/*
 * 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.
 
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.
/**
 * 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;
}