Add logging functions

The mkdir dance is a bit awkward...

1 files changed, 112 insertions, 0 deletions

diff --git a/log.c b/log.c
new file mode 100644
index 0000000..7f99ec4
--- /dev/null
+++ b/log.c
@@ -0,0 +1,112 @@
+/* Copyright (C) 2020  C. McEnroe <june@causal.agency>
+ *
+ * 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 3 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, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <err.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sysexits.h>
+#include <time.h>
+
+#include "chat.h"
+
+bool logEnable;
+
+static struct {
+	int year;
+	int month;
+	int day;
+	FILE *file;
+} logs[IDCap];
+
+static FILE *logFile(uint id, const struct tm *tm) {
+	if (
+		logs[id].file &&
+		logs[id].year == tm->tm_year &&
+		logs[id].month == tm->tm_mon &&
+		logs[id].day == tm->tm_mday
+	) return logs[id].file;
+
+	if (logs[id].file) {
+		int error = fclose(logs[id].file);
+		if (error) err(EX_IOERR, "%s", idNames[id]);
+	}
+
+	logs[id].year = tm->tm_year;
+	logs[id].month = tm->tm_mon;
+	logs[id].day = tm->tm_mday;
+
+	char path[PATH_MAX] = "log";
+	size_t len = strlen(path);
+	dataMkdir("");
+	dataMkdir(path);
+
+	path[len++] = '/';
+	for (const char *ch = network.name; *ch; ++ch) {
+		path[len++] = (*ch == '/' ? '_' : *ch);
+	}
+	path[len] = '\0';
+	dataMkdir(path);
+
+	path[len++] = '/';
+	for (const char *ch = idNames[id]; *ch; ++ch) {
+		path[len++] = (*ch == '/' ? '_' : *ch);
+	}
+	path[len] = '\0';
+	dataMkdir(path);
+
+	strftime(&path[len], sizeof(path) - len, "/%F.log", tm);
+	logs[id].file = dataOpen(path, "a");
+	if (!logs[id].file) exit(EX_CANTCREAT);
+
+	setlinebuf(logs[id].file);
+	return logs[id].file;
+}
+
+void logClose(void) {
+	if (!logEnable) return;
+	for (uint id = 0; id < IDCap; ++id) {
+		if (!logs[id].file) continue;
+		int error = fclose(logs[id].file);
+		if (error) err(EX_IOERR, "%s", idNames[id]);
+	}
+}
+
+void logFormat(uint id, const time_t *src, const char *format, ...) {
+	if (!logEnable) return;
+
+	time_t ts = (src ? *src : time(NULL));
+	struct tm *tm = localtime(&ts);
+	if (!tm) err(EX_OSERR, "localtime");
+
+	FILE *file = logFile(id, tm);
+
+	char buf[sizeof("0000-00-00T00:00:00+0000")];
+	strftime(buf, sizeof(buf), "%FT%T%z", tm);
+	fprintf(file, "[%s] ", buf);
+	if (ferror(file)) err(EX_IOERR, "%s", idNames[id]);
+
+	va_list ap;
+	va_start(ap, format);
+	vfprintf(file, format, ap);
+	va_end(ap);
+	if (ferror(file)) err(EX_IOERR, "%s", idNames[id]);
+
+	fprintf(file, "\n");
+	if (ferror(file)) err(EX_IOERR, "%s", idNames[id]);
+}