/*
 * Copyright (c) 2019, 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 9999999
 * @summary XXX
 * @library /tools/lib
 * @modules
 *      jdk.compiler/com.sun.tools.javac.api
 *      jdk.compiler/com.sun.tools.javac.main
 * @build toolbox.ToolBox CodeBuilder
 * @run main ASTBuilder
 */

import java.net.URI;
import java.util.Arrays;
import java.util.EnumSet;
import java.util.function.Consumer;

import javax.lang.model.element.Modifier;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.SimpleJavaFileObject;
import javax.tools.ToolProvider;

import com.sun.source.tree.CompilationUnitTree;
import com.sun.source.tree.Tree;
import com.sun.source.util.JavacTask;
import com.sun.source.util.TreeBuilder;
import com.sun.source.util.TreeBuilder.*;
import com.sun.source.util.Trees;
import com.sun.source.util.TreeScanner;

import javax.tools.StandardLocation;

import com.sun.source.tree.ClassTree;
import com.sun.source.tree.IdentifierTree;
import com.sun.source.tree.MemberReferenceTree;
import com.sun.source.tree.MemberSelectTree;
import com.sun.source.tree.MethodTree;
import com.sun.source.tree.ModifiersTree;
import com.sun.source.tree.VariableTree;
import toolbox.ToolBox.MemoryFileManager;

public class ASTBuilder {
    
    public static void main(String[] args) throws Exception {
        runTest("public class Test {" +
                "    public static volatile int x;" +
                "}",
                U -> U._class("Test",
                              C -> C.modifiers(M -> M.modifier(Modifier.PUBLIC))
                                    .field("x",
                                           Type::_int,
                                           F -> F.modifiers(M -> M.modifier(Modifier.PUBLIC)
                                                                  .modifier(Modifier.STATIC)
                                                                  .modifier(Modifier.VOLATILE)
                                                           )
                                          )
                             )
                );
        runTest("class Test extends Exception implements java.util.List<Map<String, String>>, CharSequence {" +
                "    int x1 = 2;" +
                "    int x2 = 2 + x1;" +
                "    int test(int param) {" +
                "        if (param == 0) return 0;" +
                "        else return 1;" +
                "    }" +
                "    int test2(int param) {" +
                "        if (param == 0) return 0;" +
                "        return 1;" +
                "    }" +
                "}");
        runTest("class Test extends java.util.Map<List<String>, Numer> {" +
                "}",
                U -> U._class("Test", C -> C.superclass("java.util.Map<List<String>, Numer>")));
        runTest("class Test {" +
                "    int i = true ? 0 : 1;" +
                "}",
                U -> U._class("Test", C -> C.field("i", Type::_int, F -> F.init("true ? 0 : 1"))));
        runTest("class Test {" +
                "    int test(int param) {" +
                "        if (param == 0) return 0;" +
                "        else return 1;" +
                "    }" +
                "}",
                U -> U._class("Test", C -> C.method("test", Type::_int, M -> M.parameter(Type::_int, P -> P.name("param")).body("{\n" +
                "        if (param == 0) return 0;\n" +
                "        else return 1;\n" +
                "    }"))));
        try {
            runTest("broken",
                    U -> U._class("Test", C -> C.superclass("java.util.Map<")));
            throw new AssertionError("The exceptec exception was not thrown.");
        } catch (IllegalArgumentException ex) {
            //OK
        }
    }

    private static void runTest(String expectedCode, Consumer<CompilationUnit> actualBuilder) throws Exception {
        final JavaCompiler tool = ToolProvider.getSystemJavaCompiler();
        assert tool != null;

        JavacTask expectedTask = (JavacTask) tool.getTask(null, null, null,
            null, null, Arrays.asList(new MyFileObject(expectedCode)));
        String expectedDump = dumpTree(expectedTask.parse().iterator().next());

        JavacTask ct = (JavacTask) tool.getTask(null, null, null,
            null, null, Arrays.asList(new MyFileObject("")));
        ct.parse(); //init javac
        Trees t = Trees.instance(ct);
        
        TreeBuilder builder = t.getTreeBuilder();

        CompilationUnitTree cut = builder.createCompilationUnitTree(actualBuilder);
        
        String actualDump = dumpTree(cut);
        
        if (!actualDump.equals(expectedDump)) {
            throw new AssertionError("Expected and actual dump differ. Expected: " + expectedDump + "; actual: " + actualDump);
        }
    }

    private static void runTest(String expectedCode) throws Exception {
        final JavaCompiler tool = ToolProvider.getSystemJavaCompiler();
        assert tool != null;

        JavacTask expectedTask = (JavacTask) tool.getTask(null, null, null,
            null, null, Arrays.asList(new MyFileObject(expectedCode)));
        CompilationUnitTree expectedCUT = expectedTask.parse().iterator().next();
        String builderCode = CodeBuilder.buildCodeToGenerate(expectedCUT, "builder");
        System.err.println("builderCode:");
        System.err.println(builderCode);
        String expectedCodeGen = "import com.sun.source.tree.*; import com.sun.source.util.*; public class CodeGen { public static CompilationUnitTree build(TreeBuilder builder) { return " + builderCode + "; } }";
        String expectedDump = dumpTree(expectedCUT);

        try (MemoryFileManager mfm = new MemoryFileManager(tool.getStandardFileManager(null, null, null))) {
            Boolean res = tool.getTask(null, mfm, null,
                                       null, null, Arrays.asList(new MyFileObject(expectedCodeGen)))
                              .call();
            if (!res) {
                throw new IllegalStateException("Could not compile the generated code!");
            }
            
            ClassLoader codeCL = new ClassLoader(ASTBuilder.class.getClassLoader()) {
                @Override
                protected java.lang.Class<?> findClass(String name) throws ClassNotFoundException {
                    byte[] bytecode = mfm.getFileBytes(StandardLocation.CLASS_OUTPUT, name);
                    if (bytecode != null) {
                        return defineClass(name, bytecode, 0, bytecode.length);
                    }
                    return super.findClass(name);
                }
            };

            JavacTask ct = (JavacTask) tool.getTask(null, null, null,
                null, null, Arrays.asList(new MyFileObject("")));
            ct.parse(); //init javac
            Trees t = Trees.instance(ct);

            TreeBuilder builder = t.getTreeBuilder();

            java.lang.Class<?> codeGen = codeCL.loadClass("CodeGen");
            CompilationUnitTree cut = (CompilationUnitTree) codeGen.getDeclaredMethod("build", TreeBuilder.class).invoke(null, builder);
            String actualDump = dumpTree(cut);

            if (!actualDump.equals(expectedDump)) {
                throw new AssertionError("Expected and actual dump differ. Expected: " + expectedDump + "; actual: " + actualDump);
            }
        }
    }

    static String dumpTree(Tree t) {
        StringBuilder result = new StringBuilder();
        new TreeScanner<Void, Void>() {
            String sep = "";
            @Override
            public Void scan(Tree tree, Void p) {
                result.append(sep);
                sep = " ";
                if (tree == null) {
                    result.append("null");
                    return null;
                }
                result.append("(");
                result.append(tree.getKind().name());
                super.scan(tree, p);
                result.append(")");
                return null;
            }
            @Override
            public Void scan(Iterable<? extends Tree> nodes, Void p) {
                result.append(sep);
                sep = " ";
                if (nodes == null) {
                    result.append("null");
                    return null;
                }
                result.append("(");
                super.scan(nodes, p);
                result.append(")");
                return null;
            }
            @Override
            public Void visitIdentifier(IdentifierTree node, Void p) {
                result.append(node.getName());
                return super.visitIdentifier(node, p);
            }
            @Override
            public Void visitMemberSelect(MemberSelectTree node, Void p) {
                result.append(node.getIdentifier());
                return super.visitMemberSelect(node, p);
            }
            @Override
            public Void visitMemberReference(MemberReferenceTree node, Void p) {
                result.append(node.getName());
                return super.visitMemberReference(node, p);
            }
            @Override
            public Void visitClass(ClassTree node, Void p) {
                result.append(node.getSimpleName());
                return super.visitClass(node, p);
            }
            @Override
            public Void visitMethod(MethodTree node, Void p) {
                result.append(node.getName());
                return super.visitMethod(node, p);
            }
            @Override
            public Void visitVariable(VariableTree node, Void p) {
                result.append(node.getName());
                return super.visitVariable(node, p);
            }
            @Override
            public Void visitModifiers(ModifiersTree node, Void p) {
                result.append(node.getFlags());
                return super.visitModifiers(node, p);
            }
        }.scan(t, null);
        return result.toString();
    }

    static class MyFileObject extends SimpleJavaFileObject {
        private String text;

        public MyFileObject(String text) {
            super(URI.create("myfo:/Test.java"), JavaFileObject.Kind.SOURCE);
            this.text = text;
        }

        @Override
        public CharSequence getCharContent(boolean ignoreEncodingErrors) {
            return text;
        }

        @Override
        public boolean isNameCompatible(String simpleName, Kind kind) {
            return true;
        }
    }
}