/*
 * 946_append_structlit_evalorder_run — task #59 (#50's eval-order kin):
 * an append/insert of a STRUCT-LITERAL value used to fill the literal's
 * fields into the destination slot AFTER cg_append_grow had already bumped
 * xs.len. So a field expression that reads `len(xs)` saw the POST-grow
 * length. Hare evaluates the value BEFORE the grow.
 *
 * #263 both-wrong-IDENTICAL: cstage and wwstage emitted byte-identical asm
 * that was wrong on BOTH (exit 6 vs the correct 3) — the asm-diff and
 * byte-id gates are BLIND to it, so a RUNTIME row is the only net.
 *
 * Fix (both stages, byte-identical per rule 10): fill the struct literal
 * into a fresh per-SITE scratch BEFORE the grow (mirror #50's tagged arm),
 * then grow, slot, raw-copy scratch->slot. insert() desugars in-place to
 * append and re-dispatches into THIS exact arm, so it is fixed by
 * construction — R2 proves the desugar twin (both stages).
 *
 * Rows assert RUNTIME on BOTH drivers AND cs==ww .s byte-identical:
 *   append_eval   `append(xs, rec{f=len(xs):i64})` x3 -> sum == 3 (pre-grow);
 *                 base bug = 6 (post-grow), main returns 1.
 *   insert_eval   `insert(xs[1], rec{f=len(xs):i64})` -> inserted.f == 2
 *                 (pre-grow len at insert time); base bug = 3.
 *
 * All K_RUN: build+run exit 0 on BOTH drivers AND cs==ww byte-identical.
 * NNN<950, self-contained (/tmp, no imports), so rule-14's selfhost-sibling
 * race does not apply (903/940/945 precedent).
 */
#include <stdio.h>
#include <stdlib.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;
}

static int
slurp_eq(const char *a, const char *b)
{
	FILE *fa = fopen(a, "rb");
	FILE *fb = fopen(b, "rb");
	if (!fa || !fb) { if (fa) fclose(fa); if (fb) fclose(fb); return -1; }
	int rc = 0;
	for (;;) {
		int ca = fgetc(fa), cb = fgetc(fb);
		if (ca != cb) { rc = -1; break; }
		if (ca == EOF) break;
	}
	fclose(fa); fclose(fb);
	return rc;
}

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

static const struct row rows[] = {
	{ "append_eval",
	  "package main;\n"
	  "type rec = struct { f: i64 };\n"
	  "export fn main() i32 = {\n"
	  "	let xs: []rec = [];\n"
	  "	append(xs, rec{ f = len(xs): i64 });\n"
	  "	append(xs, rec{ f = len(xs): i64 });\n"
	  "	append(xs, rec{ f = len(xs): i64 });\n"
	  "	let s: i64 = xs[0].f + xs[1].f + xs[2].f;\n"
	  "	if (s != 3) { return 1; };\n"
	  "	return 0;\n"
	  "};\n", 0 },
	{ "insert_eval",
	  "package main;\n"
	  "type rec = struct { f: i64 };\n"
	  "export fn main() i32 = {\n"
	  "	let xs: []rec = [];\n"
	  "	append(xs, rec{ f = 100 });\n"
	  "	append(xs, rec{ f = 200 });\n"
	  "	insert(xs[1], rec{ f = len(xs): i64 });\n"
	  "	if (xs[1].f != 2) { return 1; };\n"
	  "	if (xs[0].f != 100) { return 2; };\n"
	  "	if (xs[2].f != 200) { return 3; };\n"
	  "	return 0;\n"
	  "};\n", 0 },
	/*
	 * narrow_neighbor — a sub-8B struct (`{a: i32}`, esz=4, packs at
	 * stride 4) appended to fill the slice exactly to capacity. Catches
	 * BOTH halves of #59 in one row:
	 *   pre-fix (pristine 39432f7): field exprs eval post-grow → sum
	 *     wrong → returns 1.
	 *   8B-block-copy fix (the over-copy regression): eval-order is
	 *     correct but the last slot's 8-byte copy writes 4 bytes PAST
	 *     the 32-byte buffer into the adjacent `victim` allocation →
	 *     victim[0] clobbered → returns 2.
	 *   precise 8/4/2/1 ladder: both correct → 0.
	 * The 8-element fill makes len==cap==8 so the tail over-write lands
	 * past the buffer; `victim` is alloc'd right after xs's buffer (bump
	 * allocator) so the clobber is observable.
	 */
	{ "narrow_neighbor",
	  "package main;\n"
	  "type rec = struct { a: i32 };\n"
	  "export fn main() i32 = {\n"
	  "	let xs: []rec = [];\n"
	  "	append(xs, rec{ a = len(xs): i32 });\n"
	  "	let victim: []i64 = [];\n"
	  "	append(victim, 1234605616436508552i64);\n"
	  "	let i: i32 = 1;\n"
	  "	for (i < 8) {\n"
	  "		append(xs, rec{ a = len(xs): i32 });\n"
	  "		i += 1;\n"
	  "	};\n"
	  "	let s: i32 = 0;\n"
	  "	let j: i32 = 0;\n"
	  "	for (j < 8) { s += xs[j].a; j += 1; };\n"
	  "	if (s != 28) { return 1; };\n"
	  "	if (victim[0] != 1234605616436508552i64) { return 2; };\n"
	  "	return 0;\n"
	  "};\n", 0 },
};

/* build+run via a driver (ww / ww_ww); returns 0 pass, nonzero fail. */
static int
run_driver(const char *driver, const struct row *r, int i)
{
	char src[128], tmpdir[96], errf[128], outbin[128], rmcmd[160], cmd[1024];
	snprintf(tmpdir, sizeof tmpdir, "/tmp/ase_%d_d_%d", getpid(), i);
	mkdir(tmpdir, 0755);
	snprintf(src, sizeof src, "%s/ase_%d_%d.ww", tmpdir, getpid(), i);
	snprintf(errf, sizeof errf, "%s/ase_%d_e_%d", tmpdir, getpid(), i);
	snprintf(outbin, sizeof outbin, "%s/ase_%d_%d", tmpdir, getpid(), i);
	snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir);

	FILE *f = fopen(src, "wb");
	if (!f) { runwait(rmcmd); return -1; }
	fputs(r->src, f);
	fclose(f);

	snprintf(cmd, sizeof cmd, "%s build -o %s %s >/dev/null 2>%s",
	    driver, outbin, src, errf);
	int brc = runwait(cmd);
	if (brc != 0) {
		fprintf(stderr, "row[%s]: build via %s failed\n",
		    r->label, driver);
		runwait(rmcmd);
		return -1;
	}

	int got = runwait(outbin);

	runwait(rmcmd);
	if (got != r->want) {
		fprintf(stderr, "row[%s]: %s exit %d, want %d\n",
		    r->label, driver, got, r->want);
		return 1;
	}
	return 0;
}

/* cs==ww .s byte-id (rule 10). */
static int
byteid(const char *w6c, const char *w6c_ww, const struct row *r, int i)
{
	char src[96], cs_s[96], ws_s[96], cmd[1024];
	snprintf(src, sizeof src, "/tmp/ase_bi_%d_%d.ww", getpid(), i);
	snprintf(cs_s, sizeof cs_s, "/tmp/ase_bi_%d_%d_cs.s", getpid(), i);
	snprintf(ws_s, sizeof ws_s, "/tmp/ase_bi_%d_%d_ww.s", getpid(), i);

	FILE *f = fopen(src, "wb");
	if (!f) return -1;
	fputs(r->src, f);
	fclose(f);

	int rc = 0;
	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, cs_s, src);
	if (runwait(cmd) != 0) { fprintf(stderr, "row[%s]: w6c failed\n", r->label); rc = 1; }
	else {
		snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c_ww, ws_s, src);
		if (runwait(cmd) != 0) { fprintf(stderr, "row[%s]: w6c_ww failed\n", r->label); rc = 1; }
		else if (slurp_eq(cs_s, ws_s) != 0) {
			fprintf(stderr, "row[%s]: cstage/wwstage .s DIFFER "
			    "(rule-10 byte-id)\n", r->label);
			rc = 1;
		}
	}
	unlink(src); unlink(cs_s); unlink(ws_s);
	return rc;
}

int
main(void)
{
	const char *bin = getenv("BIN");
	if (!bin) bin = "out/bin";
	char absbin[512];
	if (bin[0] != '/') {
		char cwd[256];
		if (getcwd(cwd, sizeof cwd) == NULL) return 1;
		snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
		bin = absbin;
	}

	char cdrv[640], wdrv[640], w6c[640], w6c_ww[640];
	snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
	snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);
	snprintf(w6c, sizeof w6c, "%s/w6c", bin);
	snprintf(w6c_ww, sizeof w6c_ww, "%s/w6c_ww", bin);

	struct { const char *name; const char *path; int gated; }
	drivers[] = {
		{ "cstage",  cdrv, 0 },
		{ "wwstage", wdrv, 1 },
		{ NULL, NULL, 0 },
	};

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

	for (int d = 0; drivers[d].name; d++) {
		if (drivers[d].gated && access(drivers[d].path, X_OK) != 0) {
			fprintf(stderr, "append_structlit_evalorder: skip %s (no %s)\n",
			    drivers[d].name, drivers[d].path);
			continue;
		}
		for (int i = 0; i < n; i++) {
			total++;
			if (run_driver(drivers[d].path, &rows[i], i) != 0) fail++;
		}
	}

	if (access(w6c_ww, X_OK) == 0) {
		for (int i = 0; i < n; i++) {
			total++;
			if (byteid(w6c, w6c_ww, &rows[i], i) != 0) fail++;
		}
	}

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