#include "partitioner/partitioner.hpp"
#include "partitioner/partitioner_config.hpp"

#include "osrm/exception.hpp"
#include "util/log.hpp"
#include "util/meminfo.hpp"
#include "util/timing_util.hpp"
#include "util/version.hpp"

#include <boost/algorithm/string/join.hpp>
#include <boost/program_options.hpp>
#include <boost/range/adaptor/transformed.hpp>

#include <filesystem>
#include <iostream>
#include <iterator>
#include <regex>
#include <thread>

using namespace osrm;

enum class return_code : unsigned
{
    ok,
    fail,
    exit
};

struct MaxCellSizesArgument
{
    std::vector<size_t> value;
};

std::ostream &operator<<(std::ostream &os, const MaxCellSizesArgument &arg)
{
    auto to_string = [](std::size_t x) { return std::to_string(x); };
    return os << boost::algorithm::join(arg.value | boost::adaptors::transformed(to_string), ",");
}

void validate(boost::any &v, const std::vector<std::string> &values, MaxCellSizesArgument *, int)
{
    using namespace boost::program_options;
    using namespace boost::adaptors;

    // Make sure no previous assignment to 'v' was made.
    validators::check_first_occurrence(v);
    // Extract the first string from 'values'. If there is more than
    // one string, it's an error, and exception will be thrown.
    const std::string &s = validators::get_single_string(values);

    std::regex re(",");
    std::vector<size_t> output;
    std::transform(std::sregex_token_iterator(s.begin(), s.end(), re, -1),
                   std::sregex_token_iterator(),
                   std::back_inserter(output),
                   [](const auto &x)
                   {
                       try
                       {
                           return boost::lexical_cast<std::size_t>(x);
                       }
                       catch (const boost::bad_lexical_cast &)
                       {
                           throw validation_error(validation_error::invalid_option_value);
                       }
                   });

    v = boost::any(MaxCellSizesArgument{output});
}

return_code parseArguments(int argc,
                           char *argv[],
                           std::string &verbosity,
                           partitioner::PartitionerConfig &config)
{
    // declare a group of options that will be allowed only on command line
    boost::program_options::options_description generic_options("Options");
    generic_options.add_options()("version,v", "Show version")("help,h", "Show this help message")(
        "verbosity,l",
        boost::program_options::value<std::string>(&verbosity)->default_value("INFO"),
        std::string("Log verbosity level: " + util::LogPolicy::GetLevels()).c_str());

    // declare a group of options that will be allowed both on command line
    boost::program_options::options_description config_options("Configuration");
    config_options.add_options()
        //
        ("threads,t",
         boost::program_options::value<unsigned int>(&config.requested_num_threads)
             ->default_value(std::thread::hardware_concurrency()),
         "Number of threads to use")
        //
        ("balance",
         boost::program_options::value<double>(&config.balance)->default_value(config.balance),
         "Balance for left and right side in single bisection")
        //
        ("boundary",
         boost::program_options::value<double>(&config.boundary_factor)
             ->default_value(config.boundary_factor),
         "Percentage of embedded nodes to contract as sources and sinks")
        //
        ("optimizing-cuts",
         boost::program_options::value<std::size_t>(&config.num_optimizing_cuts)
             ->default_value(config.num_optimizing_cuts),
         "Number of cuts to use for optimizing a single bisection")
        //
        ("small-component-size",
         boost::program_options::value<std::size_t>(&config.small_component_size)
             ->default_value(config.small_component_size),
         "Size threshold for small components.")
        //
        ("max-cell-sizes",
         boost::program_options::value<MaxCellSizesArgument>()->default_value(
             MaxCellSizesArgument{config.max_cell_sizes}),
         "Maximum cell sizes starting from the level 1. The first cell size value is a bisection "
         "termination citerion");

    // hidden options, will be allowed on command line, but will not be
    // shown to the user
    boost::program_options::options_description hidden_options("Hidden options");
    hidden_options.add_options()(
        "input,i",
        boost::program_options::value<std::filesystem::path>(&config.base_path),
        "Input base file path");

    // positional option
    boost::program_options::positional_options_description positional_options;
    positional_options.add("input", 1);

    // combine above options for parsing
    boost::program_options::options_description cmdline_options;
    cmdline_options.add(generic_options).add(config_options).add(hidden_options);

    const auto *executable = argv[0];
    boost::program_options::options_description visible_options(
        std::filesystem::path(executable).filename().string() + " <input.osrm> [options]");
    visible_options.add(generic_options).add(config_options);

    // parse command line options
    boost::program_options::variables_map option_variables;
    try
    {
        boost::program_options::store(boost::program_options::command_line_parser(argc, argv)
                                          .options(cmdline_options)
                                          .positional(positional_options)
                                          .run(),
                                      option_variables);
    }
    catch (const boost::program_options::error &e)
    {
        util::Log(logERROR) << e.what();
        return return_code::fail;
    }

    if (option_variables.count("version"))
    {
        std::cout << OSRM_VERSION << std::endl;
        return return_code::exit;
    }

    if (option_variables.count("help"))
    {
        std::cout << visible_options;
        return return_code::exit;
    }

    boost::program_options::notify(option_variables);

    if (!option_variables.count("input"))
    {
        std::cout << visible_options;
        return return_code::fail;
    }

    if (option_variables.count("max-cell-sizes"))
    {
        config.max_cell_sizes = option_variables["max-cell-sizes"].as<MaxCellSizesArgument>().value;

        if (!std::is_sorted(config.max_cell_sizes.begin(), config.max_cell_sizes.end()))
        {
            util::Log(logERROR)
                << "The maximum cell sizes array must be sorted in non-descending order.";
            return return_code::fail;
        }
    }

    return return_code::ok;
}

int main(int argc, char *argv[])
try
{
    util::LogPolicy::GetInstance().Unmute();
    std::string verbosity;
    partitioner::PartitionerConfig partition_config;

    const auto result = parseArguments(argc, argv, verbosity, partition_config);

    if (return_code::fail == result)
    {
        return EXIT_FAILURE;
    }

    if (return_code::exit == result)
    {
        return EXIT_SUCCESS;
    }

    util::LogPolicy::GetInstance().SetLevel(verbosity);

    // set the default in/output names
    partition_config.UseDefaultOutputNames(partition_config.base_path);

    if (1 > partition_config.requested_num_threads)
    {
        util::Log(logERROR) << "Number of threads must be 1 or larger";
        return EXIT_FAILURE;
    }

    auto check_file = [](const std::filesystem::path &path)
    {
        if (!std::filesystem::is_regular_file(path))
        {
            util::Log(logERROR) << "Input file " << path << " not found!";
            return false;
        }
        else
        {
            return true;
        }
    };

    if (!check_file(partition_config.GetPath(".osrm.ebg")) ||
        !check_file(partition_config.GetPath(".osrm.cnbg_to_ebg")) ||
        !check_file(partition_config.GetPath(".osrm.cnbg")))
    {
        return EXIT_FAILURE;
    }

    util::Log() << "Computing recursive bisection";

    TIMER_START(bisect);
    auto exitcode = partitioner::Partitioner().Run(partition_config);
    TIMER_STOP(bisect);
    util::Log() << "Bisection took " << TIMER_SEC(bisect) << " seconds.";

    util::DumpMemoryStats();

    return exitcode;
}
catch (const osrm::RuntimeError &e)
{
    util::DumpMemoryStats();
    util::Log(logERROR) << e.what();
    return e.GetCode();
}
catch (const std::bad_alloc &e)
{
    util::DumpMemoryStats();
    util::Log(logERROR) << "[exception] " << e.what();
    util::Log(logERROR) << "Please provide more memory or consider using a larger swapfile";
    return EXIT_FAILURE;
}
#ifdef _WIN32
catch (const std::exception &e)
{
    util::Log(logERROR) << "[exception] " << e.what() << std::endl;
    return EXIT_FAILURE;
}
#endif
