/*
  Copyright 2019 Equinor ASA.

  This file is part of the Open Porous Media project (OPM).

  OPM 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.

  OPM 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 OPM.  If not, see <http://www.gnu.org/licenses/>.
*/
#include <getopt.h>

#include <iostream>
#include <iomanip>
#include <vector>

#include <opm/parser/eclipse/Parser/Parser.hpp>
#include <opm/parser/eclipse/Parser/ParseContext.hpp>
#include <opm/parser/eclipse/Parser/ErrorGuard.hpp>
#include <opm/parser/eclipse/Deck/Deck.hpp>
#include <opm/parser/eclipse/EclipseState/EclipseState.hpp>
#include <opm/parser/eclipse/EclipseState/EclipseState.hpp>
#include <opm/parser/eclipse/EclipseState/SummaryConfig/SummaryConfig.hpp>
#include <opm/parser/eclipse/EclipseState/Schedule/Schedule.hpp>


struct keyword {
    keyword(const std::string& name_arg, const std::string& filename_arg,
            std::size_t line_number_arg, std::size_t content_hash_arg) :
        name(name_arg),
        filename(filename_arg),
        line_number(line_number_arg),
        content_hash(content_hash_arg)
    {}


    std::string name;
    std::string filename;
    std::size_t line_number;
    std::size_t content_hash;
};


std::vector<keyword> load_deck(const char * deck_file) {
    Opm::ParseContext parseContext;
    Opm::ErrorGuard errors;
    Opm::Parser parser;
    std::vector<keyword> keywords;

    /* Use the same default ParseContext as flow. */
    parseContext.update(Opm::ParseContext::PARSE_RANDOM_SLASH, Opm::InputError::IGNORE);
    parseContext.update(Opm::ParseContext::PARSE_MISSING_DIMS_KEYWORD, Opm::InputError::WARN);
    parseContext.update(Opm::ParseContext::SUMMARY_UNKNOWN_WELL, Opm::InputError::WARN);
    parseContext.update(Opm::ParseContext::SUMMARY_UNKNOWN_GROUP, Opm::InputError::WARN);

    auto deck = parser.parseFile(deck_file, parseContext, errors);
    for (const auto& kw : deck) {
        std::stringstream ss;
        const auto& location = kw.location();
        ss << kw;

        keywords.emplace_back(kw.name(), location.filename, location.lineno, std::hash<std::string>{}(ss.str()));
    }
    return keywords;
}


std::size_t deck_hash(const std::vector<keyword>& keywords) {
    std::stringstream ss;
    for (const auto& kw : keywords)
        ss << kw.content_hash;

    return std::hash<std::string>{}(ss.str());
}


void print_keywords(const std::vector<keyword>& keywords, bool location_info) {
    for (const auto& kw : keywords) {
        if (location_info)
            std::cout << std::setw(8) << std::left << kw.name << " : " << kw.filename << ":" << kw.line_number << " " << kw.content_hash << std::endl;
        else
            std::cout << std::setw(8) << std::left << kw.name << " : " << kw.content_hash << std::endl;
    }
    std::cout << std::endl;
    std::cout << std::setw(8) << std::left << "Total" << " : " << deck_hash(keywords) << std::endl;
}


void print_help_and_exit() {
    const char * help_text = R"(The purpose of the opmhash program is to load a deck and create a summary, by
diffing two such summaries it is simple to determine if two decks are similar.
For each keyword a hash of the normalized content is calculated. The output of
the program will look like this:

  RUNSPEC  : 13167205945009276792
  TITLE    : 16047371705964514902
  DIMENS   : 1264233216877515756
  NONNC    : 10052807539267647959
  OIL      : 6013609912232720008
  WATER    : 14106203893673265964

  Total    : 7362809723723482303

Where the 'random' integer following each keyword is the hash of the content of
that keyword. The hashing is insensitive to changes in white-space and comments
and file location. At the bottom comes a total hash of the complete content. The
hash of each keyword is insensitive to shuffling of keywords, but the total hash
depends on the keyword order.

Options:

 -l : Add filename and linenumber information to each keyword.
 -s : Short form - only print the hash of the complete deck.

)";
    std::cerr << help_text << std::endl;
    exit(1);
}


int main(int argc, char** argv) {
    int arg_offset = 1;
    bool location_info = false;
    bool short_form = false;

    while (true) {
        int c;
        c = getopt(argc, argv, "ls");
        if (c == -1)
            break;

        switch(c) {
        case 'l':
            location_info = true;
            break;
        case 's':
            short_form = true;
            break;
        }
    }
    arg_offset = optind;
    if (arg_offset >= argc)
        print_help_and_exit();

    auto keywords = load_deck(argv[arg_offset]);
    if (short_form)
        std::cout << deck_hash(keywords) << std::endl;
    else
        print_keywords(keywords, location_info);
}