/*
 * Copyright (c) 2014, 2018, 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.
 *
 * 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.
 */

/*
 * @test
 * @bug 4981566 5028634 5094412 6304984 7025786 7025789 8001112 8028545 8000961 8030610 8028546 8188870 8173382 8173382 8193290 8205619
 * @summary Check interpretation of -target and -source options
 * @modules java.compiler
 *          jdk.compiler
 * @run main Versions
 */

import java.io.*;
import java.nio.*;
import java.nio.channels.*;

import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Set;
import java.util.function.BiConsumer;

/*
 * If not explicitly specified the latest source and latest target
 * values are the defaults. If explicitly specified, the target value
 * has to be greater than or equal to the source value.
 */
public class Versions {

    protected JavaCompiler javacompiler;
    protected int failedCases;

    public Versions() throws IOException {
        javacompiler = ToolProvider.getSystemJavaCompiler();
        genSourceFiles();
        failedCases = 0;
    }

    public static void main(String... args) throws IOException {
        Versions versions = new Versions();
        versions.run();
    }

    public static final Set<String> RETIRED_SOURCES =
        Set.of("1.2", "1.3", "1.4", "1.5" /*, 1.6 */);

    public static final Set<String> VALID_SOURCES =
        Set.of("1.7", "1.8", "1.9", "1.10", "11", "12");

    public static final String LATEST_MAJOR_VERSION = "56.0";

    static enum SourceTarget {
        SEVEN(true,   "51.0",  "7", Versions::checksrc17),
        EIGHT(true,   "52.0",  "8", Versions::checksrc18),
        NINE(true,    "53.0",  "9", Versions::checksrc19),
        TEN(true,     "54.0", "10", Versions::checksrc110),
        ELEVEN(false, "55.0", "11", Versions::checksrc111),
        TWELVE(false, "56.0", "12", Versions::checksrc112);

        private final boolean dotOne;
        private final String classFileVer;
        private final String target;
        private final BiConsumer<Versions, String[]> checker;

        private SourceTarget(boolean dotOne, String classFileVer, String target,
                             BiConsumer<Versions, String[]> checker) {
            this.dotOne = dotOne;
            this.classFileVer = classFileVer;
            this.target = target;
            this.checker = checker;
        }

        public void checksrc(Versions version, String... args) {
            checker.accept(version, args);
        }

        public boolean dotOne() {
            return dotOne;
        }

        public String classFileVer() {
            return classFileVer;
        }

        public String target() {
            return target;
        }
    }

    void run() {
        String TC = "";
        System.out.println("Version.java: Starting");

        check(LATEST_MAJOR_VERSION);
        for (String source : VALID_SOURCES) {
            check(LATEST_MAJOR_VERSION, "-source " + source);
        }

        // Verify that a -source value less than a -target value is
        // accepted and that the resulting class files are dependent
        // on the target setting alone.
        SourceTarget[] sourceTargets = SourceTarget.values();
        for (int i = 0; i < sourceTargets.length; i++) {
            SourceTarget st = sourceTargets[i];
            String classFileVer = st.classFileVer();
            String target = st.target();
            boolean dotOne = st.dotOne();
            check_source_target(dotOne, classFileVer, target, target);
            for (int j = i; j > 0; j--) {
                String source = sourceTargets[j].target();
                check_source_target(dotOne, classFileVer, source, target);
            }
        }

        // Verify acceptance of different combinations of -source N,
        // -target M; N <= M
        for (int i = 0; i < sourceTargets.length; i++) {
            SourceTarget st = sourceTargets[i];

            st.checksrc(this, "-source " + st.target());
            st.checksrc(this, "-source " + st.target(), "-target " + st.target());

            if (st.dotOne()) {
                st.checksrc(this, "-source 1." + st.target());
                st.checksrc(this, "-source 1." + st.target(), "-target 1." + st.target());
            }

            if (i == sourceTargets.length) {
                // Can use -target without -source setting only for
                // most recent target since the most recent source is
                // the default.
                st.checksrc(this, "-target " + st.target());

                if (!st.classFileVer().equals(LATEST_MAJOR_VERSION)) {
                    throw new RuntimeException(st +
                                               "does not have class file version" +
                                               LATEST_MAJOR_VERSION);
                }
            }
        }

        // Verify that -source N -target (N-1) is rejected
        for (int i = 1 /* Skip zeroth value */; i < sourceTargets.length; i++) {
            fail("-source " + sourceTargets[i].target(),
                 "-target " + sourceTargets[i-1].target(),
                 "Base.java");
        }

        // Previously supported source/target values
        for (String source  : RETIRED_SOURCES) {
            fail("-source " + source, "-target " + source, "Base.java");
        }

        if (failedCases > 0) {
            System.err.println("failedCases = " + String.valueOf(failedCases));
            throw new Error("Test failed");
        }

    }

    protected void printargs(String fname,String... args) {
        System.out.printf("test: %s", fname);
        for (String onearg : args) {
            System.out.printf(" %s", onearg);
        }
        System.out.printf("\n", fname);
    }

    protected void check_source_target(boolean dotOne, String... args) {
        printargs("check_source_target", args);
        check_target(dotOne, args[0], args[1], args[2]);
        if (dotOne) {
            check_target(dotOne, args[0], "1." + args[1], args[2]);
        }
    }

    protected void check_target(boolean dotOne, String... args) {
        check(args[0], "-source " + args[1], "-target " + args[2]);
        if (dotOne) {
            check(args[0], "-source " + args[1], "-target 1." + args[2]);
        }
    }

    protected void check(String major, String... args) {
        printargs("check", args);
        List<String> jcargs = new ArrayList<>();
        jcargs.add("-Xlint:-options");

        // add in args conforming to List requrements of JavaCompiler
        for (String onearg : args) {
            String[] fields = onearg.split(" ");
            for (String onefield : fields) {
                jcargs.add(onefield);
            }
        }

        boolean creturn = compile("Base.java", jcargs);
        if (!creturn) {
            // compilation errors note and return.. assume no class file
            System.err.println("check: Compilation Failed");
            System.err.println("\t classVersion:\t" + major);
            System.err.println("\t arguments:\t" + jcargs);
            failedCases++;

        } else if (!checkClassFileVersion("Base.class", major)) {
            failedCases++;
        }
    }

    protected void checksrc17(String... args) {
        printargs("checksrc17", args);
        int asize = args.length;
        String[] newargs = new String[asize+1];
        System.arraycopy(args, 0, newargs,0 , asize);
        newargs[asize] = "New17.java";
        pass(newargs);
        newargs[asize] = "New18.java";
        fail(newargs);
    }

    protected void checksrc18(String... args) {
        printargs("checksrc18", args);
        int asize = args.length;
        String[] newargs = new String[asize+1];
        System.arraycopy(args, 0, newargs,0 , asize);
        newargs[asize] = "New17.java";
        pass(newargs);
        newargs[asize] = "New18.java";
        pass(newargs);
        newargs[asize] = "New110.java";
        fail(newargs);
    }

    protected void checksrc19(String... args) {
        printargs("checksrc19", args);
        checksrc18(args);
    }

    protected void checksrc110(String... args) {
        printargs("checksrc110", args);
        int asize = args.length;
        String[] newargs = new String[asize+1];
        System.arraycopy(args, 0, newargs,0 , asize);
        newargs[asize] = "New17.java";
        pass(newargs);
        newargs[asize] = "New18.java";
        pass(newargs);
        newargs[asize] = "New110.java";
        pass(newargs);
    }

    protected void checksrc111(String... args) {
        printargs("checksrc111", args);
        int asize = args.length;
        String[] newargs = new String[asize+1];
        System.arraycopy(args, 0, newargs,0 , asize);
        newargs[asize] = "New17.java";
        pass(newargs);
        newargs[asize] = "New18.java";
        pass(newargs);
        newargs[asize] = "New110.java";
        pass(newargs);
        newargs[asize] = "New111.java";
        pass(newargs);
    }

    protected void checksrc112(String... args) {
        printargs("checksrc112", args);
        checksrc111(args);
    }

    protected void pass(String... args) {
        printargs("pass", args);

        List<String> jcargs = new ArrayList<String>();
        jcargs.add("-Xlint:-options");

        // add in args conforming to List requrements of JavaCompiler
        for (String onearg : args) {
            String[] fields = onearg.split(" ");
            for (String onefield : fields) {
                jcargs.add(onefield);
            }
        }

        // empty list is error
        if (jcargs.isEmpty()) {
            System.err.println("error: test error in pass() - No arguments");
            System.err.println("\t arguments:\t" + jcargs);
            failedCases++;
            return;
        }

        // the last argument is the filename *.java
        String filename = jcargs.get(jcargs.size() - 1);
        jcargs.remove(jcargs.size() - 1);

        boolean creturn = compile(filename, jcargs);
        // expect a compilation failure, failure if otherwise
        if (!creturn) {
            System.err.println("pass: Compilation erroneously failed");
            System.err.println("\t arguments:\t" + jcargs);
            System.err.println("\t file     :\t" + filename);
            failedCases++;

        }

    }

    protected void fail(String... args) {
        printargs("fail", args);

        List<String> jcargs = new ArrayList<String>();
        jcargs.add("-Xlint:-options");

        // add in args conforming to List requrements of JavaCompiler
        for (String onearg : args) {
            String[] fields = onearg.split(" ");
            for (String onefield : fields) {
                jcargs.add(onefield);
            }
        }

        // empty list is error
        if (jcargs.isEmpty()) {
            System.err.println("error: test error in fail()- No arguments");
            System.err.println("\t arguments:\t" + jcargs);
            failedCases++;
            return;
        }

        // the last argument is the filename *.java
        String filename = jcargs.get(jcargs.size() - 1);
        jcargs.remove(jcargs.size() - 1);

        boolean creturn = compile(filename, jcargs);
        // expect a compilation failure, failure if otherwise
        if (creturn) {
            System.err.println("fail: Compilation erroneously succeeded");
            System.err.println("\t arguments:\t" + jcargs);
            System.err.println("\t file     :\t" + filename);
            failedCases++;
        }
    }

    protected boolean compile(String sourceFile, List<String>options) {
        JavaCompiler.CompilationTask jctask;
        try (StandardJavaFileManager fm = javacompiler.getStandardFileManager(null, null, null)) {
            Iterable<? extends JavaFileObject> files = fm.getJavaFileObjects(sourceFile);

            jctask = javacompiler.getTask(
                null,    // Writer
                fm,      // JavaFileManager
                null,    // DiagnosticListener
                options, // Iterable<String>
                null,    // Iterable<String> classes
                files);  // Iterable<? extends JavaFileObject>

            try {
                return jctask.call();
            } catch (IllegalStateException e) {
                System.err.println(e);
                return false;
            }
        } catch (IOException e) {
            throw new Error(e);
        }
    }

    protected void writeSourceFile(String fileName, String body) throws IOException{
        try (Writer fw = new FileWriter(fileName)) {
            fw.write(body);
        }
    }

    protected void genSourceFiles() throws IOException{
        /* Create a file that executes with all supported versions. */
        writeSourceFile("Base.java","public class Base { }\n");

        /*
         * Create a file with a new feature in 1.7, not in 1.6 : "<>"
         */
        writeSourceFile("New17.java",
            "import java.util.List;\n" +
            "import java.util.ArrayList;\n" +
            "class New17 { List<String> s = new ArrayList<>(); }\n"
        );

        /*
         * Create a file with a new feature in 1.8, not in 1.7 : lambda
         */
        writeSourceFile("New18.java",
            "public class New18 { \n" +
            "    void m() { \n" +
            "    new Thread(() -> { }); \n" +
            "    } \n" +
            "} \n"
        );

        /*
         * Create a file with a new feature in 1.10, not in 1.9 : var
         */
        writeSourceFile("New110.java",
            "public class New110 { \n" +
            "    void m() { \n" +
            "    var tmp = new Thread(() -> { }); \n" +
            "    } \n" +
            "} \n"
        );

        /*
         * Create a file with a new feature in 11, not in 10 : var for lambda parameters
         */
        writeSourceFile("New111.java",
            "public class New111 { \n" +
            "    static java.util.function.Function<String,String> f = (var x) -> x.substring(0);\n" +
            "    void m(String name) { \n" +
            "    var tmp = new Thread(() -> { }, f.apply(name)); \n" +
            "    } \n" +
            "} \n"
        );
    }

    protected boolean checkClassFileVersion
        (String filename,String classVersionNumber) {
        ByteBuffer bb = ByteBuffer.allocate(1024);
        try (FileChannel fc = new FileInputStream(filename).getChannel()) {
            bb.clear();
            if (fc.read(bb) < 0)
                throw new IOException("Could not read from file : " + filename);
            bb.flip();
            int minor = bb.getShort(4);
            int major = bb.getShort(6);
            String fileVersion = major + "." + minor;
            if (fileVersion.equals(classVersionNumber)) {
                return true;
            } else {
                System.err.println("checkClassFileVersion : Failed");
                System.err.println("\tclassfile version mismatch");
                System.err.println("\texpected : " + classVersionNumber);
                System.err.println("\tfound    : " + fileVersion);
                return false;
            }
        }
        catch (IOException e) {
            System.err.println("checkClassFileVersion : Failed");
            System.err.println("\terror :\t" + e.getMessage());
            System.err.println("\tfile:\tfilename");
        }
        return false;
    }
}