/*
 * FILE:    debug.h
 * PROGRAM: RAT
 * AUTHOR:  Isidor Kouvelas + Colin Perkins + Mark Handley + Orion Hodson
 * 
 * Copyright (c) 1995-2000 University College London
 * Copyright (c) 2005-2023 CESNET, z. s. p. o.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, is permitted provided that the following conditions 
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the Computer Science
 *      Department at University College London
 * 4. Neither the name of the University nor of the Department may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _RAT_DEBUG_H
#define _RAT_DEBUG_H

#ifdef __cplusplus
#include <cstdint>
#include <cstdio> // FILE
#else
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h> // FILE
#endif // defined __cplusplus

#include "tv.h"

#define UNUSED(x)	(x=x)

#define LOG_LEVEL_QUIET   0 ///< suppress all logging
#define LOG_LEVEL_FATAL   1 ///< errors that prevent UG run
#define LOG_LEVEL_ERROR   2 ///< general errors
#define LOG_LEVEL_WARNING 3 ///< less severe errors
#define LOG_LEVEL_NOTICE  4 ///< information that may be interesting
#define LOG_LEVEL_INFO    5 ///< normal reporting
#define LOG_LEVEL_VERBOSE 6 ///< display more messages but no more than
                            ///< one of a kind every ~1 sec
#define LOG_LEVEL_DEBUG   7 ///< like LOG_LEVEL_VERBOSE, freq. approx.
                            ///< 1 message every video frame
#define LOG_LEVEL_DEBUG2  8 ///< even more verbose - eg. every packet can
                            ///< be logged
#define LOG_LEVEL_MAX LOG_LEVEL_DEBUG2
extern volatile int log_level;

enum log_timestamp_mode{
	LOG_TIMESTAMP_DISABLED = 0,
	LOG_TIMESTAMP_ENABLED = 1,
	LOG_TIMESTAMP_AUTO = -1
};

#ifdef __cplusplus
extern "C" {
#endif

void debug_dump(const void*lp, int len);

#define error_msg(...) log_msg(LOG_LEVEL_ERROR, __VA_ARGS__)
#define verbose_msg(...) log_msg(LOG_LEVEL_VERBOSE, __VA_ARGS__)
///#define debug_msg(...) log_msg(LOG_LEVEL_DEBUG, "[pid/%d +%d %s] ", getpid(), __LINE__, __FILE__), log_msg(LOG_LEVEL_DEBUG, __VA_ARGS__)
#define debug_msg(...) log_msg(LOG_LEVEL_DEBUG, __VA_ARGS__)
void log_msg(int log_level, const char *format, ...) __attribute__((format (printf, 2, 3)));
void log_msg_once(int log_level, uint32_t id, const char *msg, ...) __attribute__((format (printf, 3, 4)));
void log_perror(int log_level, const char *msg);
#define MSG(l, fmt, ...) \
        if (log_level >= LOG_LEVEL_##l) \
                log_msg(LOG_LEVEL_##l, "%s" fmt, MOD_NAME, ##__VA_ARGS__)
#define MSG_ONCE(l, fmt, ...) \
        if (log_level >= LOG_LEVEL_##l) \
                log_msg_once(LOG_LEVEL_##l, \
                             (0x80000000U | (((uintptr_t) MOD_NAME) & \
                                 0x7FFFFFFF)) +  __COUNTER__, \
                             "%s" fmt, MOD_NAME, ##__VA_ARGS__)

bool parse_log_cfg(const char *conf_str,
		int *log_lvl,
		bool *logger_skip_repeats,
		enum log_timestamp_mode *show_timestamps);

void bug_msg(int level, const char *format, ...) __attribute__((format (printf, 2, 3)));

#ifdef __cplusplus
}
#endif

#define CUMULATIVE_REPORTS_INTERVAL 30

#ifdef __cplusplus
#include <atomic>
#include <iomanip>
#include <iostream>
#include <stdio.h>
#include <set>
#include <sstream>
#include <string>
#include <string_view>
#include <mutex>
#include "tv.h"
#include "utils/color_out.h"

class Log_output{
        class Buffer{
        public:
                Buffer(Log_output& lo): lo(lo) { lo.get_internal_buffer().clear();  }

                void append(std::string_view sv){
                        get() += sv;
                }
                void append(int count, char c) { get().append(count, c); }

                void reserve(size_t size){ if(get().capacity() < size) get().reserve(size); }
                std::string& get() { return lo.get_internal_buffer(); }
                char *data() { return get().data(); }

                void submit() { lo.submit(); }
                void submit_raw() { lo.submit_raw(); }

                Buffer(const Buffer&) = delete;
                Buffer(Buffer&&) = delete;
                Buffer& operator=(const Buffer&) = delete;
                Buffer& operator=(Buffer&&) = delete;

        private:
                Log_output& lo;
        };
public:
        Log_output();
        
        Buffer get_buffer() { return Buffer(*this); }

        void set_skip_repeats(bool val) { skip_repeated.store(val, std::memory_order_relaxed); }
        bool get_skip_repeats() const { return skip_repeated.load(std::memory_order_relaxed); }

        void set_timestamp_mode(log_timestamp_mode val) { show_timestamps = val; }

        const std::string& get_level_style(int lvl);
        bool is_interactive() const { return interactive; }

        Log_output(const Log_output&) = delete;
        Log_output(Log_output&&) = delete;

        Log_output& operator=(const Log_output&) = delete;
        Log_output& operator=(Log_output&&) = delete;

private:
        void submit();
        void submit_raw(); //just pass to output as is, no styles, timestamps, etc.

        constexpr static int initial_buf_size = 256;
        std::string& get_internal_buffer(){
            thread_local static std::string buffer(initial_buf_size, '\0');
            return buffer;
        }

        std::atomic<bool> skip_repeated = true;
        log_timestamp_mode show_timestamps;

        bool interactive = false;

        /* Since writing to stdout uses locks internally anyway (C11 standard
         * 7.21.2 sections 7&8), using a mutex here does not cause any significant
         * overhead, we just wait for the lock a bit earlier. */
        std::mutex mut;
        std::string last_msg;
        int last_msg_repeats = 0;

        friend class Buffer;
};

inline const std::string& Log_output::get_level_style(int lvl){
        static std::string empty = "";

        if (!is_interactive()) {
                return empty;
        }

        switch(lvl){
        case LOG_LEVEL_FATAL: {
                static std::string style = TERM_BOLD TERM_FG_RED;
                return style;
        }
        case LOG_LEVEL_ERROR: {
                static std::string style = TERM_FG_RED;
                return style;
        }
        case LOG_LEVEL_WARNING: {
                static std::string style = TERM_FG_YELLOW;
                return style;
        }
        case LOG_LEVEL_NOTICE: {
                static std::string style = TERM_FG_GREEN;
                return style;
        }
        default:
                return empty;
        }
}

inline void Log_output::submit(){
        static constexpr int ts_bufsize = 32; //log10(2^64) is 19.3, so should be enough
        char ts_str[ts_bufsize];
        ts_str[0] = '\0';
                                              
        if (show_timestamps == LOG_TIMESTAMP_ENABLED
                || (show_timestamps == LOG_TIMESTAMP_AUTO && log_level >= LOG_LEVEL_VERBOSE))
        {
                const time_ns_t time_ns = get_time_in_ns();
                snprintf(ts_str, ts_bufsize, "[%.3f] ",
                         (double) time_ns / NS_IN_SEC_DBL);
        }

        const char *start_newline = "";
        std::lock_guard<std::mutex> lock(mut);
        if (skip_repeated && interactive) {
                if (get_internal_buffer() == last_msg) {
                        last_msg_repeats++;
                        printf("    Last message repeated %d times\r", last_msg_repeats);
                        fflush(stdout);
                        return;
                }

                if (last_msg_repeats > 0) {
                        start_newline = "\n";
                }
                last_msg_repeats = 0;
        }

        printf("%s%s%s", start_newline, ts_str, get_internal_buffer().c_str());

        std::swap(last_msg, get_internal_buffer());
}

inline void Log_output::submit_raw(){
        std::lock_guard<std::mutex> lock(mut);
        if(last_msg_repeats > 0)
                fputc('\n', stdout);
        fputs(get_internal_buffer().c_str(), stdout);
        std::swap(last_msg, get_internal_buffer());
        last_msg_repeats = 0;
}

inline Log_output& get_log_output(){
        static Log_output out;
        return out;
}

// Log, version 0.1: a simple logging class
class Logger
{
public:
        inline Logger(int l) : level(l) {
                oss << get_log_output().get_level_style(level);
        }

        inline ~Logger() {
                std::string msg = oss.str();

                if (get_log_output().is_interactive()) {
                        // add TERM_RESET (before NL if present at the end)
                        const bool eol_nl =
                            msg.size() > 0 && msg.at(msg.size() - 1) == '\n';
                        if (eol_nl) {
                                msg.resize(msg.size() - 1);
                        }
                        msg += TERM_RESET;
                        if (eol_nl) {
                                msg += "\n";
                        }
                } else {
                        msg = prune_ansi_sequences_str(msg.c_str());
                }

                auto buf = get_log_output().get_buffer();
                buf.append(msg);
                buf.submit();
        }

        inline std::ostream& Get() {
                return oss;
        }

private:
        int level;
        std::ostringstream oss;

        friend void log_msg_once(int level, uint32_t id, const char *msg, ...);
};

#define LOG(level) \
if ((level) <= log_level) Logger(level).Get()


#endif

#endif