plugins/maven/src/main/java/org/jetbrains/idea/maven/project/MavenArtifactIndex.java

package org.jetbrains.idea.maven.project;

import com.intellij.openapi.util.Comparing;
import com.intellij.util.SmartList;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.idea.maven.dom.DependencyConflictId;
import org.jetbrains.idea.maven.model.MavenArtifact;
import org.jetbrains.idea.maven.model.MavenId;

import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author Sergey Evdokimov
 */
public class MavenArtifactIndex {

  private static final MavenArtifactIndex EMPTY_INDEX = new MavenArtifactIndex(Collections.<String, Map<String, List<MavenArtifact>>>emptyMap());

  private final Map<String, Map<String, List<MavenArtifact>>> myData;

  private MavenArtifactIndex(Map<String, Map<String, List<MavenArtifact>>> data) {
    myData = data;
  }

  public Map<String, Map<String, List<MavenArtifact>>> getData() {
    return myData;
  }

  @NotNull
  public List<MavenArtifact> findArtifacts(@Nullable String groupId, @Nullable String artifactId) {
    Map<String, List<MavenArtifact>> groupMap = myData.get(groupId);
    if (groupMap == null) return Collections.emptyList();

    List<MavenArtifact> res = groupMap.get(artifactId);
    return res == null ? Collections.<MavenArtifact>emptyList() : res;
  }

  @NotNull
  public List<MavenArtifact> findArtifacts(@Nullable MavenId mavenId) {
    if (mavenId == null) return Collections.emptyList();

    return findArtifacts(mavenId.getGroupId(), mavenId.getArtifactId(), mavenId.getVersion());
  }

  @Nullable
  public MavenArtifact findArtifacts(@NotNull DependencyConflictId id) {
    for (MavenArtifact artifact : findArtifacts(id.getGroupId(), id.getArtifactId())) {
      if (id.equals(DependencyConflictId.create(artifact))) {
        return artifact;
      }
    }

    return null;
  }

  @NotNull
  public List<MavenArtifact> findArtifacts(@Nullable String groupId, @Nullable String artifactId, @Nullable String version) {
    Map<String, List<MavenArtifact>> groupMap = myData.get(groupId);
    if (groupMap == null) return Collections.emptyList();

    List<MavenArtifact> artifacts = groupMap.get(artifactId);
    if (artifacts == null) return Collections.emptyList();

    List<MavenArtifact> res = new SmartList<MavenArtifact>();
    for (MavenArtifact artifact : artifacts) {
      if (Comparing.equal(version, artifact.getVersion())) {
        res.add(artifact);
      }
    }

    return res;
  }



  public static MavenArtifactIndex build(@NotNull List<MavenArtifact> dependencies) {
    if (dependencies.isEmpty()) return EMPTY_INDEX;

    Map<String, Map<String, List<MavenArtifact>>> map = new HashMap<String, Map<String, List<MavenArtifact>>>();

    for (MavenArtifact dep : dependencies) {
      String groupId = dep.getGroupId();
      if (groupId == null) continue;

      String artifactId = dep.getArtifactId();
      if (artifactId == null) continue;

      Map<String, List<MavenArtifact>> groupMap = map.get(groupId);
      if (groupMap == null) {
        groupMap = new HashMap<String, List<MavenArtifact>>();
        map.put(groupId, groupMap);
      }

      List<MavenArtifact> artifactList = groupMap.get(artifactId);
      if (artifactList == null) {
        artifactList = new SmartList<MavenArtifact>();
        groupMap.put(artifactId, artifactList);
      }

      artifactList.add(dep);
    }

    return new MavenArtifactIndex(map);
  }

}