/*
 * Copyright (c) 2002, 2020, Oracle and/or its affiliates. All rights reserved.
 * 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.code;

import java.util.*;

import javax.lang.model.SourceVersion;
import static javax.lang.model.SourceVersion.*;

import com.sun.tools.javac.jvm.Target;
import com.sun.tools.javac.resources.CompilerProperties.Errors;
import com.sun.tools.javac.resources.CompilerProperties.Fragments;
import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.JCDiagnostic.Error;
import com.sun.tools.javac.util.JCDiagnostic.Fragment;

import static com.sun.tools.javac.main.Option.*;

The source language version accepted.
 
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.
/** The source language version accepted.
 *
 *  <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 enum Source {
    /** 1.0 had no inner classes, and so could not pass the JCK. */
    // public static final Source JDK1_0 =              new Source("1.0");

    /** 1.1 did not have strictfp, and so could not pass the JCK. */
    // public static final Source JDK1_1 =              new Source("1.1");

    
1.2 introduced strictfp. /** 1.2 introduced strictfp. */
    JDK1_2("1.2"),

    
1.3 is the same language as 1.2. /** 1.3 is the same language as 1.2. */
    JDK1_3("1.3"),

    
1.4 introduced assert. /** 1.4 introduced assert. */
    JDK1_4("1.4"),

    
1.5 introduced generics, attributes, foreach, boxing, static import,
 covariant return, enums, varargs, et al. /** 1.5 introduced generics, attributes, foreach, boxing, static import,
     *  covariant return, enums, varargs, et al. */
    JDK5("5"),

    
1.6 reports encoding problems as errors instead of warnings. /** 1.6 reports encoding problems as errors instead of warnings. */
    JDK6("6"),

    
1.7 introduced try-with-resources, multi-catch, string switch, etc. /** 1.7 introduced try-with-resources, multi-catch, string switch, etc. */
    JDK7("7"),

    
1.8 lambda expressions and default methods. /** 1.8 lambda expressions and default methods. */
    JDK8("8"),

    
1.9 modularity. /** 1.9 modularity. */
    JDK9("9"),

    
1.10 local-variable type inference (var). /** 1.10 local-variable type inference (var). */
    JDK10("10"),

    
1.11 local-variable syntax for lambda parameters /** 1.11 local-variable syntax for lambda parameters */
    JDK11("11"),

    
12, no language features; switch expression in preview /** 12, no language features; switch expression in preview */
    JDK12("12"),

    
13, no language features; text blocks and revised switch
expressions in preview
/**
     * 13, no language features; text blocks and revised switch
     * expressions in preview
     */
    JDK13("13"),

    
14, switch expressions; pattern matching, records, and revised
text blocks in preview
/**
     * 14, switch expressions; pattern matching, records, and revised
     * text blocks in preview
     */
    JDK14("14"),

    
15, text blocks
/**
      * 15, text blocks
      */
    JDK15("15"),

    
16, tbd
/**
      * 16, tbd
      */
    JDK16("16"),

    
17, tbd
/**
      * 17, tbd
      */
    JDK17("17");

    private static final Context.Key<Source> sourceKey = new Context.Key<>();

    public static Source instance(Context context) {
        Source instance = context.get(sourceKey);
        if (instance == null) {
            Options options = Options.instance(context);
            String sourceString = options.get(SOURCE);
            if (sourceString != null) instance = lookup(sourceString);
            if (instance == null) instance = DEFAULT;
            context.put(sourceKey, instance);
        }
        return instance;
    }

    public final String name;

    private static final Map<String,Source> tab = new HashMap<>();
    static {
        for (Source s : values()) {
            tab.put(s.name, s);
        }
        tab.put("1.5", JDK5); // Make 5 an alias for 1.5
        tab.put("1.6", JDK6); // Make 6 an alias for 1.6
        tab.put("1.7", JDK7); // Make 7 an alias for 1.7
        tab.put("1.8", JDK8); // Make 8 an alias for 1.8
        tab.put("1.9", JDK9); // Make 9 an alias for 1.9
        tab.put("1.10", JDK10); // Make 10 an alias for 1.10
        // Decline to make 1.11 an alias for 11.
    }

    private Source(String name) {
        this.name = name;
    }

    public static final Source MIN = Source.JDK7;

    private static final Source MAX = values()[values().length - 1];

    public static final Source DEFAULT = MAX;

    public static Source lookup(String name) {
        return tab.get(name);
    }

    public boolean isSupported() {
        return this.compareTo(MIN) >= 0;
    }

    public Target requiredTarget() {
        return switch(this) {
        case JDK17  -> Target.JDK1_17;
        case JDK16  -> Target.JDK1_16;
        case JDK15  -> Target.JDK1_15;
        case JDK14  -> Target.JDK1_14;
        case JDK13  -> Target.JDK1_13;
        case JDK12  -> Target.JDK1_12;
        case JDK11  -> Target.JDK1_11;
        case JDK10  -> Target.JDK1_10;
        case JDK9   -> Target.JDK1_9;
        case JDK8   -> Target.JDK1_8;
        case JDK7   -> Target.JDK1_7;
        case JDK6   -> Target.JDK1_6;
        case JDK5   -> Target.JDK1_5;
        case JDK1_4 -> Target.JDK1_4;
        default     -> Target.JDK1_1;
        };
    }

    
Models a feature of the Java programming language. Each feature can be associated with a minimum source level, a maximum source level and a diagnostic fragment describing the feature, which is used to generate error messages of the kind feature XYZ not supported in source N. /**
     * Models a feature of the Java programming language. Each feature can be associated with a
     * minimum source level, a maximum source level and a diagnostic fragment describing the feature,
     * which is used to generate error messages of the kind {@code feature XYZ not supported in source N}.
     */
    public enum Feature {

        DIAMOND(JDK7, Fragments.FeatureDiamond, DiagKind.NORMAL),
        MODULES(JDK9, Fragments.FeatureModules, DiagKind.PLURAL),
        EFFECTIVELY_FINAL_VARIABLES_IN_TRY_WITH_RESOURCES(JDK9, Fragments.FeatureVarInTryWithResources, DiagKind.PLURAL),
        DEPRECATION_ON_IMPORT(MIN, JDK8),
        POLY(JDK8),
        LAMBDA(JDK8, Fragments.FeatureLambda, DiagKind.PLURAL),
        METHOD_REFERENCES(JDK8, Fragments.FeatureMethodReferences, DiagKind.PLURAL),
        DEFAULT_METHODS(JDK8, Fragments.FeatureDefaultMethods, DiagKind.PLURAL),
        STATIC_INTERFACE_METHODS(JDK8, Fragments.FeatureStaticIntfMethods, DiagKind.PLURAL),
        STATIC_INTERFACE_METHODS_INVOKE(JDK8, Fragments.FeatureStaticIntfMethodInvoke, DiagKind.PLURAL),
        STRICT_METHOD_CLASH_CHECK(JDK8),
        EFFECTIVELY_FINAL_IN_INNER_CLASSES(JDK8),
        TYPE_ANNOTATIONS(JDK8, Fragments.FeatureTypeAnnotations, DiagKind.PLURAL),
        ANNOTATIONS_AFTER_TYPE_PARAMS(JDK8, Fragments.FeatureAnnotationsAfterTypeParams, DiagKind.PLURAL),
        REPEATED_ANNOTATIONS(JDK8, Fragments.FeatureRepeatableAnnotations, DiagKind.PLURAL),
        INTERSECTION_TYPES_IN_CAST(JDK8, Fragments.FeatureIntersectionTypesInCast, DiagKind.PLURAL),
        GRAPH_INFERENCE(JDK8),
        FUNCTIONAL_INTERFACE_MOST_SPECIFIC(JDK8),
        POST_APPLICABILITY_VARARGS_ACCESS_CHECK(JDK8),
        MAP_CAPTURES_TO_BOUNDS(MIN, JDK7),
        PRIVATE_SAFE_VARARGS(JDK9),
        DIAMOND_WITH_ANONYMOUS_CLASS_CREATION(JDK9, Fragments.FeatureDiamondAndAnonClass, DiagKind.NORMAL),
        UNDERSCORE_IDENTIFIER(MIN, JDK8),
        PRIVATE_INTERFACE_METHODS(JDK9, Fragments.FeaturePrivateIntfMethods, DiagKind.PLURAL),
        LOCAL_VARIABLE_TYPE_INFERENCE(JDK10),
        VAR_SYNTAX_IMPLICIT_LAMBDAS(JDK11, Fragments.FeatureVarSyntaxInImplicitLambda, DiagKind.PLURAL),
        IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES(JDK1_2, JDK8),
        SWITCH_MULTIPLE_CASE_LABELS(JDK14, Fragments.FeatureMultipleCaseLabels, DiagKind.PLURAL),
        SWITCH_RULE(JDK14, Fragments.FeatureSwitchRules, DiagKind.PLURAL),
        SWITCH_EXPRESSION(JDK14, Fragments.FeatureSwitchExpressions, DiagKind.PLURAL),
        TEXT_BLOCKS(JDK15, Fragments.FeatureTextBlocks, DiagKind.PLURAL),
        PATTERN_MATCHING_IN_INSTANCEOF(JDK16, Fragments.FeaturePatternMatchingInstanceof, DiagKind.NORMAL),
        REIFIABLE_TYPES_INSTANCEOF(JDK16, Fragments.FeatureReifiableTypesInstanceof, DiagKind.PLURAL),
        RECORDS(JDK16, Fragments.FeatureRecords, DiagKind.PLURAL),
        SEALED_CLASSES(JDK17, Fragments.FeatureSealedClasses, DiagKind.PLURAL),
        ;

        enum DiagKind {
            NORMAL,
            PLURAL;
        }

        private final Source minLevel;
        private final Source maxLevel;
        private final Fragment optFragment;
        private final DiagKind optKind;

        Feature(Source minLevel) {
            this(minLevel, null, null);
        }

        Feature(Source minLevel, Fragment optFragment, DiagKind optKind) {
            this(minLevel, MAX, optFragment, optKind);
        }

        Feature(Source minLevel, Source maxLevel) {
            this(minLevel, maxLevel, null, null);
        }

        Feature(Source minLevel, Source maxLevel, Fragment optFragment, DiagKind optKind) {
            this.minLevel = minLevel;
            this.maxLevel = maxLevel;
            this.optFragment = optFragment;
            this.optKind = optKind;
        }

        public boolean allowedInSource(Source source) {
            return source.compareTo(minLevel) >= 0 &&
                    source.compareTo(maxLevel) <= 0;
        }

        public boolean isPlural() {
            Assert.checkNonNull(optKind);
            return optKind == DiagKind.PLURAL;
        }

        public Fragment nameFragment() {
            Assert.checkNonNull(optFragment);
            return optFragment;
        }

        public Fragment fragment(String sourceName) {
            Assert.checkNonNull(optFragment);
            return optKind == DiagKind.NORMAL ?
                    Fragments.FeatureNotSupportedInSource(optFragment, sourceName, minLevel.name) :
                    Fragments.FeatureNotSupportedInSourcePlural(optFragment, sourceName, minLevel.name);
        }

        public Error error(String sourceName) {
            Assert.checkNonNull(optFragment);
            return optKind == DiagKind.NORMAL ?
                    Errors.FeatureNotSupportedInSource(optFragment, sourceName, minLevel.name) :
                    Errors.FeatureNotSupportedInSourcePlural(optFragment, sourceName, minLevel.name);
        }
    }

    public static SourceVersion toSourceVersion(Source source) {
        return switch(source) {
        case JDK1_2 -> RELEASE_2;
        case JDK1_3 -> RELEASE_3;
        case JDK1_4 -> RELEASE_4;
        case JDK5   -> RELEASE_5;
        case JDK6   -> RELEASE_6;
        case JDK7   -> RELEASE_7;
        case JDK8   -> RELEASE_8;
        case JDK9   -> RELEASE_9;
        case JDK10  -> RELEASE_10;
        case JDK11  -> RELEASE_11;
        case JDK12  -> RELEASE_12;
        case JDK13  -> RELEASE_13;
        case JDK14  -> RELEASE_14;
        case JDK15  -> RELEASE_15;
        case JDK16  -> RELEASE_16;
        case JDK17  -> RELEASE_17;
        default     -> null;
        };
    }
}