/*
 * 949_intbinop_mismatch — #26: ww requires an explicit integer
 * conversion in binary ops (Go-faithful, user-blessed). cstage's cbinop
 * routes arithmetic/bitwise/comparison through unify_arith
 * (cmd/wcc/check.c:1034), which loud-rejects a typed/typed operand
 * mismatch (check.c:1068). The wwstage checker's unifyarith returned the
 * lhs type for any mismatch (silent accept) AND the comparison arm never
 * called it at all, so `int < len(s)` (len() = i32) and `int & i32`
 * silently compiled where cstage rejects — a rule-10 break (and a latent
 * signed/unsigned miscompile for `int < uint`).
 *
 * The fix (selfhost/cmd/wcc/check.ww) aligns wwstage DOWN: unifyarith
 * loud-rejects a mismatched typed pair, keeping only cstage's one-sided
 * alias-vs-base promotion (check.c:1060), and the ORDERED comparison arm
 * now routes through unifyarith. A rune LITERAL stays assignable to an
 * integer (cstage's untyped_rune, type.c:379), so `c - '0'` is unaffected.
 *
 * K_BUILDERR rows: build FAILS with the differing-types diagnostic on
 * BOTH drivers. K_RUN rows: build+run exit 0 on BOTH drivers AND the
 * cs==ww .s is byte-identical — the positive controls pin that matched
 * pairs, an explicit cast, the alias-vs-base promotion (part (a), the
 * LOAD-BEARING row), and a rune-literal arithmetic mix all still pass.
 *
 * 940/945 precedent: ww_ww builds /tmp fixtures, so the selfhost-tree
 * sibling-write race does not apply.
 */
#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;
}

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;
}

static int
file_contains(const char *path, const char *needle)
{
	FILE *f = fopen(path, "rb");
	if (!f) return 0;
	char buf[8192];
	size_t n = fread(buf, 1, sizeof buf - 1, f);
	fclose(f);
	buf[n] = '\0';
	return strstr(buf, needle) != NULL;
}

#define K_RUN      0	/* build+run both drivers, exit==want, + cs==ww byte-id */
#define K_BUILDERR 1	/* build must FAIL with experr on BOTH drivers (rule 7) */

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

static const struct row rows[] = {
	/* headline #26: `int < len(s)` (len() returns i32) — the latent
	 * signed-mix comparison that wwstage silently accepted. */
	{ "int_lt_len_i32",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: int = 1;\n"
	  "	let s: []u8 = [];\n"
	  "	if (a < len(s)) { return 1; };\n"
	  "	return 0;\n"
	  "};\n",
	  K_BUILDERR, 0, "operands have differing types" },
	/* signed/unsigned mismatch — the miscompile-prone shape. */
	{ "int_lt_uint",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: int = 1;\n"
	  "	let b: uint = 2;\n"
	  "	if (a < b) { return 1; };\n"
	  "	return 0;\n"
	  "};\n",
	  K_BUILDERR, 0, "operands have differing types" },
	/* differing-width signed pair. */
	{ "int_lt_i64",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: int = 1;\n"
	  "	let b: i64 = 2i64;\n"
	  "	if (a < b) { return 1; };\n"
	  "	return 0;\n"
	  "};\n",
	  K_BUILDERR, 0, "operands have differing types" },
	/* bitwise feeds the same unifyarith path (check.ww :2598). */
	{ "int_and_i32",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: int = 1;\n"
	  "	let b: i32 = 2;\n"
	  "	let r: int = a & b;\n"
	  "	if (r < 0) { return 1; };\n"
	  "	return 0;\n"
	  "};\n",
	  K_BUILDERR, 0, "operands have differing types" },
	/* positive control: matched int/int comparison. */
	{ "int_lt_int",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: int = 1;\n"
	  "	let b: int = 2;\n"
	  "	if (a < b) { return 0; };\n"
	  "	return 0;\n"
	  "};\n",
	  K_RUN, 0, NULL },
	/* positive control: matched i32/i32. */
	{ "i32_lt_i32",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: i32 = 1;\n"
	  "	let b: i32 = 2;\n"
	  "	if (a < b) { return 0; };\n"
	  "	return 0;\n"
	  "};\n",
	  K_RUN, 0, NULL },
	/* positive control: i32 < len(s) — both i32, the canonical loop. */
	{ "i32_lt_len",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let s: []u8 = [];\n"
	  "	let a: i32 = 0;\n"
	  "	if (a < len(s)) { return 0; };\n"
	  "	return 0;\n"
	  "};\n",
	  K_RUN, 0, NULL },
	/* positive control: explicit cast resolves the #26 mix. */
	{ "int_cast_len",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let s: []u8 = [];\n"
	  "	let a: int = 0;\n"
	  "	if (a < len(s): int) { return 0; };\n"
	  "	return 0;\n"
	  "};\n",
	  K_RUN, 0, NULL },
	/* LOAD-BEARING positive control for part (a): a one-sided alias vs
	 * its base promotes (cstage check.c:1060). Drops if the alias-chase
	 * arm is missing or mis-detects a primitive as a named type. */
	{ "alias_vs_base",
	  "package main;\n"
	  "type myint = i32;\n"
	  "export fn main() i32 = {\n"
	  "	let a: myint = 1: myint;\n"
	  "	let b: i32 = 2;\n"
	  "	if (a < b) { return 0; };\n"
	  "	return 0;\n"
	  "};\n",
	  K_RUN, 0, NULL },
	/* positive control: a rune LITERAL stays assignable to an integer
	 * (cstage's untyped_rune, type.c:379); `c - '0'` must NOT trip the
	 * #26 reject. */
	{ "rune_lit_arith",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let c: u8 = 53u8;\n"
	  "	let r: u8 = c - '0';\n"
	  "	if (r < 10u8) { return 0; };\n"
	  "	return 0;\n"
	  "};\n",
	  K_RUN, 0, NULL },
	/* LOAD-BEARING positive control: a chained same-enum bitwise OR
	 * (`flag.A | flag.B | flag.C`, the w6l os.flag pattern). Both operands
	 * are the SAME enum type, which cstage's unify_arith accepts via
	 * type_eq's identity check (type.c:250) — wwstage must accept it too.
	 * Drops if typeeqast lacks the identity fast-path: the #26 reject then
	 * over-rejects a same-enum binop, breaking the w6l self-compile (994). */
	{ "enum_flag_or",
	  "package main;\n"
	  "type flag = enum uint { A = 1, B = 2, C = 4 };\n"
	  "export fn main() i32 = {\n"
	  "	let f: flag = flag.A | flag.B | flag.C;\n"
	  "	return (f: i32) - 7;\n"
	  "};\n",
	  K_RUN, 0, NULL },
};

/* 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[96], tmpdir[96], errf[96], cmd[1024];
	snprintf(src, sizeof src, "/tmp/ibm_%d_%d.ww", getpid(), i);
	snprintf(tmpdir, sizeof tmpdir, "/tmp/ibm_%d_d_%d", getpid(), i);
	snprintf(errf, sizeof errf, "/tmp/ibm_%d_e_%d", getpid(), i);

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

	mkdir(tmpdir, 0755);
	snprintf(cmd, sizeof cmd, "cd %s && %s build %s >/dev/null 2>%s",
	    tmpdir, driver, src, errf);
	int brc = runwait(cmd);

	if (r->kind == K_BUILDERR) {
		int ok = (brc != 0)
		    && (r->experr == NULL || file_contains(errf, r->experr));
		if (!ok)
			fprintf(stderr, "row[%s]: %s expected loud #26 builderr "
			    "(brc=%d)\n", r->label, driver, brc);
		unlink(src); unlink(errf); rmdir(tmpdir);
		return ok ? 0 : 1;
	}

	if (brc != 0) {
		fprintf(stderr, "row[%s]: build via %s failed\n",
		    r->label, driver);
		unlink(src); unlink(errf); rmdir(tmpdir);
		return -1;
	}

	const char *base = strrchr(src, '/');
	base = base ? base + 1 : src;
	char outbin[256];
	snprintf(outbin, sizeof outbin, "%s/%s", tmpdir, base);
	char *dot = strrchr(outbin, '.');
	if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';
	int got = runwait(outbin);

	unlink(src); unlink(outbin); unlink(errf); rmdir(tmpdir);
	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) for the K_RUN rows. */
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/ibm_bi_%d_%d.ww", getpid(), i);
	snprintf(cs_s, sizeof cs_s, "/tmp/ibm_bi_%d_%d_cs.s", getpid(), i);
	snprintf(ws_s, sizeof ws_s, "/tmp/ibm_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 (#26)\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, "intbinop_mismatch: 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++) {
			if (rows[i].kind != K_RUN) continue;
			total++;
			if (byteid(w6c, w6c_ww, &rows[i], i) != 0) fail++;
		}
	}

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