/*
 * 989_zerotest_run (#64, F15 c7) — `ww test <dir>` over a directory with no
 * *_test.ww files must fail loud, not return rc=0 with a silent false-green.
 *
 * THE BUG (wwstage driver only, cat-A silent false-green under rc=0):
 * rundirtests had no zero-count check — a directory with no *_test.ww files
 * yielded pass=0 fail=0 → `return 0` with no output at all. A typo'd or empty
 * test dir got a silent green from the wwstage driver, while cstage do_test
 * errors "ww test: no *_test.ww files in %s" rc=1 (cmd/ww/main.c:945). THE FIX:
 * count *_test.ww matches and loud-fail (rc=1 + the same message) when zero.
 *
 *   row     | dir contents              | result (cs==ww)
 *   --------+---------------------------+----------------------------
 *   empty   | no files                  | rc != 0 (loud "no *_test.ww")
 *   nomatch | foo.ww (not *_test.ww)    | rc != 0 (loud)
 *   healthy | foo_test.ww (1 @test)     | rc == 0 (control)
 *
 * empty / nomatch were RED pre-c7 on wwstage (rc=0, no output, false-green).
 * healthy pins the real-test path: both stages run it and exit 0.
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>

static int
runwait(const char *cmd)
{
	int rc = system(cmd);
	if (rc == -1) return -1;
	if (WIFEXITED(rc)) return WEXITSTATUS(rc);
	return -1;
}

/* Set up a fresh dir; optionally drop a file with `body` named `fname`.
 * Returns the dir path in `dir`. */
static void
make_dir(char *dir, size_t dsz, const char *tag, const char *fname,
    const char *body)
{
	char cmd[256], fp[256];
	snprintf(dir, dsz, "/tmp/zt_%d_%s", getpid(), tag);
	snprintf(cmd, sizeof cmd, "rm -rf %s && mkdir -p %s", dir, dir);
	system(cmd);
	if (fname) {
		snprintf(fp, sizeof fp, "%s/%s", dir, fname);
		FILE *f = fopen(fp, "wb");
		if (f) { fputs(body, f); fclose(f); }
	}
}

/* `<driver> test <dir>` rc. */
static int
run_test(const char *driver, const char *dir)
{
	char cmd[1024];
	snprintf(cmd, sizeof cmd, "%s test %s >/dev/null 2>&1", driver, dir);
	return runwait(cmd);
}

int
main(void)
{
	const char *bin = getenv("BIN");
	if (!bin) bin = "out/bin";
	char absbin[1024];
	if (bin[0] != '/') {
		char cwd[1024];
		if (getcwd(cwd, sizeof cwd) == NULL) return 1;
		snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
		bin = absbin;
	}
	char cdrv[1024], wdrv[1024];
	snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
	snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);
	int have_ww = (access(wdrv, X_OK) == 0);
	if (!have_ww)
		fprintf(stderr, "zerotest: skip wwstage (no %s)\n", wdrv);

	struct row { const char *tag; const char *fname; const char *body;
	    int want_loud; };
	struct row rows[] = {
		{ "empty",   NULL, NULL, 1 },
		{ "nomatch", "foo.ww",
		  "package main;\nexport fn main() i32 = { return 0; };\n", 1 },
		{ "healthy", "foo_test.ww",
		  "package zt_test;\n@test fn t_ok() void = { };\n", 0 },
	};

	int n = (int)(sizeof rows / sizeof rows[0]);
	int fail = 0, total = 0;
	for (int i = 0; i < n; i++) {
		total++;
		char dir[128];
		make_dir(dir, sizeof dir, rows[i].tag, rows[i].fname, rows[i].body);

		int crc = run_test(cdrv, dir);
		if (rows[i].want_loud) {
			if (crc == 0) {
				fprintf(stderr, "zerotest[cstage][%s]: rc=0, expected loud "
				    "no-tests failure\n", rows[i].tag);
				fail++;
			}
		} else if (crc != 0) {
			fprintf(stderr, "zerotest[cstage][%s]: rc=%d, expected 0\n",
			    rows[i].tag, crc);
			fail++;
		}

		if (have_ww) {
			int wrc = run_test(wdrv, dir);
			if (rows[i].want_loud) {
				if (wrc == 0) {
					fprintf(stderr, "zerotest[wwstage][%s]: rc=0 on a dir with "
					    "no *_test.ww (silent false-green — #64)\n", rows[i].tag);
					fail++;
				}
				if ((crc == 0) != (wrc == 0)) {
					fprintf(stderr, "zerotest[%s]: loud divergence cs_rc=%d "
					    "ww_rc=%d (#64)\n", rows[i].tag, crc, wrc);
					fail++;
				}
			} else {
				if (wrc != 0) {
					fprintf(stderr, "zerotest[wwstage][%s]: rc=%d, expected 0\n",
					    rows[i].tag, wrc);
					fail++;
				}
			}
		}

		char cmd[160];
		snprintf(cmd, sizeof cmd, "rm -rf %s", dir);
		system(cmd);
	}

	if (fail) {
		fprintf(stderr, "zerotest_run: %d/%d check(s) failed\n", fail, total);
		return 1;
	}
	printf("zerotest_run: %d/%d ok\n", total, total);
	return 0;
}