/*
 * 957_assert_builtin_run — runtime + byte-id + reject net for #58: the
 * `assert(cond[, msg])` / `abort([msg])` builtins (the harec
 * EXPR_ASSERT family) in BOTH stages.
 *
 * Root: wwstage had NO builtin intercept for assert/abort — the checker
 * left the call untyped (asserttyped gate 4 deliberately skipped it)
 * and cgcall fell through to the regular call path, emitting
 * `CALL assert(SB)` for a symbol that exists nowhere → link-fail.
 * cstage lowers both inline via rt_abort (checker tags the callee
 * ty_err at cmd/wcc/check.c:1536-1572, cgen keys on the tag at
 * cmd/w6c/cgen.c:6618-6663). The fix mirrors that tag-then-lower pair
 * into check.ww exprtype N_CALL + cgenexpr.ww cgcall.
 *
 * THIS TEST MUST CATCH A WWSTAGE-ONLY DIVERGENCE, so every positive
 * row carries both dimensions (modelled on 953/954):
 *   (a) cstage `ww build` + run, asserting the exit code AND the
 *       runtime stderr (rt_abort writes msg verbatim; a NULL want_msg
 *       pins the (NULL, 0) no-msg shape as EMPTY stderr).
 *   (b) w6c vs w6c_ww `.s` cmp — FAILS if the stages diverge. On
 *       pre-fix master every assert/abort row diverges (wwstage emits
 *       the bogus CALL).
 *
 * Shadow rows pin the gate's other half: a user fn named assert/abort
 * (same-module or cross-module, the #45 shape) suppresses the builtin
 * and routes the regular call path in BOTH stages. The cross-module
 * row pins the CURRENT flat-scope semantics — if the #45 root (filed
 * as task #14: cross-module bare resolution of a foreign decl) is
 * later ruled a reject, that row flips to expect_fail with it.
 *
 * Reject rows pin the checker mirror ON CONTENT: non-bool cond /
 * non-str msg / arity overflows fail the build in BOTH stages with the
 * shared diagnostic substring (cstage prefixes pos, wwstage's cerr is
 * bare — strstr covers both). The alias-cond row pins the rule-10
 * down-alignment: cstage compares ty_bool by identity (check.c:1560),
 * so wwstage must not alias-peel either (widening = task #5 alias arc).
 */
#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 long
slurp(const char *path, char *buf, long cap)
{
	FILE *f = fopen(path, "rb");
	if (!f) return -1;
	long n = (long)fread(buf, 1, cap - 1, f);
	fclose(f);
	if (n < 0) n = 0;
	buf[n] = '\0';
	return n;
}

struct row {
	const char *label;
	const char *src;
	int want_exit;
	const char *want_msg;	/* run stderr must contain this; NULL = must be empty */
	int expect_fail;	/* 1 = BOTH stages must reject; want_exit/want_msg ignored */
	const char *diag;	/* reject rows: both stages' stderr must contain this */
};

static const struct row rows[] = {
	/* Passing asserts (bare and with msg) fall through; exit 42. */
	{ "pass",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "\tassert(1 + 1 == 2);\n"
	  "\tassert(2 > 1, \"never fires\");\n"
	  "\treturn 42;\n"
	  "};\n", 42, NULL, 0, NULL },
	/* Failing assert without msg: rt_abort(NULL, 0), exit 1, silent. */
	{ "fail_nomsg",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "\tassert(1 == 2);\n"
	  "\treturn 0;\n"
	  "};\n", 1, NULL, 0, NULL },
	/* Failing assert with msg: rt_abort(ptr, len) writes it to stderr. */
	{ "fail_msg",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "\tassert(false, \"assert fired\\n\");\n"
	  "\treturn 0;\n"
	  "};\n", 1, "assert fired", 0, NULL },
	/* abort with msg: unconditional rt_abort, exit 1, msg on stderr. */
	{ "abort_msg",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "\tabort(\"boom\\n\");\n"
	  "\treturn 0;\n"
	  "};\n", 1, "boom", 0, NULL },
	/* bare abort(): rt_abort(NULL, 0), exit 1, silent. */
	{ "abort_bare",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "\tabort();\n"
	  "\treturn 0;\n"
	  "};\n", 1, NULL, 0, NULL },
	/* assert inside an IMPORTED module's fn (single-file multi-package
	 * form, like 953) — the regex fold-5 consumer shape. */
	{ "imported_mod",
	  "package m;\n"
	  "export fn f() i32 = {\n"
	  "\tassert(3 > 2, \"m.f invariant\");\n"
	  "\treturn 42;\n"
	  "};\n"
	  "package main;\n"
	  "import m;\n"
	  "export fn main() i32 = { return m.f(); };\n", 42, NULL, 0, NULL },
	/* SHADOW control, same-module: a user fn `assert` suppresses the
	 * builtin; the call routes the regular path (no-op fn), so the
	 * false cond does NOT abort. Exit 7 proves the user fn ran. */
	{ "shadow_samemod",
	  "package main;\n"
	  "let g: i32 = 0;\n"
	  "fn assert(b: bool) void = { g = 7; };\n"
	  "export fn main() i32 = {\n"
	  "\tassert(false);\n"
	  "\treturn g;\n"
	  "};\n", 7, NULL, 0, NULL },
	/* SHADOW control, cross-module (#45 shape, task #14): a foreign
	 * exported fn `assert` in the flat scope also suppresses the
	 * builtin; bare `assert(false, ...)` binds it and does NOT abort. */
	{ "shadow_xmod",
	  "package m;\n"
	  "export fn assert(b: bool, msg: str) void = { };\n"
	  "package main;\n"
	  "import m;\n"
	  "export fn main() i32 = {\n"
	  "\tassert(false, \"routed to m.assert\");\n"
	  "\treturn 42;\n"
	  "};\n", 42, NULL, 0, NULL },
	/* Checker rejects, mirrored both stages — pinned on diagnostic
	 * CONTENT, not just a non-zero exit. */
	{ "reject_nonbool",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "\tassert(\"not a bool\");\n"
	  "\treturn 0;\n"
	  "};\n", 0, NULL, 1, "assert: cond must be bool" },
	/* Alias-of-bool cond: ty_bool identity in cstage (check.c:1560)
	 * → reject; wwstage aligned down (no resolvealias peel). */
	{ "reject_alias_cond",
	  "package main;\n"
	  "type myb = bool;\n"
	  "export fn main() i32 = {\n"
	  "\tlet b: myb = true;\n"
	  "\tassert(b);\n"
	  "\treturn 0;\n"
	  "};\n", 0, NULL, 1, "assert: cond must be bool" },
	{ "reject_assert_arity",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "\tassert(true, \"m\", \"extra\");\n"
	  "\treturn 0;\n"
	  "};\n", 0, NULL, 1, "assert: at most two args" },
	{ "reject_abort_nonstr",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "\tabort(42);\n"
	  "\treturn 0;\n"
	  "};\n", 0, NULL, 1, "abort: message must be str" },
	{ "reject_abort_arity",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "\tabort(\"a\", \"b\");\n"
	  "\treturn 0;\n"
	  "};\n", 0, NULL, 1, "abort: at most one arg" },
	{ NULL, NULL, 0, NULL, 0, NULL }
};

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, "assert_builtin: w6c_ww missing — cannot run "
		    "the cs==ww byte-id gate (the whole point of #58)\n");
		return 1;
	}

	char errbuf[4096];
	int n = 0, fail = 0;
	for (int i = 0; rows[i].src; i++, n++) {
		char src[64], errf[64];
		snprintf(src, sizeof src, "/tmp/wwasrt_%d_%d.ww", getpid(), i);
		snprintf(errf, sizeof errf, "/tmp/wwasrt_%d_%d.err",
		    getpid(), i);
		FILE *f = fopen(src, "wb");
		if (f == NULL) { fail++; continue; }
		fputs(rows[i].src, f);
		fclose(f);

		if (rows[i].expect_fail) {
			char cmd[2048];
			const char *stage[2] = { w6c, w6c_ww };
			const char *sname[2] = { "cstage", "wwstage" };
			for (int s = 0; s < 2; s++) {
				snprintf(cmd, sizeof cmd,
				    "%s -o /dev/null %s 2>%s",
				    stage[s], src, errf);
				if (runwait(cmd) == 0) {
					fprintf(stderr, "row[%s]: %s accepted, "
					    "expected reject\n",
					    rows[i].label, sname[s]);
					fail++;
					continue;
				}
				if (slurp(errf, errbuf, sizeof errbuf) < 0 ||
				    strstr(errbuf, rows[i].diag) == NULL) {
					fprintf(stderr, "row[%s]: %s rejected "
					    "without \"%s\" on stderr\n",
					    rows[i].label, sname[s],
					    rows[i].diag);
					fail++;
				}
			}
			unlink(src); unlink(errf);
			continue;
		}

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

		char cmd[2048];
		snprintf(cmd, sizeof cmd, "cd %s && %s/ww build %s "
		    ">/dev/null 2>&1", 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';

		snprintf(cmd, sizeof cmd, "%s >/dev/null 2>%s", outbin, errf);
		int got = runwait(cmd);
		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++;
		}
		long elen = slurp(errf, errbuf, sizeof errbuf);
		if (rows[i].want_msg) {
			if (elen < 0 || strstr(errbuf, rows[i].want_msg) == NULL) {
				fprintf(stderr, "row[%s]: run stderr missing "
				    "\"%s\"\n", rows[i].label,
				    rows[i].want_msg);
				fail++;
			}
		} else if (elen != 0) {
			fprintf(stderr, "row[%s]: run stderr not empty "
			    "(rt_abort no-msg must be (NULL, 0))\n",
			    rows[i].label);
			fail++;
		}
		unlink(outbin); rmdir(tmpdir); unlink(errf);

		/* (b) cs==ww byte-id gate. */
		char cs_s[64], ws_s[64];
		snprintf(cs_s, sizeof cs_s, "/tmp/wwasrt_%d_%d_cs.s",
		    getpid(), i);
		snprintf(ws_s, sizeof ws_s, "/tmp/wwasrt_%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 assert-builtin tests failed\n",
		    fail, n);
		return 1;
	}
	printf("assert_builtin: %d/%d ok (cstage run+stderr + cs==ww byte-id + reject diags)\n",
	    n, n);
	return 0;
}