/*

 * Copyright (c) 2002, 2014, 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.javah;

import java.io.OutputStream;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.HashSet;

import java.util.List;

import java.util.Set;

import javax.lang.model.element.Element;

import javax.lang.model.element.ExecutableElement;

import javax.lang.model.element.Modifier;

import javax.lang.model.element.Name;

import javax.lang.model.element.TypeElement;

import javax.lang.model.element.VariableElement;

import javax.lang.model.type.ArrayType;

import javax.lang.model.type.PrimitiveType;

import javax.lang.model.type.TypeKind;

import javax.lang.model.type.TypeMirror;

import javax.lang.model.type.TypeVisitor;

import javax.lang.model.util.ElementFilter;

import javax.lang.model.util.SimpleTypeVisitor9;

/*

 * <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></p>

 *

 * @author  Sucheta Dambalkar(Revised)

 */

public class LLNI extends Gen {

    protected final char  innerDelim = '$';     /* For inner classes */

    protected Set<String>  doneHandleTypes;

    List<VariableElement> fields;

    List<ExecutableElement> methods;

    private boolean       doubleAlign;

    private int           padFieldNum = 0;

    LLNI(boolean doubleAlign, Util util) {

        super(util);

        this.doubleAlign = doubleAlign;

    }

    protected String getIncludes() {

        return "";

    }

    protected void write(OutputStream o, TypeElement clazz) throws Util.Exit {

        try {

            String cname     = mangleClassName(clazz.getQualifiedName().toString());

            PrintWriter pw   = wrapWriter(o);

            fields = ElementFilter.fieldsIn(clazz.getEnclosedElements());

            methods = ElementFilter.methodsIn(clazz.getEnclosedElements());

            generateDeclsForClass(pw, clazz, cname);

            // FIXME check if errors occurred on the PrintWriter and throw exception if so

        } catch (TypeSignature.SignatureException e) {

            util.error("llni.sigerror", e.getMessage());

        }

    }

    protected void generateDeclsForClass(PrintWriter pw,

            TypeElement clazz, String cname)

            throws TypeSignature.SignatureException, Util.Exit {

        doneHandleTypes  = new HashSet<>();

        /* The following handle types are predefined in "typedefs.h". Suppress

           inclusion in the output by generating them "into the blue" here. */

        genHandleType(null, "java.lang.Class");

        genHandleType(null, "java.lang.ClassLoader");

        genHandleType(null, "java.lang.Object");

        genHandleType(null, "java.lang.String");

        genHandleType(null, "java.lang.Thread");

        genHandleType(null, "java.lang.ThreadGroup");

        genHandleType(null, "java.lang.Throwable");

        pw.println("/* LLNI Header for class " + clazz.getQualifiedName() + " */" + lineSep);

        pw.println("#ifndef _Included_" + cname);

        pw.println("#define _Included_" + cname);

        pw.println("#include \"typedefs.h\"");

        pw.println("#include \"llni.h\"");

        pw.println("#include \"jni.h\"" + lineSep);

        forwardDecls(pw, clazz);

        structSectionForClass(pw, clazz, cname);

        methodSectionForClass(pw, clazz, cname);

        pw.println("#endif");

    }

    protected void genHandleType(PrintWriter pw, String clazzname) {

        String cname = mangleClassName(clazzname);

        if (!doneHandleTypes.contains(cname)) {

            doneHandleTypes.add(cname);

            if (pw != null) {

                pw.println("#ifndef DEFINED_" + cname);

                pw.println("    #define DEFINED_" + cname);

                pw.println("    GEN_HANDLE_TYPES(" + cname + ");");

                pw.println("#endif" + lineSep);

            }

        }

    }

    protected String mangleClassName(String s) {

        return s.replace('.', '_')

            .replace('/', '_')

            .replace(innerDelim, '_');

    }

    protected void forwardDecls(PrintWriter pw, TypeElement clazz)

            throws TypeSignature.SignatureException {

        TypeElement object = elems.getTypeElement("java.lang.Object");

        if (clazz.equals(object))

            return;

        genHandleType(pw, clazz.getQualifiedName().toString());

        TypeElement superClass = (TypeElement) (types.asElement(clazz.getSuperclass()));

        if (superClass != null) {

            String superClassName = superClass.getQualifiedName().toString();

            forwardDecls(pw, superClass);

        }

        for (VariableElement field: fields) {

            if (!field.getModifiers().contains(Modifier.STATIC)) {

                TypeMirror t = types.erasure(field.asType());

                TypeSignature newTypeSig = new TypeSignature(elems);

                String tname = newTypeSig.qualifiedTypeName(t);

                String sig = newTypeSig.getTypeSignature(tname);

                if (sig.charAt(0) != '[')

                    forwardDeclsFromSig(pw, sig);

            }

        }

        for (ExecutableElement method: methods) {

            if (method.getModifiers().contains(Modifier.NATIVE)) {

                TypeMirror retType = types.erasure(method.getReturnType());

                String typesig = signature(method);

                TypeSignature newTypeSig = new TypeSignature(elems);

                String sig = newTypeSig.getTypeSignature(typesig, retType);

                if (sig.charAt(0) != '[')

                    forwardDeclsFromSig(pw, sig);

            }

        }

    }

    protected void forwardDeclsFromSig(PrintWriter pw, String sig) {

        int    len = sig.length();

        int    i   = sig.charAt(0) == '(' ? 1 : 0;

        /* Skip the initial "(". */

        while (i < len) {

            if (sig.charAt(i) == 'L') {

                int j = i + 1;

                while (sig.charAt(j) != ';') j++;

                genHandleType(pw, sig.substring(i + 1, j));

                i = j + 1;

            } else {

                i++;

            }

        }

    }

    protected void structSectionForClass(PrintWriter pw,

                                         TypeElement jclazz, String cname) {

        String jname = jclazz.getQualifiedName().toString();

        if (cname.equals("java_lang_Object")) {

            pw.println("/* struct java_lang_Object is defined in typedefs.h. */");

            pw.println();

            return;

        }

        pw.println("#if !defined(__i386)");

        pw.println("#pragma pack(4)");

        pw.println("#endif");

        pw.println();

        pw.println("struct " + cname + " {");

        pw.println("    ObjHeader h;");

        pw.print(fieldDefs(jclazz, cname));

        if (jname.equals("java.lang.Class"))

            pw.println("    Class *LLNI_mask(cClass);" +

                       "  /* Fake field; don't access (see oobj.h) */");

        pw.println("};" + lineSep + lineSep + "#pragma pack()");

        pw.println();

        return;

    }

    private static class FieldDefsRes {

        public String className;        /* Name of the current class. */

        public FieldDefsRes parent;

        public String s;

        public int byteSize;

        public boolean bottomMost;

        public boolean printedOne = false;

        FieldDefsRes(TypeElement clazz, FieldDefsRes parent, boolean bottomMost) {

            this.className = clazz.getQualifiedName().toString();

            this.parent = parent;

            this.bottomMost = bottomMost;

            int byteSize = 0;

            if (parent == null) this.s = "";

            else this.s = parent.s;

        }

    }

    /* Returns "true" iff added a field. */

    private boolean doField(FieldDefsRes res, VariableElement field,

                            String cname, boolean padWord) {

        String fieldDef = addStructMember(field, cname, padWord);

        if (fieldDef != null) {

            if (!res.printedOne) { /* add separator */

                if (res.bottomMost) {

                    if (res.s.length() != 0)

                        res.s = res.s + "    /* local members: */" + lineSep;

                } else {

                    res.s = res.s + "    /* inherited members from " +

                        res.className + ": */" + lineSep;

                }

                res.printedOne = true;

            }

            res.s = res.s + fieldDef;

            return true;

        }

        // Otherwise.

        return false;

    }

    private int doTwoWordFields(FieldDefsRes res, TypeElement clazz,

                                int offset, String cname, boolean padWord) {

        boolean first = true;

        List<VariableElement> fields = ElementFilter.fieldsIn(clazz.getEnclosedElements());

        for (VariableElement field: fields) {

            TypeKind tk = field.asType().getKind();

            boolean twoWords = (tk == TypeKind.LONG || tk == TypeKind.DOUBLE);

            if (twoWords && doField(res, field, cname, first && padWord)) {

                offset += 8; first = false;

            }

        }

        return offset;

    }

    String fieldDefs(TypeElement clazz, String cname) {

        FieldDefsRes res = fieldDefs(clazz, cname, true);

        return res.s;

    }

    FieldDefsRes fieldDefs(TypeElement clazz, String cname,

                                     boolean bottomMost){

        FieldDefsRes res;

        int offset;

        boolean didTwoWordFields = false;

        TypeElement superclazz = (TypeElement) types.asElement(clazz.getSuperclass());

        if (superclazz != null) {

            String supername = superclazz.getQualifiedName().toString();

            res = new FieldDefsRes(clazz,

                                   fieldDefs(superclazz, cname, false),

                                   bottomMost);

            offset = res.parent.byteSize;

        } else {

            res = new FieldDefsRes(clazz, null, bottomMost);

            offset = 0;

        }

        List<VariableElement> fields = ElementFilter.fieldsIn(clazz.getEnclosedElements());

        for (VariableElement field: fields) {

            if (doubleAlign && !didTwoWordFields && (offset % 8) == 0) {

                offset = doTwoWordFields(res, clazz, offset, cname, false);

                didTwoWordFields = true;

            }

            TypeKind tk = field.asType().getKind();

            boolean twoWords = (tk == TypeKind.LONG || tk == TypeKind.DOUBLE);

            if (!doubleAlign || !twoWords) {

                if (doField(res, field, cname, false)) offset += 4;

            }

        }

        if (doubleAlign && !didTwoWordFields) {

            if ((offset % 8) != 0) offset += 4;

            offset = doTwoWordFields(res, clazz, offset, cname, true);

        }

        res.byteSize = offset;

        return res;

    }

    /* OVERRIDE: This method handles instance fields */

    protected String addStructMember(VariableElement member, String cname,

                                     boolean padWord) {

        String res = null;

        if (member.getModifiers().contains(Modifier.STATIC)) {

            res = addStaticStructMember(member, cname);

            //   if (res == null) /* JNI didn't handle it, print comment. */

            //  res = "    /* Inaccessible static: " + member + " */" + lineSep;

        } else {

            TypeMirror mt = types.erasure(member.asType());

            if (padWord) res = "    java_int padWord" + padFieldNum++ + ";" + lineSep;

            res = "    " + llniType(mt, false, false) + " " + llniFieldName(member);

            if (isLongOrDouble(mt)) res = res + "[2]";

            res = res + ";" + lineSep;

        }

        return res;

    }

    static private final boolean isWindows =

        System.getProperty("os.name").startsWith("Windows");

    /*

     * This method only handles static final fields.

     */

    protected String addStaticStructMember(VariableElement field, String cname) {

        String res = null;

        Object exp = null;

        if (!field.getModifiers().contains(Modifier.STATIC))

            return res;

        if (!field.getModifiers().contains(Modifier.FINAL))

            return res;

        exp = field.getConstantValue();

        if (exp != null) {

            /* Constant. */

            String     cn     = cname + "_" + field.getSimpleName();

            String     suffix = null;

            long           val = 0;

            /* Can only handle int, long, float, and double fields. */

            if (exp instanceof Byte

                || exp instanceof Short

                || exp instanceof Integer) {

                suffix = "L";

                val = ((Number)exp).intValue();

            }

            else if (exp instanceof Long) {

                // Visual C++ supports the i64 suffix, not LL

                suffix = isWindows ? "i64" : "LL";

                val = ((Long)exp).longValue();

            }

            else if (exp instanceof Float)  suffix = "f";

            else if (exp instanceof Double) suffix = "";

            else if (exp instanceof Character) {

                suffix = "L";

                Character ch = (Character) exp;

                val = ((int) ch) & 0xffff;

            }

            if (suffix != null) {

                // Some compilers will generate a spurious warning

                // for the integer constants for Integer.MIN_VALUE

                // and Long.MIN_VALUE so we handle them specially.

                if ((suffix.equals("L") && (val == Integer.MIN_VALUE)) ||

                    (suffix.equals("LL") && (val == Long.MIN_VALUE))) {

                    res = "    #undef  " + cn + lineSep

                        + "    #define " + cn

                        + " (" + (val + 1) + suffix + "-1)" + lineSep;

                } else if (suffix.equals("L") || suffix.endsWith("LL")) {

                    res = "    #undef  " + cn + lineSep

                        + "    #define " + cn + " " + val + suffix + lineSep;

                } else {

                    res = "    #undef  " + cn + lineSep

                        + "    #define " + cn + " " + exp + suffix + lineSep;

                }

            }

        }

        return res;

    }

    protected void methodSectionForClass(PrintWriter pw,

            TypeElement clazz, String cname)

            throws TypeSignature.SignatureException, Util.Exit {

        String methods = methodDecls(clazz, cname);

        if (methods.length() != 0) {

            pw.println("/* Native method declarations: */" + lineSep);

            pw.println("#ifdef __cplusplus");

            pw.println("extern \"C\" {");

            pw.println("#endif" + lineSep);

            pw.println(methods);

            pw.println("#ifdef __cplusplus");

            pw.println("}");

            pw.println("#endif");

        }

    }

    protected String methodDecls(TypeElement clazz, String cname)

            throws TypeSignature.SignatureException, Util.Exit {

        String res = "";

        for (ExecutableElement method: methods) {

            if (method.getModifiers().contains(Modifier.NATIVE))

                res = res + methodDecl(method, clazz, cname);

        }

        return res;

    }

    protected String methodDecl(ExecutableElement method,

                                TypeElement clazz, String cname)

            throws TypeSignature.SignatureException, Util.Exit {

        String res = null;

        TypeMirror retType = types.erasure(method.getReturnType());

        String typesig = signature(method);

        TypeSignature newTypeSig = new TypeSignature(elems);

        String sig = newTypeSig.getTypeSignature(typesig, retType);

        boolean longName = needLongName(method, clazz);

        if (sig.charAt(0) != '(')

            util.error("invalid.method.signature", sig);

        res = "JNIEXPORT " + jniType(retType) + " JNICALL" + lineSep + jniMethodName(method, cname, longName)

            + "(JNIEnv *, " + cRcvrDecl(method, cname);

        List<? extends VariableElement> params = method.getParameters();

        List<TypeMirror> argTypes = new ArrayList<>();

        for (VariableElement p: params){

            argTypes.add(types.erasure(p.asType()));

        }

        /* It would have been nice to include the argument names in the

           declaration, but there seems to be a bug in the "BinaryField"

           class, causing the getArguments() method to return "null" for

           most (non-constructor) methods. */

        for (TypeMirror argType: argTypes)

            res = res + ", " + jniType(argType);

        res = res + ");" + lineSep;

        return res;

    }

    protected final boolean needLongName(ExecutableElement method,

                                         TypeElement clazz) {

        Name methodName = method.getSimpleName();

        for (ExecutableElement memberMethod: methods) {

            if ((memberMethod != method) &&

                memberMethod.getModifiers().contains(Modifier.NATIVE) &&

                    (methodName.equals(memberMethod.getSimpleName())))

                return true;

        }

        return false;

    }

    protected final String jniMethodName(ExecutableElement method, String cname,

                                         boolean longName)

                throws TypeSignature.SignatureException {

        String res = "Java_" + cname + "_" + method.getSimpleName();

        if (longName) {

            TypeMirror mType =  types.erasure(method.getReturnType());

            List<? extends VariableElement> params = method.getParameters();

            List<TypeMirror> argTypes = new ArrayList<>();

            for (VariableElement param: params) {

                argTypes.add(types.erasure(param.asType()));

            }

            res = res + "__";

            for (TypeMirror t: argTypes) {

                String tname = t.toString();

                TypeSignature newTypeSig = new TypeSignature(elems);

                String sig = newTypeSig.getTypeSignature(tname);

                res = res + nameToIdentifier(sig);

            }

        }

        return res;

    }