// stringutils.cpp

/*    Copyright 2009 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    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 Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects
 *    for all of the code used other than as permitted herein. If you modify
 *    file(s) with this exception, you may extend this exception to your
 *    version of the file(s), but you are not obligated to do so. If you do not
 *    wish to do so, delete this exception statement from your version. If you
 *    delete this exception statement from all source files in the program,
 *    then also delete it in the license file.
 */

#include "mongo/platform/basic.h"

#include "mongo/util/stringutils.h"

namespace mongo {

    using std::string;
    using std::vector;

    void splitStringDelim( const string& str , vector<string>* res , char delim ) {
        if ( str.empty() )
            return;

        size_t beg = 0;
        size_t pos = str.find( delim );
        while ( pos != string::npos ) {
            res->push_back( str.substr( beg, pos - beg) );
            beg = ++pos;
            pos = str.find( delim, beg );
        }
        res->push_back( str.substr( beg ) );
    }

    void joinStringDelim( const vector<string>& strs , string* res , char delim ) {
        for ( vector<string>::const_iterator it = strs.begin(); it != strs.end(); ++it ) {
            if ( it !=strs.begin() ) res->push_back( delim );
            res->append( *it );
        }
    }

    LexNumCmp::LexNumCmp( bool lexOnly ) :
    _lexOnly( lexOnly ) {
    }

    int LexNumCmp::cmp( StringData sd1, StringData sd2, bool lexOnly ) {
        bool startWord = true;

        size_t s1 = 0;
        size_t s2 = 0;

        while( s1 < sd1.size() && s2 < sd2.size() ) {
            bool d1 = ( sd1[s1] == '.' );
            bool d2 = ( sd2[s2] == '.' );
            if ( d1 && !d2 )
                return -1;
            if ( d2 && !d1 )
                return 1;
            if ( d1 && d2 ) {
                ++s1; ++s2;
                startWord = true;
                continue;
            }

            bool p1 = ( sd1[s1] == (char)255 );
            bool p2 = ( sd2[s2] == (char)255 );

            if ( p1 && !p2 )
                return 1;
            if ( p2 && !p1 )
                return -1;

            if ( !lexOnly ) {
                bool n1 = isdigit( sd1[s1] );
                bool n2 = isdigit( sd2[s2] );

                if ( n1 && n2 ) {
                    // get rid of leading 0s
                    if ( startWord ) {
                        while ( s1 < sd1.size() && sd1[s1] == '0' ) s1++;
                        while ( s2 < sd2.size() && sd2[s2] == '0' ) s2++;
                    }

                    size_t e1 = s1;
                    size_t e2 = s2;

                    while ( e1 < sd1.size() && isdigit( sd1[e1] ) ) e1++;
                    while ( e2 < sd2.size() && isdigit( sd2[e2] ) ) e2++;

                    size_t len1 = e1-s1;
                    size_t len2 = e2-s2;

                    int result;
                    // if one is longer than the other, return
                    if ( len1 > len2 ) {
                        return 1;
                    }
                    else if ( len2 > len1 ) {
                        return -1;
                    }
                    // if the lengths are equal, just strcmp
                    else {
                        result = strncmp( sd1.rawData() + s1,
                                          sd2.rawData() + s2,
                                          len1 );
                        if ( result )
                            return ( result > 0) ? 1 : -1;
                    }

                    // otherwise, the numbers are equal
                    s1 = e1;
                    s2 = e2;
                    startWord = false;
                    continue;
                }

                if ( n1 )
                    return 1;

                if ( n2 )
                    return -1;
            }

            if ( sd1[s1] > sd2[s2] )
                return 1;

            if ( sd2[s2] > sd1[s1] )
                return -1;

            s1++; s2++;
            startWord = false;
        }

        if ( s1 < sd1.size() && sd1[s1] )
            return 1;
        if ( s2 < sd2.size() && sd2[s2] )
            return -1;
        return 0;
    }

    int LexNumCmp::cmp( StringData s1, StringData s2 ) const {
        return cmp( s1, s2, _lexOnly );
    }
    bool LexNumCmp::operator()( StringData s1, StringData s2 ) const {
        return cmp( s1, s2 ) < 0;
    }

    int versionCmp(const StringData rhs, const StringData lhs) {
        if (rhs == lhs) return 0;

        // handle "1.2.3-" and "1.2.3-pre"
        if (rhs.size() < lhs.size()) {
            if (strncmp(rhs.rawData(), lhs.rawData(), rhs.size()) == 0 && lhs[rhs.size()] == '-') return +1;
        }
        else if (rhs.size() > lhs.size()) {
            if (strncmp(rhs.rawData(), lhs.rawData(), lhs.size()) == 0 && rhs[lhs.size()] == '-') return -1;
        }

        return LexNumCmp::cmp(rhs, lhs, false);
    }

} // namespace mongo