/*
 * 956_modqualdestr_run — runtime + byte-id + stamp regression net for
 * #6a-A: module-qualified destructure binding types.
 *
 * THE GAP: the wwstage N_MLET handler (check.ww) backfilled destructure
 * binding types only when the call rhs had a bare N_IDENT callee. A
 * module-qualified `let (frac, exp) = myf.frexp(x)` has an N_DOT callee,
 * so the bindings stayed un-stamped (n.type_ nil). cstage never gated on
 * callee kind (cmd/wcc/check.c N_MLET → cexpr ungated), so this was a
 * wwstage-only stamp gap. #6a-A broadens the backfill to ANY call rhs;
 * exprtype's N_CALL arm resolves the N_DOT callee's leaf for the
 * resolvable case (leaf unique across modules — the myf.* shapes here).
 *
 * THE PAYOFF (float row): an un-stamped f64 destructure binding fed to
 * float arithmetic mis-classifies as integer-kind 0 in cgen's
 * exprfloatkind (n.type_ is the SSoT after the #121 collapse). The
 * residual cgbin float-arith sibling-evidence guard turns that into a
 * loud abort, so pre-fix w6c_ww FAILS TO COMPILE the float row (no .s
 * emitted) — the cs==ww gate (b) and the stamp gate (c) both catch it.
 * Post-fix the binding stamps f64, the SSE-cursor receive lands, and
 * both stages emit byte-identical asm.
 *
 * Sibling of 956_tuprecv_f64_run (same-module float destructure, bare
 * N_IDENT callee) and 953_f64crossmod_run (single-call module-qualified
 * f64). Single-file multi-package form (like 953) so w6c/w6c_ww see the
 * cross-module call without -I plumbing. Each row carries three
 * dimensions:
 *   (a) cstage `ww build` + run, asserting the exit code (cstage is the
 *       reference — correct pre- and post-fix).
 *   (b) w6c vs w6c_ww `.s` cmp — rule-10 byte-id; pre-fix the float row
 *       diverges (w6c_ww loud-aborts, emits no .s).
 *   (c) #6a-A stamp gate: w6c_ww must emit no `asserttyped:` diagnostic
 *       on the destructure binding idents. Pre-fix fires on every use.
 */
#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[] = {
	/* HEADLINE — module-qualified FLOAT destructure (f64, i64). frac is
	 * fed to float arith (`frac + 1.0`), forcing exprfloatkind to read
	 * its stamp. Pre-fix frac.type_==nil -> kind 0 -> cgbin float-arith
	 * loud-abort in w6c_ww. Post-fix frac stamps f64. frac=8.0 -> g=9.0;
	 * exp=1. */
	{ "mq_f64_i64_destr",
	  "package myf;\n"
	  "export fn frexp(n: f64) (f64, i64) = {\n"
	  "\tif (n == 0.0) { return (0.0, 0i64); };\n"
	  "\treturn (n, 1i64);\n"
	  "};\n"
	  "package main;\n"
	  "import myf;\n"
	  "export fn main() i32 = {\n"
	  "\tlet (frac, exp) = myf.frexp(8.0);\n"
	  "\tlet g: f64 = frac + 1.0;\n"
	  "\tif (g != 9.0) { return 1; };\n"
	  "\tif (exp != 1i64) { return 2; };\n"
	  "\treturn 0;\n"
	  "};\n", 0 },
	/* DOMINANT CLASS-A — module-qualified INTEGER destructure (the
	 * checked.addXX shape: `let (res, ov) = checked.addi64(a, b)`). cgen's
	 * structural classifier already routed the integer codegen, so this
	 * is byte-id pre- and post-fix; the discriminator is the (c) stamp
	 * gate — pre-fix res/ov fire asserttyped. res=15, ov=false. */
	{ "mq_i64_bool_destr",
	  "package myf;\n"
	  "export fn addi64(a: i64, b: i64) (i64, bool) = {\n"
	  "\tlet s: i64 = a + b;\n"
	  "\treturn (s, false);\n"
	  "};\n"
	  "package main;\n"
	  "import myf;\n"
	  "export fn main() i32 = {\n"
	  "\tlet (res, ov) = myf.addi64(7i64, 8i64);\n"
	  "\tif (res != 15i64) { return 1; };\n"
	  "\tif (ov) { return 2; };\n"
	  "\treturn (res: i32);\n"
	  "};\n", 15 },
	/* MIXED — module-qualified (f64, str) destructure: the float rides
	 * the SSE cursor (X0), the str rides the integer cursor (AX,DX,CX).
	 * Confirms the stamp distributes correctly onto a wide-header binding
	 * alongside the float. f=4.0 -> 4; s.len=5 ("hello"). */
	{ "mq_f64_str_destr",
	  "package myf;\n"
	  "export fn fs(n: f64) (f64, str) = {\n"
	  "\tif (n == 0.0) { return (n, \"x\"); };\n"
	  "\treturn (n, \"hello\");\n"
	  "};\n"
	  "package main;\n"
	  "import myf;\n"
	  "export fn main() i32 = {\n"
	  "\tlet (f, s) = myf.fs(4.0);\n"
	  "\tlet g: f64 = f + 0.0;\n"
	  "\tif (g != 4.0) { return 1; };\n"
	  "\tif (s.len != 5) { return 2; };\n"
	  "\treturn (f: i32);\n"
	  "};\n", 4 },
	/* CLASS-CLOSURE — NON-destructure cross-module same-leaf shadow. The
	 * #6a-A fix lives at the exprtype N_CALL root, so it closes the whole
	 * class, not just the destructure surface (same coverage-trap as the
	 * 6.0b gap-corpus probe). beta.dup -> (i64,i64), alpha.dup -> (i64,str);
	 * alpha is source-ordered LAST so its (i64,str) heads the flat-scope
	 * bare-leaf bucket (753_convwrap_audit's trick). `let r = beta.dup()`
	 * is a SINGLE-VAR receive (no destructure). Pre-fix the bare-leaf
	 * scopelookup stamped r off alpha.dup's (i64,str) 32B shape, so the
	 * wwstage cglet sized a $32 / AX,DX,CX,R8 slot while cstage (typed AST)
	 * sized $16 -> a cs!=ww rule-10 DIVERGENCE this row catches. Post-fix
	 * the SK_USE-gated scopelookupinmodule resolves beta.dup -> $16, byte-
	 * id. r.0=3, r.1=7 -> 10. */
	{ "mq_nondestr_shadow",
	  "package beta;\n"
	  "export fn dup() (i64, i64) = { return (3i64, 7i64); };\n"
	  "package main;\n"
	  "import beta;\n"
	  "export fn main() i32 = {\n"
	  "\tlet r = beta.dup();\n"
	  "\tif (r.1 != 7i64) { return 1; };\n"
	  "\treturn (r.0: i32) + (r.1: i32);\n"
	  "};\n"
	  "package alpha;\n"
	  "export fn dup() (i64, str) = { return (9i64, \"wrong\"); };\n", 10 },
	{ 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, "modqualdestr: 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/wwmqd_%d_%d.ww", getpid(), i);
		FILE *f = fopen(src, "wb");
		if (f == NULL) { fail++; continue; }
		fputs(rows[i].src, f);
		fclose(f);

		char cmd[2048];

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

		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: emit .s from both stages, cmp. */
		char cs_s[64], ws_s[64];
		snprintf(cs_s, sizeof cs_s, "/tmp/wwmqd_%d_%d_cs.s",
		    getpid(), i);
		snprintf(ws_s, sizeof ws_s, "/tmp/wwmqd_%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++;
		}

		/* (c) #6a-A stamp gate: the module-qualified destructure
		 * binding must carry a checker type stamp, so w6c_ww emits no
		 * `asserttyped:` diagnostic on its idents. Non-vacuous —
		 * pre-fix (HEAD) w6c_ww fires asserttyped on every binding use
		 * (and the float row loud-aborts in cgen above). */
		char errf[80];
		snprintf(errf, sizeof errf,
		    "/tmp/wwmqd_%d_%d_err.txt", getpid(), i);
		snprintf(cmd, sizeof cmd,
		    "%s -o /dev/null %s 2>%s", w6c_ww, src, errf);
		runwait(cmd);
		snprintf(cmd, sizeof cmd, "grep -q asserttyped %s", errf);
		if (runwait(cmd) == 0) {
			fprintf(stderr, "row[%s]: w6c_ww emitted asserttyped "
			    "(destructure binding unstamped)\n", rows[i].label);
			fail++;
		}
		unlink(errf);
		unlink(src); unlink(cs_s); unlink(ws_s);
	}

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