/*
 * 793_xmod_struct_argpush_collide_run — project #21/#224 runtime + byte-id
 * net. An inferred-let struct LOCAL whose type leaf collides with a
 * DIFFERENT module's same-leaf struct miscompiled in wwstage at THREE
 * caller-side register-ABI sites, all keyed off the name-resolved
 * (collision-prone) struct instead of the checker-STAMPED tinfo:
 *
 *   - push  (cgenutil.ww pushargsrev): the by-value struct call-arg
 *     COUNT came from name-keyed structparamsize(lc.tnode). On the
 *     collision lc.tnode is a bare leaf structlookup mis-resolves to the
 *     foreign same-leaf struct (>16B → 0), so the fast path was skipped
 *     and the arg dropped to a scalar single-PUSHQ — the 2nd eightbyte
 *     (the sub-8 tail) was lost. [the original #21 site]
 *   - recv  (cgenstmt.ww cgletbody): `let s = m1.mk()` sized the
 *     register receive via structlookup(tn.str) → the foreign struct's
 *     word count, OVER-copying a 24B foreign over a 16B local (spilling
 *     CX into a neighbour slot).
 *   - field (cgenexpr.ww cgdot direct-struct arm): `s.<field>` resolved
 *     the offset via structlookupchain(tn) → the foreign struct's layout,
 *     reading the field at the WRONG offset + wrong load-op. [#224, filed
 *     not-fixed by 784/#223]
 *
 * cstage is correct at all three — it keys on args[i]->type / lu->size /
 * t->fields (the checker-STAMPED type), never a name re-lookup. Fix
 * (wwstage-only align-UP, #21/#224, ONE commit): route all three off the
 * stamped tinfo — structabisizetn(arg/tn.type_) for the push+recv COUNT,
 * tichase(dotlhs.type_).fields (tfield) for the field offset+type.
 *
 * GATE-BLIND in the bootstrap (same class as 784/#223): the trigger needs
 * a SECOND module contributing a same-leaf struct of a DIFFERENT size, so
 * the name-keyed lookup mis-resolves. A single-module synthetic resolves
 * correctly (structlookup's same-module pass) and stays byte-id — it does
 * NOT redden. Hence this 2-module probe.
 *
 *   row              | m1.pair (local)      | m2.pair (foreign) | site(s)       | exit
 *   -----------------+----------------------+-------------------+---------------+-----
 *   recvpush_t16     | {u64,u16} 16B        | 24B               | recv + push   | 107
 *   fieldread_t16    | {u64,u16} 16B        | 24B               | recv + field  | 107
 *   combined_t16     | {u64,u16} 16B        | 24B               | recv+field+push| 114
 *   recvpush_t12     | {u32,u32,u32} 12B    | 24B               | recv + push   |  6
 *
 * cstage `ww build` + run pins runtime; the wwstage binary is run
 * too (the bug WAS a wrong wwstage runtime value); raw cs.s vs ww.s cmp
 * over the driver-produced per-package asm pins rule-10 byte-id (the
 * discriminating net — pre-fix __root.s diverges at the push/recv/field).
 */
#include <stdio.h>
#include <stdlib.h>
#include <errno.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);
		int cb = fgetc(fb);
		if (ca != cb) { rc = -1; break; }
		if (ca == EOF) break;
	}
	if (ferror(fa) || ferror(fb)) rc = -1;
	if (fclose(fa) != 0) rc = -1;
	if (fclose(fb) != 0) rc = -1;
	return rc;
}

struct file { const char *name; const char *src; };

struct scenario {
	const char *label;
	const struct file *files;	/* name==NULL terminates */
	int want_exit;
};

/* m2.pair is a 24B struct sharing the leaf `pair` with m1.pair — the
 * name-keyed lookup's any-module fallback mis-resolves m1.pair to it. */
static const char m2_24[] =
	"package m2;\n"
	"export type pair = struct { hi: u64, mid: u64, lo: u64 };\n"
	"export fn use2(p: pair) i32 = { return (p.hi + p.mid + p.lo): i32; };\n";

/* ---- recvpush_t16: inferred-let recv + by-value push (the #21 site) -- */
static const struct file recvpush_t16_files[] = {
	{ "m1.ww",
	  "package m1;\n"
	  "export type pair = struct { hi: u64, lo: u16 };\n"
	  "export fn mk() pair = { return pair { hi = 100: u64, lo = 7: u16 }; };\n"
	  "export fn consume(p: pair) i32 = { return (p.hi + (p.lo: u64)): i32; };\n" },
	{ "m2.ww", m2_24 },
	{ "main.ww",
	  "package main;\n"
	  "import m1;\n"
	  "import m2;\n"
	  "fn main() i32 = {\n"
	  "	let dummy: m2.pair;\n"
	  "	dummy.hi = 0: u64;\n"
	  "	let s = m1.mk();\n"
	  "	return m1.consume(s);\n"
	  "};\n" },
	{ NULL, NULL }
};

/* ---- fieldread_t16: inferred-let recv + direct field read (#224) ----- */
static const struct file fieldread_t16_files[] = {
	{ "m1.ww",
	  "package m1;\n"
	  "export type pair = struct { hi: u64, lo: u16 };\n"
	  "export fn mk() pair = { return pair { hi = 100: u64, lo = 7: u16 }; };\n" },
	{ "m2.ww", m2_24 },
	{ "main.ww",
	  "package main;\n"
	  "import m1;\n"
	  "import m2;\n"
	  "fn main() i32 = {\n"
	  "	let dummy: m2.pair;\n"
	  "	dummy.hi = 0: u64;\n"
	  "	let s = m1.mk();\n"
	  "	return (s.hi + (s.lo: u64)): i32;\n"
	  "};\n" },
	{ NULL, NULL }
};

/* ---- combined_t16: recv + field + push in one fn -------------------- */
static const struct file combined_t16_files[] = {
	{ "m1.ww",
	  "package m1;\n"
	  "export type pair = struct { hi: u64, lo: u16 };\n"
	  "export fn mk() pair = { return pair { hi = 100: u64, lo = 7: u16 }; };\n"
	  "export fn consume(p: pair) i32 = { return (p.hi + (p.lo: u64)): i32; };\n" },
	{ "m2.ww", m2_24 },
	{ "main.ww",
	  "package main;\n"
	  "import m1;\n"
	  "import m2;\n"
	  "fn main() i32 = {\n"
	  "	let dummy: m2.pair;\n"
	  "	dummy.hi = 0: u64;\n"
	  "	let s = m1.mk();\n"
	  "	let x: i32 = (s.lo: i32);\n"
	  "	return m1.consume(s) + x;\n"
	  "};\n" },
	{ NULL, NULL }
};

/* ---- recvpush_t12: a maxalign-4 12B sub-8-tail tail shape ----------- */
static const struct file recvpush_t12_files[] = {
	{ "m1.ww",
	  "package m1;\n"
	  "export type pair = struct { a: u32, b: u32, c: u32 };\n"
	  "export fn mk() pair = { return pair { a = 1: u32, b = 2: u32, c = 3: u32 }; };\n"
	  "export fn consume(p: pair) i32 = { return (p.a + p.b + p.c): i32; };\n" },
	{ "m2.ww", m2_24 },
	{ "main.ww",
	  "package main;\n"
	  "import m1;\n"
	  "import m2;\n"
	  "fn main() i32 = {\n"
	  "	let dummy: m2.pair;\n"
	  "	dummy.hi = 0: u64;\n"
	  "	let s = m1.mk();\n"
	  "	return m1.consume(s);\n"
	  "};\n" },
	{ NULL, NULL }
};

static const struct scenario scenarios[] = {
	{ "recvpush_t16",  recvpush_t16_files,  107 },
	{ "fieldread_t16", fieldread_t16_files, 107 },
	{ "combined_t16",  combined_t16_files,  114 },
	{ "recvpush_t12",  recvpush_t12_files,    6 },
};

static int
run_scenario(const char *cdrv, const char *wdrv, const struct scenario *sc)
{
	/* Private fixture dir — the driver's srcd-first import search can't
	 * pick up a polluting same-name file (mirrors 784/#215). */
	char dir[] = "/tmp/ww793_XXXXXX";
	if (mkdtemp(dir) == NULL) {
		fprintf(stderr, "793[%s]: mkdtemp failed\n", sc->label);
		return -1;
	}

	char path[1024], cmd[4096];
	int rc = 0;

	for (int i = 0; sc->files[i].name; i++) {
		snprintf(path, sizeof path, "%s/%s", dir, sc->files[i].name);
		FILE *f = fopen(path, "wb");
		if (!f) { fprintf(stderr, "793[%s]: write %s\n", sc->label,
		    sc->files[i].name); rc = -1; goto done; }
		int bad = fputs(sc->files[i].src, f) == EOF;
		if (fclose(f) != 0) bad = 1;
		if (bad) { fprintf(stderr, "793[%s]: write %s\n", sc->label,
		    sc->files[i].name); rc = -1; goto done; }
	}

	/* cstage build + run pins runtime; all outputs remain under the
	 * scratch dir. */
	snprintf(cmd, sizeof cmd,
	    "cd %s && %s build -I %s -o %s/main %s/main.ww",
	    dir, cdrv, dir, dir, dir);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "793[%s]: cstage build failed\n", sc->label);
		rc = -1; goto done;
	}
	snprintf(path, sizeof path, "%s/main", dir);
	int gotc = runwait(path);
	if (gotc != sc->want_exit) {
		fprintf(stderr, "793[%s]: cstage exit %d, want %d\n",
		    sc->label, gotc, sc->want_exit);
		rc = -1;
	}

	/* wwstage build + run: the bug WAS a wrong wwstage runtime
	 * value (a dropped/over-copied field), so run the wwstage binary too. */
	snprintf(cmd, sizeof cmd,
	    "cd %s && %s build -I %s -o %s/mainww %s/main.ww",
	    dir, wdrv, dir, dir, dir);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "793[%s]: ww_ww build failed\n", sc->label);
		rc = -1; goto done;
	}
	snprintf(path, sizeof path, "%s/mainww", dir);
	int gotw = runwait(path);
	if (gotw != sc->want_exit) {
		fprintf(stderr, "793[%s]: wwstage exit %d, want %d\n",
		    sc->label, gotw, sc->want_exit);
		rc = -1;
	}

	/* Byte-id net (the discriminator): per-package asm under
	 * <stem>.sepwork/<pkg>.s; concat (sorted glob, identical set both
	 * stages) for the compare. Pre-fix __root.s diverges. */
	char cs_s[1024], ws_s[1024];
	snprintf(cs_s, sizeof cs_s, "%s/all_cs.s", dir);
	snprintf(ws_s, sizeof ws_s, "%s/all_ww.s", dir);
	snprintf(cmd, sizeof cmd,
	    "cat %s/main.sepwork/*.s > %s 2>/dev/null && test -s %s",
	    dir, cs_s, cs_s);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "793[%s]: cstage asm aggregation failed\n",
		    sc->label);
		rc = -1; goto done;
	}
	snprintf(cmd, sizeof cmd,
	    "cat %s/mainww.sepwork/*.s > %s 2>/dev/null && test -s %s",
	    dir, ws_s, ws_s);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "793[%s]: wwstage asm aggregation failed\n",
		    sc->label);
		rc = -1; goto done;
	}
	if (slurp_eq(cs_s, ws_s) != 0) {
		fprintf(stderr, "793[%s]: cs.s/ww.s DIFFER (rule-10 byte-id "
		    "violation — #21/#224 regression)\n", sc->label);
		rc = -1;
	}

done:
	snprintf(cmd, sizeof cmd, "rm -rf %s/main.sepwork", dir);
	if (runwait(cmd) != 0) { fprintf(stderr, "793[%s]: cleanup main.sepwork\n",
	    sc->label); rc = -1; }
	snprintf(cmd, sizeof cmd, "rm -rf %s/mainww.sepwork", dir);
	if (runwait(cmd) != 0) { fprintf(stderr, "793[%s]: cleanup mainww.sepwork\n",
	    sc->label); rc = -1; }
	for (int i = 0; sc->files[i].name; i++) {
		snprintf(path, sizeof path, "%s/%s", dir, sc->files[i].name);
		if (unlink(path) != 0 && errno != ENOENT) {
			fprintf(stderr, "793[%s]: cleanup %s\n", sc->label,
			    sc->files[i].name);
			rc = -1;
		}
	}
	const char *children[] = { "main", "mainww", "all_cs.s", "all_ww.s", NULL };
	for (int i = 0; children[i]; i++) {
		snprintf(path, sizeof path, "%s/%s", dir, children[i]);
		if (unlink(path) != 0 && errno != ENOENT) {
			fprintf(stderr, "793[%s]: cleanup %s\n", sc->label,
			    children[i]);
			rc = -1;
		}
	}
	if (rmdir(dir) != 0) {
		fprintf(stderr, "793[%s]: cleanup directory\n", sc->label);
		rc = -1;
	}
	return rc;
}

int
main(void)
{
	const char *bin = getenv("BIN");
	if (!bin) bin = "out/bin";
	char absbin[2048];
	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[2100], wdrv[2100];
	snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
	snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);
	if (access(wdrv, X_OK) != 0) {
		fprintf(stderr, "793: ww_ww missing — cannot run the cs==ww "
		    "byte-id gate (the whole point of this test)\n");
		return 1;
	}

	int n = (int)(sizeof scenarios / sizeof scenarios[0]);
	int fail = 0;
	for (int i = 0; i < n; i++) {
		if (run_scenario(cdrv, wdrv, &scenarios[i]) != 0)
			fail++;
	}

	if (fail) {
		fprintf(stderr, "793 xmod_struct_argpush_collide: %d/%d "
		    "scenarios failed\n", fail, n);
		return 1;
	}
	printf("xmod_struct_argpush_collide: %d/%d ok (cstage+wwstage run + "
	    "cs==ww byte-id)\n", n, n);
	return 0;
}