/* -*- c++ -*- */
/*
 * Copyright 2006,2013 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 <gr_prefs.h>
#include <gr_sys_paths.h>
#include <gr_constants.h>
#include <algorithm>

#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/filesystem/fstream.hpp>
namespace fs = boost::filesystem;

/*
 * Stub implementations
 */

static gr_prefs	 s_default_singleton;
static gr_prefs  *s_singleton = &s_default_singleton;

gr_prefs *
gr_prefs::singleton()
{
  return s_singleton;
}

void
gr_prefs::set_singleton(gr_prefs *p)
{
  s_singleton = p;
}

gr_prefs::gr_prefs()
{
  _read_files();
}

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

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

  fs::path dir = gr_prefsdir();
  if(!fs::is_directory(dir))
    return fnames;

  fs::directory_iterator diritr(dir);
  while(diritr != fs::directory_iterator()) {
    fs::path p = *diritr++;
    if(p.extension() != ".swp")
      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 homedir = fs::path(gr_appdata_path());
  homedir = homedir/".gnuradio/config.conf";
  if(fs::exists(homedir)) {
    fnames.push_back(homedir.string());
  }    

  return fnames;
}

void
gr_prefs::_read_files()
{
  std::string config;

  std::vector<std::string> filenames = _sys_prefs_filenames();
  std::vector<std::string>::iterator sitr;
  char tmp[1024];
  for(sitr = filenames.begin(); sitr != filenames.end(); sitr++) {
    fs::ifstream fin(*sitr);
    while(!fin.eof()) {
      fin.getline(tmp, 1024);
      std::string t(tmp);
      // ignore empty lines or lines of just comments
      if((t.size() > 0) && (t[0] != '#')) {
	// remove any comments in the line
	size_t hash = t.find("#");

	// Use hash marks at the end of each segment as a delimiter
	config += t.substr(0, hash) + '#';
      }
    }
    fin.close();
  }

  // Remove all whitespace.
  config.erase(std::remove_if(config.begin(), config.end(), ::isspace), config.end());

  // Convert the string into a map
  _convert_to_map(config);
}

void
gr_prefs::_convert_to_map(const std::string &conf)
{
  // Convert the string into an map of maps
  // Map is structured as {section name: map of options}
  // And options map is simply: {option name: option value}
  std::string sub = conf;
  size_t sec_start = sub.find("[");
  while(sec_start != std::string::npos) {
    sub = sub.substr(sec_start);
    
    size_t sec_end = sub.find("]");
    if(sec_end == std::string::npos)
      throw std::runtime_error("Config file error: Mismatched section label.\n");
   
    std::string sec = sub.substr(1, sec_end-1);
    size_t next_sec_start = sub.find("[", sec_end);
    std::string subsec = sub.substr(sec_end+1, next_sec_start-sec_end-2);

    std::transform(sec.begin(), sec.end(), sec.begin(), ::tolower);

    std::map<std::string, std::string> options_map = d_config_map[sec];
    size_t next_opt = 0;
    size_t next_val = 0;
    next_opt = subsec.find("#");
    while(next_opt < subsec.size()-1) {
      next_val = subsec.find("=", next_opt);
      std::string option = subsec.substr(next_opt+1, next_val-next_opt-1);
      
      next_opt = subsec.find("#", next_val);
      std::string value = subsec.substr(next_val+1, next_opt-next_val-1);

      std::transform(option.begin(), option.end(), option.begin(), ::tolower);
      options_map[option] = value;
    }

    d_config_map[sec] = options_map;

    sec_start = sub.find("[", sec_end);
  }
}

std::string
gr_prefs::to_string()
{
  gr_config_map_itr sections;
  gr_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
gr_prefs::save()
{
  std::string conf = to_string();

  fs::path homedir = fs::path(gr_appdata_path());
  homedir = homedir/".gnuradio/config.conf";
  fs::ofstream fout(homedir);
  fout << conf;
  fout.close();
}

char *
gr_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
gr_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
gr_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);

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

const std::string
gr_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);

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

void
gr_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
gr_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 == "") {
      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
gr_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
gr_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 == "") {
      return default_val;
    }
    std::stringstream sstr(str);
    long n;
    sstr >> n;
    return n;
  }
  else {
    return default_val;
  }
}

void
gr_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
gr_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 == "") {
      return default_val;
    }
    std::stringstream sstr(str);
    double n;
    sstr >> n;
    return n;
  }
  else {
    return default_val;
  }
}

void
gr_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;
}