/*

 * Copyright (c) 2009, 2010, 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.javap;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.StringReader;

import java.util.ArrayList;

import java.util.List;

import java.util.Set;

import java.util.SortedMap;

import java.util.SortedSet;

import java.util.TreeMap;

import java.util.TreeSet;

import javax.tools.JavaFileManager;

import javax.tools.JavaFileManager.Location;

import javax.tools.JavaFileObject;

import javax.tools.StandardLocation;

import com.sun.tools.classfile.Attribute;

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.Code_attribute;

import com.sun.tools.classfile.ConstantPoolException;

import com.sun.tools.classfile.Instruction;

import com.sun.tools.classfile.LineNumberTable_attribute;

import com.sun.tools.classfile.SourceFile_attribute;

/**

 * Annotate instructions with source code.

 *

 *  <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 class SourceWriter extends InstructionDetailWriter {

    static SourceWriter instance(Context context) {

        SourceWriter instance = context.get(SourceWriter.class);

        if (instance == null)

            instance = new SourceWriter(context);

        return instance;

    }

    protected SourceWriter(Context context) {

        super(context);

        context.put(SourceWriter.class, this);

    }

    void setFileManager(JavaFileManager fileManager) {

        this.fileManager = fileManager;

    }

    public void reset(ClassFile cf, Code_attribute attr) {

        setSource(cf);

        setLineMap(attr);

    }

    public void writeDetails(Instruction instr) {

        String indent = space(40); // could get from Options?

        Set<Integer> lines = lineMap.get(instr.getPC());

        if (lines != null) {

            for (int line: lines) {

                print(indent);

                print(String.format(" %4d ", line));

                if (line < sourceLines.length)

                    print(sourceLines[line]);

                println();

                int nextLine = nextLine(line);

                for (int i = line + 1; i < nextLine; i++) {

                    print(indent);

                    print(String.format("(%4d)", i));

                    if (i < sourceLines.length)

                        print(sourceLines[i]);

                    println();

                }

            }

        }

    }

    public boolean hasSource() {

        return (sourceLines.length > 0);

    }

    private void setLineMap(Code_attribute attr) {

        SortedMap<Integer, SortedSet<Integer>> map = new TreeMap<>();

        SortedSet<Integer> allLines = new TreeSet<>();

        for (Attribute a: attr.attributes) {

            if (a instanceof LineNumberTable_attribute) {

                LineNumberTable_attribute t = (LineNumberTable_attribute) a;

                for (LineNumberTable_attribute.Entry e: t.line_number_table) {

                    int start_pc = e.start_pc;

                    int line = e.line_number;

                    SortedSet<Integer> pcLines = map.get(start_pc);

                    if (pcLines == null) {

                        pcLines = new TreeSet<>();

                        map.put(start_pc, pcLines);

                    }

                    pcLines.add(line);

                    allLines.add(line);

                }

            }

        }

        lineMap = map;

        lineList = new ArrayList<>(allLines);

    }

    private void setSource(ClassFile cf) {

        if (cf != classFile) {

            classFile = cf;

            sourceLines = splitLines(readSource(cf));

        }

    }

    private String readSource(ClassFile cf) {

        if (fileManager == null)

            return null;

        Location location;

        if (fileManager.hasLocation((StandardLocation.SOURCE_PATH)))

            location = StandardLocation.SOURCE_PATH;

        else

            location = StandardLocation.CLASS_PATH;

        // Guess the source file for a class from the package name for this

        // class and the base of the source file. This avoids having to read

        // additional classes to determine the outmost class from any

        // InnerClasses and EnclosingMethod attributes.

        try {

            String className = cf.getName();

            SourceFile_attribute sf =

                    (SourceFile_attribute) cf.attributes.get(Attribute.SourceFile);

            if (sf == null) {

                report(messages.getMessage("err.no.SourceFile.attribute"));

                return null;

            }

            String sourceFile = sf.getSourceFile(cf.constant_pool);

            String fileBase = sourceFile.endsWith(".java")

                ? sourceFile.substring(0, sourceFile.length() - 5) : sourceFile;

            int sep = className.lastIndexOf("/");

            String pkgName = (sep == -1 ? "" : className.substring(0, sep+1));

            String topClassName = (pkgName + fileBase).replace('/', '.');

            JavaFileObject fo =

                    fileManager.getJavaFileForInput(location,

                    topClassName,

                    JavaFileObject.Kind.SOURCE);

            if (fo == null) {

                report(messages.getMessage("err.source.file.not.found"));

                return null;

            }

            return fo.getCharContent(true).toString();

        } catch (ConstantPoolException e) {

            report(e);

            return null;

        } catch (IOException e) {

            report(e.getLocalizedMessage());

            return null;

        }

    }

    private static String[] splitLines(String text) {

        if (text == null)

            return new String[0];

        List<String> lines = new ArrayList<>();

        lines.add(""); // dummy line 0

        try {

            BufferedReader r = new BufferedReader(new StringReader(text));

            String line;

            while ((line = r.readLine()) != null)

                lines.add(line);

        } catch (IOException ignore) {

        }

        return lines.toArray(new String[lines.size()]);

    }

    private int nextLine(int line) {

        int i = lineList.indexOf(line);

        if (i == -1 || i == lineList.size() - 1)

            return - 1;

        return lineList.get(i + 1);

    }

    private JavaFileManager fileManager;

    private ClassFile classFile;

    private SortedMap<Integer, SortedSet<Integer>> lineMap;

    private List<Integer> lineList;

    private String[] sourceLines;

}