/* b01902062 藍挺瑋 */
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "chttpd-log.h"
#include "memwrap.h"
#include <l4list.h>
#include <l4posix.h>

#include <fcntl.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

ChttpdLog* chttpd_log_new (const char* name, int log_fd) {
	char* name_start = strrchr (name, '/');
	name = name_start == NULL ? name : name_start + 1;
	size_t name_len = (name == NULL) ? 0 : strlen (name);
	char* mem = xmalloc (sizeof (ChttpdLog) + name_len + 1);
	void* mem_generic = mem;

	ChttpdLog* hlog = mem_generic;
	hlog->name = mem + sizeof (ChttpdLog);
	if (name != NULL) {
		strncpy (hlog->name, name, name_len + 1);
	}
	hlog->name[name_len] = '\0';

	hlog->ref_count = 1;
	hlog->pid = getpid ();
	hlog->log_fd = log_fd;
	hlog->log_data = lbs_list_meta_new (free);
	pthread_cond_init (&hlog->ref_change, NULL);
	pthread_mutex_init (&hlog->ref_mutex, NULL);
	pthread_rwlock_init (&hlog->log_lock, NULL);

	return hlog;
}

ChttpdLog* chttpd_log_new_file (const char* name, const char* file) {
	int log_fd = open (file, O_WRONLY | O_APPEND | O_CREAT | O_CLOEXEC, 0600);
	if (log_fd < 0) {
		return NULL;
	}

	return chttpd_log_new (name, log_fd);
}

ChttpdLog* chttpd_log_ref (ChttpdLog* hlog) {
	pthread_mutex_lock (&hlog->ref_mutex);
	hlog->ref_count++;
	pthread_mutex_unlock (&hlog->ref_mutex);
	pthread_cond_broadcast (&hlog->ref_change);
	return hlog;
}

void chttpd_log_unref (ChttpdLog* hlog) {
	pthread_mutex_lock (&hlog->ref_mutex);
	hlog->ref_count--;
	if (hlog->ref_count <= 0) {
		/* No thread has a reference on hlog, so we are going to destory it */
		pthread_mutex_unlock (&hlog->ref_mutex);
		pthread_mutex_destroy (&hlog->ref_mutex);
		pthread_cond_destroy (&hlog->ref_change);
		pthread_rwlock_destroy (&hlog->log_lock);
		lbs_list_meta_free (hlog->log_data);
		free (hlog);
	} else {
		pthread_mutex_unlock (&hlog->ref_mutex);
		pthread_cond_broadcast (&hlog->ref_change);
	}
}

int chttpd_log_read_start (ChttpdLog* hlog) {
	return pthread_rwlock_tryrdlock (&hlog->log_lock);
}

void chttpd_log_read_stop (ChttpdLog* hlog) {
	pthread_rwlock_unlock (&hlog->log_lock);
}

size_t chttpd_log_write (ChttpdLog* hlog, const char* format, ...) {
	va_list ap;
	char* str;
	size_t r;

	va_start (ap, format);
	str = lbs_str_vprintf (format, ap);
	va_end (ap);

	r = chttpd_log_write_str (hlog, str);
	free (str);
	return r;
}

size_t chttpd_log_write_str (ChttpdLog* hlog, const char* string) {
	time_t t;
	struct tm tmd;
	char* msg;
	size_t r;

	time (&t);
	localtime_r (&t, &tmd);
	msg = lbs_str_printf ("%04d-%02d-%02d %02d:%02d:%02d %s[%ld]: %s\n",
		tmd.tm_year + 1900, tmd.tm_mon + 1, tmd.tm_mday,
		tmd.tm_hour, tmd.tm_min, tmd.tm_sec,
		hlog->name, (long)(hlog->pid), string);

	pthread_rwlock_wrlock (&hlog->log_lock);
	lbs_list_push_back (hlog->log_data, msg, NULL);
	r = lbs_posix_write_all (hlog->log_fd, msg, 0);
	pthread_rwlock_unlock (&hlog->log_lock);

	return r;
}