/* 
 * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
 * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 */
#ifndef __PJ_LOG_H__
#define __PJ_LOG_H__

/**
 * @file log.h
 * @brief Logging Utility.
 */

#include <pj/types.h>
#include <stdarg.h>

PJ_BEGIN_DECL

/**
 * @defgroup PJ_MISC Miscelaneous
 */

/**
 * @defgroup PJ_LOG Logging Facility
 * @ingroup PJ_MISC
 * @{
 *
 * The PJLIB logging facility is a configurable, flexible, and convenient
 * way to write logging or trace information.
 *
 * To write to the log, one uses construct like below:
 *
 * <pre>
 *   ...
 *   PJ_LOG(3, ("main.c", "Starting hello..."));
 *   ...
 *   PJ_LOG(3, ("main.c", "Hello world from process %d", pj_getpid()));
 *   ...
 * </pre>
 *
 * In the above example, the number @b 3 controls the verbosity level of
 * the information (which means "information", by convention). The string
 * "main.c" specifies the source or sender of the message.
 *
 *
 * \section pj_log_quick_sample_sec Examples
 *
 * For examples, see:
 *  - Simple Log sample: \src{pjlib/src/pjlib-samples/log.c}
 *
 */

/**
 * Log decoration flag, to be specified with #pj_log_set_decor().
 */
enum pj_log_decoration
{
    PJ_LOG_HAS_DAY_NAME   =    1, /**< Include day name [default: no]         */
    PJ_LOG_HAS_YEAR       =    2, /**< Include year digit [no]                */
    PJ_LOG_HAS_MONTH      =    4, /**< Include month [no]                     */
    PJ_LOG_HAS_DAY_OF_MON =    8, /**< Include day of month [no]              */
    PJ_LOG_HAS_TIME       =   16, /**< Include time [yes]                     */
    PJ_LOG_HAS_MICRO_SEC  =   32, /**< Include microseconds [yes]             */
    PJ_LOG_HAS_SENDER     =   64, /**< Include sender in the log [yes]        */
    PJ_LOG_HAS_NEWLINE    =  128, /**< Terminate each call with newline [yes] */
    PJ_LOG_HAS_CR         =  256, /**< Include carriage return [no]           */
    PJ_LOG_HAS_SPACE      =  512, /**< Include two spaces before log [yes]    */
    PJ_LOG_HAS_COLOR      = 1024, /**< Colorize logs [yes on win32]           */
    PJ_LOG_HAS_LEVEL_TEXT = 2048, /**< Include level text string [no]         */
    PJ_LOG_HAS_THREAD_ID  = 4096, /**< Include thread identification [no]     */
    PJ_LOG_HAS_THREAD_SWC = 8192, /**< Add mark when thread has switched [yes]*/
    PJ_LOG_HAS_INDENT     =16384  /**< Indentation. Say yes! [yes]            */
};

/**
 * Write log message.
 * This is the main macro used to write text to the logging backend. 
 *
 * @param level     The logging verbosity level. Lower number indicates higher
 *                  importance, with level zero indicates fatal error. Only
 *                  numeral argument is permitted (e.g. not variable).
 * @param arg       Enclosed 'printf' like arguments, with the first 
 *                  argument is the sender, the second argument is format 
 *                  string and the following arguments are variable number of 
 *                  arguments suitable for the format string.
 *
 * Sample:
 * \verbatim
   PJ_LOG(2, (__FILE__, "current value is %d", value));
   \endverbatim
 * @hideinitializer
 */
#define PJ_LOG(level,arg)       do { \
                                    if (level <= pj_log_get_level()) { \
                                        pj_log_wrapper_##level(arg); \
                                    } \
                                } while (0)

/**
 * Signature for function to be registered to the logging subsystem to
 * write the actual log message to some output device.
 *
 * @param level     Log level.
 * @param data      Log message, which will be NULL terminated.
 * @param len       Message length.
 */
typedef void pj_log_func(int level, const char *data, int len);

/**
 * Default logging writer function used by front end logger function.
 * This function will print the log message to stdout only.
 * Application normally should NOT need to call this function, but
 * rather use the PJ_LOG macro.
 *
 * @param level     Log level.
 * @param buffer    Log message.
 * @param len       Message length.
 */
PJ_DECL(void) pj_log_write(int level, const char *buffer, int len);


#if PJ_LOG_MAX_LEVEL >= 1

/**
 * Write to log.
 *
 * @param sender    Source of the message.
 * @param level     Verbosity level.
 * @param format    Format.
 * @param marker    Marker.
 */
PJ_DECL(void) pj_log(const char *sender, int level, 
                     const char *format, va_list marker);

/**
 * Change log output function. The front-end logging functions will call
 * this function to write the actual message to the desired device. 
 * By default, the front-end functions use pj_log_write() to write
 * the messages, unless it's changed by calling this function.
 *
 * @param func      The function that will be called to write the log
 *                  messages to the desired device.
 */
PJ_DECL(void) pj_log_set_log_func( pj_log_func *func );

/**
 * Get the current log output function that is used to write log messages.
 *
 * @return          Current log output function.
 */
PJ_DECL(pj_log_func*) pj_log_get_log_func(void);

/**
 * Set maximum log level. Application can call this function to set 
 * the desired level of verbosity of the logging messages. The bigger the
 * value, the more verbose the logging messages will be printed. However,
 * the maximum level of verbosity can not exceed compile time value of
 * PJ_LOG_MAX_LEVEL.
 *
 * @param level     The maximum level of verbosity of the logging
 *                  messages (6=very detailed..1=error only, 0=disabled)
 */
PJ_DECL(void) pj_log_set_level(int level);

/**
 * Get current maximum log verbositylevel.
 *
 * @return          Current log maximum level.
 */
#if 1
PJ_DECL(int) pj_log_get_level(void);
#else
PJ_DECL_DATA(int) pj_log_max_level;
#define pj_log_get_level()  pj_log_max_level
#endif

/**
 * Set log decoration. The log decoration flag controls what are printed
 * to output device alongside the actual message. For example, application
 * can specify that date/time information should be displayed with each
 * log message.
 *
 * @param decor     Bitmask combination of #pj_log_decoration to control
 *                  the layout of the log message.
 */
PJ_DECL(void) pj_log_set_decor(unsigned decor);

/**
 * Get current log decoration flag.
 *
 * @return          Log decoration flag.
 */
PJ_DECL(unsigned) pj_log_get_decor(void);

/**
 * Add indentation to log message. Indentation will add PJ_LOG_INDENT_CHAR
 * before the message, and is useful to show the depth of function calls.
 *
 * @param indent    The indentation to add or substract. Positive value
 *                  adds current indent, negative value subtracts current
 *                  indent.
 */
PJ_DECL(void) pj_log_add_indent(int indent);

/**
 * Set indentation to specific value.
 *
 * @param indent    The indentation value.
 */
PJ_DECL(void) pj_log_set_indent(int indent);

/**
 * Get current indentation value.
 *
 * @return          Current indentation value.
 */
PJ_DECL(int) pj_log_get_indent(void);

/**
 * Push indentation to the right by default value (PJ_LOG_INDENT_SIZE).
 */
PJ_DECL(void) pj_log_push_indent(void);

/**
 * Pop indentation (to the left) by default value (PJ_LOG_INDENT_SIZE).
 */
PJ_DECL(void) pj_log_pop_indent(void);

/**
 * Set color of log messages.
 *
 * @param level     Log level which color will be changed.
 * @param color     Desired color.
 */
PJ_DECL(void) pj_log_set_color(int level, pj_color_t color);

/**
 * Get color of log messages.
 *
 * @param level     Log level which color will be returned.
 * @return          Log color.
 */
PJ_DECL(pj_color_t) pj_log_get_color(int level);

/**
 * Internal function to be called by pj_init()
 */
pj_status_t pj_log_init(void);

#else   /* #if PJ_LOG_MAX_LEVEL >= 1 */

/**
 * Change log output function. The front-end logging functions will call
 * this function to write the actual message to the desired device. 
 * By default, the front-end functions use pj_log_write() to write
 * the messages, unless it's changed by calling this function.
 *
 * @param func      The function that will be called to write the log
 *                  messages to the desired device.
 */
#  define pj_log_set_log_func(func)

/**
 * Write to log.
 *
 * @param sender    Source of the message.
 * @param level     Verbosity level.
 * @param format    Format.
 * @param marker    Marker.
 */
#  define pj_log(sender, level, format, marker)

/**
 * Set maximum log level. Application can call this function to set 
 * the desired level of verbosity of the logging messages. The bigger the
 * value, the more verbose the logging messages will be printed. However,
 * the maximum level of verbosity can not exceed compile time value of
 * PJ_LOG_MAX_LEVEL.
 *
 * @param level     The maximum level of verbosity of the logging
 *                  messages (6=very detailed..1=error only, 0=disabled)
 */
#  define pj_log_set_level(level)

/**
 * Set log decoration. The log decoration flag controls what are printed
 * to output device alongside the actual message. For example, application
 * can specify that date/time information should be displayed with each
 * log message.
 *
 * @param decor     Bitmask combination of #pj_log_decoration to control
 *                  the layout of the log message.
 */
#  define pj_log_set_decor(decor)

/**
 * Add indentation to log message. Indentation will add PJ_LOG_INDENT_CHAR
 * before the message, and is useful to show the depth of function calls.
 *
 * @param indent    The indentation to add or substract. Positive value
 *                  adds current indent, negative value subtracts current
 *                  indent.
 */
#  define pj_log_add_indent(indent)

/**
 * Set indentation to specific value.
 *
 * @param indent    The indentation value.
 */
#  define pj_log_set_indent(indent)

/**
 * Get current indentation value.
 *
 * @return          Current indentation value.
 */
#  define pj_log_get_indent()   0

/**
 * Push indentation to the right by default value (PJ_LOG_INDENT_SIZE).
 */
#  define pj_log_push_indent()

/**
 * Pop indentation (to the left) by default value (PJ_LOG_INDENT_SIZE).
 */
#  define pj_log_pop_indent()

/**
 * Set color of log messages.
 *
 * @param level     Log level which color will be changed.
 * @param color     Desired color.
 */
#  define pj_log_set_color(level, color)

/**
 * Get current maximum log verbositylevel.
 *
 * @return          Current log maximum level.
 */
#  define pj_log_get_level()    0

/**
 * Get current log decoration flag.
 *
 * @return          Log decoration flag.
 */
#  define pj_log_get_decor()    0

/**
 * Get color of log messages.
 *
 * @param level     Log level which color will be returned.
 * @return          Log color.
 */
#  define pj_log_get_color(level) 0


/**
 * Internal.
 */
#   define pj_log_init()        PJ_SUCCESS

#endif  /* #if PJ_LOG_MAX_LEVEL >= 1 */

/** 
 * @}
 */

/* **************************************************************************/
/*
 * Log functions implementation prototypes.
 * These functions are called by PJ_LOG macros according to verbosity
 * level specified when calling the macro. Applications should not normally
 * need to call these functions directly.
 */

/**
 * @def pj_log_wrapper_1(arg)
 * Internal function to write log with verbosity 1. Will evaluate to
 * empty expression if PJ_LOG_MAX_LEVEL is below 1.
 * @param arg       Log expression.
 */
#if PJ_LOG_MAX_LEVEL >= 1
    #define pj_log_wrapper_1(arg)       pj_log_1 arg
    /** Internal function. */
    PJ_DECL(void) pj_log_1(const char *src, const char *format, ...)
                  PJ_PRINT_FUNC_DECOR(2);
#else
    #define pj_log_wrapper_1(arg)
#endif

/**
 * @def pj_log_wrapper_2(arg)
 * Internal function to write log with verbosity 2. Will evaluate to
 * empty expression if PJ_LOG_MAX_LEVEL is below 2.
 * @param arg       Log expression.
 */
#if PJ_LOG_MAX_LEVEL >= 2
    #define pj_log_wrapper_2(arg)       pj_log_2 arg
    /** Internal function. */
    PJ_DECL(void) pj_log_2(const char *src, const char *format, ...)
                  PJ_PRINT_FUNC_DECOR(2);
#else
    #define pj_log_wrapper_2(arg)
#endif

/**
 * @def pj_log_wrapper_3(arg)
 * Internal function to write log with verbosity 3. Will evaluate to
 * empty expression if PJ_LOG_MAX_LEVEL is below 3.
 * @param arg       Log expression.
 */
#if PJ_LOG_MAX_LEVEL >= 3
    #define pj_log_wrapper_3(arg)       pj_log_3 arg
    /** Internal function. */
    PJ_DECL(void) pj_log_3(const char *src, const char *format, ...)
                  PJ_PRINT_FUNC_DECOR(2);
#else
    #define pj_log_wrapper_3(arg)
#endif

/**
 * @def pj_log_wrapper_4(arg)
 * Internal function to write log with verbosity 4. Will evaluate to
 * empty expression if PJ_LOG_MAX_LEVEL is below 4.
 * @param arg       Log expression.
 */
#if PJ_LOG_MAX_LEVEL >= 4
    #define pj_log_wrapper_4(arg)       pj_log_4 arg
    /** Internal function. */
    PJ_DECL(void) pj_log_4(const char *src, const char *format, ...)
                  PJ_PRINT_FUNC_DECOR(2);
#else
    #define pj_log_wrapper_4(arg)
#endif

/**
 * @def pj_log_wrapper_5(arg)
 * Internal function to write log with verbosity 5. Will evaluate to
 * empty expression if PJ_LOG_MAX_LEVEL is below 5.
 * @param arg       Log expression.
 */
#if PJ_LOG_MAX_LEVEL >= 5
    #define pj_log_wrapper_5(arg)       pj_log_5 arg
    /** Internal function. */
    PJ_DECL(void) pj_log_5(const char *src, const char *format, ...)
                  PJ_PRINT_FUNC_DECOR(2);
#else
    #define pj_log_wrapper_5(arg)
#endif

/**
 * @def pj_log_wrapper_6(arg)
 * Internal function to write log with verbosity 6. Will evaluate to
 * empty expression if PJ_LOG_MAX_LEVEL is below 6.
 * @param arg       Log expression.
 */
#if PJ_LOG_MAX_LEVEL >= 6
    #define pj_log_wrapper_6(arg)       pj_log_6 arg
    /** Internal function. */
    PJ_DECL(void) pj_log_6(const char *src, const char *format, ...)
                  PJ_PRINT_FUNC_DECOR(2);
#else
    #define pj_log_wrapper_6(arg)
#endif


PJ_END_DECL 

#endif  /* __PJ_LOG_H__ */

