/*
Copyright (c) 2016-present, Przemyslaw Skibinski
All rights reserved.

BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

You can contact the author at :
- LZ4 homepage : http://www.lz4.org
- LZ4 source repository : https://github.com/lz4/lz4
*/

#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
using namespace std;


/* trim string at the beginning and at the end */
void trim(string& s, string characters)
{
    size_t p = s.find_first_not_of(characters);
    s.erase(0, p);

    p = s.find_last_not_of(characters);
    if (string::npos != p)
       s.erase(p+1);
}


/* trim C++ style comments */
void trim_comments(string &s)
{
    size_t spos, epos;

    spos = s.find("/*");
    epos = s.find("*/");
    s = s.substr(spos+3, epos-(spos+3));
}


/* get lines until a given terminator */
vector<string> get_lines(vector<string>& input, int& linenum, string terminator)
{
    vector<string> out;
    string line;

    while ((size_t)linenum < input.size()) {
        line = input[linenum];

        if (terminator.empty() && line.empty()) { linenum--; break; }

        size_t const epos = line.find(terminator);
        if (!terminator.empty() && epos!=string::npos) {
            out.push_back(line);
            break;
        }
        out.push_back(line);
        linenum++;
    }
    return out;
}


/* print line with LZ4LIB_API removed and C++ comments not bold */
void print_line(stringstream &sout, string line)
{
    size_t spos, epos;

    if (line.substr(0,11) == "LZ4LIB_API ") line = line.substr(11);
    if (line.substr(0,12) == "LZ4FLIB_API ") line = line.substr(12);
    spos = line.find("/*");
    epos = line.find("*/");
    if (spos!=string::npos && epos!=string::npos) {
        sout << line.substr(0, spos);
        sout << "</b>" << line.substr(spos) << "<b>" << '\n';
    } else {
        sout << line << '\n';
    }
}


int main(int argc, char *argv[]) {
    char exclam;
    int linenum, chapter = 1;
    vector<string> input, lines, comments, chapters;
    string line, version;
    size_t spos, l;
    stringstream sout;
    ifstream istream;
    ofstream ostream;

    if (argc < 4) {
        cout << "usage: " << argv[0] << " [lz4_version] [input_file] [output_html]" << endl;
        return 1;
    }

    version = string(argv[1]) + " Manual";

    istream.open(argv[2], ifstream::in);
    if (!istream.is_open()) {
        cout << "Error opening file " << argv[2] << endl;
        return 1;
    }

    ostream.open(argv[3], ifstream::out);
    if (!ostream.is_open()) {
        cout << "Error opening file " << argv[3] << endl;
        return 1;
   }

    while (getline(istream, line)) {
        input.push_back(line);
    }

    for (linenum=0; (size_t)linenum < input.size(); linenum++) {
        line = input[linenum];

        /* typedefs are detected and included even if uncommented */
        if (line.substr(0,7) == "typedef" && line.find("{")!=string::npos) {
            lines = get_lines(input, linenum, "}");
            sout << "<pre><b>";
            for (l=0; l<lines.size(); l++) {
                print_line(sout, lines[l]);
            }
            sout << "</b></pre><BR>" << endl;
            continue;
        }

        /* comments of type  / * * < and  / * ! <  are detected, and only function declaration is highlighted (bold) */
        if ((line.find("/**<")!=string::npos || line.find("/*!<")!=string::npos)
          && line.find("*/")!=string::npos) {
            sout << "<pre><b>";
            print_line(sout, line);
            sout << "</b></pre><BR>" << endl;
            continue;
        }

        spos = line.find("/**=");
        if (spos==string::npos) {
            spos = line.find("/*!");
            if (spos==string::npos)
                spos = line.find("/**");
            if (spos==string::npos)
                spos = line.find("/*-");
            if (spos==string::npos)
                spos = line.find("/*=");
            if (spos==string::npos)
                continue;
            exclam = line[spos+2];
        }
        else exclam = '=';

        comments = get_lines(input, linenum, "*/");
        if (!comments.empty()) comments[0] = line.substr(spos+3);
        if (!comments.empty())
            comments[comments.size()-1] = comments[comments.size()-1].substr(0, comments[comments.size()-1].find("*/"));
        for (l=0; l<comments.size(); l++) {
            if (comments[l].compare(0, 2, " *") == 0)
                comments[l] = comments[l].substr(2);
            else if (comments[l].compare(0, 3, "  *") == 0)
                comments[l] = comments[l].substr(3);
            trim(comments[l], "*-=");
        }
        while (!comments.empty() && comments[comments.size()-1].empty()) comments.pop_back(); // remove empty line at the end
        while (!comments.empty() && comments[0].empty()) comments.erase(comments.begin()); // remove empty line at the start

        /* comments of type  / * !  mean: this is a function declaration; switch comments with declarations */
        if (exclam == '!') {
            if (!comments.empty()) comments.erase(comments.begin()); /* remove first line like "LZ4_XXX() :" */
            linenum++;
            lines = get_lines(input, linenum, "");

            sout << "<pre><b>";
            for (l=0; l<lines.size(); l++) {
                print_line(sout, lines[l]);
            }
            sout << "</b><p>";
            for (l=0; l<comments.size(); l++) {
                print_line(sout, comments[l]);
            }
            sout << "</p></pre><BR>" << endl << endl;
        } else if (exclam == '=') { /* comments of type  / * =  and  / * * =  mean: use a <H3> header and show also all functions until first empty line */
            trim(comments[0], " ");
            sout << "<h3>" << comments[0] << "</h3><pre>";
            for (l=1; l<comments.size(); l++) {
                print_line(sout, comments[l]);
            }
            sout << "</pre><b><pre>";
            lines = get_lines(input, ++linenum, "");
            for (l=0; l<lines.size(); l++) {
                print_line(sout, lines[l]);
            }
            sout << "</pre></b><BR>" << endl;
        } else { /* comments of type  / * *  and  / * -  mean: this is a comment; use a <H2> header for the first line */
            if (comments.empty()) continue;

            trim(comments[0], " ");
            sout << "<a name=\"Chapter" << chapter << "\"></a><h2>" << comments[0] << "</h2><pre>";
            chapters.push_back(comments[0]);
            chapter++;

            for (l=1; l<comments.size(); l++) {
                print_line(sout, comments[l]);
            }
            if (comments.size() > 1)
                sout << "<BR></pre>" << endl << endl;
            else
                sout << "</pre>" << endl << endl;
        }
    }

    ostream << "<html>\n<head>\n<meta http-equiv=\"Content-Type\" content=\"text/html; charset=ISO-8859-1\">\n<title>" << version << "</title>\n</head>\n<body>" << endl;
    ostream << "<h1>" << version << "</h1>\n";

    ostream << "<hr>\n<a name=\"Contents\"></a><h2>Contents</h2>\n<ol>\n";
    for (size_t i=0; i<chapters.size(); i++)
        ostream << "<li><a href=\"#Chapter" << i+1 << "\">" << chapters[i].c_str() << "</a></li>\n";
    ostream << "</ol>\n<hr>\n";

    ostream << sout.str();
    ostream << "</html>" << endl << "</body>" << endl;

    return 0;
}