/*

 * Copyright 2002-2008 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package com.sun.tools.javah;

import java.io.UnsupportedEncodingException;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.OutputStream;

import java.io.PrintWriter;

import com.sun.javadoc.*;

import java.io.*;

import java.util.Stack;

import java.util.Vector;

import java.util.Arrays;

/**

 * An abstraction for generating support files required by native methods.

 * Subclasses are for specific native interfaces. At the time of its

 * original writing, this interface is rich enough to support JNI and the

 * old 1.0-style native method interface.

 *

 * @author  Sucheta Dambalkar(Revised)

 */

public abstract class Gen {

    protected String lineSep = System.getProperty("line.separator");

    RootDoc root;

    /*

     * List of classes for which we must generate output.

     */

    protected ClassDoc[] classes;

    static private final boolean isWindows =

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

    public Gen(RootDoc root){

        this.root = root;

    }

    /**

     * Override this abstract method, generating content for the named

     * class into the outputstream.

     */

    protected abstract void write(OutputStream o, ClassDoc clazz)

        throws ClassNotFoundException;

    /**

     * Override this method to provide a list of #include statements

     * required by the native interface.

     */

    protected abstract String getIncludes();

    /*

     * Output location.

     */

    protected String outDir;

    protected String outFile;

    public void setOutDir(String outDir) {

        /* Check important, otherwise concatenation of two null strings

         * produces the "nullnull" String.

         */

        if (outDir != null) {

            this.outDir = outDir + System.getProperty("file.separator");

            File d = new File(outDir);

            if (!d.exists())

                if (!d.mkdirs())

                    Util.error("cant.create.dir", d.toString());

        }

    }

    public void setOutFile(String outFile) {

        this.outFile = outFile;

    }

    public void setClasses(ClassDoc[] classes) {

        this.classes = classes;

    }

    /*

     * Smartness with generated files.

     */

    protected boolean force = false;

    public void setForce(boolean state) {

        force = state;

    }

    /**

     * We explicitly need to write ASCII files because that is what C

     * compilers understand.

     */

    protected PrintWriter wrapWriter(OutputStream o) {

        try {

            return new

            PrintWriter(new OutputStreamWriter(o, "ISO8859_1"), true);

        } catch (UnsupportedEncodingException use) {

            Util.bug("encoding.iso8859_1.not.found");

            return null; /* dead code */

        }

    }

    /**

     * After initializing state of an instance, use this method to start

     * processing.

     *

     * Buffer size chosen as an approximation from a single sampling of:

     *         expr `du -sk` / `ls *.h | wc -l`

     */

    public void run() throws IOException, ClassNotFoundException {

        int i = 0;

        if (outFile != null) {

            /* Everything goes to one big file... */

            ByteArrayOutputStream bout = new ByteArrayOutputStream(8192);

            writeFileTop(bout); /* only once */

            for (i = 0; i < classes.length; i++) {

                write(bout, classes[i]);

            }

            writeIfChanged(bout.toByteArray(), outFile);

        } else {

            /* Each class goes to its own file... */

            for (i = 0; i < classes.length; i++) {

                ByteArrayOutputStream bout = new ByteArrayOutputStream(8192);

                writeFileTop(bout);

                ClassDoc clazz = classes[i];

                write(bout, clazz);

                writeIfChanged(bout.toByteArray(), getFileName(clazz.qualifiedName()));

            }

        }

    }

    /*

     * Write the contents of byte[] b to a file named file.  Writing

     * is done if either the file doesn't exist or if the contents are

     * different.

     */

    private void writeIfChanged(byte[] b, String file) throws IOException {

        File f = new File(file);

        boolean mustWrite = false;

        String event = "[No need to update file ";

        if (force) {

            mustWrite = true;

            event = "[Forcefully writing file ";

        } else {

            if (!f.exists()) {

                mustWrite = true;

                event = "[Creating file ";

            } else {

                int l = (int)f.length();

                if (b.length != l) {

                    mustWrite = true;

                    event = "[Overwriting file ";

                } else {

                    /* Lengths are equal, so read it. */

                    byte[] a = new byte[l];

                    FileInputStream in = new FileInputStream(f);

                    if (in.read(a) != l) {

                        in.close();

                        /* This can't happen, we already checked the length. */

                        Util.error("not.enough.bytes", Integer.toString(l),

                                   f.toString());

                    }

                    in.close();

                    while (--l >= 0) {

                        if (a[l] != b[l]) {

                            mustWrite = true;

                            event = "[Overwriting file ";

                        }

                    }

                }

            }

        }

        if (Util.verbose)

            Util.log(event + file + "]");

        if (mustWrite) {

            OutputStream out = new FileOutputStream(file);

            out.write(b); /* No buffering, just one big write! */

            out.close();

        }

    }

    protected String defineForStatic(ClassDoc c, FieldDoc f){

        String cnamedoc = c.qualifiedName();

        String fnamedoc = f.name();

        String cname = Mangle.mangle(cnamedoc, Mangle.Type.CLASS);

        String fname = Mangle.mangle(fnamedoc, Mangle.Type.FIELDSTUB);

        if (!f.isStatic())

            Util.bug("tried.to.define.non.static");

        if (f.isFinal()) {

            Object value = null;

            value = f.constantValue();

            if (value != null) { /* so it is a ConstantExpression */

                String constString = null;

                if ((value instanceof Integer)

                    || (value instanceof Byte)

                    || (value instanceof Character)

                    || (value instanceof Short)

                    || (value instanceof Boolean)) {

                    /* covers byte, boolean, char, short, int */

                    if(value instanceof Boolean)

                        constString = (value.toString() == "true") ? "1L" : "0L";

                    else

                        constString = value.toString() + "L";

                } else if (value instanceof Long) {

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

                    if (isWindows)

                        constString = value.toString() + "i64";

                    else

                        constString = value.toString() + "LL";

                } else if (value instanceof Float) {

                    /* bug for bug */

                    float fv = ((Float)value).floatValue();

                    if (Float.isInfinite(fv))

                        constString = ((fv < 0) ? "-" : "") + "Inff";

                    else

                        constString = value.toString() + "f";

                } else if (value instanceof Double) {

                    /* bug for bug */

                    double d = ((Double)value).doubleValue();

                    if (Double.isInfinite(d))

                        constString = ((d < 0) ? "-" : "") + "InfD";

                    else

                        constString = value.toString();

                }

                if (constString != null) {

                    StringBuffer s = new StringBuffer("#undef ");

                    s.append(cname); s.append("_"); s.append(fname); s.append(lineSep);

                    s.append("#define "); s.append(cname); s.append("_");

                    s.append(fname); s.append(" "); s.append(constString);

                    return s.toString();

                }

            }

        }

        return null;

    }

    /*

     * Deal with the C pre-processor.

     */

    protected String cppGuardBegin() {

        return "#ifdef __cplusplus" + lineSep + "extern \"C\" {" + lineSep + "#endif";

    }

    protected String cppGuardEnd() {

        return "#ifdef __cplusplus" + lineSep + "}" + lineSep + "#endif";

    }

    protected String guardBegin(String cname) {

        return "/* Header for class " + cname + " */" + lineSep + lineSep +

            "#ifndef _Included_" + cname + lineSep +

            "#define _Included_" + cname;

    }

    protected String guardEnd(String cname) {

        return "#endif";

    }

    /*

     * File name and file preamble related operations.

     */

    protected void writeFileTop(OutputStream o) {

        PrintWriter pw = wrapWriter(o);

        pw.println("/* DO NOT EDIT THIS FILE - it is machine generated */" + lineSep +

                   getIncludes());

    }

    protected String baseFileName(String clazz) {

        StringBuffer f =

            new StringBuffer(Mangle.mangle(clazz,

                                           Mangle.Type.CLASS));

        if (outDir != null) {

            f.insert(0, outDir);

        }

        return f.toString();

    }

    protected String getFileName(String clazz) {

        return baseFileName(clazz) + getFileSuffix();

    }

    protected String getFileSuffix() {

        return ".h";

    }

    /**

     * Including super classes' fields.

     */

    FieldDoc[] getAllFields(ClassDoc subclazz)

                throws ClassNotFoundException {

        Vector<FieldDoc> fields = new Vector<FieldDoc>();

        ClassDoc cd = null;

        cd = subclazz;

        while (true) {

            s.push(cd);

            ClassDoc c = cd.superclass();

            if (c == null)

                break;

            cd = c;

        }

        while (!s.empty()) {

            cd = (ClassDoc)s.pop();

            fields.addAll(Arrays.asList(cd.fields()));

        }

        return (FieldDoc[]) fields.toArray(new FieldDoc[fields.size()]);

    }

}