#include "log.h"

#include <assert.h>
#include <stdarg.h>
#include <time.h>

#include <openssl/err.h>

#include "util/sorted_str_set.h"

static const char* LOG_LEVEL_STRING_TABLE[] = {
	"ERROR",
	"WARN",
	"INFO",
	"DEBUG",
	"TRACE"
};

// Maybe add __attribute__((constructor)) in the future if available to skip _config_initialized
static bool _user_default_config_initialized = false;
static struct log_config_s _user_default_config;

static sorted_str_set* _module_configs = NULL;

static inline struct log_config_s _default_config() {
	
	if (_user_default_config_initialized) {
		return _user_default_config;
	}

	return (struct log_config_s) {
		.loc_error = LOG_LOC_STDS(stderr),
		.loc_warn  = LOG_LOC_STDS(stderr),
		.loc_info  = LOG_LOC_STDS(stdout),
		.loc_debug = LOG_LOC_NONE(),
		.loc_trace = LOG_LOC_NONE(),

		.timestamp = true,
	};	
}

void log_set_default_config(struct log_config_s config) {
	_user_default_config = config;
	_user_default_config_initialized = true;
}

struct log_config_s* log_get_config(const char* module_name) {

	assert(module_name != NULL);

	if (!_module_configs) {
		if (!(_module_configs = sorted_str_set_new(sizeof(struct log_config_s)))) {
			return NULL;
		}
	}
	
	struct log_config_s default_conf = _default_config();
	return sorted_str_set_insert(_module_configs, module_name, &default_conf);
}

void log_log(const char* module, enum LOG_LEVEL log_level, const char* fmt, ...) {
	
	assert(module != NULL);

	struct log_config_s* config = log_get_config(module);
	assert(config);

	struct log_loc* dest_loc;
	switch (log_level) {
		case LOG_ERR:   dest_loc = &config->loc_error; break;
		case LOG_WARN:  dest_loc = &config->loc_warn;  break;
		case LOG_INFO:  dest_loc = &config->loc_info;  break;
		case LOG_DEBUG: dest_loc = &config->loc_debug; break;
		case LOG_TRACE: dest_loc = &config->loc_trace; break;
		default: return;
	}

	if (dest_loc->type == LOG_LOC_TYPE_DISABLED) {
		return;
	} else if (dest_loc->type == LOG_LOC_TYPE_FS) {

		if (!dest_loc->location) {
			if (!(dest_loc->location = fopen(dest_loc->file_name, "a"))) {
				return;
			}
		}

	} else if (dest_loc->type != LOG_LOC_TYPE_STDS) {
		return;
	}

	FILE* dest = dest_loc->location;
	
	va_list varargs;
	va_start(varargs, fmt);

	if (config->timestamp) {
		struct timespec utc_time;
		struct tm local_time;
		char time_str_buf[10+1+8+1];
		timespec_get(&utc_time, TIME_UTC);
		localtime_r(&(utc_time.tv_sec), &local_time);
		
		if(strftime(time_str_buf, sizeof(time_str_buf), "%F %T", &local_time)) {
			fprintf(dest, "[%s.%9lu] ", time_str_buf, utc_time.tv_nsec);	
		}
	}

	fprintf(dest, "[%s] %s: ", LOG_LEVEL_STRING_TABLE[log_level], module);
	vfprintf(dest, fmt, varargs);
	fprintf(dest, "\n");

	if (dest_loc->type == LOG_LOC_TYPE_FS && !dest_loc->keep_file_open) {
		fclose(dest_loc->location);
		dest_loc->location = NULL;
	}
}

void log_log_ssl_err(const char* module, enum LOG_LEVEL log_level, const char* fmt, ...) {
	assert(module != NULL);

	struct log_config_s* config = log_get_config(module);
	assert(config);

	struct log_loc* dest_loc;
	switch (log_level) {
		case LOG_ERR:   dest_loc = &config->loc_error; break;
		case LOG_WARN:  dest_loc = &config->loc_warn;  break;
		case LOG_INFO:  dest_loc = &config->loc_info;  break;
		case LOG_DEBUG: dest_loc = &config->loc_debug; break;
		case LOG_TRACE: dest_loc = &config->loc_trace; break;
		default: return;
	}

	if (dest_loc->type == LOG_LOC_TYPE_DISABLED) {
		return;
	} else if (dest_loc->type == LOG_LOC_TYPE_FS) {

		if (!dest_loc->location) {
			if (!(dest_loc->location = fopen(dest_loc->file_name, "a"))) {
				return;
			}
		}

	} else if (dest_loc->type != LOG_LOC_TYPE_STDS) {
		return;
	}

	FILE* dest = dest_loc->location;
	
	va_list varargs;
	va_start(varargs, fmt);

	if (config->timestamp) {
		struct timespec utc_time;
		struct tm local_time;
		char time_str_buf[10+1+8+1];
		timespec_get(&utc_time, TIME_UTC);
		localtime_r(&(utc_time.tv_sec), &local_time);
		
		if(strftime(time_str_buf, sizeof(time_str_buf), "%F %T", &local_time)) {
			fprintf(dest, "[%s.%9lu] ", time_str_buf, utc_time.tv_nsec);	
		}
	}

	fprintf(dest, "[%s] %s: ", LOG_LEVEL_STRING_TABLE[log_level], module);
	vfprintf(dest, fmt, varargs);
	fprintf(dest, "\n");
	ERR_print_errors_fp(dest);

	if (dest_loc->type == LOG_LOC_TYPE_FS && !dest_loc->keep_file_open) {
		fclose(dest_loc->location);
		dest_loc->location = NULL;
	}

}