
+  private String version;
+
+  public UnavailableContributedLibrary(ContributedLibraryDependency dependency) {
+    this(dependency.getName(), dependency.getVersionRequired());
+  }
+
+  public UnavailableContributedLibrary(String _name, String _version) {
+    name = _name;
+    version = _version;
+  }
+
+  @Override
+  public String getName() {
+    return name;
+  }
+
+  @Override
+  public String getMaintainer() {
+    return "Unknown";
+  }
+
+  @Override
+  public String getAuthor() {
+    return "Unknown";
+  }
+
+  @Override
+  public String getWebsite() {
+    return "Unknown";
+  }
+
+  @Override
+  public String getCategory() {
+    return "Uncategorized";
+  }
+
+  @Override
+  public void setCategory(String category) {
+  }
+
+  @Override
+  public String getLicense() {
+    return "Unknown";
+  }
+
+  @Override
+  public String getParagraph() {
+    return "";
+  }
+
+  @Override
+  public String getSentence() {
+    return "";
+  }
+
+  @Override
+  public List<String> getArchitectures() {
+    return new ArrayList<>();
+  }
+
+  @Override
+  public List<String> getTypes() {
+    return new ArrayList<>();
+  }
+
+  @Override
+  public List<ContributedLibraryDependency> getRequires() {
+    return new ArrayList<>();
+  }
+
+  @Override
+  public String getUrl() {
+    return "";
+  }
+
+  @Override
+  public String getVersion() {
+    return version;
+  }
+
+  @Override
+  public String getChecksum() {
+    return "";
+  }
+
+  @Override
+  public long getSize() {
+    return 0;
+  }
+
+  @Override
+  public String getArchiveFileName() {
+    return "";
+  }
+
+  @Override
+  public String toString() {
+    return "!" + super.toString();
+  }
+
+  @Override
+  public List<String> getProvidesIncludes() {
+    return new ArrayList<>();
+  }
+}