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 package org.netbeans.modules.jackpot30.file.conditionapi;

 import com.sun.source.tree.CompilationUnitTree;

 import com.sun.source.tree.Tree.Kind;

 import com.sun.source.util.TreePath;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.Collections;

 import java.util.EnumSet;

 import java.util.HashMap;

 import java.util.LinkedList;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 import java.util.concurrent.atomic.AtomicInteger;

 import javax.lang.model.SourceVersion;

 import javax.lang.model.element.Element;

 import javax.lang.model.element.ElementKind;

 import javax.lang.model.element.Modifier;

 import javax.lang.model.element.TypeElement;

 import javax.lang.model.type.TypeKind;

 import javax.lang.model.type.TypeMirror;

 import org.netbeans.api.annotations.common.CheckForNull;

 import org.netbeans.api.annotations.common.NonNull;

 import org.netbeans.api.java.queries.SourceLevelQuery;

 import org.netbeans.api.java.source.TreeUtilities;

 import org.netbeans.modules.jackpot30.file.APIAccessor;

 import org.netbeans.modules.jackpot30.spi.Hacks;

 import org.netbeans.modules.jackpot30.spi.HintContext;

 /**

  *

  * @author lahvac

  */

 public class Context {

             final HintContext ctx;

             final List<Map<String, TreePath>> variables = new LinkedList<Map<String, TreePath>>();

             final List<Map<String, Collection<? extends TreePath>>> multiVariables = new LinkedList<Map<String, Collection<? extends TreePath>>>();

             final List<Map<String, String>> variableNames = new LinkedList<Map<String, String>>();

     private final AtomicInteger auxiliaryVariableCounter = new AtomicInteger();

     //XXX: should not be public:

     public Context(HintContext ctx) {

         this.ctx = ctx;

         this.variables.add(Collections.unmodifiableMap(ctx.getVariables()));

         this.multiVariables.add(Collections.unmodifiableMap(ctx.getMultiVariables()));

         this.variableNames.add(Collections.unmodifiableMap(ctx.getVariableNames()));

     }

     public @NonNull SourceVersion sourceVersion() {

         String sourceLevel = SourceLevelQuery.getSourceLevel(ctx.getInfo().getFileObject());

         if (sourceLevel == null) {

             return SourceVersion.latest(); //TODO

         }

         String[] splited = sourceLevel.split("\\.");

         String   spec    = splited[1];

         return SourceVersion.valueOf("RELEASE_"+  spec);//!!!

     }

     public @NonNull Set<Modifier> modifiers(@NonNull Variable variable) {

         final Element e = ctx.getInfo().getTrees().getElement(getSingleVariable(variable));

         if (e == null) {

             return Collections.unmodifiableSet(EnumSet.noneOf(Modifier.class));

         }

         return Collections.unmodifiableSet(e.getModifiers());

     }

     public @CheckForNull ElementKind elementKind(@NonNull Variable variable) {

         final Element e = ctx.getInfo().getTrees().getElement(getSingleVariable(variable));

         if (e == null) {

             return null;

         }

         return e.getKind();

     }

     public @CheckForNull TypeKind typeKind(@NonNull Variable variable) {

         final TypeMirror tm = ctx.getInfo().getTrees().getTypeMirror(getSingleVariable(variable));

         if (tm == null) {

             return null;

         }

         return tm.getKind();

     }

     public @CheckForNull String name(@NonNull Variable variable) {

         final Element e = ctx.getInfo().getTrees().getElement(getSingleVariable(variable));

         if (e == null) {

             return null;

         }

         return e.getSimpleName().toString();

     }

     public @CheckForNull Variable parent(@NonNull Variable variable) {

         TreePath tp = getSingleVariable(variable);

         if (tp.getParentPath() == null) {

             return null;

         }

         return enterAuxiliaryVariable(tp.getParentPath());

     }

     private Variable enterAuxiliaryVariable(TreePath path) {

         String output = "*" + auxiliaryVariableCounter.getAndIncrement();

         variables.get(0).put(output, path);

         return new Variable(output);

     }

     public @NonNull Variable variableForName(@NonNull String variableName) {

         Variable result = new Variable(variableName);

         if (getSingleVariable(result) == null) {

             throw new IllegalStateException("Unknown variable");

         }

         return result;

     }

     public void createRenamed(@NonNull Variable from, @NonNull Variable to, @NonNull String newName) {

         //TODO: check (the variable should not exist)

         variableNames.get(0).put(to.variableName, newName);

         TreePath origVariablePath = getSingleVariable(from);

         TreePath newVariablePath = new TreePath(origVariablePath.getParentPath(), Hacks.createRenameTree(origVariablePath.getLeaf(), newName));

         variables.get(0).put(to.variableName, newVariablePath);

     }

     public boolean isNullLiteral(@NonNull Variable var) {

         TreePath varPath = getSingleVariable(var);

         return varPath.getLeaf().getKind() == Kind.NULL_LITERAL;

     }

     public @NonNull Iterable<? extends Variable> getIndexedVariables(@NonNull Variable multiVariable) {

         Iterable<? extends TreePath> paths = getMultiVariable(multiVariable);

         if (paths == null) {

             throw new IllegalArgumentException("TODO: explanation");

         }

         Collection<Variable> result = new LinkedList<Variable>();

         int index = 0;

         for (TreePath tp : paths) {

             result.add(new Variable(multiVariable.variableName, index++));

         }

         return result;

     }

     public void enterScope() {

         variables.add(0, new HashMap<String, TreePath>());

         multiVariables.add(0, new HashMap<String, Collection<? extends TreePath>>());

         variableNames.add(0, new HashMap<String, String>());

     }

     public void leaveScope() {

         variables.remove(0);

         multiVariables.remove(0);

         variableNames.remove(0);

     }

     Iterable<? extends TreePath> getVariable(Variable v) {

         if (isMultistatementWildcard(v.variableName) && v.index == (-1)) {

             return getMultiVariable(v);

         } else {

             return Collections.singletonList(getSingleVariable(v));

         }

     }

     //XXX: copied from jackpot30.impl.Utilities:

     private static boolean isMultistatementWildcard(/*@NonNull */CharSequence name) {

         return name.charAt(name.length() - 1) == '$';

     }

     //TODO: check if correct variable is provided:

     TreePath getSingleVariable(Variable v) {

         if (v.index == (-1)) {

             for (Map<String, TreePath> map : variables) {

                 if (map.containsKey(v.variableName)) {

                     return map.get(v.variableName);

                 }

             }

             return null;

         } else {

             return new ArrayList<TreePath>(getMultiVariable(v)).get(v.index);

         }

     }

     private Collection<? extends TreePath> getMultiVariable(Variable v) {

         for (Map<String, Collection<? extends TreePath>> multi : multiVariables) {

             if (multi.containsKey(v.variableName)) {

                 return multi.get(v.variableName);

             }

         }

         return null;

     }

     static {

         APIAccessor.IMPL = new APIAccessorImpl();

     }

     /**Returns canonical names of classes that enclose the {@link Variable}.

      * If the given {@link Variable} represents a class, its canonical name is also listed.

      * The names are given from the innermost class to the outermost class.

      *

      * @return the canonical names of the enclosing classes

      */

     public @NonNull Iterable<? extends String> enclosingClasses(Variable forVariable) {

         List<String> result = new ArrayList<String>();

         TreePath path = getSingleVariable(forVariable);

         while (path != null) {

             TreePath current = path;

             path = path.getParentPath();

             if (!TreeUtilities.CLASS_TREE_KINDS.contains(current.getLeaf().getKind())) continue;

             Element e = ctx.getInfo().getTrees().getElement(current);

             if (e == null) continue;

             if (e.getKind().isClass() || e.getKind().isInterface()) {

                 result.add(((TypeElement) e).getQualifiedName().toString());

             }

         }

         return result;

     }

     /**Returns name of package in which the current file is located. Default package

      * is represented by an empty string.

      *

      * @return the name of the enclosing package

      */

     public @NonNull String enclosingPackage() {

         CompilationUnitTree cut = ctx.getInfo().getCompilationUnit();

         return cut.getPackageName() != null ? cut.getPackageName().toString() : "";

     }

     static final class APIAccessorImpl extends APIAccessor {

         @Override

         public TreePath getSingleVariable(Context ctx, Variable var) {

             return ctx.getSingleVariable(var);

         }

         @Override

         public HintContext getHintContext(Context ctx) {

             return ctx.ctx;

         }

         @Override

         public Map<String, TreePath> getVariables(Context ctx) {

             Map<String, TreePath> result = new HashMap<String, TreePath>();

             for (Map<String, TreePath> m : reverse(ctx.variables)) {

                 result.putAll(m);

             }

             return result;

         }

         @Override

         public Map<String, Collection<? extends TreePath>> getMultiVariables(Context ctx) {

             Map<String, Collection<? extends TreePath>> result = new HashMap<String, Collection<? extends TreePath>>();

             for (Map<String, Collection<? extends TreePath>> m : reverse(ctx.multiVariables)) {

                 result.putAll(m);

             }

             return result;

         }

         @Override

         public Map<String, String> getVariableNames(Context ctx) {

             Map<String, String> result = new HashMap<String, String>();

             for (Map<String, String> m : reverse(ctx.variableNames)) {

                 result.putAll(m);

             }

             return result;

         }

         private <T> List<T> reverse(List<T> original) {

             List<T> result = new LinkedList<T>();

             for (T t : original) {

                 result.add(0, t);

             }

             return result;

         }

         @Override

         public Variable enterAuxiliaryVariable(Context ctx, TreePath source) {

             return ctx.enterAuxiliaryVariable(source);

         }

     }

 }