/*******************************************************************************
 * Copyright (c) 2009 STMicroelectronics.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Xavier Raynaud <xavier.raynaud@st.com> - initial API and implementation
 *******************************************************************************/
package org.eclipse.linuxtools.internal.gcov.parser;

import java.io.DataInput;
import java.io.DataInputStream;
import java.io.EOFException;
import java.io.IOException;
import java.util.ArrayList;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.linuxtools.internal.gcov.Activator;
import org.eclipse.linuxtools.internal.gcov.utils.BEDataInputStream;
import org.eclipse.linuxtools.internal.gcov.utils.LEDataInputStream;
import org.eclipse.linuxtools.internal.gcov.utils.MasksGenerator;
import org.eclipse.osgi.util.NLS;

public class GcdaRecordsParser {

    private static final int GCOV_DATA_MAGIC = 0x67636461; // en ASCII: 67=g 63=c 64=d 61=a
    private static final int GCOV_TAG_FUNCTION = 0x01000000;
    private static final int GCOV_COUNTER_ARCS = 0x01a10000;
    private static final int GCOV_TAG_OBJECT_SYMMARY = 0xa1000000;
    private static final int GCOV_TAG_PROGRAM_SUMMARY = 0xa3000000;

    private final ArrayList<GcnoFunction> fnctns;
    private long objSmryNbrPgmRuns = 0;
    private long pgmSmryChksm = 0;
    private long objSmryChksm = 0;
    private long objSmryArcCnts = 0;
    private long objSmrytotalCnts = 0;
    private long objSmryRunMax = 0;
    private long objSmrySumMax = 0;

    public GcdaRecordsParser(ArrayList<GcnoFunction> fnctns) {
        this.fnctns = fnctns;
    }

    public void parseGcdaRecord(DataInput stream) throws IOException, CoreException {
        // header data
        int magic = 0;

        // data & flags to process tests
        GcnoFunction currentFnctn = null;

        // read magic
        magic = stream.readInt();

        if (magic == GCOV_DATA_MAGIC) {
            stream = new BEDataInputStream((DataInputStream) stream);
        } else {
            magic = (magic >> 16) | (magic << 16);
            magic = ((magic & 0xff00ff) << 8) | ((magic >> 8) & 0xff00ff);
            if (magic == GCOV_DATA_MAGIC) {
                stream = new LEDataInputStream((DataInputStream) stream);
            } else {
                String message = NLS.bind(Messages.GcdaRecordsParser_magic_num_error, magic);
                Status status = new Status(IStatus.ERROR, Activator.PLUGIN_ID, message);
                throw new CoreException(status);
            }
        }

        // read version
        int version = stream.readInt();
        // read stamp
        // stamp = stream.readInt();
        stream.readInt();

        while (true) {
            try {
                // parse header
                int tag = stream.readInt();

                /*
                 * Move on to the next tag if an unused level (tag == O) is encountered, these do no have corresponding
                 * data lengths.
                 */
                if (tag == 0) {
                    continue;
                }

                long length = (stream.readInt() & MasksGenerator.UNSIGNED_INT_MASK);
                // parse gcda data
                switch (tag) {
                case GCOV_TAG_FUNCTION: {
                    long fnctnId = stream.readInt() & MasksGenerator.UNSIGNED_INT_MASK;
                    if (!fnctns.isEmpty()) {
                        boolean fnctnFound = false;
                        for (GcnoFunction f : fnctns) {
                            if (f.getIdent() == fnctnId) {
                                fnctnFound = true;
                                currentFnctn = f;
                                long fnctnChksm = stream.readInt() & MasksGenerator.UNSIGNED_INT_MASK;
                                if (f.getCheksum() != fnctnChksm) {
                                    String message = NLS.bind(Messages.GcdaRecordsParser_checksum_error, new Object[] {
                                            currentFnctn.getName(), fnctnId });
                                    Status status = new Status(IStatus.ERROR, Activator.PLUGIN_ID, message);
                                    throw new CoreException(status);
                                }

                                /*
                                 * danielhb, 2012-08-06: Gcov versions 4.7.0 or later (long value = 875575082) has
                                 * different format for the data file: prior format: announce_function: header
                                 * int32:ident int32:checksum new format: announce_function: header int32:ident
                                 * int32:lineno_checksum int32:cfg_checksum TL;DR Need to consume the extra long value.
                                 */
                                if (version >= 875575082) {
                                    // long cfgChksm = (stream.readInt()&MasksGenerator.UNSIGNED_INT_MASK);
                                    stream.readInt();
                                }

                                break;
                            }
                        }

                        if (fnctnFound == false) {
                            currentFnctn = null;
                            String message = NLS.bind(Messages.GcdaRecordsParser_func_not_found, fnctnId);
                            Status status = new Status(IStatus.ERROR, Activator.PLUGIN_ID, message);
                            throw new CoreException(status);
                        }

                    }
                    break;
                }

                case GCOV_COUNTER_ARCS: {
                    if (currentFnctn == null) {
                        String message = Messages.GcdaRecordsParser_func_counter_error;
                        Status status = new Status(IStatus.ERROR, Activator.PLUGIN_ID, message);
                        throw new CoreException(status);
                    }

                    if (length != 2 * (currentFnctn.getNumCounts())) {
                        String message = Messages.GcdaRecordsParser_content_inconsistent;
                        Status status = new Status(IStatus.ERROR, Activator.PLUGIN_ID, message);
                        throw new CoreException(status);
                    }

                    ArrayList<Block> fnctnBlcks = currentFnctn.getFunctionBlocks();
                    if (fnctnBlcks.isEmpty()) {
                        String message = Messages.GcdaRecordsParser_func_block_empty;
                        Status status = new Status(IStatus.ERROR, Activator.PLUGIN_ID, message);
                        throw new CoreException(status);
                    }

                    for (int i = 0; i < fnctnBlcks.size(); i++) {
                        Block b = fnctnBlcks.get(i);
                        int nonFakeExit = 0;

                        ArrayList<Arc> arcsExit = b.getExitArcs();
                        for (Arc extArc : arcsExit) {
                            if (extArc.isFake() == false)
                                nonFakeExit++;
                            if (extArc.isOnTree() == false) {
                                long arcsCnts = stream.readLong();
                                extArc.setCount(arcsCnts);
                                extArc.setCountValid(true);
                                b.decNumSuccs();
                                extArc.getDstnatnBlock().decNumPreds();
                            }
                        }

                        // If there is only one non-fake exit, it is an
                        // unconditional branch.
                        if (nonFakeExit == 1) {
                            for (Arc extArc : arcsExit) {
                                if (extArc.isFake() == false) {
                                    extArc.setUnconditionnal(true);

                                    // If this block is instrumenting a call, it might be
                                    // an artificial block. It is not artificial if it has
                                    // a non-fallthrough exit, or the destination of this
                                    // arc has more than one entry. Mark the destination
                                    // block as a return site, if none of those conditions hold.

                                    if (b.isCallSite() == true && extArc.isFallthrough() == true
                                            && extArc.getDstnatnBlock().getEntryArcs().get(0).equals(extArc)
                                            && extArc.getDstnatnBlock().getEntryArcs().size() == 1)
                                        extArc.getDstnatnBlock().setCallReturn(true);
                                }
                            }
                        }
                    }

                    // counters arcs process data reset
                    currentFnctn = null;
                    break;
                }

                case GCOV_TAG_OBJECT_SYMMARY: {
                    objSmryChksm = (stream.readInt() & MasksGenerator.UNSIGNED_INT_MASK);
                    objSmryArcCnts = (stream.readInt() & MasksGenerator.UNSIGNED_INT_MASK);
                    objSmryNbrPgmRuns = (stream.readInt() & MasksGenerator.UNSIGNED_INT_MASK);
                    objSmrytotalCnts = stream.readLong();
                    objSmryRunMax = stream.readLong();
                    objSmrySumMax = stream.readLong();
                    break;
                }

                // program summary tag
                case GCOV_TAG_PROGRAM_SUMMARY: {
                    // long[] pgmSmryskips = new long[(int) length];
                    pgmSmryChksm = (stream.readInt() & MasksGenerator.UNSIGNED_INT_MASK);
                    for (int i = 0; i < length - 1; i++) {
                        // pgmSmryskips[i] = (stream.readInt() & MasksGenerator.UNSIGNED_INT_MASK);
                        stream.readInt();
                    }
                    break;
                }

                default: {
                    // System.out.println("wrong gcda tag");
                    break;
                }
                }
            } catch (EOFException _) {
                break;
            }
        }
    }

    /**
     * @return the objSmryNbrPgmRuns
     */
    public long getObjSmryNbrPgmRuns() {
        return objSmryNbrPgmRuns;
    }

    /**
     * @return the objSmryChksm
     */
    public long getObjSmryChksm() {
        return objSmryChksm;
    }

    /**
     * @return the objSmryArcCnts
     */
    public long getObjSmryArcCnts() {
        return objSmryArcCnts;
    }

    /**
     * @return the objSmrytotalCnts
     */
    public long getObjSmrytotalCnts() {
        return objSmrytotalCnts;
    }

    /**
     * @return the objSmryRunMax
     */
    public long getObjSmryRunMax() {
        return objSmryRunMax;
    }

    /**
     * @return the objSmrySumMax
     */
    public long getObjSmrySumMax() {
        return objSmrySumMax;
    }

    /**
     * @return the pgmSmryChksm
     */
    public long getPgmSmryChksm() {
        return pgmSmryChksm;
    }

}
