/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.tools.javac.util;

import java.util.EnumSet;

import java.util.Locale;

import java.util.Set;

import java.util.stream.Stream;

import javax.tools.Diagnostic;

import javax.tools.JavaFileObject;

import com.sun.tools.javac.api.DiagnosticFormatter;

import com.sun.tools.javac.code.Lint.LintCategory;

import com.sun.tools.javac.tree.EndPosTable;

import com.sun.tools.javac.tree.JCTree;

import com.sun.tools.javac.util.DefinedBy.Api;

import static com.sun.tools.javac.util.JCDiagnostic.DiagnosticType.*;

/** An abstraction of a diagnostic message generated by the compiler.

 *

 *  <p><b>This is NOT part of any supported API.

 *  If you write code that depends on this, you do so at your own risk.

 *  This code and its internal interfaces are subject to change or

 *  deletion without notice.</b>

 */

public class JCDiagnostic implements Diagnostic<JavaFileObject> {

    /** A factory for creating diagnostic objects. */

    public static class Factory {

        /** The context key for the diagnostic factory. */

        protected static final Context.Key<JCDiagnostic.Factory> diagnosticFactoryKey = new Context.Key<>();

        /** Get the Factory instance for this context. */

        public static Factory instance(Context context) {

            Factory instance = context.get(diagnosticFactoryKey);

            if (instance == null)

                instance = new Factory(context);

            return instance;

        }

        DiagnosticFormatter<JCDiagnostic> formatter;

        final String prefix;

        final Set<DiagnosticFlag> defaultErrorFlags;

        /** Create a new diagnostic factory. */

        protected Factory(Context context) {

            this(JavacMessages.instance(context), "compiler");

            context.put(diagnosticFactoryKey, this);

            final Options options = Options.instance(context);

            initOptions(options);

            options.addListener(new Runnable() {

               public void run() {

                   initOptions(options);

               }

            });

        }

        private void initOptions(Options options) {

            if (options.isSet("onlySyntaxErrorsUnrecoverable"))

                defaultErrorFlags.add(DiagnosticFlag.RECOVERABLE);

        }

        /** Create a new diagnostic factory. */

        public Factory(JavacMessages messages, String prefix) {

            this.prefix = prefix;

            this.formatter = new BasicDiagnosticFormatter(messages);

            defaultErrorFlags = EnumSet.of(DiagnosticFlag.MANDATORY);

        }

        /**

         * Create an error diagnostic

         *  @param source The source of the compilation unit, if any, in which to report the error.

         *  @param pos    The source position at which to report the error.

         *  @param key    The key for the localized error message.

         *  @param args   Fields of the error message.

         */

        public JCDiagnostic error(

                DiagnosticFlag flag, DiagnosticSource source, DiagnosticPosition pos, String key, Object... args) {

            return error(flag, source, pos, errorKey(key, args));

        }

        /**

         * Create an error diagnostic

         *  @param source The source of the compilation unit, if any, in which to report the error.

         *  @param pos    The source position at which to report the error.

         *  @param errorKey    The key for the localized error message.

         */

        public JCDiagnostic error(

                DiagnosticFlag flag, DiagnosticSource source, DiagnosticPosition pos, Error errorKey) {

            if (flag != null) {

                diag.setFlag(flag);

            }

            return diag;

        }

        /**

         * Create a warning diagnostic that will not be hidden by the -nowarn or -Xlint:none options.

         *  @param lc     The lint category for the diagnostic

         *  @param source The source of the compilation unit, if any, in which to report the warning.

         *  @param pos    The source position at which to report the warning.

         *  @param key    The key for the localized warning message.

         *  @param args   Fields of the warning message.

         *  @see MandatoryWarningHandler

         */

        public JCDiagnostic mandatoryWarning(

                LintCategory lc,

                DiagnosticSource source, DiagnosticPosition pos, String key, Object... args) {

            return mandatoryWarning(lc, source, pos, warningKey(key, args));

        }

        /**

         * Create a warning diagnostic that will not be hidden by the -nowarn or -Xlint:none options.

         *  @param lc     The lint category for the diagnostic

         *  @param source The source of the compilation unit, if any, in which to report the warning.

         *  @param pos    The source position at which to report the warning.

         *  @param warningKey    The key for the localized warning message.

         *  @see MandatoryWarningHandler

         */

        public JCDiagnostic mandatoryWarning(

                LintCategory lc,

                DiagnosticSource source, DiagnosticPosition pos, Warning warningKey) {

            return create(lc, EnumSet.of(DiagnosticFlag.MANDATORY), source, pos, warningKey);

        }

        /**

         * Create a warning diagnostic.

         *  @param lc     The lint category for the diagnostic

         *  @param source The source of the compilation unit, if any, in which to report the warning.

         *  @param pos    The source position at which to report the warning.

         *  @param key    The key for the localized error message.

         *  @param args   Fields of the warning message.

         *  @see MandatoryWarningHandler

         */

        public JCDiagnostic warning(

                LintCategory lc, DiagnosticSource source, DiagnosticPosition pos, String key, Object... args) {

            return warning(lc, source, pos, warningKey(key, args));

        }

        /**

         * Create a warning diagnostic.

         *  @param lc     The lint category for the diagnostic

         *  @param source The source of the compilation unit, if any, in which to report the warning.

         *  @param pos    The source position at which to report the warning.

         *  @param warningKey    The key for the localized warning message.

         *  @see MandatoryWarningHandler

         */

        public JCDiagnostic warning(

                LintCategory lc, DiagnosticSource source, DiagnosticPosition pos, Warning warningKey) {

            return create(lc, EnumSet.noneOf(DiagnosticFlag.class), source, pos, warningKey);

        }

        /**

         * Create a note diagnostic that will not be hidden by the -nowarn or -Xlint:none options.

         *  @param source The source of the compilation unit, if any, in which to report the warning.

         *  @param key    The key for the localized warning message.

         *  @param args   Fields of the warning message.

         *  @see MandatoryWarningHandler

         */

        public JCDiagnostic mandatoryNote(DiagnosticSource source, String key, Object... args) {

            return mandatoryNote(source, noteKey(key, args));

        }

        /**

         * Create a note diagnostic that will not be hidden by the -nowarn or -Xlint:none options.

         *  @param noteKey    The key for the localized note message.

         *  @see MandatoryWarningHandler

         */

        public JCDiagnostic mandatoryNote(DiagnosticSource source, Note noteKey) {

            return create(null, EnumSet.of(DiagnosticFlag.MANDATORY), source, null, noteKey);

        }

        /**

         * Create a note diagnostic.

         *  @param key    The key for the localized error message.

         *  @param args   Fields of the message.

         */

        public JCDiagnostic note(

                DiagnosticSource source, DiagnosticPosition pos, String key, Object... args) {

            return note(source, pos, noteKey(key, args));

        }

        /**

         * Create a note diagnostic.

         *  @param source The source of the compilation unit, if any, in which to report the note.

         *  @param pos    The source position at which to report the note.

         *  @param noteKey    The key for the localized note message.

         */

        public JCDiagnostic note(

                DiagnosticSource source, DiagnosticPosition pos, Note noteKey) {

            return create(null, EnumSet.noneOf(DiagnosticFlag.class), source, pos, noteKey);

        }

        /**

         * Create a fragment diagnostic, for use as an argument in other diagnostics

         *  @param key    The key for the localized message.

         *  @param args   Fields of the message.

         */

        public JCDiagnostic fragment(String key, Object... args) {

            return fragment(fragmentKey(key, args));

        }

        /**

         * Create a fragment diagnostic, for use as an argument in other diagnostics

         *  @param fragmentKey    The key for the localized subdiagnostic message.

         */

        public JCDiagnostic fragment(Fragment fragmentKey) {

            return create(null, EnumSet.noneOf(DiagnosticFlag.class), null, null, fragmentKey);

        }

        /**

         * Create a new diagnostic of the given kind, which is not mandatory and which has

         * no lint category.

         *  @param kind        The diagnostic kind

         *  @param source      The source of the compilation unit, if any, in which to report the message.

         *  @param pos         The source position at which to report the message.

         *  @param key         The key for the localized message.

         *  @param args        Fields of the message.

         */

        public JCDiagnostic create(

                DiagnosticType kind, DiagnosticSource source, DiagnosticPosition pos, String key, Object... args) {

            return create(null, EnumSet.noneOf(DiagnosticFlag.class), source, pos, DiagnosticInfo.of(kind, prefix, key, args));

        }

        /**

         * Create a new diagnostic of the given kind, which is not mandatory and which has

         * no lint category.

         *  @param source      The source of the compilation unit, if any, in which to report the message.

         *  @param pos         The source position at which to report the message.

         *  @param diagnosticInfo         The key for the localized message.

         */

        public JCDiagnostic create(

                DiagnosticSource source, DiagnosticPosition pos, DiagnosticInfo diagnosticInfo) {

            return create(null, EnumSet.noneOf(DiagnosticFlag.class), source, pos, diagnosticInfo);

        }

        /**

         * Create a new diagnostic of the given kind.

         *  @param kind        The diagnostic kind

         *  @param lc          The lint category, if applicable, or null

         *  @param flags       The set of flags for the diagnostic

         *  @param source      The source of the compilation unit, if any, in which to report the message.

         *  @param pos         The source position at which to report the message.

         *  @param key         The key for the localized message.

         *  @param args        Fields of the message.

         */

        public JCDiagnostic create(DiagnosticType kind,

                LintCategory lc, Set<DiagnosticFlag> flags, DiagnosticSource source, DiagnosticPosition pos, String key, Object... args) {

            return create(lc, flags, source, pos, DiagnosticInfo.of(kind, prefix, key, args));

        }

        /**

         * Create a new diagnostic with given key.

         *  @param lc          The lint category, if applicable, or null

         *  @param flags       The set of flags for the diagnostic

         *  @param source      The source of the compilation unit, if any, in which to report the message.

         *  @param pos         The source position at which to report the message.

         *  @param diagnosticInfo    The key for the localized message.

         */

        public JCDiagnostic create(

                LintCategory lc, Set<DiagnosticFlag> flags, DiagnosticSource source, DiagnosticPosition pos, DiagnosticInfo diagnosticInfo) {

            return new JCDiagnostic(formatter, normalize(diagnosticInfo), lc, flags, source, pos);

        }

        //where

            DiagnosticInfo normalize(DiagnosticInfo diagnosticInfo) {

                //replace all nested FragmentKey with full-blown JCDiagnostic objects

                return DiagnosticInfo.of(diagnosticInfo.type, diagnosticInfo.prefix, diagnosticInfo.code,

                        Stream.of(diagnosticInfo.args).map(o -> {

                            return (o instanceof Fragment) ?

                                    fragment((Fragment)o) : o;

                        }).toArray());

            }

        /**

         * Create a new error key.

         */

        Error errorKey(String code, Object... args) {

            return (Error)DiagnosticInfo.of(ERROR, prefix, code, args);

        }

        /**

         * Create a new warning key.

         */

        Warning warningKey(String code, Object... args) {

            return (Warning)DiagnosticInfo.of(WARNING, prefix, code, args);

        }

        /**

         * Create a new note key.

         */

        Note noteKey(String code, Object... args) {

            return (Note)DiagnosticInfo.of(NOTE, prefix, code, args);

        }

        /**

         * Create a new fragment key.

         */

        Fragment fragmentKey(String code, Object... args) {

            return (Fragment)DiagnosticInfo.of(FRAGMENT, prefix, code, args);

        }

    }

    /**

     * Create a fragment diagnostic, for use as an argument in other diagnostics

     *  @param key    The key for the localized error message.

     *  @param args   Fields of the error message.

     *

     */

    @Deprecated

    public static JCDiagnostic fragment(String key, Object... args) {

        return new JCDiagnostic(getFragmentFormatter(),

                              DiagnosticInfo.of(FRAGMENT,

                                      "compiler",

                                      key,

                                      args),

                              null,

                              EnumSet.noneOf(DiagnosticFlag.class),

                              null,

                              null);

    }

    //where

    @Deprecated

    public static DiagnosticFormatter<JCDiagnostic> getFragmentFormatter() {

        if (fragmentFormatter == null) {

            fragmentFormatter = new BasicDiagnosticFormatter(JavacMessages.getDefaultMessages());

        }

        return fragmentFormatter;

    }

    /**

     * A DiagnosticType defines the type of the diagnostic.

     **/

    public enum DiagnosticType {

        /** A fragment of an enclosing diagnostic. */

        FRAGMENT("misc"),

        /** A note: similar to, but less serious than, a warning. */

        NOTE("note"),

        /** A warning. */

        WARNING("warn"),

        /** An error. */

        ERROR("err");

        final String key;

        /** Create a DiagnosticType.

         * @param key A string used to create the resource key for the diagnostic.

         */

        DiagnosticType(String key) {

            this.key = key;

        }

    }

    /**

     * A DiagnosticPosition provides information about the positions in a file

     * that gave rise to a diagnostic. It always defines a "preferred" position

     * that most accurately defines the location of the diagnostic, it may also

     * provide a related tree node that spans that location.

     */

    public static interface DiagnosticPosition {

        /** Gets the tree node, if any, to which the diagnostic applies. */

        JCTree getTree();

        /** If there is a tree node, get the start position of the tree node.

         *  Otherwise, just returns the same as getPreferredPosition(). */

        int getStartPosition();

        /** Get the position within the file that most accurately defines the

         *  location for the diagnostic. */

        int getPreferredPosition();

        /** If there is a tree node, and if endPositions are available, get

         *  the end position of the tree node. Otherwise, just returns the

         *  same as getPreferredPosition(). */

        int getEndPosition(EndPosTable endPosTable);

    }

    /**

     * A DiagnosticPosition that simply identifies a position, but no related

     * tree node, as the location for a diagnostic. Used for scanner and parser

     * diagnostics. */

    public static class SimpleDiagnosticPosition implements DiagnosticPosition {

        public SimpleDiagnosticPosition(int pos) {

            this.pos = pos;

        }

        public JCTree getTree() {

            return null;

        }

        public int getStartPosition() {

            return pos;

        }

        public int getPreferredPosition() {

            return pos;

        }

        public int getEndPosition(EndPosTable endPosTable) {

            return pos;

        }

        private final int pos;

    }

    public enum DiagnosticFlag {

        MANDATORY,

        RESOLVE_ERROR,

        SYNTAX,

        RECOVERABLE,

        NON_DEFERRABLE,

    }

    private final DiagnosticSource source;

    private final DiagnosticPosition position;

    private final DiagnosticInfo diagnosticInfo;

    private final Set<DiagnosticFlag> flags;

    private final LintCategory lintCategory;

    /** source line position (set lazily) */

    private SourcePosition sourcePosition;

    /**

     * This class is used to defer the line/column position fetch logic after diagnostic construction.

     */

    class SourcePosition {

        private final int line;

        private final int column;

        SourcePosition() {

            int n = (position == null ? Position.NOPOS : position.getPreferredPosition());

            if (n == Position.NOPOS || source == null)

                line = column = -1;

            else {

                line = source.getLineNumber(n);

                column = source.getColumnNumber(n, true);

            }

        }

        public int getLineNumber() {

            return line;

        }

        public int getColumnNumber() {

            return column;

        }

    }

    /**

     * A diagnostic key object encapsulates basic properties of a diagnostic, such as the resource key,

     * the arguments and the kind associated with the diagnostic object. Diagnostic keys can be either

     * created programmatically (by using the supplied factory method) or obtained through build-time

     * generated factory methods.

     */

    public static abstract class DiagnosticInfo {

        /** The diagnostic kind (i.e. error). */

        DiagnosticType type;

        /** The diagnostic prefix (i.e. 'javac'); used to compute full resource key. */

        String prefix;

        /** The diagnostic code (i.e. 'cannot.resolve.sym'); together with {@code prefix} it forms

         * the full resource key. */

        String code;

        /** The diagnostic arguments. */

        Object[] args;

        private DiagnosticInfo(DiagnosticType type, String prefix, String code, Object... args) {

            this.type = type;

            this.prefix = prefix;