/*
 * 989_arrlit_tail_zero_run (#13) — an UNDER-LENGTH array literal zero-fills
 * the unspecified tail (Hare: unspecified array elements are zeroed; the
 * #16-task zero-value ruling), not the last value.
 *
 * THE BUG (wwstage only, gate-blind cs!=ww): emitarraylitbytes' int-element
 * tail loop defaulted each unfilled slot to `last` (the previously emitted
 * value), so `let g: [4]u64 = [1, 2]` emitted [1,2,2,2] — the DATAW tail
 * repeated \x02. cstage already zeroes the tail (cg_array_data). THE FIX:
 * default the tail to 0; replay `last` only inside a `...` repeat.
 *
 * The float / struct / nested-array element paths already zero-filled their
 * tails; only the int path defaulted to `last`. The str/slice element paths
 * ride a different helper (emitstrarraydata / emitslicedata) and were also
 * already correct — the str_tail row documents the family is uniformly
 * zeroed, it is coverage, not a teeth on this fix.
 *
 *   row           | shape                          | exit (cs==ww)
 *   --------------+--------------------------------+--------------
 *   scalar_tail   | [4]u64=[1,2]; sum              | 3   (1+2+0+0)
 *   repeat_ctl    | [4]u64=[7,9...]; sum (control) | 34  (7+9+9+9)
 *   str_tail      | [4]str=["ab","cde"]; tail.len  | 5   (2+3, tail len 0)
 * Pre-fix (int tail = last): scalar_tail ww=7 (1+2+2+2) != cs=3.
 */
#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;
}

struct row { const char *label; const char *src; int want_exit; };

static const struct row rows[] = {
	{ "scalar_tail",
	  "package main;\n"
	  "let g: [4]u64 = [1, 2];\n"
	  "export fn main() i32 = {\n"
	  "	return (g[0] + g[1] + g[2] + g[3]): i32;\n"
	  "};\n",
	  3 },

	{ "repeat_ctl",
	  "package main;\n"
	  "let g: [4]u64 = [7, 9...];\n"
	  "export fn main() i32 = {\n"
	  "	return (g[0] + g[1] + g[2] + g[3]): i32;\n"
	  "};\n",
	  34 },

	{ "str_tail",
	  "package main;\n"
	  "let g: [4]str = [\"ab\", \"cde\"];\n"
	  "export fn main() i32 = {\n"
	  "	if (g[2].len != 0) { return 21; };\n"
	  "	if (g[3].len != 0) { return 22; };\n"
	  "	return (g[0].len + g[1].len): i32;\n"
	  "};\n",
	  5 },
};

static int
run_build(const char *driver, const struct row *r, int i)
{
	char src[64], tmpdir[64], cmd[1024];
	snprintf(src, sizeof src, "/tmp/atz_%d_%d.ww", getpid(), i);
	snprintf(tmpdir, sizeof tmpdir, "/tmp/atz_%d_d_%d", getpid(), i);

	FILE *f = fopen(src, "wb");
	if (!f) return -2;
	fputs(r->src, f);
	fclose(f);

	mkdir(tmpdir, 0755);
	snprintf(cmd, sizeof cmd, "cd %s && %s build %s 2>/dev/null",
	    tmpdir, driver, src);
	int brc = runwait(cmd);

	const char *base = strrchr(src, '/');
	base = base ? base + 1 : src;
	char outbin[128];
	snprintf(outbin, sizeof outbin, "%s/%s", tmpdir, base);
	char *dot = strrchr(outbin, '.');
	if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';

	int got = -1;
	if (brc == 0) got = runwait(outbin);

	unlink(src); unlink(outbin); rmdir(tmpdir);
	return brc == 0 ? got : -1;
}

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);

	int n = (int)(sizeof rows / sizeof rows[0]);
	int total = 0, fail = 0;

	for (int i = 0; i < n; i++) {
		total++;
		int gc = run_build(cdrv, &rows[i], i);
		if (gc < 0) {
			fprintf(stderr, "arrlit_tail_zero[cstage][%s]: build/run "
			    "failed (got %d)\n", rows[i].label, gc);
			fail++;
			continue;
		}
		if (gc != rows[i].want_exit) {
			fprintf(stderr, "arrlit_tail_zero[cstage][%s]: exit=%d "
			    "want=%d\n", rows[i].label, gc, rows[i].want_exit);
			fail++;
		}
		if (!have_ww) {
			fprintf(stderr, "arrlit_tail_zero: skip wwstage (no %s)\n", wdrv);
			continue;
		}
		int gw = run_build(wdrv, &rows[i], i);
		if (gw != gc) {
			fprintf(stderr, "arrlit_tail_zero[%s]: cs=%d != ww=%d "
			    "(tail fill divergence — #13)\n", rows[i].label, gc, gw);
			fail++;
		}
		if (gw != rows[i].want_exit) {
			fprintf(stderr, "arrlit_tail_zero[wwstage][%s]: exit=%d "
			    "want=%d\n", rows[i].label, gw, rows[i].want_exit);
			fail++;
		}
	}

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