////////////////////////////////////////////////////////////////////////////////
   // checkstyle: Checks Java source code for adherence to a set of rules.
   // Copyright (C) 2001-2019 the original author or authors.
   //
   // This library is free software; you can redistribute it and/or
   // modify it under the terms of the GNU Lesser General Public
   // License as published by the Free Software Foundation; either
   // version 2.1 of the License, or (at your option) any later version.
   //
  // This library 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
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.checks.imports;
  
  import java.util.Locale;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.FullIdent;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
  
  /**
   * <p>
   * Checks the ordering/grouping of imports. Features are:
   * </p>
   * <ul>
   * <li>
   * groups type/static imports: ensures that groups of imports come in a specific order
   * (e.g., java. comes first, javax. comes second, then everything else)
   * </li>
   * <li>
   * adds a separation between type import groups : ensures that a blank line sit between each group
   * </li>
   * <li>
   * type/static import groups aren't separated internally: ensures that each group aren't separated
   * internally by blank line or comment
   * </li>
   * <li>
   * sorts type/static imports inside each group: ensures that imports within each group are in
   * lexicographic order
   * </li>
   * <li>
   * sorts according to case: ensures that the comparison between imports is case sensitive, in
   * <a href="https://en.wikipedia.org/wiki/ASCII#Order">ASCII sort order</a>
   * </li>
   * <li>
   * arrange static imports: ensures the relative order between type imports and static imports
   * (see <a href="property_types.html#importOrder">import orders</a>)
   * </li>
   * </ul>
   * <ul>
   * <li>
   * Property {@code option} - specify policy on the relative order between type imports and static
   * imports.
   * Default value is {@code under}.
   * </li>
   * <li>
   * Property {@code groups} - specify list of <b>type import</b> groups (every group identified
   * either by a common prefix string, or by a regular expression enclosed in forward slashes
   * (e.g. {@code /regexp/}). All type imports, which does not match any group, falls into an
   * additional group, located at the end.
   * Thus, the empty list of type groups (the default value) means one group for all type imports.
   * Default value is {@code {}}.
   * </li>
   * <li>
   * Property {@code ordered} - control whether type imports within each group should be
   * sorted.
   * It doesn't affect sorting for static imports.
   * Default value is true.
   * </li>
   * <li>
   * Property {@code separated} - control whether type import groups should be separated
   * by, at least, one blank line or comment and aren't separated internally.
   * It doesn't affect separations for static imports.
   * Default value is false.
   * </li>
   * <li>
   * Property {@code separatedStaticGroups} - control whether static import groups should
   * be separated by, at least, one blank line or comment and aren't separated internally.
   * This property has effect only when the property {@code option} is is set to {@code top}
   * or {@code bottom}.
   * Default value is false.
   * </li>
   * <li>
   * Property {@code caseSensitive} - control whether string comparison should be case
   * sensitive or not. Case sensitive sorting is in
   * <a href="https://en.wikipedia.org/wiki/ASCII#Order">ASCII sort order</a>.
   * It affects both type imports and static imports.
  * Default value is true.
  * </li>
  * <li>
  * Property {@code staticGroups} - specify list of <b>static</b> import groups (every group
  * identified either by a common prefix string, or by a regular expression enclosed in forward
  * slashes (e.g. {@code /regexp/}). All static imports, which does not match any group, falls into
  * an additional group, located at the end. Thus, the empty list of static groups (the default
  * value) means one group for all static imports. This property has effect only when the property
  * {@code option} is set to {@code top} or {@code bottom}.
  * Default value is {@code {}}.
  * </li>
  * <li>
  * Property {@code sortStaticImportsAlphabetically} - control whether
  * <b>static imports</b> located at <b>top</b> or <b>bottom</b> are sorted within the group.
  * Default value is false.
  * </li>
  * <li>
  * Property {@code useContainerOrderingForStatic} - control whether to use container
  * ordering (Eclipse IDE term) for static imports or not.
  * Default value is false.
  * </li>
  * <li>
  * Property {@code tokens} - tokens to check
  * Default value is:
  * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#STATIC_IMPORT">
  * STATIC_IMPORT</a>.
  * </li>
  * </ul>
  * <p>
  * To configure the check so that it matches default Eclipse formatter configuration
  * (tested on Kepler and Luna releases):
  * </p>
  * <ul>
  * <li>
  * group of static imports is on the top
  * </li>
  * <li>
  * groups of type imports: "java" and "javax" packages first, then "org" and then all other imports
  * </li>
  * <li>
  * imports will be sorted in the groups
  * </li>
  * <li>
  * groups are separated by, at least, one blank line and aren't separated internally
  * </li>
  * </ul>
  * <p>
  * Notes:
  * </p>
  * <ul>
  * <li>
  * "com" package is not mentioned on configuration, because it is ignored by Eclipse Kepler and Luna
  * (looks like Eclipse defect)
  * </li>
  * <li>
  * configuration below doesn't work in all 100% cases due to inconsistent behavior prior to
  * Mars release, but covers most scenarios
  * </li>
  * </ul>
  * <pre>
  * &lt;module name=&quot;ImportOrder&quot;&gt;
  *   &lt;property name=&quot;groups&quot; value=&quot;/^java\./,javax,org&quot;/&gt;
  *   &lt;property name=&quot;ordered&quot; value=&quot;true&quot;/&gt;
  *   &lt;property name=&quot;separated&quot; value=&quot;true&quot;/&gt;
  *   &lt;property name=&quot;option&quot; value=&quot;above&quot;/&gt;
  *   &lt;property name=&quot;sortStaticImportsAlphabetically&quot; value=&quot;true&quot;/&gt;
  * &lt;/module&gt;
  * </pre>
  * <p>
  * To configure the check so that it matches default Eclipse formatter configuration
  * (tested on Mars release):
  * </p>
  * <ul>
  * <li>
  * group of static imports is on the top
  * </li>
  * <li>
  * groups of type imports: "java" and "javax" packages first, then "org" and "com",
  * then all other imports as one group
  * </li>
  * <li>
  * imports will be sorted in the groups
  * </li>
  * <li>
  * groups are separated by, at least, one blank line and aren't separated internally
  * </li>
  * </ul>
  * <pre>
  * &lt;module name=&quot;ImportOrder&quot;&gt;
  *   &lt;property name=&quot;groups&quot; value=&quot;/^java\./,javax,org,com&quot;/&gt;
  *   &lt;property name=&quot;ordered&quot; value=&quot;true&quot;/&gt;
  *   &lt;property name=&quot;separated&quot; value=&quot;true&quot;/&gt;
  *   &lt;property name=&quot;option&quot; value=&quot;above&quot;/&gt;
  *   &lt;property name=&quot;sortStaticImportsAlphabetically&quot; value=&quot;true&quot;/&gt;
  * &lt;/module&gt;
  * </pre>
  * <p>
  * To configure the check so that it matches default IntelliJ IDEA formatter configuration
  * (tested on v2018.2):
  * </p>
  * <ul>
  * <li>
  * group of static imports is on the bottom
  * </li>
  * <li>
  * groups of type imports: all imports except of "javax" and "java", then "javax" and "java"
  * </li>
  * <li>
  * imports will be sorted in the groups
  * </li>
  * <li>
  * groups are separated by, at least, one blank line and aren't separated internally
  * </li>
  * </ul>
  * <p>
  * Note: a <a href="config_filters.html#SuppressionXpathSingleFilter">
  * suppression xpath single filter</a> is needed because
  * IDEA has no blank line between "javax" and "java".
  * ImportOrder has a limitation by design to enforce an empty line between groups ("java", "javax").
  * There is no flexibility to enforce empty lines between some groups and no empty lines between
  * other groups.
  * </p>
  * <p>
  * Note: "separated" option is disabled because IDEA default has blank line between "java" and
  * static imports, and no blank line between "javax" and "java".
  * </p>
  * <pre>
  * &lt;module name=&quot;ImportOrder&quot;&gt;
  *   &lt;property name=&quot;groups&quot; value=&quot;*,javax,java&quot;/&gt;
  *   &lt;property name=&quot;ordered&quot; value=&quot;true&quot;/&gt;
  *   &lt;property name=&quot;separated&quot; value=&quot;false&quot;/&gt;
  *   &lt;property name=&quot;option&quot; value=&quot;bottom&quot;/&gt;
  *   &lt;property name=&quot;sortStaticImportsAlphabetically&quot; value=&quot;true&quot;/&gt;
  * &lt;/module&gt;
  * &lt;module name="SuppressionXpathSingleFilter"&gt;
  *   &lt;property name="checks" value="ImportOrder"/&gt;
  *   &lt;property name="message" value="^'java\..*'.*"/&gt;
  * &lt;/module&gt;
  * </pre>
  * <p>
  * To configure the check so that it matches default NetBeans formatter configuration
  * (tested on v8):
  * </p>
  * <ul>
  * <li>
  * groups of type imports are not defined, all imports will be sorted as a one group
  * </li>
  * <li>
  * static imports are not separated, they will be sorted along with other imports
  * </li>
  * </ul>
  * <pre>
  * &lt;module name=&quot;ImportOrder&quot;&gt;
  *   &lt;property name=&quot;option&quot; value=&quot;inflow&quot;/&gt;
  * &lt;/module&gt;
  * </pre>
  * <p>
  * Group descriptions enclosed in slashes are interpreted as regular expressions.
  * If multiple groups match, the one matching a longer substring of the imported name
  * will take precedence, with ties broken first in favor of earlier matches and finally
  * in favor of the first matching group.
  * </p>
  * <p>
  * There is always a wildcard group to which everything not in a named group belongs.
  * If an import does not match a named group, the group belongs to this wildcard group.
  * The wildcard group position can be specified using the {@code *} character.
  * </p>
  * <p>
  * Check also has on option making it more flexible: <b>sortStaticImportsAlphabetically</b>
  * - sets whether static imports grouped by <b>top</b> or <b>bottom</b> option should be sorted
  * alphabetically or not, default value is <b>false</b>. It is applied to static imports grouped
  * with <b>top</b> or <b>bottom</b> options. This option is helping in reconciling of this
  * Check and other tools like Eclipse's Organize Imports feature.
  * </p>
  * <p>
  * To configure the Check allows static imports grouped to the <b>top</b> being sorted
  * alphabetically:
  * </p>
  * <pre>
  * &lt;module name=&quot;ImportOrder&quot;&gt;
  *   &lt;property name=&quot;sortStaticImportsAlphabetically&quot; value=&quot;true&quot;/&gt;
  *   &lt;property name=&quot;option&quot; value=&quot;top&quot;/&gt;
  * &lt;/module&gt;
  * </pre>
  * <pre>
  * import static java.lang.Math.PI;
  * import static java.lang.Math.abs; // OK, alphabetical case sensitive ASCII order, 'P' &lt; 'a'
  * import static org.abego.treelayout.Configuration.AlignmentInLevel; // OK, alphabetical order
  *
  * import org.abego.*;
  *
  * import java.util.Set; //  Wrong order for 'java.util.Set' import.
  *
  * public class SomeClass { ... }
  * </pre>
  * <p>
  * To configure the Check with groups of static imports:
  * </p>
  * <pre>
  * &lt;module name=&quot;ImportOrder&quot;&gt;
  *   &lt;property name=&quot;staticGroups&quot; value=&quot;org,java&quot;/&gt;
  *   &lt;property name=&quot;sortStaticImportsAlphabetically&quot; value=&quot;true&quot;/&gt;
  * &lt;/module&gt;
  * </pre>
  * <pre>
  * import static org.abego.treelayout.Configuration.AlignmentInLevel; // Group 1
  * import static java.lang.Math.abs; // Group 2
  * import static java.lang.String.format; // Group 2
  * import static com.google.common.primitives.Doubles.BYTES; // Group "everything else"
  *
  * public class SomeClass { ... }
  * </pre>
  * <p>
  * The following example shows the idea of 'useContainerOrderingForStatic' option that is
  * useful for Eclipse IDE users to match ordering validation.
  * This is how the import comparison works for static imports: we first compare
  * the container of the static import, container is the type enclosing the static element
  * being imported. When the result of the comparison is 0 (containers are equal),
  * we compare the fully qualified import names.
  * For e.g. this is what is considered to be container names for the given example:
  *
  * import static HttpConstants.COLON     =&gt; HttpConstants
  * import static HttpHeaders.addHeader   =&gt; HttpHeaders
  * import static HttpHeaders.setHeader   =&gt; HttpHeaders
  * import static HttpHeaders.Names.DATE  =&gt; HttpHeaders.Names
  *
  * According to this logic, HttpHeaders.Names should come after HttpHeaders.
  * </p>
  * <p>
  * Example for {@code useContainerOrderingForStatic=true}
  * </p>
  * <pre>
  * &lt;module name=&quot;ImportOrder&quot;&gt;
  *   &lt;property name=&quot;useContainerOrderingForStatic&quot; value=&quot;true&quot;/&gt;
  *   &lt;property name=&quot;ordered&quot; value=&quot;true&quot;/&gt;
  *   &lt;property name=&quot;option&quot; value=&quot;top&quot;/&gt;
  *   &lt;property name=&quot;caseSensitive&quot; value=&quot;false&quot;/&gt;
  *   &lt;property name=&quot;sortStaticImportsAlphabetically&quot; value=&quot;true&quot;/&gt;
  * &lt;/module&gt;
  * </pre>
  * <pre>
  * import static io.netty.handler.codec.http.HttpConstants.COLON;
  * import static io.netty.handler.codec.http.HttpHeaders.addHeader;
  * import static io.netty.handler.codec.http.HttpHeaders.setHeader;
  * import static io.netty.handler.codec.http.HttpHeaders.Names.DATE;
  *
  * public class InputEclipseStaticImportsOrder { }
  * </pre>
  * <p>
  * Example for {@code useContainerOrderingForStatic=false}
  * </p>
  * <pre>
  * &lt;module name=&quot;ImportOrder&quot;&gt;
  *   &lt;property name=&quot;useContainerOrderingForStatic&quot; value=&quot;false&quot;/&gt;
  *   &lt;property name=&quot;ordered&quot; value=&quot;true&quot;/&gt;
  *   &lt;property name=&quot;option&quot; value=&quot;top&quot;/&gt;
  *   &lt;property name=&quot;caseSensitive&quot; value=&quot;false&quot;/&gt;
  *   &lt;property name=&quot;sortStaticImportsAlphabetically&quot; value=&quot;true&quot;/&gt;
  * &lt;/module&gt;
  * </pre>
  * <pre>
  * import static io.netty.handler.codec.http.HttpConstants.COLON;
  * import static io.netty.handler.codec.http.HttpHeaders.addHeader;
  * import static io.netty.handler.codec.http.HttpHeaders.setHeader;
  * import static io.netty.handler.codec.http.HttpHeaders.Names.DATE; // violation
  *
  * public class InputEclipseStaticImportsOrder { }
  * </pre>
  *
  * @since 3.2
  */
 @FileStatefulCheck
 public class ImportOrderCheck
     extends AbstractCheck {
 
     /**
      * A key is pointing to the warning message text in "messages.properties"
      * file.
      */
     public static final String MSG_SEPARATION = "import.separation";
 
     /**
      * A key is pointing to the warning message text in "messages.properties"
      * file.
      */
     public static final String MSG_ORDERING = "import.ordering";
 
     /**
      * A key is pointing to the warning message text in "messages.properties"
      * file.
      */
     public static final String MSG_SEPARATED_IN_GROUP = "import.groups.separated.internally";
 
     /** The special wildcard that catches all remaining groups. */
     private static final String WILDCARD_GROUP_NAME = "*";
 
     /** Empty array of pattern type needed to initialize check. */
     private static final Pattern[] EMPTY_PATTERN_ARRAY = new Pattern[0];
 
     /**
      * Specify list of <b>type import</b> groups (every group identified either by a common prefix
      * string, or by a regular expression enclosed in forward slashes (e.g. {@code /regexp/}).
      * All type imports, which does not match any group, falls into an additional group,
      * located at the end. Thus, the empty list of type groups (the default value) means one group
      * for all type imports.
      */
     private Pattern[] groups = EMPTY_PATTERN_ARRAY;
 
     /**
      * Specify list of <b>static</b> import groups (every group identified either by a common prefix
      * string, or by a regular expression enclosed in forward slashes (e.g. {@code /regexp/}).
      * All static imports, which does not match any group, falls into an additional group, located
      * at the end. Thus, the empty list of static groups (the default value) means one group for all
      * static imports. This property has effect only when the property {@code option} is set to
      * {@code top} or {@code bottom}.
      */
     private Pattern[] staticGroups = EMPTY_PATTERN_ARRAY;
 
     /**
      * Control whether type import groups should be separated by, at least, one blank
      * line or comment and aren't separated internally. It doesn't affect separations for static
      * imports.
      */
     private boolean separated;
 
     /**
      * Control whether static import groups should be separated by, at least, one blank
      * line or comment and aren't separated internally. This property has effect only when the
      * property {@code option} is is set to {@code top} or {@code bottom}.
      */
     private boolean separatedStaticGroups;
 
     /**
      * Control whether type imports within each group should be sorted.
      * It doesn't affect sorting for static imports.
      */
     private boolean ordered = true;
 
     /**
      * Control whether string comparison should be case sensitive or not. Case sensitive
      * sorting is in <a href="https://en.wikipedia.org/wiki/ASCII#Order">ASCII sort order</a>.
      * It affects both type imports and static imports.
      */
     private boolean caseSensitive = true;
 
     /** Last imported group. */
     private int lastGroup;
     /** Line number of last import. */
     private int lastImportLine;
     /** Name of last import. */
     private String lastImport;
     /** If last import was static. */
     private boolean lastImportStatic;
     /** Whether there was any imports. */
     private boolean beforeFirstImport;
     /** Whether static and type import groups should be split apart.
      * When the {@code option} property is set to {@code INFLOW}, {@code BELOW} or {@code UNDER},
      * both the type and static imports use the properties {@code groups} and {@code separated}.
      * When the {@code option} property is set to {@code TOP} or {@code BOTTOM}, static imports
      * uses the properties {@code staticGroups} and {@code separatedStaticGroups}.
      **/
     private boolean staticImportsApart;
 
     /**
      * Control whether <b>static imports</b> located at <b>top</b> or <b>bottom</b> are
      * sorted within the group.
      */
     private boolean sortStaticImportsAlphabetically;
 
     /**
      * Control whether to use container ordering (Eclipse IDE term) for static imports
      * or not.
      */
     private boolean useContainerOrderingForStatic;
 
     /**
      * Specify policy on the relative order between type imports and static imports.
      */
     private ImportOrderOption option = ImportOrderOption.UNDER;
 
     /**
      * Setter to specify policy on the relative order between type imports and static imports.
      * @param optionStr string to decode option from
      * @throws IllegalArgumentException if unable to decode
      */
     public void setOption(String optionStr) {
         option = ImportOrderOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
     }
 
     /**
      * Setter to specify list of <b>type import</b> groups (every group identified either by a
      * common prefix string, or by a regular expression enclosed in forward slashes
      * (e.g. {@code /regexp/}). All type imports, which does not match any group, falls into an
      * additional group, located at the end. Thus, the empty list of type groups (the default value)
      * means one group for all type imports.
      *
      * @param packageGroups a comma-separated list of package names/prefixes.
      */
     public void setGroups(String... packageGroups) {
         groups = compilePatterns(packageGroups);
     }
 
     /**
      * Setter to specify list of <b>static</b> import groups (every group identified either by a
      * common prefix string, or by a regular expression enclosed in forward slashes
      * (e.g. {@code /regexp/}). All static imports, which does not match any group, falls into an
      * additional group, located at the end. Thus, the empty list of static groups (the default
      * value) means one group for all static imports. This property has effect only when
      * the property {@code option} is set to {@code top} or {@code bottom}.
      *
      * @param packageGroups a comma-separated list of package names/prefixes.
      */
     public void setStaticGroups(String... packageGroups) {
         staticGroups = compilePatterns(packageGroups);
     }
 
     /**
      * Setter to control whether type imports within each group should be sorted.
      * It doesn't affect sorting for static imports.
      *
      * @param ordered
      *            whether lexicographic ordering of imports within a group
      *            required or not.
      */
     public void setOrdered(boolean ordered) {
         this.ordered = ordered;
     }
 
     /**
      * Setter to control whether type import groups should be separated by, at least,
      * one blank line or comment and aren't separated internally.
      * It doesn't affect separations for static imports.
      *
      * @param separated
      *            whether groups should be separated by one blank line or comment.
      */
     public void setSeparated(boolean separated) {
         this.separated = separated;
     }
 
     /**
      * Setter to control whether static import groups should be separated by, at least,
      * one blank line or comment and aren't separated internally.
      * This property has effect only when the property
      * {@code option} is is set to {@code top} or {@code bottom}.
      *
      * @param separatedStaticGroups
      *            whether groups should be separated by one blank line or comment.
      */
     public void setSeparatedStaticGroups(boolean separatedStaticGroups) {
         this.separatedStaticGroups = separatedStaticGroups;
     }
 
     /**
      * Setter to control whether string comparison should be case sensitive or not.
      * Case sensitive sorting is in
      * <a href="https://en.wikipedia.org/wiki/ASCII#Order">ASCII sort order</a>.
      * It affects both type imports and static imports.
      * @param caseSensitive
      *            whether string comparison should be case sensitive.
      */
     public void setCaseSensitive(boolean caseSensitive) {
         this.caseSensitive = caseSensitive;
     }
 
     /**
      * Setter to control whether <b>static imports</b> located at <b>top</b> or
      * <b>bottom</b> are sorted within the group.
      * @param sortAlphabetically true or false.
      */
     public void setSortStaticImportsAlphabetically(boolean sortAlphabetically) {
         sortStaticImportsAlphabetically = sortAlphabetically;
     }
 
     /**
      * Setter to control whether to use container ordering (Eclipse IDE term) for static
      * imports or not.
      * @param useContainerOrdering whether to use container ordering for static imports or not.
      */
     public void setUseContainerOrderingForStatic(boolean useContainerOrdering) {
         useContainerOrderingForStatic = useContainerOrdering;
     }
 
     @Override
     public int[] getDefaultTokens() {
         return getAcceptableTokens();
     }
 
     @Override
     public int[] getAcceptableTokens() {
         return new int[] {TokenTypes.IMPORT, TokenTypes.STATIC_IMPORT};
     }
 
     @Override
     public int[] getRequiredTokens() {
         return new int[] {TokenTypes.IMPORT};
     }
 
     @Override
     public void beginTree(DetailAST rootAST) {
         lastGroup = Integer.MIN_VALUE;
         lastImportLine = Integer.MIN_VALUE;
         lastImport = "";
         lastImportStatic = false;
         beforeFirstImport = true;
         staticImportsApart =
             option == ImportOrderOption.TOP || option == ImportOrderOption.BOTTOM;
     }
 
     // -@cs[CyclomaticComplexity] SWITCH was transformed into IF-ELSE.
     @Override
     public void visitToken(DetailAST ast) {
         final int line = ast.getLineNo();
         final FullIdent ident;
         final boolean isStatic;
 
         if (ast.getType() == TokenTypes.IMPORT) {
             ident = FullIdent.createFullIdentBelow(ast);
             isStatic = false;
         }
         else {
             ident = FullIdent.createFullIdent(ast.getFirstChild()
                     .getNextSibling());
             isStatic = true;
         }
 
         // using set of IF instead of SWITCH to analyze Enum options to satisfy coverage.
         // https://github.com/checkstyle/checkstyle/issues/1387
         if (option == ImportOrderOption.TOP || option == ImportOrderOption.ABOVE) {
             final boolean isStaticAndNotLastImport = isStatic && !lastImportStatic;
             doVisitToken(ident, isStatic, isStaticAndNotLastImport, line);
         }
         else if (option == ImportOrderOption.BOTTOM || option == ImportOrderOption.UNDER) {
             final boolean isLastImportAndNonStatic = lastImportStatic && !isStatic;
             doVisitToken(ident, isStatic, isLastImportAndNonStatic, line);
         }
         else if (option == ImportOrderOption.INFLOW) {
             // "previous" argument is useless here
             doVisitToken(ident, isStatic, true, line);
         }
         else {
             throw new IllegalStateException(
                     "Unexpected option for static imports: " + option);
         }
 
         lastImportLine = ast.findFirstToken(TokenTypes.SEMI).getLineNo();
         lastImportStatic = isStatic;
         beforeFirstImport = false;
     }
 
     /**
      * Shares processing...
      *
      * @param ident the import to process.
      * @param isStatic whether the token is static or not.
      * @param previous previous non-static but current is static (above), or
      *                  previous static but current is non-static (under).
      * @param line the line of the current import.
      */
     private void doVisitToken(FullIdent ident, boolean isStatic, boolean previous, int line) {
         final String name = ident.getText();
         final int groupIdx = getGroupNumber(isStatic && staticImportsApart, name);
 
         if (groupIdx > lastGroup) {
             if (!beforeFirstImport && line - lastImportLine < 2 && needSeparator(isStatic)) {
                 log(line, MSG_SEPARATION, name);
             }
         }
         else if (groupIdx == lastGroup) {
             doVisitTokenInSameGroup(isStatic, previous, name, line);
         }
         else {
             log(line, MSG_ORDERING, name);
         }
         if (isSeparatorInGroup(groupIdx, isStatic, line)) {
             log(line, MSG_SEPARATED_IN_GROUP, name);
         }
 
         lastGroup = groupIdx;
         lastImport = name;
     }
 
     /**
      * Checks whether import groups should be separated.
      * @param isStatic whether the token is static or not.
      * @return true if imports groups should be separated.
      */
     private boolean needSeparator(boolean isStatic) {
         final boolean typeImportSeparator = !isStatic && separated;
         final boolean staticImportSeparator;
         if (staticImportsApart) {
             staticImportSeparator = isStatic && separatedStaticGroups;
         }
         else {
             staticImportSeparator = isStatic && separated;
         }
         final boolean separatorBetween = isStatic != lastImportStatic
             && (separated || separatedStaticGroups) && staticImportsApart;
 
         return typeImportSeparator || staticImportSeparator || separatorBetween;
     }
 
     /**
      * Checks whether imports group separated internally.
      * @param groupIdx group number.
      * @param isStatic whether the token is static or not.
      * @param line the line of the current import.
      * @return true if imports group are separated internally.
      */
     private boolean isSeparatorInGroup(int groupIdx, boolean isStatic, int line) {
         final boolean inSameGroup = groupIdx == lastGroup;
         return (inSameGroup || !needSeparator(isStatic)) && isSeparatorBeforeImport(line);
     }
 
     /**
      * Checks whether there is any separator before current import.
      * @param line the line of the current import.
      * @return true if there is separator before current import which isn't the first import.
      */
     private boolean isSeparatorBeforeImport(int line) {
         return !beforeFirstImport && line - lastImportLine > 1;
     }
 
     /**
      * Shares processing...
      *
      * @param isStatic whether the token is static or not.
      * @param previous previous non-static but current is static (above), or
      *     previous static but current is non-static (under).
      * @param name the name of the current import.
      * @param line the line of the current import.
      */
     private void doVisitTokenInSameGroup(boolean isStatic,
             boolean previous, String name, int line) {
         if (ordered) {
             if (option == ImportOrderOption.INFLOW) {
                 if (isWrongOrder(name, isStatic)) {
                     log(line, MSG_ORDERING, name);
                 }
             }
             else {
                 final boolean shouldFireError =
                     // previous non-static but current is static (above)
                     // or
                     // previous static but current is non-static (under)
                     previous
                         ||
                         // current and previous static or current and
                         // previous non-static
                         lastImportStatic == isStatic
                     && isWrongOrder(name, isStatic);
 
                 if (shouldFireError) {
                     log(line, MSG_ORDERING, name);
                 }
             }
         }
     }
 
     /**
      * Checks whether import name is in wrong order.
      * @param name import name.
      * @param isStatic whether it is a static import name.
      * @return true if import name is in wrong order.
      */
     private boolean isWrongOrder(String name, boolean isStatic) {
         final boolean result;
         if (isStatic) {
             if (useContainerOrderingForStatic) {
                 result = compareContainerOrder(lastImport, name, caseSensitive) > 0;
             }
             else if (staticImportsApart) {
                 result = sortStaticImportsAlphabetically
                     && compare(lastImport, name, caseSensitive) > 0;
             }
             else {
                 result = compare(lastImport, name, caseSensitive) > 0;
             }
         }
         else {
             // out of lexicographic order
             result = compare(lastImport, name, caseSensitive) > 0;
         }
         return result;
     }
 
     /**
      * Compares two import strings.
      * We first compare the container of the static import, container being the type enclosing
      * the static element being imported. When this returns 0, we compare the qualified
      * import name. For e.g. this is what is considered to be container names:
      * <p>
      * import static HttpConstants.COLON     => HttpConstants
      * import static HttpHeaders.addHeader   => HttpHeaders
      * import static HttpHeaders.setHeader   => HttpHeaders
      * import static HttpHeaders.Names.DATE  => HttpHeaders.Names
      * </p>
      * <p>
      * According to this logic, HttpHeaders.Names would come after HttpHeaders.
      *
      * For more details, see <a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=473629#c3">
      * static imports comparison method</a> in Eclipse.
      * </p>
      *
      * @param importName1 first import name.
      * @param importName2 second import name.
      * @param caseSensitive whether the comparison of fully qualified import names is case
      *                      sensitive.
      * @return the value {@code 0} if str1 is equal to str2; a value
      *         less than {@code 0} if str is less than the str2 (container order
      *         or lexicographical); and a value greater than {@code 0} if str1 is greater than str2
      *         (container order or lexicographically).
      */
     private static int compareContainerOrder(String importName1, String importName2,
                                              boolean caseSensitive) {
         final String container1 = getImportContainer(importName1);
         final String container2 = getImportContainer(importName2);
         final int compareContainersOrderResult;
         if (caseSensitive) {
             compareContainersOrderResult = container1.compareTo(container2);
         }
         else {
             compareContainersOrderResult = container1.compareToIgnoreCase(container2);
         }
         final int result;
         if (compareContainersOrderResult == 0) {
             result = compare(importName1, importName2, caseSensitive);
         }
         else {
             result = compareContainersOrderResult;
         }
         return result;
     }
 
     /**
      * Extracts import container name from fully qualified import name.
      * An import container name is the type which encloses the static element being imported.
      * For example, HttpConstants, HttpHeaders, HttpHeaders.Names are import container names:
      * <p>
      * import static HttpConstants.COLON     => HttpConstants
      * import static HttpHeaders.addHeader   => HttpHeaders
      * import static HttpHeaders.setHeader   => HttpHeaders
      * import static HttpHeaders.Names.DATE  => HttpHeaders.Names
      * </p>
      * @param qualifiedImportName fully qualified import name.
      * @return import container name.
      */
     private static String getImportContainer(String qualifiedImportName) {
         final int lastDotIndex = qualifiedImportName.lastIndexOf('.');
         return qualifiedImportName.substring(0, lastDotIndex);
     }
 
     /**
      * Finds out what group the specified import belongs to.
      *
      * @param isStatic whether the token is static or not.
      * @param name the import name to find.
      * @return group number for given import name.
      */
     private int getGroupNumber(boolean isStatic, String name) {
         final Pattern[] patterns;
         if (isStatic) {
             patterns = staticGroups;
         }
         else {
             patterns = groups;
         }
 
         int number = getGroupNumber(patterns, name);
 
         if (isStatic && option == ImportOrderOption.BOTTOM) {
             number += groups.length + 1;
         }
         else if (!isStatic && option == ImportOrderOption.TOP) {
             number += staticGroups.length + 1;
         }
         return number;
     }
 
     /**
      * Finds out what group the specified import belongs to.
      *
      * @param patterns groups to check.
      * @param name the import name to find.
      * @return group number for given import name.
      */
     private static int getGroupNumber(Pattern[] patterns, String name) {
         int bestIndex = patterns.length;
         int bestEnd = -1;
         int bestPos = Integer.MAX_VALUE;
 
         // find out what group this belongs in
         // loop over patterns and get index
         for (int i = 0; i < patterns.length; i++) {
             final Matcher matcher = patterns[i].matcher(name);
             if (matcher.find()) {
                 if (matcher.start() < bestPos) {
                     bestIndex = i;
                     bestEnd = matcher.end();
                     bestPos = matcher.start();
                 }
                 else if (matcher.start() == bestPos && matcher.end() > bestEnd) {
                     bestIndex = i;
                     bestEnd = matcher.end();
                 }
             }
         }
         return bestIndex;
     }
 
     /**
      * Compares two strings.
      *
      * @param string1
      *            the first string.
      * @param string2
      *            the second string.
      * @param caseSensitive
      *            whether the comparison is case sensitive.
      * @return the value {@code 0} if string1 is equal to string2; a value
      *         less than {@code 0} if string1 is lexicographically less
      *         than the string2; and a value greater than {@code 0} if
      *         string1 is lexicographically greater than string2.
      */
     private static int compare(String string1, String string2,
             boolean caseSensitive) {
         final int result;
         if (caseSensitive) {
             result = string1.compareTo(string2);
         }
         else {
             result = string1.compareToIgnoreCase(string2);
         }
 
         return result;
     }
 
     /**
      * Compiles the list of package groups and the order they should occur in the file.
      *
      * @param packageGroups a comma-separated list of package names/prefixes.
      * @return array of compiled patterns.
      */
     private static Pattern[] compilePatterns(String... packageGroups) {
         final Pattern[] patterns = new Pattern[packageGroups.length];
 
         for (int i = 0; i < packageGroups.length; i++) {
             String pkg = packageGroups[i];
             final Pattern grp;
 
             // if the pkg name is the wildcard, make it match zero chars
             // from any name, so it will always be used as last resort.
             if (WILDCARD_GROUP_NAME.equals(pkg)) {
                 // matches any package
                 grp = Pattern.compile("");
             }
             else if (CommonUtil.startsWithChar(pkg, '/')) {
                 if (!CommonUtil.endsWithChar(pkg, '/')) {
                     throw new IllegalArgumentException("Invalid group: " + pkg);
                 }
                 pkg = pkg.substring(1, pkg.length() - 1);
                 grp = Pattern.compile(pkg);
             }
             else {
                 final StringBuilder pkgBuilder = new StringBuilder(pkg);
                 if (!CommonUtil.endsWithChar(pkg, '.')) {
                     pkgBuilder.append('.');
                 }
                 grp = Pattern.compile("^" + Pattern.quote(pkgBuilder.toString()));
             }
 
             patterns[i] = grp;
         }
         return patterns;
     }
 
 }