/* -*- c++ -*- */
/*
 * Copyright 2006,2013,2015 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio 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, or (at your option)
 * any later version.
 *
 * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <gnuradio/constants.h>
#include <gnuradio/prefs.h>
#include <gnuradio/sys_paths.h>

#include <algorithm>
#include <fstream>
#include <iostream>

#include <boost/filesystem/fstream.hpp>
#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/foreach.hpp>
#include <boost/program_options.hpp>
namespace fs = boost::filesystem;
namespace po = boost::program_options;
typedef std::ifstream::char_type char_t;

namespace gr {

prefs* prefs::singleton()
{
    static prefs instance; // Guaranteed to be destroyed.
                           // Instantiated on first use.
    return &instance;
}

prefs::prefs() { _read_files(_sys_prefs_filenames()); }

prefs::~prefs()
{
    // nop
}

std::vector<std::string> prefs::_sys_prefs_filenames()
{
    std::vector<std::string> fnames;

    fs::path dir = prefsdir();
    if (fs::is_directory(dir)) {
        fs::directory_iterator diritr(dir);
        while (diritr != fs::directory_iterator()) {
            fs::path p = *diritr++;
            if (p.extension() == ".conf")
                fnames.push_back(p.string());
        }
        std::sort(fnames.begin(), fnames.end());
    }

    // Find if there is a ~/.gnuradio/config.conf file and add this to
    // the end of the file list to override any preferences in the
    // installed path config files.
    fs::path userconf = fs::path(gr::userconf_path()) / "config.conf";
    if (fs::exists(userconf)) {
        fnames.push_back(userconf.string());
    }

    return fnames;
}

void prefs::_read_files(const std::vector<std::string>& filenames)
{
    BOOST_FOREACH (std::string fname, filenames) {
        std::ifstream infile(fname.c_str());
        if (infile.good()) {
            try {
                po::basic_parsed_options<char_t> parsed =
                    po::parse_config_file(infile, po::options_description(), true);
                BOOST_FOREACH (po::basic_option<char_t> o, (parsed.options)) {
                    std::string okey = o.string_key;
                    size_t pos = okey.find(".");
                    std::string section, key;
                    if (pos != std::string::npos) {
                        section = okey.substr(0, pos);
                        key = okey.substr(pos + 1);
                    } else {
                        section = "default";
                        key = okey;
                    }
                    std::transform(
                        section.begin(), section.end(), section.begin(), ::tolower);
                    std::transform(key.begin(), key.end(), key.begin(), ::tolower);
                    // value of a basic_option is always a std::vector<string>; we only
                    // allow single values, so:
                    std::string value = o.value[0];
                    d_config_map[section][key] = value;
                }
            } catch (std::exception& e) {
                std::cerr << "WARNING: Config file '" << fname
                          << "' failed to parse:" << std::endl;
                std::cerr << e.what() << std::endl;
                std::cerr << "Skipping it" << std::endl;
            }
        } else { // infile.good();
            std::cerr << "WARNING: Config file '" << fname
                      << "' could not be opened for reading." << std::endl;
        }
    }
}

void prefs::add_config_file(const std::string& configfile)
{
    std::vector<std::string> filenames;
    filenames.push_back(configfile);

    _read_files(filenames);
}


std::string prefs::to_string()
{
    config_map_itr sections;
    config_map_elem_itr options;
    std::stringstream s;

    for (sections = d_config_map.begin(); sections != d_config_map.end(); sections++) {
        s << "[" << sections->first << "]" << std::endl;
        for (options = sections->second.begin(); options != sections->second.end();
             options++) {
            s << options->first << " = " << options->second << std::endl;
        }
        s << std::endl;
    }

    return s.str();
}

void prefs::save()
{
    std::string conf = to_string();
    fs::path userconf = fs::path(gr::userconf_path()) / "config.conf";
    fs::ofstream fout(userconf);
    fout << conf;
    fout.close();
}

char* prefs::option_to_env(std::string section, std::string option)
{
    std::stringstream envname;
    std::string secname = section, optname = option;

    std::transform(section.begin(), section.end(), secname.begin(), ::toupper);
    std::transform(option.begin(), option.end(), optname.begin(), ::toupper);
    envname << "GR_CONF_" << secname << "_" << optname;

    return getenv(envname.str().c_str());
}

bool prefs::has_section(const std::string& section)
{
    std::string s = section;
    std::transform(section.begin(), section.end(), s.begin(), ::tolower);
    return d_config_map.count(s) > 0;
}

bool prefs::has_option(const std::string& section, const std::string& option)
{
    if (option_to_env(section, option))
        return true;

    if (has_section(section)) {
        std::string s = section;
        std::transform(section.begin(), section.end(), s.begin(), ::tolower);

        std::string o = option;
        std::transform(option.begin(), option.end(), o.begin(), ::tolower);

        config_map_itr sec = d_config_map.find(s);
        return sec->second.count(o) > 0;
    } else {
        return false;
    }
}

const std::string prefs::get_string(const std::string& section,
                                    const std::string& option,
                                    const std::string& default_val)
{
    char* env = option_to_env(section, option);
    if (env)
        return std::string(env);

    if (has_option(section, option)) {
        std::string s = section;
        std::transform(section.begin(), section.end(), s.begin(), ::tolower);

        std::string o = option;
        std::transform(option.begin(), option.end(), o.begin(), ::tolower);

        config_map_itr sec = d_config_map.find(s);
        config_map_elem_itr opt = sec->second.find(o);
        return opt->second;
    } else {
        return default_val;
    }
}

void prefs::set_string(const std::string& section,
                       const std::string& option,
                       const std::string& val)
{
    std::string s = section;
    std::transform(section.begin(), section.end(), s.begin(), ::tolower);

    std::string o = option;
    std::transform(option.begin(), option.end(), o.begin(), ::tolower);

    std::map<std::string, std::string> opt_map = d_config_map[s];

    opt_map[o] = val;

    d_config_map[s] = opt_map;
}

bool prefs::get_bool(const std::string& section,
                     const std::string& option,
                     bool default_val)
{
    if (has_option(section, option)) {
        std::string str = get_string(section, option, "");
        if (str.empty()) {
            return default_val;
        }
        std::transform(str.begin(), str.end(), str.begin(), ::tolower);
        if ((str == "true") || (str == "on") || (str == "1"))
            return true;
        else if ((str == "false") || (str == "off") || (str == "0"))
            return false;
        else
            return default_val;
    } else {
        return default_val;
    }
}

void prefs::set_bool(const std::string& section, const std::string& option, bool val)
{
    std::string s = section;
    std::transform(section.begin(), section.end(), s.begin(), ::tolower);

    std::string o = option;
    std::transform(option.begin(), option.end(), o.begin(), ::tolower);

    std::map<std::string, std::string> opt_map = d_config_map[s];

    std::stringstream sstr;
    sstr << (val == true);
    opt_map[o] = sstr.str();

    d_config_map[s] = opt_map;
}

long prefs::get_long(const std::string& section,
                     const std::string& option,
                     long default_val)
{
    if (has_option(section, option)) {
        std::string str = get_string(section, option, "");
        if (str.empty()) {
            return default_val;
        }
        std::stringstream sstr(str);
        long n;
        sstr >> n;
        return n;
    } else {
        return default_val;
    }
}

void prefs::set_long(const std::string& section, const std::string& option, long val)
{
    std::string s = section;
    std::transform(section.begin(), section.end(), s.begin(), ::tolower);

    std::string o = option;
    std::transform(option.begin(), option.end(), o.begin(), ::tolower);

    std::map<std::string, std::string> opt_map = d_config_map[s];

    std::stringstream sstr;
    sstr << val;
    opt_map[o] = sstr.str();

    d_config_map[s] = opt_map;
}

double prefs::get_double(const std::string& section,
                         const std::string& option,
                         double default_val)
{
    if (has_option(section, option)) {
        std::string str = get_string(section, option, "");
        if (str.empty()) {
            return default_val;
        }
        std::stringstream sstr(str);
        double n;
        sstr >> n;
        return n;
    } else {
        return default_val;
    }
}

void prefs::set_double(const std::string& section, const std::string& option, double val)
{
    std::string s = section;
    std::transform(section.begin(), section.end(), s.begin(), ::tolower);

    std::string o = option;
    std::transform(option.begin(), option.end(), o.begin(), ::tolower);

    std::map<std::string, std::string> opt_map = d_config_map[s];

    std::stringstream sstr;
    sstr << val;
    opt_map[o] = sstr.str();

    d_config_map[s] = opt_map;
}

} /* namespace gr */
