/* See LICENSE file for copyright and license details. */
#include "common.h"


static char *
substitute(struct libgeome_context *ctx, const char *text, uint64_t features)
{
	size_t len = 0, sublen;
	size_t i;
	int negative, include;
	uint64_t if_features, digit;
	char *ret, *p;

	for (i = 0; text[i];) {
		if (text[i] != '%') {
			i += 1U;
			len += 1U;
		} else if (text[i + 1U] == '%') {
			i += 2U;
			len += 1U;
		} else if (text[i + 1U] == '{') {
			i += 2U;
			negative = text[i] == '!';
			i += (size_t)negative;
			if_features = 0;
			for (; isdigit(text[i]); i++) {
				digit = (uint64_t)(text[i] & 15);
				if (if_features > (UINT64_MAX - digit) / 10U)
					goto invalid;
				if_features = if_features * 10U + digit;
			}
			if (!if_features || text[i++] != ':')
				goto invalid;
			include = !!(if_features & features);
			include ^= negative;
			sublen = 0;
			for (;;) {
				if (text[i] == '}') {
					i += 1U;
					break;
				} else if (!text[i]) {
					goto invalid;
				} else if (text[i] != '%') {
					i += 1U;
					sublen += 1U;
				} else if (text[i + 1U] == '%') {
					i += 1U;
					sublen += 2U;
				} else if (text[i + 1U] == '}') {
					i += 1U;
					sublen += 2U;
				} else {
					goto invalid;
				}
			}
			if (include ^ negative)
				len += sublen;
		} else {
		invalid:
			ctx->print_error(ctx, "invalid %-pattern in `%s'\n", text);
			return NULL;
		}
	}

	p = ret = malloc(len + 1U);
	if (!ret) {
		ctx->print_error(ctx, "malloc: %s\n", strerror(errno));
		return NULL;
	}

	while (*text) {
		if (*text != '%') {
			*p++ = *text++;
		} else if (text[i + 1U] == '%') {
			text = &text[2];
			*p++ = '%';
		} else if (text[i + 1U] == '{') {
			text = &text[2];
			negative = *text == '!';
			text = &text[negative];
			if_features = 0;
			while (isdigit(*text)) {
				digit = (uint64_t)(*text++ & 15);
				if_features = if_features * 10U + digit;
			}
			text++;
			include = !!(if_features & features);
			include ^= negative;
			for (; *text != '}'; text++) {
				if (include)
					*p++ = text[*text == '%'];
				if (*text == '%')
					text++;
			}
			text++;
		}
	}
	*p = '\0';

	return ret;
}


int
libgeome_get_from_patterned_command(struct libgeome_context *ctx, struct libgeome_data *out, size_t limit, /* TODO test */
                                    unsigned int alarm_sec, const char *path, const char *const *argv)
{
	const char **argv_new = NULL;
	char **array;
	size_t count = 0;
	size_t index = 0;
	size_t i, argc = 0;
	int ret = -1;

	if (strchr(path, '%'))
		count += 1U;

	for (i = 0; argv[i]; i++)
		if (strchr(argv[i], '%'))
			count += 1U;
	argc = i;

	if (!count)
		return libgeome_get_from_patterned_command(ctx, out, limit, alarm_sec, path, argv);

	array = calloc(count, sizeof(*array));
	if (!array) {
		ctx->print_error(ctx, "calloc: %s\n", strerror(errno));
		return -1;
	}

	if (strchr(path, '%')) {
		path = array[index++] = substitute(ctx, path, out->requested_data);
		if (!path)
			goto out;
	}

	if (index != count) {
		argv_new = calloc(argc + 1U, sizeof(*argv_new));
		if (!argv_new) {
			ctx->print_error(ctx, "calloc: %s\n", strerror(errno));
			goto out;
		}
		argv_new[argc] = NULL;
		for (i = 0; argv[i]; i++) {
			if (strchr(argv[i], '%')) {
				argv_new[i] = array[index++] = substitute(ctx, argv[i], out->requested_data);
				if (!argv_new[i])
					goto out;
			} else {
				argv_new[i] = argv[i];
			}
		}
		argv = argv_new;
	}

	ret = libgeome_get_from_patterned_command(ctx, out, limit, alarm_sec, path, argv);
out:
	for (i = 0; i < count; i++)
		free(array[i]);
	free(array);
	free(argv_new);
	return ret;
}