/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2015 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

#include <iostream>
#include <vector>
#include <string>
#include <fstream>

#include <mapnik/util/fs.hpp>
#include <mapnik/geometry_envelope.hpp>
#include <mapnik/quad_tree.hpp>
#include "../../plugins/input/csv/csv_utils.hpp"

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#pragma GCC diagnostic ignored "-Wunused-local-typedef"
#include <boost/algorithm/string.hpp>
#include <boost/program_options.hpp>
#pragma GCC diagnostic pop

#include <boost/interprocess/mapped_region.hpp>
#include <boost/interprocess/streams/bufferstream.hpp>
#include <mapnik/mapped_memory_cache.hpp>
#include <boost/version.hpp>

const int DEFAULT_DEPTH = 8;
const double DEFAULT_RATIO = 0.55;

int main (int argc, char** argv)
{
    //using namespace mapnik;
    namespace po = boost::program_options;
    using std::string;
    using std::vector;
    using std::clog;
    using std::endl;

    bool verbose = false;
    unsigned int depth = DEFAULT_DEPTH;
    double ratio = DEFAULT_RATIO;
    vector<string> csv_files;
    std::string separator;
    std::string escape;
    std::string quote;
    std::string manual_headers;
    try
    {
        po::options_description desc("csvindex utility");
        desc.add_options()
            ("help,h", "produce usage message")
            ("version,V","print version string")
            ("verbose,v","verbose output")
            ("depth,d", po::value<unsigned int>(), "max tree depth\n(default 8)")
            ("ratio,r",po::value<double>(),"split ratio (default 0.55)")
            ("separator,s", po::value<std::string>(), "CSV columns separator")
            ("escape,e", po::value<std::string>(), "CSV columns escape")
            ("quote,q", po::value<std::string>(), "CSV columns quote")
            ("manual-headers,H", po::value<std::string>(), "CSV manual headers string")
            ("csv_files",po::value<vector<string> >(),"CSV files to index: file1 file2 ...fileN")
            ;

        po::positional_options_description p;
        p.add("csv_files",-1);
        po::variables_map vm;
        po::store(po::command_line_parser(argc, argv).options(desc).positional(p).run(), vm);
        po::notify(vm);

        if (vm.count("version"))
        {
            clog << "version 0.3.0" <<std::endl;
            return 1;
        }

        if (vm.count("help"))
        {
            clog << desc << endl;
            return 1;
        }
        if (vm.count("verbose"))
        {
            verbose = true;
        }
        if (vm.count("depth"))
        {
            depth = vm["depth"].as<unsigned int>();
        }
        if (vm.count("ratio"))
        {
            ratio = vm["ratio"].as<double>();
        }
        if (vm.count("separator"))
        {
            separator = vm["separator"].as<std::string>();
        }
        if (vm.count("escape"))
        {
            separator = vm["escape"].as<std::string>();
        }
        if (vm.count("quote"))
        {
            separator = vm["quote"].as<std::string>();
        }
        if (vm.count("manual-headers"))
        {
            manual_headers = vm["manual-headers"].as<std::string>();
        }
        if (vm.count("csv_files"))
        {
            csv_files=vm["csv_files"].as< vector<string> >();
        }
    }
    catch (std::exception const& ex)
    {
        clog << "Error: " << ex.what() << endl;
        return -1;
    }

    clog << "max tree depth:" << depth << endl;
    clog << "split ratio:" << ratio << endl;

    if (csv_files.size() == 0)
    {
        clog << "no csv files to index" << endl;
        return 0;
    }

    for (auto const& filename : csv_files)
    {
        clog << "processing " << filename << endl;
        std::string csvname (filename);
        if (! mapnik::util::exists (csvname))
        {
            clog << "Error : file " << csvname << " does not exist" << endl;
            continue;
        }

        //std::ifstream csv_file(csvname.c_str(),std::ios_base::in | std::ios_base::binary);

        using file_source_type = boost::interprocess::ibufferstream;
        file_source_type csv_file;

        mapnik::mapped_region_ptr mapped_region;
        boost::optional<mapnik::mapped_region_ptr> memory =
            mapnik::mapped_memory_cache::instance().find(csvname, true);
        if (memory)
        {
            mapped_region = *memory;
            csv_file.buffer(static_cast<char*>(mapped_region->get_address()),mapped_region->get_size());
        }
        else
        {
            clog << "Error : cannot mmap " << csvname << endl;
            continue;
        }

        auto file_length = detail::file_length(csv_file);
        // set back to start
        csv_file.seekg(0, std::ios::beg);
        char newline;
        bool has_newline;
        std::tie(newline, has_newline) = detail::autodect_newline(csv_file, file_length);

        // set back to start
        csv_file.seekg(0, std::ios::beg);
        // get first line
        std::string csv_line;
        std::getline(csv_file, csv_line, csv_file.widen(newline));
        mapnik::util::trim(separator);
        if (separator.empty())  separator = detail::detect_separator(csv_line);
        csv_file.seekg(0, std::ios::beg);

        mapnik::util::trim(escape);
        if (escape.empty()) escape = "\\";

        mapnik::util::trim(quote);
        if (quote.empty()) quote = "\"";
        int line_number = 1;
        detail::geometry_column_locator locator;
        std::vector<std::string> headers;
        if (!manual_headers.empty())
        {
            std::size_t index = 0;
            headers = csv_utils::parse_line(manual_headers, separator);
            for (auto const& header : headers)
            {
                std::string val = mapnik::util::trim_copy(header);
                detail::locate_geometry_column(val, index++, locator);
                headers.push_back(val);
            }
        }
        else // parse first line as headers
        {
            while (std::getline(csv_file,csv_line,csv_file.widen(newline)))
            {
                try
                {
                    headers = csv_utils::parse_line(csv_line, separator);
                    // skip blank lines
                    if (headers.size() > 0 && headers[0].empty()) ++line_number;
                    else
                    {
                        std::size_t index = 0;
                        for (auto & header : headers)
                        {
                            mapnik::util::trim(header);
                            if (header.empty())
                            {
                                // create a placeholder for the empty header
                                std::ostringstream s;
                                s << "_" << index;
                                header = s.str();
                            }
                            else
                            {
                                detail::locate_geometry_column(header, index, locator);
                            }
                            ++index;
                        }
                        ++line_number;
                        break;
                    }
                }
                catch (std::exception const& ex)
                {
                    std::string s("CSV index: error parsing headers: ");
                    s += ex.what();
                    std::clog << s << std::endl;
                    return 1;
                }
            }
        }

        if (locator.type == detail::geometry_column_locator::UNKNOWN)
        {
            std::clog << "CSV index: could not detect column headers with the name of wkt, geojson, x/y, or "
                      << "latitude/longitude - this is required for reading geometry data" << std::endl;
            return 1;
        }

        std::size_t num_headers = headers.size();
        auto pos = csv_file.tellg();

        // handle rare case of a single line of data and user-provided headers
        // where a lack of a newline will mean that std::getline returns false
        bool is_first_row = false;
        if (!has_newline)
        {
            csv_file.setstate(std::ios::failbit);
            pos = 0;
            if (!csv_line.empty())
            {
                is_first_row = true;
            }
        }

        mapnik::box2d<double> extent;
        using box_type = mapnik::box2d<double>;
        using item_type = std::pair<box_type, std::pair<unsigned, unsigned>>;
        std::vector<item_type> boxes;

        while (is_first_row || std::getline(csv_file, csv_line, csv_file.widen(newline)))
        {
            auto record_offset = pos;
            auto record_size = csv_line.length();
            pos = csv_file.tellg();
            is_first_row = false;
            // skip blank lines
            unsigned line_length = csv_line.length();
            if (line_length <= 10)
            {
                std::string trimmed = csv_line;
                boost::trim_if(trimmed, boost::algorithm::is_any_of("\",'\r\n "));
                if (trimmed.empty())
                {
                    std::clog << "CSV index: empty row encountered at line: " << line_number << std::endl;
                    continue;
                }
            }
            try
            {
                auto values = csv_utils::parse_line(csv_line, separator);
                unsigned num_fields = values.size();
                if (num_fields > num_headers)
                {
                    std::ostringstream s;
                    s << "CSV Index: # of columns("
                      << num_fields << ") > # of headers("
                      << num_headers << ") parsed for row " << line_number << "\n";
                    std::clog << s.str() << std::endl;
                    return 1;
                }
                else if (num_fields < num_headers)
                {
                    std::ostringstream s;
                    s << "CSV Index: # of headers("
                      << num_headers << ") > # of columns("
                      << num_fields << ") parsed for row " << line_number << "\n";
                    std::clog << s.str() << std::endl;
                    return 1;
                }

                auto geom = detail::extract_geometry(values, locator);
                if (!geom.is<mapnik::geometry::geometry_empty>())
                {
                    auto box = mapnik::geometry::envelope(geom);
                    if (!extent.valid()) extent = box;
                    else extent.expand_to_include(box);
                    boxes.emplace_back(std::move(box), make_pair(record_offset, record_size));
                }
                else
                {
                    std::ostringstream s;
                    s << "CSV Index: expected geometry column: could not parse row "
                      << line_number << " "
                      << values[locator.index] << "'";
                    std::clog << s.str() << std::endl;;
                }
            }
            catch (std::exception const& ex)
            {
                std::ostringstream s;
                s << "CSV Index: unexpected error parsing line: " << line_number
                  << " - found " << headers.size() << " with values like: " << csv_line << "\n"
                  << " and got error like: " << ex.what();
                std::clog << s.str() << std::endl;
                return 1;
            }
        }

        std::clog << extent << std::endl;
        mapnik::quad_tree<std::pair<std::size_t, std::size_t>> tree(extent, depth, ratio);
        for (auto const& item : boxes)
        {
            tree.insert(std::get<1>(item), std::get<0>(item));
        }

        std::fstream file((csvname + ".index").c_str(),
                          std::ios::in | std::ios::out | std::ios::trunc | std::ios::binary);
        if (!file)
        {
            clog << "cannot open index file for writing file \""
                 << (csvname + ".index") << "\"" << endl;
        }
        else
        {
            tree.trim();
            std::clog <<  "number nodes=" << tree.count() << std::endl;
            //tree.print();
            file.exceptions(std::ios::failbit | std::ios::badbit);
            tree.write(file);
            file.flush();
            file.close();
        }
    }
    clog << "done!" << endl;
    return 0;
}