////////////////////////////////////////////////////////////////////////
// FILE:        versioncomparator.cpp
// AUTHOR:      Johannes Winkelmann, jw@tks6.net
// COPYRIGHT:   (c) 2004 by Johannes Winkelmann
// ---------------------------------------------------------------------
//  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 2 of the License, or
//  (at your option) any later version.
////////////////////////////////////////////////////////////////////////

// Get a test application with the following command:
// g++ -o vcomp -DTEST stringhelper.cpp versioncomparator.cpp


#include <string>
#include <cctype>
#include <vector>
#include <iostream>
#include <stdlib.h>
#include <cstring>
using namespace std;

#include "stringhelper.h"
using namespace StringHelper;

#include "versioncomparator.h"

namespace VersionComparator
{

// this is a one day hack; I'll refactor that to be nicer, clearer and
// hopefully faster. It should work pretty well though

COMP_RESULT compareVersions(const string& v1, const string& v2)
{
    vector<string> blocks1;
    vector<string> blocks2;

    tokenizeIntoBlocks(v1, blocks1);
    tokenizeIntoBlocks(v2, blocks2);
    int blockLen = normalizeVectors(blocks1, blocks2);

    for (int i = 0; i < blockLen; ++i) {
        vector<string> tokens1;
        vector<string> tokens2;
        split(blocks1[i], '.', tokens1);
        split(blocks2[i], '.', tokens2);
        int tokLen = normalizeVectors(tokens1, tokens2);

        for (int j = 0; j < tokLen; ++j) {
            if (tokens1[j] == tokens2[j]) {
                continue;
            }

            char* error1 = 0;
            char* error2 = 0;
            error1 = 0;
            error2 = 0;
            long vl1 = strtol(tokens1[j].c_str(), &error1, 10);
            long vl2 = strtol(tokens2[j].c_str(), &error2, 10);

            if (*error1 != 0 || *error2 != 0) {
                // subtokenize
                vector<string> subtokens1;
                vector<string> subtokens2;

                tokenizeMixed(tokens1[j], subtokens1);
                tokenizeMixed(tokens2[j], subtokens2);
                int subTokLen = normalizeVectors(subtokens1, subtokens2);
                for (int k = 0; k < subTokLen; ++k) {
                    long sl1 = strtol(subtokens1[k].c_str(), &error1, 10);
                    long sl2 = strtol(subtokens2[k].c_str(), &error2, 10);
                    if (*error1 == 0 && *error2 == 0) {
                        if (sl1 < sl2) {
                            return LESS;
                        } else if (sl1 > sl2) {
                            return GREATER;
                        }
                    } else {

                        // string tokens
                        if (subtokens1[k][1] == 0 && subtokens2[k][1] == 0) {

                            if (subtokens1[k][0] < subtokens2[k][0]) {
                                return LESS;
                            } else if (subtokens1[k][0] > subtokens2[k][0]) {
                                return GREATER;
                            }
                        } else {
                            // smart guessing...
                            // leaving out 'test', 'pre' and 'rc'
                            static const string versions =
                                "alpha beta gamma delta";
                            string::size_type pos1 =
                                versions.find(subtokens1[k]);
                            string::size_type pos2 =
                                versions.find(subtokens2[k]);
                            if (pos1 != string::npos && pos2 != string::npos) {
                                if (pos1 < pos2) {
                                    return LESS;
                                } else if (pos1 > pos2) {
                                    return GREATER;
                                }
                            }
                        }

                        if (subtokens1[k] != subtokens2[k]) {
                            return UNDEFINED;
                        }
                    }
                }

            } else if (vl1 < vl2) {
                return LESS;
            } else if (vl1 > vl2) {
                return GREATER;
            }
        }
    }


    return EQUAL;
}

int normalizeVectors(vector<string>& v1, vector<string>& v2)
{
    int length = max(v1.size(), v2.size());

    while (v1.size() < length) {
        v1.push_back("-1");
    }
    while (v2.size() < length) {
        v2.push_back("-1");
    }

    return length;
}

void tokenizeMixed(const string& s, vector<string>& tokens)
{
    vector<bool> digitMask;
    for (int i = 0; i < s.length(); ++i) {
        digitMask.push_back(isdigit(s[i]));
    }

    bool state = digitMask[0];
    string tok;
    tok = s[0];
    for (int i = 1; i < digitMask.size(); ++i) {
        if (digitMask[i] != state) {
            tokens.push_back(tok);
            tok = s[i];
            state = digitMask[i];
        } else {
            tok += s[i];
        }
    }
    if (tok.length() > 0) {
        tokens.push_back(tok);
    }
}

/*
  find last - (for release) -> version, release
  subdivide version in blocks, where a block is separated by any of
  the following: [-_]

  -> list of blocks, e.g.
  .  1.4.2-pre1-2 ->  [ (1.4.2) (-pre1) (2) ]
  .  1.4.2pre1-1  ->  [ (1.4.2pre1) (-1) ]
  .  1_2_2pre2-2  ->  [ (1) (2) (2pre2) (2)
*/
void tokenizeIntoBlocks(const string& version, vector<string>& blocks)
{
    string v = version;
    v = replaceAll(v, "-", "_");
    split(v, '_', blocks);
}

}


#ifdef TEST

void check(const string& v1, const string& v2,
           VersionComparator::COMP_RESULT expected, bool compare=true)
{
    VersionComparator::COMP_RESULT result =
        VersionComparator::compareVersions(v1, v2);

    if (compare) {
        cout << ((result == expected) ? "OK   " : "FAIL ");
    }

    cout << v1 << " ";
    switch (result)
    {
        case VersionComparator::LESS:
            cout << "<";
            break;
        case VersionComparator::GREATER:
            cout << ">";
            break;
        case VersionComparator::EQUAL:
            cout << "=";
            break;
        case VersionComparator::UNDEFINED:
            cout << "?";
            break;
    }

    cout << " " << v2 << endl;
}



int main(int argc, char** argv)
{
    using namespace VersionComparator;

    if (argc < 3) {
        check("1", "2", LESS);
        check("1.1", "1.2", LESS);
        check("1.1pre1", "1.1pre2", LESS);
        check("1.1pre1", "1.2pre1", LESS);
        check("1.1-pre1", "1.1-pre2", LESS);
        check("1.1_2", "1.1.2", LESS);
        check("1.1", "1.1", EQUAL);

        check("1.0PR1", "1.0PR1", EQUAL);
        check("1.0PR1", "1.0PR2", LESS);
        check("1.0PR1", "1.0RC1", UNDEFINED);

        check("1.2.3-2", "1.2.3-1", GREATER);
        check("1.0.0", "0.9", GREATER);

        check("1.4.2_3-1", "1.4.3-2", LESS);
        check("1.4.2_3-1", "1.4.2_3-2", LESS);
        check("1.4.2_3-1", "1.4.2_1-1", GREATER);

        check("1.4.2-alpha2", "1.4.2-beta1", LESS);
        check("1.4.2a-2", "1.4.2a-3", LESS);
        check("1.4.2a-2", "1.4.2b-2", LESS);
        check("1.4.2aa-2", "1.4.2bb-2", UNDEFINED);
        check("1.4.2a1-2", "1.4.2a2-2", LESS);
        check("1.4.2b1-2", "1.4.2a2-2", GREATER);
        check("1.4.2beta3", "1.4.2alpha2", GREATER);
        check("1.4.2-some", "1.4.2-1", UNDEFINED);
        check("1.4.2-1", "1.4.2-some", UNDEFINED);

        check("7.0r63-3", "7.0r68-1", LESS);
        check("27", "28e", LESS);
        
    } else {
        check(argv[1], argv[2], UNDEFINED, false);
    }
}
#endif