/*
 * 806_tryprop_multisuccess — the `?` operator's interim single-success
 * gate (F8, task #5) and the direct try-form is/match reject parity
 * (F9, task #12).
 *
 * F8: ww's `?` assumes ONE success member end-to-end — the checker
 * collapses the result to the first non-error variant and cgen emits a
 * single tag compare — so `f()?` over (A|B|err) silently PROPAGATED
 * the other success member to the caller as if it were an error
 * (scratch/fold2b_probes/p11h, exit 21; graduated below as
 * reject_success2). Until the honest subset-union result typing lands
 * (task #14, harec check.c:2759-2835), BOTH stages loud-reject
 * |success| > 1 at the checker; (T|err1|err2) — one success, many
 * errors — stays legal (runtime canary: 925_tryprop_tag_remap_run).
 *
 * F9: cstage types `f()?` as the success variant, so the direct forms
 * `f()? is T` / `match (f()?)` hit its non-tagged is/match gates and
 * reject — while wwstage's scruttype (IDENT/DOT-only) silently
 * ACCEPTED the same files (cs≠ww, gate-blind). Align-richer-DOWN:
 * wwstage gains the same verdicts (text differs per per-stage diag
 * conventions, asserted exactly per stage below). A success variant
 * that is itself a named tagged union must KEEP being accepted
 * (accept_nested_tagged — guards the mirror against over-rejecting).
 *
 *   row                   | shape                                | want
 *   ----------------------+--------------------------------------+------
 *   reject_success2       | (void|[]capture|nomem)? — p11h       | BUILD_FAIL
 *   reject_success3       | (i32|bool|u64|nomem)?                | BUILD_FAIL
 *   reject_try_is         | f()? is i32, success = i32           | BUILD_FAIL
 *   reject_try_match      | match (f()?), success = i32          | BUILD_FAIL
 *   reject_unw_success2   | (void|[]capture|nomem)! — `!` is the | BUILD_FAIL
 *                         | same class (rob ruling, #133)        |
 *   reject_tryunw_is      | f()! is i32 — kind-agnostic sibling  | BUILD_FAIL
 *   reject_callarg        | g(f()?) — gate in call-arg position  | BUILD_FAIL
 *   accept_two_member     | (i32|nomem)? unwrap runtime          | 0
 *   accept_unw_multi_error| (i32|e1|e2)! unwrap runtime          | 0
 *   accept_void_success   | (void|nomem)? statement runtime      | 0
 *   accept_nested_tagged  | (ab|nomem)? is i32, ab = (i32|bool)  | 0
 *
 * BUILD_FAIL rows assert the diagnostic TEXT per stage (a build that
 * fails for any other reason is a vacuous reject and fails the row).
 * Accept rows also assert cstage/wwstage asm byte-id.
 */
#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;
}

/* want == BUILD_FAIL: the row must FAIL to build on both stages AND
 * emit the per-stage expected diagnostic on stderr (rule 7 — never a
 * silent acceptance). */
#define BUILD_FAIL (-2147483647 - 1)

struct row {
	const char *label;
	const char *src;
	int want;
	const char *expect_cs;	/* BUILD_FAIL: required cstage stderr substring */
	const char *expect_ww;	/* BUILD_FAIL: required wwstage stderr substring */
};

#define MULTISUCC_DIAG \
	"?: multi-success union unwired (task #14): bind and match instead"

static const struct row rows[] = {
	/* p11h graduated: pre-gate this BUILT and exited 21 (the []capture
	 * success wrongly propagated and read back as nomem). */
	{ "reject_success2",
	  "package main;\n"
	  "type capture = struct { content: str, start: size, end: size };\n"
	  "fn search2(k: i32) (void | []capture | nomem) = {\n"
	  "\tif (k == 0) { return; };\n"
	  "\tlet caps: []capture = [];\n"
	  "\tappend(caps, capture { content = \"xy\", start = 1, end = 3 });\n"
	  "\treturn caps;\n"
	  "};\n"
	  "fn tb(k: i32) (i32 | nomem) = {\n"
	  "\tlet r: (void | []capture) = search2(k)?;\n"
	  "\tif (r is []capture) { return 7; };\n"
	  "\treturn 8;\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "\tlet x: (i32 | nomem) = tb(1);\n"
	  "\tif (x is nomem) { return 21; };\n"
	  "\tif (x is i32) { return 22; };\n"
	  "\treturn 23;\n"
	  "};\n",
	  BUILD_FAIL, MULTISUCC_DIAG, MULTISUCC_DIAG },

	{ "reject_success3",
	  "package main;\n"
	  "fn f(k: i32) (i32 | bool | u64 | nomem) = { return 7; };\n"
	  "fn g() (i32 | nomem) = {\n"
	  "\tlet v: i32 = f(1)?;\n"
	  "\treturn v;\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "\tlet x: (i32 | nomem) = g();\n"
	  "\tif (x is i32) { return 0; };\n"
	  "\treturn 1;\n"
	  "};\n",
	  BUILD_FAIL, MULTISUCC_DIAG, MULTISUCC_DIAG },

	/* F9 graduation rows: the ?-result is bare i32, so `is`/`match`
	 * over it must reject on BOTH stages (pre-fix wwstage accepted). */
	{ "reject_try_is",
	  "package main;\n"
	  "fn f(k: i32) (i32 | nomem) = { return 7; };\n"
	  "fn g() (i32 | nomem) = {\n"
	  "\tif (f(1)? is i32) { return 1; };\n"
	  "\treturn 0;\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "\tlet x: (i32 | nomem) = g();\n"
	  "\tif (x is i32) { return 0; };\n"
	  "\treturn 1;\n"
	  "};\n",
	  BUILD_FAIL,
	  "is on non-tagged-union",
	  "is/as: operand is not a tagged union" },

	{ "reject_try_match",
	  "package main;\n"
	  "fn f(k: i32) (i32 | nomem) = { return 7; };\n"
	  "fn g() (i32 | nomem) = {\n"
	  "\tmatch (f(1)?) {\n"
	  "\tcase i32 => return 1;\n"
	  "\t};\n"
	  "\treturn 0;\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "\tlet x: (i32 | nomem) = g();\n"
	  "\tif (x is i32) { return 0; };\n"
	  "\treturn 1;\n"
	  "};\n",
	  BUILD_FAIL,
	  "match on non-tagged-union",
	  "match on non-tagged-union try-result" },

	/* `!` shares the single-success collapse — one class, both ops
	 * (rob ruling, #133 precedent): pre-gate this BUILT on BOTH stages
	 * and silently aborted-on-success at runtime (probe q_card2_unw,
	 * graduated). */
	{ "reject_unw_success2",
	  "package main;\n"
	  "type capture = struct { content: str, start: size, end: size };\n"
	  "fn search2(k: i32) (void | []capture | nomem) = {\n"
	  "\tif (k == 0) { return; };\n"
	  "\tlet caps: []capture = [];\n"
	  "\tappend(caps, capture { content = \"xy\", start = 1, end = 3 });\n"
	  "\treturn caps;\n"
	  "};\n"
	  "fn tb(k: i32) i32 = {\n"
	  "\tlet r: (void | []capture) = search2(k)!;\n"
	  "\tif (r is []capture) { return 7; };\n"
	  "\treturn 8;\n"
	  "};\n"
	  "export fn main() i32 = { return tb(1); };\n",
	  BUILD_FAIL,
	  "!: multi-success union unwired (task #14): bind and match instead",
	  "!: multi-success union unwired (task #14): bind and match instead" },

	/* cstage's reject derives from the typed result, not the operator
	 * kind — `!` collapses identically, so its direct form must match
	 * verdicts too (pre-fix wwstage built this and misbehaved). */
	{ "reject_tryunw_is",
	  "package main;\n"
	  "fn f(k: i32) (i32 | nomem) = { return 7; };\n"
	  "fn g() i32 = {\n"
	  "\tif (f(1)! is i32) { return 1; };\n"
	  "\treturn 0;\n"
	  "};\n"
	  "export fn main() i32 = { return g() - 1; };\n",
	  BUILD_FAIL,
	  "is on non-tagged-union",
	  "is/as: operand is not a tagged union" },

	/* `?` nested in a CALL-ARG: the gate keys on the operand's type at
	 * the checker expression walk, so position must not matter — guards
	 * against a walker path that types call args without visiting the
	 * try node. */
	{ "reject_callarg",
	  "package main;\n"
	  "fn f(k: i32) (i32 | bool | nomem) = { return 7; };\n"
	  "fn g(v: i32) i32 = { return v; };\n"
	  "fn h() (i32 | nomem) = {\n"
	  "\treturn g(f(1)?);\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "\tlet x: (i32 | nomem) = h();\n"
	  "\tif (x is i32) { return 0; };\n"
	  "\treturn 1;\n"
	  "};\n",
	  BUILD_FAIL, MULTISUCC_DIAG, MULTISUCC_DIAG },

	/* |success| == 1: the gate must not fire and the unwrap must keep
	 * working at runtime. The 3-member single-success shape
	 * (i32|e1|e2) is pinned by 925_tryprop_tag_remap_run. */
	{ "accept_two_member",
	  "package main;\n"
	  "fn f(k: i32) (i32 | nomem) = { return 7; };\n"
	  "fn g() (i32 | nomem) = {\n"
	  "\tlet v: i32 = f(1)?;\n"
	  "\treturn v + 1;\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "\tmatch (g()) {\n"
	  "\tcase let v: i32 => return v - 8;\n"
	  "\tcase nomem      => return 2;\n"
	  "\t};\n"
	  "\treturn 3;\n"
	  "};\n",
	  0, NULL, NULL },

	/* |success| == 1 with MULTIPLE errors under `!`: the gate must not
	 * fire and the success unwrap must keep working at runtime (the
	 * `!` twin of 925's ? canary shape). */
	{ "accept_unw_multi_error",
	  "package main;\n"
	  "type e1 = !void;\n"
	  "type e2 = !void;\n"
	  "fn g(which: i32) (i32 | e1 | e2) = {\n"
	  "\tif (which == 1) { return e1{}; };\n"
	  "\tif (which == 2) { return e2{}; };\n"
	  "\treturn 100;\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "\tlet v: i32 = g(0)!;\n"
	  "\treturn v - 100;\n"
	  "};\n",
	  0, NULL, NULL },

	/* VOID success: (void|nomem)? as an expression-statement is the
	 * dominant lib/ shape (io writes etc.) — void counts as the one
	 * success member, nsucc == 1, the gate must not fire. */
	{ "accept_void_success",
	  "package main;\n"
	  "fn f(k: i32) (void | nomem) = {\n"
	  "\treturn;\n"
	  "};\n"
	  "fn g() (i32 | nomem) = {\n"
	  "\tf(1)?;\n"
	  "\treturn 5;\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "\tlet x: (i32 | nomem) = g();\n"
	  "\tmatch (x) {\n"
	  "\tcase let v: i32 => return v - 5;\n"
	  "\tcase nomem      => return 2;\n"
	  "\t};\n"
	  "\treturn 3;\n"
	  "};\n",
	  0, NULL, NULL },

	/* Success variant is itself a NAMED tagged union: `f()? is i32`
	 * is `is` over (i32|bool) — tagged — and cstage ACCEPTS. The
	 * wwstage F9 mirror must key on the resolved success type, not
	 * on the try syntax, or this over-rejects. */
	{ "accept_nested_tagged",
	  "package main;\n"
	  "type ab = (i32 | bool);\n"
	  "fn f(k: i32) (ab | nomem) = {\n"
	  "\tlet v: ab = 7;\n"
	  "\treturn v;\n"
	  "};\n"
	  "fn g() (i32 | nomem) = {\n"
	  "\tif (f(1)? is i32) { return 0; };\n"
	  "\treturn 1;\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "\tlet x: (i32 | nomem) = g();\n"
	  "\tmatch (x) {\n"
	  "\tcase let v: i32 => return v;\n"
	  "\tcase nomem      => return 2;\n"
	  "\t};\n"
	  "\treturn 3;\n"
	  "};\n",
	  0, NULL, NULL },
};

/* errlog_has — the build-failure stderr must carry the row's expected
 * diagnostic; any other failure (parse error, crash) is a vacuous
 * reject and must not pass. */
static int
errlog_has(const char *path, const char *needle)
{
	FILE *f = fopen(path, "rb");
	if (!f) return 0;
	char buf[8192];
	size_t got = fread(buf, 1, sizeof buf - 1, f);
	fclose(f);
	buf[got] = '\0';
	return strstr(buf, needle) != NULL;
}

static int
run_driver(const char *driver, const char *expect, const struct row *r, int i)
{
	char tmpdir[64], src[128], outbin[128], errlog[128], rmcmd[160], cmd[1200];
	snprintf(tmpdir, sizeof tmpdir, "/tmp/tpms_%d_d_%d", getpid(), i);
	mkdir(tmpdir, 0755);
	snprintf(src,    sizeof src,    "%s/tpms_%d_%d.ww", tmpdir, getpid(), i);
	snprintf(outbin, sizeof outbin, "%s/tpms_%d_%d",    tmpdir, getpid(), i);
	snprintf(errlog, sizeof errlog, "%s/err", tmpdir);
	snprintf(rmcmd,  sizeof rmcmd,  "rm -rf %s", tmpdir);

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

	snprintf(cmd, sizeof cmd, "%s build -o %s %s 2>%s",
	    driver, outbin, src, errlog);
	if (runwait(cmd) != 0) {
		int rc = -1;
		if (r->want != BUILD_FAIL) {
			fprintf(stderr, "row[%s]: build via %s failed\n",
			    r->label, driver);
		} else if (expect && !errlog_has(errlog, expect)) {
			fprintf(stderr, "row[%s]: %s build failed without "
			    "expected diagnostic \"%s\"\n",
			    r->label, driver, expect);
			rc = -3;	/* failed, but for the wrong reason */
		}
		runwait(rmcmd);
		return rc;
	}

	int got = runwait(outbin);

	runwait(rmcmd);
	return got;
}

/* asm_byte_identical — generate .s via cstage's w6c and wwstage's
 * w6c_ww and diff (rule 10 on the accept rows). */
static int
asm_byte_identical(const char *bin, const struct row *r, int i)
{
	char src[64], cs[64], ws[64], cmd[1024];
	snprintf(src, sizeof src, "/tmp/tpms_asm_%d_%d.ww", getpid(), i);
	snprintf(cs,  sizeof cs,  "/tmp/tpms_asm_%d_%d_c.s", getpid(), i);
	snprintf(ws,  sizeof ws,  "/tmp/tpms_asm_%d_%d_w.s", getpid(), i);

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

	snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "row[%s]: w6c errored\n", r->label);
		unlink(src);
		return -1;
	}
	snprintf(cmd, sizeof cmd, "%s/w6c_ww -o %s %s 2>/dev/null",
	    bin, ws, src);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "row[%s]: w6c_ww errored\n", r->label);
		unlink(src); unlink(cs);
		return -1;
	}

	FILE *fc = fopen(cs, "rb");
	FILE *fw = fopen(ws, "rb");
	int rc = 0;
	if (!fc || !fw) {
		rc = -1;
	} else {
		for (;;) {
			int a = fgetc(fc);
			int b = fgetc(fw);
			if (a != b) { rc = -1; break; }
			if (a == EOF) break;
		}
	}
	if (fc) fclose(fc);
	if (fw) fclose(fw);
	if (rc != 0)
		fprintf(stderr, "row[%s]: cstage vs wwstage asm differs\n",
		    r->label);
	unlink(src); unlink(cs); unlink(ws);
	return rc;
}

int
main(void)
{
	const char *bin = getenv("BIN");
	if (!bin) bin = "out/bin";
	char absbin[2080];
	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[2120];
	snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
	char wdrv[2120];
	snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);

	struct {
		const char *name;
		const char *path;
		int is_ww;
		int gated_on_existence;
	} drivers[] = {
		{ "cstage",  cdrv, 0, 0 },
		{ "wwstage", wdrv, 1, 1 },
		{ NULL, NULL, 0, 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_on_existence
		    && access(drivers[d].path, X_OK) != 0) {
			fprintf(stderr,
			    "tryprop_multisuccess: skip %s (no %s)\n",
			    drivers[d].name, drivers[d].path);
			continue;
		}
		for (int i = 0; i < n; i++) {
			const char *expect = drivers[d].is_ww
			    ? rows[i].expect_ww : rows[i].expect_cs;
			int got = run_driver(drivers[d].path, expect,
			    &rows[i], i);
			total++;
			int bad = rows[i].want == BUILD_FAIL
			    ? (got != -1) : (got != rows[i].want);
			if (bad) {
				fprintf(stderr,
				    "tryprop_multisuccess[%s][%s]: exit=%d want=%d\n",
				    drivers[d].name, rows[i].label,
				    got, rows[i].want);
				fail++;
			}
		}
	}

	if (access(wdrv, X_OK) == 0) {
		for (int i = 0; i < n; i++) {
			if (rows[i].want == BUILD_FAIL)
				continue;
			total++;
			if (asm_byte_identical(bin, &rows[i], i) != 0)
				fail++;
		}
	}

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