degesch: add logging to file

degesch.c

@@ -1018,6 +1018,8 @@ struct buffer
 	unsigned unseen_messages_count;     ///< # messages since last visited
 	bool highlighted;                   ///< We've been highlighted
 
+	FILE *log_file;                     ///< Log file
+
 	// Origin information:
 
 	struct server *server;              ///< Reference to server
@@ -1041,6 +1043,8 @@ buffer_destroy (struct buffer *self)
 		input_buffer_destroy (self->input_data);
 	LIST_FOR_EACH (struct buffer_line, iter, self->lines)
 		buffer_line_destroy (iter);
+	if (self->log_file)
+		(void) fclose (self->log_file);
 	if (self->user)
 		user_unref (self->user);
 	if (self->channel)
@@ -1550,6 +1554,10 @@ static struct config_schema g_config_behaviour[] =
 	  .comment   = "Beep when highlighted or on a new invisible PM",
 	  .type      = CONFIG_ITEM_BOOLEAN,
 	  .default_  = "on" },
+	{ .name      = "logging",
+	  .comment   = "Log buffer contents to file",
+	  .type      = CONFIG_ITEM_BOOLEAN,
+	  .default_  = "off" },
 	{}
 };
 
@@ -2482,6 +2490,20 @@ buffer_update_time (struct app_context *ctx, time_t now)
 	// Else the buffer was too small, which is pretty weird
 }
 
+static void
+buffer_line_flush (struct buffer_line *line, struct formatter *f, FILE *output)
+{
+	int flags = line->flags;
+	if (flags & BUFFER_LINE_INDENT)  formatter_add (f, "    ");
+	if (flags & BUFFER_LINE_STATUS)  formatter_add (f, " -  ");
+	if (flags & BUFFER_LINE_ERROR)   formatter_add (f, "#a=!=#r ", ATTR_ERROR);
+
+	formatter_add_from (f, line->formatter);
+	formatter_add (f, "\n");
+	formatter_flush (f, output);
+	formatter_free (f);
+}
+
 static void
 buffer_line_display (struct app_context *ctx,
 	struct buffer_line *line, bool is_external)
@@ -2494,12 +2516,13 @@ buffer_line_display (struct app_context *ctx,
 	formatter_init (&f, ctx, NULL);
 
 	struct tm current;
+	char buf[9];
 	if (!localtime_r (&line->when, &current))
 		print_error ("%s: %s", "localtime_r", strerror (errno));
+	else if (!strftime (buf, sizeof buf, "%T", &current))
+		print_error ("%s: %s", "strftime", "buffer too small");
 	else
-		formatter_add (&f, "#a#&s#r ", ATTR_TIMESTAMP,
+		formatter_add (&f, "#a#s#r ", ATTR_TIMESTAMP, buf);
-			xstrdup_printf ("%02d:%02d:%02d",
-				current.tm_hour, current.tm_min, current.tm_sec));
 
 	// Ignore all formatting for messages coming from other buffers, that is
 	// either from the global or server buffer.  Instead print them in grey.
@@ -2509,26 +2532,33 @@ buffer_line_display (struct app_context *ctx,
 		FORMATTER_ADD_ITEM (&f, IGNORE_ATTR, .attribute = 1);
 	}
 
-	if (line->flags & BUFFER_LINE_INDENT)
-		formatter_add (&f, "    ");
-	if (line->flags & BUFFER_LINE_STATUS)
-		formatter_add (&f, " -  ");
-	if (line->flags & BUFFER_LINE_ERROR)
-		formatter_add (&f, "#a=!=#r ", ATTR_ERROR);
-	formatter_add_from (&f, line->formatter);
-
 	input_hide (&ctx->input);
-
+	buffer_line_flush (line, &f, stdout);
-	// TODO: write the line to a log file; note that the global and server
-	//   buffers musn't collide with filenames
-
-	formatter_add (&f, "\n");
-	formatter_flush (&f, stdout);
-	formatter_free (&f);
-
 	input_show (&ctx->input);
 }
 
+static void
+buffer_line_write_to_log (struct app_context *ctx,
+	struct buffer_line *line, FILE *log_file)
+{
+	if (line->flags & BUFFER_LINE_SKIP_FILE)
+		return;
+
+	struct formatter f;
+	formatter_init (&f, ctx, NULL);
+
+	struct tm current;
+	char buf[20];
+	if (!gmtime_r (&line->when, &current))
+		print_error ("%s: %s", "gmtime_r", strerror (errno));
+	else if (!strftime (buf, sizeof buf, "%F %T", &current))
+		print_error ("%s: %s", "strftime", "buffer too small");
+	else
+		formatter_add (&f, "#s ", buf);
+
+	buffer_line_flush (line, &f, log_file);
+}
+
 static void
 log_formatter (struct app_context *ctx,
 	struct buffer *buffer, int flags, struct formatter *f)
@@ -2547,6 +2577,9 @@ log_formatter (struct app_context *ctx,
 	LIST_APPEND_WITH_TAIL (buffer->lines, buffer->lines_tail, line);
 	buffer->lines_count++;
 
+	if (buffer->log_file)
+		buffer_line_write_to_log (ctx, line, buffer->log_file);
+
 	if (get_config_boolean (ctx->config.root, "behaviour.beep_on_highlight"))
 		if ((flags & BUFFER_LINE_HIGHLIGHT)
 		 || (buffer->type == BUFFER_PM && buffer != ctx->current_buffer))
@@ -2634,6 +2667,41 @@ log_full (struct app_context *ctx, struct server *s, struct buffer *buffer,
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+static void
+make_log_filename (const char *filename, struct str *output)
+{
+	for (const char *p = filename; *p; p++)
+		// XXX: anything more to replace?
+		if (strchr ("/\\ ", *p))
+			str_append_c (output, '_');
+		else
+			str_append_c (output, tolower_ascii (*p));
+}
+
+static void
+buffer_open_log_file (struct app_context *ctx, struct buffer *buffer)
+{
+	if (!get_config_boolean (ctx->config.root, "behaviour.logging"))
+		return;
+
+	struct str path;
+	str_init (&path);
+	get_xdg_home_dir (&path, "XDG_DATA_HOME", ".local/share");
+	str_append_printf (&path, "/%s/%s", PROGRAM_NAME, "logs");
+
+	(void) mkdir_with_parents (path.str, NULL);
+
+	// TODO: make sure global and server buffers don't collide with filenames
+	str_append_c (&path, '/');
+	make_log_filename (buffer->name, &path);
+	str_append (&path, ".log");
+
+	if (!(buffer->log_file = fopen (path.str, "ab")))
+		log_global_error (ctx, "Couldn't open log file `#s': #s",
+			path.str, strerror (errno));
+	str_free (&path);
+}
+
 static struct buffer *
 buffer_by_name (struct app_context *ctx, const char *name)
 {
@@ -2648,6 +2716,8 @@ buffer_add (struct app_context *ctx, struct buffer *buffer)
 	str_map_set (&ctx->buffers_by_name, buffer->name, buffer);
 	LIST_APPEND_WITH_TAIL (ctx->buffers, ctx->buffers_tail, buffer);
 
+	buffer_open_log_file (ctx, buffer);
+
 	// In theory this can't cause changes in the prompt
 	refresh_prompt (ctx);
 }
@@ -2776,6 +2846,13 @@ buffer_rename (struct app_context *ctx,
 	str_map_set (&ctx->buffers_by_name, buffer->name, NULL);
 	str_map_set (&ctx->buffers_by_name, new_name, buffer);
 
+	if (buffer->log_file)
+	{
+		(void) fclose (buffer->log_file);
+		buffer->log_file = NULL;
+	}
+	buffer_open_log_file (ctx, buffer);
+
 	free (buffer->name);
 	buffer->name = xstrdup (new_name);