/*
 * 797_len_strglobal_run — project #231. Runtime + cs==ww byte-id net for
 * the `len(str-global)` miscompile.
 *
 * THE BUG (both stages wrong, DIFFERENTLY → byte-id was BLIND because the
 * stages also DIVERGED, but no bootstrap source exercised the shape):
 *   cstage: a top-level str global N_IDENT fell into the len() arm's
 *           BP-relative slot load. localfind returns 0 for a global, so it
 *           emitted `MOVQ 8(BP),AX` — a bogus stack slot (runtime 72).
 *   wwstage: the len() arm only handled locals (localfindnode != nil);
 *           a global fell through to cgexpr, which loads the whole header
 *           and leaves AX=.ptr, not .len (runtime garbage / 37).
 * The local-str case (`let g: str = "hello"; len(g)`) is correct in both
 * (control), so the fix targets only the global path.
 *
 * THE FIX (#231): both stages emit the global .len load — LEAQ name(SB),CX;
 * MOVQ 8(CX),AX (.len field; str/slice header is ptr@0/len@8/cap@16). The
 * LEAQ symbol routes through the post-#1 value mangle (cstage mahint with
 * c->cur_mod, wwstage emitsymnamehint with c.curmod), NOT a raw name —
 * else a private same-module same-leaf str global would re-open the #1
 * collision.
 *
 * SCOPE NOTE: a []u8 (slice) global would exercise the same arm (the gate
 * covers TY_SLICE || TY_STR), but `let g: []u8 = [...]` literal-init is
 * currently REJECTED by cstage ("let g init not assignable", #233), so the
 * cstage `ww build` + byte-id rows below cannot compile a slice global yet.
 * Rowed once #233 lands; the str global proves the code path now.
 *
 * EACH ROW CARRIES BOTH DIMENSIONS (795/796 model):
 *   (a) cstage `ww build` + run, asserting the exit — pins the converged
 *       asm is runtime-correct (len("hello") == 5).
 *   (b) w6c vs w6c_ww `.s` cmp — FAILS if the stages diverge (they did,
 *       differently, pre-fix).
 *
 * GATE POLARITY: must stay GREEN. A wrong exit means the global .len load
 * regressed; a byte-id FAIL means the stages diverged (rule-10).
 */
#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[] = {
	/* str global: len("hello") == 5. Pre-fix cstage 72, wwstage garbage. */
	{ "str_global_len",
	  "package main;\n"
	  "let g: str = \"hello\";\n"
	  "export fn main() i32 = { return len(g): i32; };\n", 5 },
	/* control: the local-str case both stages already get right. */
	{ "str_local_len",
	  "package main;\n"
	  "export fn main() i32 = { let g: str = \"hello\"; "
	  "return len(g): i32; };\n", 5 },
	{ NULL, NULL, 0 }
};

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);
		int cb = fgetc(fb);
		if (ca != cb) { rc = -1; break; }
		if (ca == EOF) break;
	}
	fclose(fa); fclose(fb);
	return rc;
}

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 w6c[1100], w6c_ww[1100];
	snprintf(w6c, sizeof w6c, "%s/w6c", bin);
	snprintf(w6c_ww, sizeof w6c_ww, "%s/w6c_ww", bin);
	if (access(w6c_ww, X_OK) != 0) {
		fprintf(stderr, "len_strglobal: w6c_ww missing — cannot run the "
		    "cs==ww byte-id gate\n");
		return 1;
	}

	int n = 0, fail = 0;
	for (int i = 0; rows[i].src; i++, n++) {
		char src[64];
		snprintf(src, sizeof src, "/tmp/wwlsg_%d_%d.ww", getpid(), i);
		FILE *f = fopen(src, "wb");
		if (f == NULL) { fail++; continue; }
		fputs(rows[i].src, f);
		fclose(f);

		/* (a) cstage build + run in a scratch dir. */
		char tmpdir[64];
		snprintf(tmpdir, sizeof tmpdir, "/tmp/wwlsg_%d_d_%d", getpid(), i);
		mkdir(tmpdir, 0755);

		char cmd[2048];
		snprintf(cmd, sizeof cmd, "cd %s && %s/ww build %s",
		    tmpdir, bin, src);
		if (runwait(cmd) != 0) {
			fprintf(stderr, "row[%s]: cstage build failed\n",
			    rows[i].label);
			fail++;
			unlink(src); rmdir(tmpdir);
			continue;
		}

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

		int got = runwait(outbin);
		if (got != rows[i].want_exit) {
			fprintf(stderr, "row[%s]: cstage exit %d, want %d\n",
			    rows[i].label, got, rows[i].want_exit);
			fail++;
		}
		unlink(outbin); rmdir(tmpdir);

		/* (b) cs==ww byte-id gate. */
		char cs_s[64], ws_s[64];
		snprintf(cs_s, sizeof cs_s, "/tmp/wwlsg_%d_%d_cs.s", getpid(), i);
		snprintf(ws_s, sizeof ws_s, "/tmp/wwlsg_%d_%d_ww.s", getpid(), i);

		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", rows[i].label);
			fail++; unlink(src); continue;
		}
		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", rows[i].label);
			fail++; unlink(src); unlink(cs_s); continue;
		}
		if (slurp_eq(cs_s, ws_s) != 0) {
			fprintf(stderr, "row[%s]: cstage/wwstage .s DIFFER "
			    "(rule-10 byte-id violation)\n", rows[i].label);
			fail++;
		}
		unlink(src); unlink(cs_s); unlink(ws_s);
	}

	if (fail) {
		fprintf(stderr, "%d/%d len str-global tests failed\n", fail, n);
		return 1;
	}
	printf("len_strglobal: %d/%d ok (cstage run + cs==ww byte-id)\n", n, n);
	return 0;
}