/*
 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
module ffmpeg.libavutil.log;
import std.stdint;
import core.vararg;
import ffmpeg.libavutil.opt;

@nogc nothrow extern(C):

enum AVClassCategory {
    AV_CLASS_CATEGORY_NA = 0,
    AV_CLASS_CATEGORY_INPUT,
    AV_CLASS_CATEGORY_OUTPUT,
    AV_CLASS_CATEGORY_MUXER,
    AV_CLASS_CATEGORY_DEMUXER,
    AV_CLASS_CATEGORY_ENCODER,
    AV_CLASS_CATEGORY_DECODER,
    AV_CLASS_CATEGORY_FILTER,
    AV_CLASS_CATEGORY_BITSTREAM_FILTER,
    AV_CLASS_CATEGORY_SWSCALER,
    AV_CLASS_CATEGORY_SWRESAMPLER,
    AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT = 40,
    AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
    AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT,
    AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,
    AV_CLASS_CATEGORY_DEVICE_OUTPUT,
    AV_CLASS_CATEGORY_DEVICE_INPUT,
    AV_CLASS_CATEGORY_NB ///< not part of ABI/API
}

struct AVOptionRanges;

/**
 * Describe the class of an AVClass context structure. That is an
 * arbitrary struct of which the first field is a pointer to an
 * AVClass struct (e.g. AVCodecContext, AVFormatContext etc.).
 */
struct AVClass {
    /**
     * The name of the class; usually it is the same name as the
     * context structure type to which the AVClass is associated.
     */
    const char* class_name;

    /**
     * A pointer to a function which returns the name of a context
     * instance ctx associated with the class.
     */
    const char* function(void* ctx) item_name;

    /**
     * a pointer to the first option specified in the class if any or NULL
     *
     * @see av_set_default_options()
     */
    const AVOption *option;

    /**
     * LIBAVUTIL_VERSION with which this structure was created.
     * This is used to allow fields to be added without requiring major
     * version bumps everywhere.
     */

    int ver;

    /**
     * Offset in the structure where log_level_offset is stored.
     * 0 means there is no such variable
     */
    int log_level_offset_offset;

    /**
     * Offset in the structure where a pointer to the parent context for loging is stored.
     * for example a decoder that uses eval.c could pass its AVCodecContext to eval as such
     * parent context. And a av_log() implementation could then display the parent context
     * can be NULL of course
     */
    int parent_log_context_offset;

    /**
     * Return next AVOptions-enabled child or NULL
     */
    void* function(void *obj, void *prev) child_next;

    /**
     * Return an AVClass corresponding to next potential
     * AVOptions-enabled child.
     *
     * The difference between child_next and this is that
     * child_next iterates over _already existing_ objects, while
     * child_class_next iterates over _all possible_ children.
     */
    const AVClass* function(const AVClass *prev) child_class_next;

    /**
     * Category used for visualization (like color)
     * This is only set if the category is equal for all objects using this class.
     * available since version (51 << 16 | 56 << 8 | 100)
     */
    AVClassCategory category;

    /**
     * Callback to return the category.
     * available since version (51 << 16 | 59 << 8 | 100)
     */
    AVClassCategory function(void* ctx) get_category;

    /**
     * Callback to return the supported/allowed ranges.
     * available since version (52.12)
     */
    int function(AVOptionRanges **, void *obj, const char *key, int flags) query_ranges;
}

/* av_log API */

enum AV_LOG_QUIET  = -8;

/**
 * Something went really wrong and we will crash now.
 */
enum AV_LOG_PANIC   = 0;

/**
 * Something went wrong and recovery is not possible.
 * For example, no header was found for a format which depends
 * on headers or an illegal combination of parameters is used.
 */
enum AV_LOG_FATAL   = 8;

/**
 * Something went wrong and cannot losslessly be recovered.
 * However, not all future data is affected.
 */
enum AV_LOG_ERROR   =16;

/**
 * Something somehow does not look correct. This may or may not
 * lead to problems. An example would be the use of '-vstrict -2'.
 */
enum AV_LOG_WARNING =24;

enum AV_LOG_INFO    =32;
enum AV_LOG_VERBOSE =40;

/**
 * Stuff which is only useful for libav* developers.
 */
enum AV_LOG_DEBUG   =48;

/**
 * Extremely verbose debugging, useful for libav* development.
 */
enum AV_LOG_TRACE   =56;

enum AV_LOG_MAX_OFFSET = (AV_LOG_TRACE - AV_LOG_QUIET);

/**
 * Send the specified message to the log if the level is less than or equal
 * to the current av_log_level. By default, all logging messages are sent to
 * stderr. This behavior can be altered by setting a different logging callback
 * function.
 * @see av_log_set_callback
 *
 * @param avcl A pointer to an arbitrary struct of which the first field is a
 *        pointer to an AVClass struct or NULL if general log.
 * @param level The importance level of the message expressed using a @ref
 *        lavu_log_constants "Logging Constant".
 * @param fmt The format string (printf-compatible) that specifies how
 *        subsequent arguments are converted to output.
 */
void av_log(void *avcl, int level, const char *fmt, ...);

/**
 * Send the specified message to the log if the level is less than or equal
 * to the current av_log_level. By default, all logging messages are sent to
 * stderr. This behavior can be altered by setting a different logging callback
 * function.
 * @see av_log_set_callback
 *
 * @param avcl A pointer to an arbitrary struct of which the first field is a
 *        pointer to an AVClass struct.
 * @param level The importance level of the message expressed using a @ref
 *        lavu_log_constants "Logging Constant".
 * @param fmt The format string (printf-compatible) that specifies how
 *        subsequent arguments are converted to output.
 * @param vl The arguments referenced by the format string.
 */
void av_vlog(void *avcl, int level, const char *fmt, va_list vl);

/**
 * Get the current log level
 *
 * @see lavu_log_constants
 *
 * @return Current log level
 */
int av_log_get_level();

/**
 * Set the log level
 *
 * @see lavu_log_constants
 *
 * @param level Logging level
 */
void av_log_set_level(int);

/**
 * Set the logging callback
 *
 * @note The callback must be thread safe, even if the application does not use
 *       threads itself as some codecs are multithreaded.
 *
 * @see av_log_default_callback
 *
 * @param callback A logging function with a compatible signature.
 */
void av_log_set_callback(void* function(void*, int, const char*, va_list) log_callback);

/**
 * Default logging callback
 *
 * It prints the message to stderr, optionally colorizing it.
 *
 * @param avcl A pointer to an arbitrary struct of which the first field is a
 *        pointer to an AVClass struct.
 * @param level The importance level of the message expressed using a @ref
 *        lavu_log_constants "Logging Constant".
 * @param fmt The format string (printf-compatible) that specifies how
 *        subsequent arguments are converted to output.
 * @param vl The arguments referenced by the format string.
 */
void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl);

/**
 * Return the context name
 *
 * @param  ctx The AVClass context
 *
 * @return The AVClass class_name
 */
char* av_default_item_name(void* ctx);
AVClassCategory av_default_get_category(void *ptr);

/**
 * Format a line of log the same way as the default callback.
 * @param line          buffer to receive the formated line
 * @param line_size     size of the buffer
 * @param print_prefix  used to store whether the prefix must be printed;
 *                      must point to a persistent integer initially set to 1
 */
void av_log_format_line(void *ptr, int level, const char *fmt, va_list vl,
                        char *line, int line_size, int *print_prefix);

/**
 * Format a line of log the same way as the default callback.
 * @param line          buffer to receive the formatted line;
 *                      may be NULL if line_size is 0
 * @param line_size     size of the buffer; at most line_size-1 characters will
 *                      be written to the buffer, plus one null terminator
 * @param print_prefix  used to store whether the prefix must be printed;
 *                      must point to a persistent integer initially set to 1
 * @return Returns a negative value if an error occurred, otherwise returns
 *         the number of characters that would have been written for a
 *         sufficiently large buffer, not including the terminating null
 *         character. If the return value is not less than line_size, it means
 *         that the log message was truncated to fit the buffer.
 */
int av_log_format_line2(void *ptr, int level, const char *fmt, va_list vl,
                        char *line, int line_size, int *print_prefix);

/**
 * av_dlog macros
 * Useful to print debug messages that shouldn't get compiled in normally.
 */

/**
#ifdef DEBUG
#    define av_dlog(pctx, ...) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__)
#else
#    define av_dlog(pctx, ...) do { if (0) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
#endif
*/

/**
 * Skip repeated messages, this requires the user app to use av_log() instead of
 * (f)printf as the 2 would otherwise interfere and lead to
 * "Last message repeated x times" messages below (f)printf messages with some
 * bad luck.
 * Also to receive the last, "last repeated" line if any, the user app must
 * call av_log(NULL, AV_LOG_QUIET, "%s", ""); at the end
 */
enum AV_LOG_SKIP_REPEATED = 1;

/**
 * Include the log severity in messages originating from codecs.
 *
 * Results in messages such as:
 * [rawvideo @ 0xDEADBEEF] [error] encode did not produce valid pts
 */
enum AV_LOG_PRINT_LEVEL = 2;

void av_log_set_flags(int arg);
int av_log_get_flags();