/*
 *  Copyright (C) 2007  Thiago Macieira <thiago@kde.org>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <QTextStream>
#include <QList>
#include <QFile>
#include <QDebug>

#include "ruleparser.h"

Rules::Rules(const QString &fn)
    : filename(fn)
{
}

Rules::~Rules()
{
}

const QList<Rules::Repository> Rules::repositories() const
{
    return m_repositories;
}

const QList<Rules::Match> Rules::matchRules() const
{
    return m_matchRules;
}

QStringList Rules::readRules(const QString &filename) const
{
    QFile file(filename);
    if (!file.open(QIODevice::ReadOnly))
        qFatal("Could not read the rules file: %s", qPrintable(filename));
    QStringList allLines;
    QRegExp includeLine("include\\s+(.*)", Qt::CaseInsensitive);

    QTextStream s(&file);
    QStringList lines = s.readAll().split('\n', QString::KeepEmptyParts);

    QStringList::iterator it;
    for(it = lines.begin(); it != lines.end(); ++it) {
        QString line = *it;
        bool isIncludeRule = includeLine.exactMatch(line);

        if (isIncludeRule) {
            int index = filename.lastIndexOf("/");
            QString includeFile = filename.left( index + 1) + includeLine.cap(1);
            allLines.append( readRules(includeFile));
        } else {
            allLines.append(line);
        }
    }
    file.close();
    return allLines;
}

void Rules::load()
{
    QStringList lines = readRules(filename);
    // initialize the regexps we will use
    QRegExp repoLine("create repository\\s+(\\S+)", Qt::CaseInsensitive);

    QRegExp matchLine("match\\s+(.*)", Qt::CaseInsensitive);
    QRegExp matchActionLine("action\\s+(\\w+)", Qt::CaseInsensitive);
    QRegExp matchRepoLine("repository\\s+(\\S+)", Qt::CaseInsensitive);
    QRegExp matchBranchLine("branch\\s+(\\S+)", Qt::CaseInsensitive);
    QRegExp matchRevLine("(min|max) revision (\\d+)", Qt::CaseInsensitive);
    QRegExp matchAnnotateLine("annotated\\s+(\\S+)", Qt::CaseInsensitive);
    QRegExp matchPrefixLine("prefix\\s+(\\S+)", Qt::CaseInsensitive);
    QRegExp declareLine("declare\\s+(\\S+)\\s*=\\s*(\\S+)", Qt::CaseInsensitive);
    QRegExp variableLine("\\$\\{(\\S+)\\}", Qt::CaseInsensitive);

    QMap<QString,QString> variables;

    enum { ReadingNone, ReadingRepository, ReadingMatch } state = ReadingNone;
    Repository repo;
    Match match;
    int lineNumber = 0;

    QStringList::iterator it;
    for(it = lines.begin(); it != lines.end(); ++it) {
        ++lineNumber;
        QString origLine = *it;
        QString line = origLine;

        int hash = line.indexOf('#');
        if (hash != -1)
            line.truncate(hash);
        line = line.trimmed();
        if (line.isEmpty())
            continue;

        int index = variableLine.indexIn(line);
        if ( index != -1 ) {
            if (!variables.contains(variableLine.cap(1)))
                qFatal("Undeclared variable: %s", qPrintable(variableLine.cap(1)));
            line = line.replace(variableLine, variables[variableLine.cap(1)]);
        }
        if (state == ReadingRepository) {
            if (matchBranchLine.exactMatch(line)) {
                Repository::Branch branch;
                branch.name = matchBranchLine.cap(1);

                repo.branches += branch;
                continue;
            } else if (matchRepoLine.exactMatch(line)) {
                repo.forwardTo = matchRepoLine.cap(1);
                continue;
            } else if (matchPrefixLine.exactMatch(line)) {
                repo.prefix = matchPrefixLine.cap(1);
                continue;
            } else if (line == "end repository") {
                m_repositories += repo;
                {
                    // clear out 'repo'
                    Repository temp;
                    std::swap(repo, temp);
                }
                state = ReadingNone;
                continue;
            }
        } else if (state == ReadingMatch) {
            if (matchRepoLine.exactMatch(line)) {
                match.repository = matchRepoLine.cap(1);
                continue;
            } else if (matchBranchLine.exactMatch(line)) {
                match.branch = matchBranchLine.cap(1);
                continue;
            } else if (matchRevLine.exactMatch(line)) {
                if (matchRevLine.cap(1) == "min")
                    match.minRevision = matchRevLine.cap(2).toInt();
                else            // must be max
                    match.maxRevision = matchRevLine.cap(2).toInt();
                continue;
            } else if (matchPrefixLine.exactMatch(line)) {
                match.prefix = matchPrefixLine.cap(1);
                if( match.prefix.startsWith('/'))
                    match.prefix = match.prefix.mid(1);
                if( !match.prefix.endsWith('/'))
                    match.prefix.append('/');
                continue;
            } else if (matchActionLine.exactMatch(line)) {
                QString action = matchActionLine.cap(1);
                if (action == "export")
                    match.action = Match::Export;
                else if (action == "ignore")
                    match.action = Match::Ignore;
                else if (action == "recurse")
                    match.action = Match::Recurse;
                else
                    qFatal("Invalid action \"%s\" on line %d", qPrintable(action), lineNumber);
                continue;
            } else if (matchAnnotateLine.exactMatch(line)) {
                match.annotate = matchAnnotateLine.cap(1) == "true";
                continue;
            } else if (line == "end match") {
                if (!match.repository.isEmpty())
                    match.action = Match::Export;
                m_matchRules += match;
                state = ReadingNone;
                continue;
            }
        }

        bool isRepositoryRule = repoLine.exactMatch(line);
        bool isMatchRule = matchLine.exactMatch(line);
        bool isVariableRule = declareLine.exactMatch(line);

        if (isRepositoryRule) {
            // repository rule
            state = ReadingRepository;
            repo = Repository(); // clear
            repo.name = repoLine.cap(1);
            repo.lineNumber = lineNumber;
            repo.filename = filename;
        } else if (isMatchRule) {
            // match rule
            state = ReadingMatch;
            match = Match();
            match.rx = QRegExp(matchLine.cap(1), Qt::CaseSensitive, QRegExp::RegExp2);
            if( !match.rx.isValid() )
                qFatal("Malformed regular expression '%s' in file:'%s':%d, Error: %s",
                       qPrintable(matchLine.cap(1)), qPrintable(filename), lineNumber,
                       qPrintable(match.rx.errorString()));
            match.lineNumber = lineNumber;
            match.filename = filename;
        } else if (isVariableRule) {
            QString variable = declareLine.cap(1);
            QString value = declareLine.cap(2);
            variables.insert(variable, value);
        } else {
            qFatal("Malformed line in rules file: line %d: %s",
                   lineNumber, qPrintable(origLine));
        }
    }
}

#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug s, const Rules::Match &rule)
{
    s.nospace() << rule.info();
    return s.space();
}

#endif