    // Copyright (C) 2007  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #ifndef DLIB_LOGGER_CONFIg_FILE_CPP
    #define DLIB_LOGGER_CONFIg_FILE_CPP

    #include "logger_config_file.h"
    #include <string>
    #include "../config_reader.h"
    #include <fstream>
    #include <sstream>
    #include "../error.h"
    #include "../map.h"
    #include "../string.h"

    // ----------------------------------------------------------------------------------------

    namespace dlib
    {

        namespace logger_config_file_helpers
        {
            typedef config_reader::kernel_1a cr_type;

    // ----------------------------------------------------------------------------------------

            std::ostream& get_file_stream (
                const std::string& file_name
            )
            {
                using namespace std;
                static dlib::mutex m;
                auto_mutex M(m);
                static dlib::map<string,ostream*>::kernel_1a_c file_map;

                if (file_map.is_in_domain(file_name) == false)
                {
                    // We won't ever delete this output stream.  It should be around for the
                    // entire life of the program so just let the OS take care of it.
                    ostream* fout = new ofstream(file_name.c_str());
                    if (!(*fout))
                    {
                        delete fout;
                        throw error("logger_config: unable to open output file " + file_name);
                    }

                    // add this file to our file map
                    string temp(file_name);
                    file_map.add(temp,fout);
                }

                return *file_map[file_name];
            }

    // ----------------------------------------------------------------------------------------

            log_level string_to_log_level (
                const std::string& level
            )
            {
                using namespace std;
                if (level == "LALL" || level == "ALL" || level == "all")
                    return LALL;
                else if (level == "LNONE" || level == "NONE" || level == "none")
                    return LNONE;
                else if (level == "LTRACE" || level == "TRACE" || level == "trace")
                    return LTRACE;
                else if (level == "LDEBUG" || level == "DEBUG" || level == "debug")
                    return LDEBUG;
                else if (level == "LINFO" || level == "INFO" || level == "info")
                    return LINFO;
                else if (level == "LWARN" || level == "WARN" || level == "warn")
                    return LWARN;
                else if (level == "LERROR" || level == "ERROR" || level == "error")
                    return LERROR;
                else if (level == "LFATAL" || level == "FATAL" || level == "fatal")
                    return LFATAL;
                else
                {
                    const int priority = string_cast<int>(level);
                    return log_level(priority,"CONFIG_FILE_DEFINED");
                }
            }

    // ----------------------------------------------------------------------------------------

            void configure_sub_blocks (
                const cr_type& cr,
                const std::string& name
            )
            {
                using namespace std;

                logger dlog(name.c_str());

                if (cr.is_key_defined("logging_level"))
                {
                    dlog.set_level(string_to_log_level(cr["logging_level"]));
                }

                if (cr.is_key_defined("output"))
                {
                    string output = cr["output"];
                    if (output == "cout")
                        dlog.set_output_stream(cout);
                    else if (output == "cerr")
                        dlog.set_output_stream(cerr);
                    else if (output == "clog")
                        dlog.set_output_stream(clog);
                    else
                    {
                        istringstream sin(output);
                        string one, two, three;
                        sin >> one;
                        sin >> two;
                        sin >> three;
                        if (one == "file" && three.size() == 0)
                            dlog.set_output_stream(get_file_stream(two));
                        else
                            throw error("logger_config: invalid argument to output option: " + output);
                    }

                } // if (cr.is_key_defined("output"))

                // now configure all the sub-blocks
                std_vector_c<std::string> blocks;
                cr.get_blocks(blocks);
                for (unsigned long i = 0; i < blocks.size(); ++i)
                {
                    configure_sub_blocks(cr.block(blocks[i]), name + "." + blocks[i]);
                }

            }

    // ----------------------------------------------------------------------------------------

        } // namespace

    // ----------------------------------------------------------------------------------------

        void configure_loggers_from_file (
            const std::string& file_name
        )
        {
            using namespace logger_config_file_helpers;
            using namespace std;
            ifstream fin(file_name.c_str());

            if (!fin)
                throw logger_config_file_error("logger_config: unable to open config file " + file_name);

            cr_type main_cr;
            main_cr.load_from(fin);

            if (main_cr.is_block_defined("logger_config"))
            {
                const cr_type& cr = main_cr.block("logger_config");

                if (cr.is_key_defined("logging_level"))
                {
                    set_all_logging_levels(string_to_log_level(cr["logging_level"]));
                }

                if (cr.is_key_defined("output"))
                {
                    string output = cr["output"];
                    if (output == "cout")
                        set_all_logging_output_streams(cout);
                    else if (output == "cerr")
                        set_all_logging_output_streams(cerr);
                    else if (output == "clog")
                        set_all_logging_output_streams(clog);
                    else
                    {
                        istringstream sin(output);
                        string one, two, three;
                        sin >> one;
                        sin >> two;
                        sin >> three;
                        if (one == "file" && three.size() == 0)
                            set_all_logging_output_streams(get_file_stream(two));
                        else
                            throw logger_config_file_error("logger_config: invalid argument to output option: " + output);
                    }

                } // if (cr.is_key_defined("output"))

                // now configure all the sub-blocks
                std_vector_c<std::string> blocks;
                cr.get_blocks(blocks);
                for (unsigned long i = 0; i < blocks.size(); ++i)
                {
                    configure_sub_blocks(cr.block(blocks[i]), blocks[i]);
                }

            }
        }

    // ----------------------------------------------------------------------------------------

    }

    // ----------------------------------------------------------------------------------------

    #endif // DLIB_LOGGER_CONFIg_FILE_CPP