/*
 * 801_litstr_pseudo_run — BUG #14. Runtime + cs==ww byte-id net for the
 * string-LITERAL `.len` / `.ptr` pseudo-field.
 *
 * THE BUG (cstage wrong, wwstage correct — rule-10 divergence):
 *   `"hi".len` returned the POINTER, not the length. A string literal is
 *   TY_UNTYPED_STR (not TY_STR), so it missed the typed slice/str
 *   pseudo-field gate in cgen.c's N_DOT and fell to the final fallback
 *   `cgexpr(lhs)`, which leaves AX=.ptr — `.len` then returned AX (the
 *   ptr) instead of shuffling BX (the len) into AX. wwstage's cgdot
 *   catch-all (cgenexpr.ww) already did the BX->AX shuffle, so the two
 *   stages DISAGREED. byte-id was BLIND: no bootstrap source uses
 *   literal `.len` (devs hardcoded the lengths around it, e.g.
 *   `os.write(2, "...".ptr, 9u64)`), so the gate never exercised it.
 *   The str-VARIABLE `.len` path was correct on both (control).
 *
 * THE FIX (#14): align cstage UP to wwstage — the final N_DOT fallback
 * emits `MOVQ BX, AX` for `.len` (cgen.c). `.ptr` already returned AX
 * (correct) and is unchanged.
 *
 * EACH ROW CARRIES BOTH DIMENSIONS (795/796/797 model):
 *   (a) cstage `ww build` + run, asserting the exit — pins the converged
 *       asm is runtime-correct (literal lengths reach the program).
 *   (b) w6c vs w6c_ww `.s` cmp — FAILS if the stages diverge (they did,
 *       pre-fix: cstage emitted the ptr, wwstage the len).
 *
 * GATE POLARITY: must stay GREEN. A wrong exit means literal `.len`/`.ptr`
 * 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[] = {
	/* literal .len: "hello".len == 5. Pre-fix cstage returned the ptr. */
	{ "lit_len",
	  "package main;\n"
	  "export fn main() i32 = { return \"hello\".len: i32; };\n", 5 },
	/* empty + multi-byte: ""/"héllo\\n" — é is 2 UTF-8 bytes, so the
	 * literal is 7 bytes (h,é=2,l,l,o,\\n). Guards against a .ptr/.len
	 * length confusion (a ptr would not be 7). */
	{ "lit_len_empty_multibyte",
	  "package main;\n"
	  "export fn main() i32 = { if (\"\".len != 0) { return 9; }; "
	  "return \"héllo\\n\".len: i32; };\n", 7 },
	/* literal .ptr still points at the bytes (deref first byte == 'h'),
	 * then .len == 5 — proves the fix left .ptr untouched. */
	{ "lit_ptr_deref",
	  "package main;\n"
	  "export fn main() i32 = { let p: *u8 = \"hello\".ptr; "
	  "if (*p != 'h') { return 1; }; return \"hello\".len: i32; };\n", 5 },
	/* callee-side .len on a literal passed as a str arg — the real-world
	 * shape (os.write(1, lit.ptr, lit.len)) that surfaced #14. */
	{ "lit_arg_passthrough",
	  "package main;\n"
	  "fn slen(s: str) i32 = { return s.len: i32; };\n"
	  "export fn main() i32 = { if (slen(\"abcdef\") != 6) { return 1; }; "
	  "return \"abcdef\".len: i32; };\n", 6 },
	{ 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, "litstr_pseudo: 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/wwlsp_%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/wwlsp_%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/wwlsp_%d_%d_cs.s", getpid(), i);
		snprintf(ws_s, sizeof ws_s, "/tmp/wwlsp_%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 litstr pseudo-field tests failed\n", fail, n);
		return 1;
	}
	printf("litstr_pseudo: %d/%d ok (cstage run + cs==ww byte-id)\n", n, n);
	return 0;
}