setup: add simple stdio setup_interactively()

Preliminary means for interactively configuring settings and defaults

1 files changed, 124 insertions, 0 deletions

diff --git a/src/setup.c b/src/setup.c
new file mode 100644
index 0000000..6c4a87f
--- /dev/null
+++ b/src/setup.c
@@ -0,0 +1,124 @@
+#include <assert.h>
+#include <stdio.h>
+
+#include "settings.h"
+#include "util.h"
+
+/* add key=value, but if key is NULL, use value as key. */
+static int add_value(settings_t *settings, const char *key, const char *value)
+{
+	assert(settings);
+
+	if (!key) {
+		key = value;
+		value = NULL;
+	}
+
+	assert(key);
+
+	return settings_add_value(settings, key, value);
+}
+
+
+/* returns negative on error, otherwise number of additions made to settings */
+int setup_interactively(settings_t *settings, int (*setup_func)(settings_t *settings, setting_desc_t **next), int defaults)
+{
+	unsigned	additions = 0;
+	char		buf[256] = "\n";
+	setting_desc_t	*next;
+	int		r;
+
+	assert(settings);
+	assert(setup_func);
+
+	/* TODO: regex and error handling */
+
+	while ((r = setup_func(settings, &next)) > 0) {
+		additions++;
+
+		if (!defaults)
+			puts("");
+
+		if (next->values) {
+			unsigned	i, preferred = 0;
+			int		width = 0;
+
+			for (i = 0; next->values[i]; i++) {
+				int	len;
+
+				len = strlen(next->values[i]);
+				if (len > width)
+					width = len;
+			}
+
+			/* multiple choice */
+			if (!defaults)
+				printf("Select %s:\n", next->name);
+
+			for (i = 0; next->values[i]; i++) {
+				if (!defaults)
+					printf(" %u: %*s%s%s\n", i, width, next->values[i],
+						next->annotations ? ": " : "",
+						next->annotations ? next->annotations[i] : "");
+
+				if (!strcmp(next->preferred, next->values[i]))
+					preferred = i;
+			}
+
+			if (!defaults)
+				printf("Enter a value 0-%u [%u (%s)]: ",
+					i - 1, preferred, next->preferred);
+		} else {
+			/* arbitrarily typed input */
+			if (!defaults)
+				printf("%s [%s]: ", next->name, next->preferred);
+		}
+
+		if (!defaults) {
+			fflush(stdout);
+			fgets(buf, sizeof(buf), stdin);
+		}
+
+		if (*buf == '\n') {
+			/* accept preferred */
+			add_value(settings, next->key, next->preferred);
+		} else {
+			buf[strlen(buf) - 1] = '\0';
+
+			if (next->values) {
+				unsigned	i, j, found;
+
+				/* multiple choice, map numeric input to values entry */
+				if (sscanf(buf, "%u", &j) < 1) {
+					printf("Invalid input: \"%s\"\n", buf);
+
+					goto _next;
+				}
+
+				for (found = i = 0; next->values[i]; i++) {
+					if (i == j) {
+						add_value(settings, next->key, next->values[i]);
+						found = 1;
+						break;
+					}
+				}
+
+				if (!found) {
+					printf("Invalid option: %u outside of range [0-%u]\n",
+						j, i - 1);
+
+					goto _next;
+				}
+
+			} else {
+				/* use typed input as setting, TODO: apply regex */
+				add_value(settings, next->key, buf);
+			}
+		}
+
+_next:
+		setting_desc_free(next);
+	}
+
+	return r < 0 ? r : additions;
+}