/*
 * 910_at_test — drives the compiler's `-T` @test mode (task #15).
 *
 * Under `w6c -T`, the checker collects every @test fn and synthesizes
 * `export fn main() i32 { t0(); t1(); ...; return 0; }`, calling each in
 * source order; a test that runs to completion passes, an abort/div0/
 * nonzero exit FAILS the run. This replaces the old driver-side regex
 * scan (find_attest) — the @test set now comes from the AST, the single
 * source of truth (rob #15 ruling). cgen is untouched: the synthesized
 * entry rides the existing cgfn path.
 *
 * Probes:
 *   1. RUN — `w6c -T` the @test-only fixture, assemble, link, run; the
 *      synthesized entry must exit 0 (every @test passed). Imports are
 *      resolved by `ww build` into a *.combined.ww (the fixture uses
 *      `alloc`, whose rt_malloc symbol the driver concatenates); we then
 *      compile that combined unit with `-T`.
 *   2. REJECT — `-T` of a fixture that also defines a user `main` must
 *      exit nonzero (the synth entry owns main).
 *   3. GUARD — `-T` of a fixture whose @test fn is not `fn() void` must
 *      exit nonzero (rule-7 loud, no silent skip/coerce).
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.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 const char *
absbin(void)
{
	const char *b = getenv("BIN");
	if (!b) b = "out/bin";
	if (b[0] == '/') return b;
	static char buf[2048];
	char cwd[1024];
	if (getcwd(cwd, sizeof cwd) == NULL) return NULL;
	snprintf(buf, sizeof buf, "%s/%s", cwd, b);
	return buf;
}

/* run_fixture — `<comp> -T` the @test fixture (import-resolved into a
 * combined unit by <drv> build), assemble, link, run; the synthesized
 * entry must exit 0. Returns 0 on success. */
static int
run_fixture(const char *bin, const char *comp, const char *drv)
{
	int pid = getpid();
	char src[256], comb[256], binout[256], asmf[256], obj[256], exe[256];
	char rt[1024], cmd[4096];
	snprintf(src,  sizeof src,  "/tmp/at910_%s_%d.ww", comp, pid);
	snprintf(binout, sizeof binout, "/tmp/at910_%s_%d", comp, pid);
	snprintf(comb, sizeof comb, "/tmp/at910_%s_%d.combined.ww", comp, pid);
	snprintf(asmf, sizeof asmf, "/tmp/at910_%s_%d.s", comp, pid);
	snprintf(obj,  sizeof obj,  "/tmp/at910_%s_%d.o", comp, pid);
	snprintf(exe,  sizeof exe,  "/tmp/at910_%s_%d.exe", comp, pid);
	snprintf(rt,   sizeof rt,   "%s/../lib/libwwrt.a", bin);

	snprintf(cmd, sizeof cmd, "cp test/wcc/data/attest_pass.ww %s", src);
	if (runwait(cmd) != 0) { fprintf(stderr, "910 FAIL: cp\n"); return 1; }

	/* `test -c -o <stem>` (compile-only) resolves imports AND auto-bundles
	 * lib/test (#17) into <stem>.combined.ww — the synth's run() callee
	 * must link below — WITHOUT running the harness. We depend on the
	 * combined ARTIFACT; `-o` keeps the binary off the CWD. */
	snprintf(cmd, sizeof cmd, "%s/%s test -c -o %s %s > /dev/null 2>&1",
	    bin, drv, binout, src);
	runwait(cmd);
	if (access(comb, 0) != 0) {
		fprintf(stderr, "910 FAIL: %s build produced no %s\n", drv, comb);
		return 1;
	}

	snprintf(cmd, sizeof cmd, "%s/%s -T %s -o %s 2>/dev/null", bin, comp, comb, asmf);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "910 FAIL: %s -T errored\n", comp);
		return 1;
	}
	snprintf(cmd, sizeof cmd, "%s/w6a -o %s %s 2>/dev/null", bin, obj, asmf);
	if (runwait(cmd) != 0) { fprintf(stderr, "910 FAIL: w6a\n"); return 1; }
	snprintf(cmd, sizeof cmd, "%s/w6l -o %s %s %s 2>/dev/null", bin, exe, obj, rt);
	if (runwait(cmd) != 0) { fprintf(stderr, "910 FAIL: w6l\n"); return 1; }

	int rc = runwait(exe);
	if (rc != 0) {
		fprintf(stderr, "910 FAIL: synth entry exited %d (a @test failed)\n", rc);
		return 1;
	}
	unlink(src); unlink(comb); unlink(asmf); unlink(obj); unlink(exe);
	unlink(binout);
	char tmp[300];
	snprintf(tmp, sizeof tmp, "%s.s", binout); unlink(tmp);
	snprintf(tmp, sizeof tmp, "%s.o", binout); unlink(tmp);
	return 0;
}

/* reject — `<comp> -T <fixture>` must exit nonzero. */
static int
reject(const char *bin, const char *comp, const char *fixture, const char *what)
{
	char cmd[4096];
	snprintf(cmd, sizeof cmd, "%s/%s -T %s -o /dev/null 2>/dev/null",
	    bin, comp, fixture);
	if (runwait(cmd) == 0) {
		fprintf(stderr, "910 FAIL: %s -T accepted %s (expected reject)\n",
		    comp, what);
		return 1;
	}
	return 0;
}

/* Each row: a fixture `-T` must loud-reject, and why. */
static const struct {
	const char *fixture;
	const char *what;
} rejects[] = {
	{ "test/wcc/data/attest_userman.ww", "user main" },
	{ "test/wcc/data/attest_badsig.ww",  "non-void @test" },
};

/*
 * #6: each row asserts whether a symbol's TEXT def appears in the asm
 * `<comp>` emits for attest_nondrop.ww in a given mode. A @test fn is
 * spliced out of a non-test build (harec ref/harec/src/check.c:3941 —
 * checked but never emitted) and kept under -T (the synth entry calls
 * it); a plain fn is always emitted.
 */
static const struct {
	const char *sym;	/* TEXT label to grep for */
	int testmode;		/* 1 => -T, 0 => plain build */
	int present;		/* expected: 1 present, 0 absent */
	const char *what;
} nondrop_rows[] = {
	{ "data.nondrop_keep",   0, 1, "plain fn kept non-T" },
	{ "data.nondrop_test_a", 0, 0, "head @test dropped non-T" },
	{ "data.nondrop_test_b", 0, 0, "mid @test dropped non-T" },
	{ "data.nondrop_test_c", 0, 0, "consecutive @test dropped non-T" },
	{ "data.nondrop_keep",   1, 1, "plain fn kept under -T" },
	{ "data.nondrop_test_a", 1, 1, "head @test kept under -T" },
	{ "data.nondrop_test_b", 1, 1, "mid @test kept under -T" },
	{ "data.nondrop_test_c", 1, 1, "consecutive @test kept under -T" },
};

/* nondrop — compile attest_nondrop.ww plain and `-T`, then assert each
 * row's TEXT def is present/absent. */
static int
nondrop(const char *bin, const char *comp)
{
	int pid = getpid();
	char plain[256], tee[256], cmd[4096];
	snprintf(plain, sizeof plain, "/tmp/at910nd_%s_p_%d.s", comp, pid);
	snprintf(tee,   sizeof tee,   "/tmp/at910nd_%s_t_%d.s", comp, pid);

	snprintf(cmd, sizeof cmd,
	    "%s/%s test/wcc/data/attest_nondrop.ww -o %s 2>/dev/null",
	    bin, comp, plain);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "910 FAIL: %s non-T nondrop compile\n", comp);
		return 1;
	}
	/* The -T compile synthesizes a main that calls lib/test's run(), so it
	 * needs the lib/test-inclusive combined `ww test -c` writes (the plain
	 * compile above has no synth, so it stays on the raw fixture). */
	char stem[256], comb[300];
	snprintf(stem, sizeof stem, "/tmp/at910nd_%s_c_%d", comp, pid);
	snprintf(comb, sizeof comb, "%s.combined.ww", stem);
	snprintf(cmd, sizeof cmd,
	    "%s/ww test -c -o %s test/wcc/data/attest_nondrop.ww > /dev/null 2>&1",
	    bin, stem);
	runwait(cmd);
	snprintf(cmd, sizeof cmd,
	    "%s/%s -T %s -o %s 2>/dev/null", bin, comp, comb, tee);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "910 FAIL: %s -T nondrop compile\n", comp);
		return 1;
	}

	int rc = 0;
	for (size_t i = 0; i < sizeof nondrop_rows / sizeof nondrop_rows[0]; i++) {
		const char *f = nondrop_rows[i].testmode ? tee : plain;
		snprintf(cmd, sizeof cmd, "grep -q '^TEXT %s,' %s",
		    nondrop_rows[i].sym, f);
		int found = runwait(cmd) == 0;
		if (found != nondrop_rows[i].present) {
			fprintf(stderr, "910 FAIL: %s — %s: %s %s (expected %s)\n",
			    comp, nondrop_rows[i].what, nondrop_rows[i].sym,
			    found ? "present" : "absent",
			    nondrop_rows[i].present ? "present" : "absent");
			rc = 1;
			break;
		}
	}
	unlink(plain); unlink(tee); unlink(comb);
	char tmp[300];
	snprintf(tmp, sizeof tmp, "%s.s", stem); unlink(tmp);
	snprintf(tmp, sizeof tmp, "%s.o", stem); unlink(tmp);
	unlink(stem);
	return rc;
}

/* reject_plain — `<comp> <fixture>` (NON-T) must exit nonzero. Pins that
 * a @test body is type-checked before the #6 splice drops it: an
 * undefined symbol in the body is caught loud even though the fn never
 * reaches codegen (harec checks at :3913, drops at :3941). */
static int
reject_plain(const char *bin, const char *comp, const char *fixture,
    const char *what)
{
	char cmd[4096];
	snprintf(cmd, sizeof cmd, "%s/%s %s -o /dev/null 2>/dev/null",
	    bin, comp, fixture);
	if (runwait(cmd) == 0) {
		fprintf(stderr, "910 FAIL: %s (non-T) accepted %s "
		    "(expected reject)\n", comp, what);
		return 1;
	}
	return 0;
}

/* linkfail — a plain fn calling a @test fn, built non-T: compile +
 * assemble succeed, but the link MUST fail (the dropped @test def leaves
 * the call's symbol dangling — harec-faithful loud failure, never a
 * silent mis-link). Linker behavior is stage-independent, so cstage
 * suffices; 997's byte-id proves the wwstage .s is identical. */
static int
linkfail(const char *bin, const char *comp)
{
	int pid = getpid();
	char asmf[256], obj[256], exe[256], rt[1024], cmd[4096];
	snprintf(asmf, sizeof asmf, "/tmp/at910lf_%s_%d.s", comp, pid);
	snprintf(obj,  sizeof obj,  "/tmp/at910lf_%s_%d.o", comp, pid);
	snprintf(exe,  sizeof exe,  "/tmp/at910lf_%s_%d.exe", comp, pid);
	snprintf(rt,   sizeof rt,   "%s/../lib/libwwrt.a", bin);

	snprintf(cmd, sizeof cmd,
	    "%s/%s test/wcc/data/attest_calldropped.ww -o %s 2>/dev/null",
	    bin, comp, asmf);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "910 FAIL: %s non-T calldropped compile\n", comp);
		return 1;
	}
	snprintf(cmd, sizeof cmd, "%s/w6a -o %s %s 2>/dev/null", bin, obj, asmf);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "910 FAIL: w6a calldropped\n");
		unlink(asmf);
		return 1;
	}
	snprintf(cmd, sizeof cmd, "%s/w6l -o %s %s %s 2>/dev/null",
	    bin, exe, obj, rt);
	int rc = 0;
	if (runwait(cmd) == 0) {
		fprintf(stderr, "910 FAIL: calldropped linked (expected "
		    "undefined-reference to the dropped @test sym)\n");
		rc = 1;
	}
	unlink(asmf); unlink(obj); unlink(exe);
	return rc;
}

/* accept — `<comp> <fixture>` (NON-T) must exit zero. The #23 cross-package
 * legal control: distinct-mod same-leaf decls coexist, so the dup reject
 * keyed on (name, mod) must NOT fire. */
static int
accept(const char *bin, const char *comp, const char *fixture, const char *what)
{
	char cmd[4096];
	snprintf(cmd, sizeof cmd, "%s/%s %s -o /dev/null 2>/dev/null",
	    bin, comp, fixture);
	if (runwait(cmd) != 0) {
		fprintf(stderr, "910 FAIL: %s rejected %s (expected accept)\n",
		    comp, what);
		return 1;
	}
	return 0;
}

/* collide_run — a @test unit defining a user `fn run` collides with
 * lib/test's bound runner once `<drv> test -c` bundles it; `<comp> -T` of
 * the combined must loud-reject the duplicate (#23). Pre-fix wwstage built
 * a binary that called the user run and silently skipped every @test. */
static int
collide_run(const char *bin, const char *comp, const char *drv)
{
	int pid = getpid();
	char stem[256], comb[300], cmd[4096];
	snprintf(stem, sizeof stem, "/tmp/at910cr_%s_%d", comp, pid);
	snprintf(comb, sizeof comb, "%s.combined.ww", stem);
	snprintf(cmd, sizeof cmd,
	    "%s/%s test -c -o %s test/wcc/data/attest_userrun.ww > /dev/null 2>&1",
	    bin, drv, stem);
	runwait(cmd);
	if (access(comb, 0) != 0) {
		fprintf(stderr, "910 FAIL: %s build produced no %s\n", drv, comb);
		return 1;
	}
	snprintf(cmd, sizeof cmd, "%s/%s -T %s -o /dev/null 2>/dev/null",
	    bin, comp, comb);
	int rc = 0;
	if (runwait(cmd) == 0) {
		fprintf(stderr, "910 FAIL: %s -T accepted user `fn run` collision "
		    "(expected duplicate-fn reject)\n", comp);
		rc = 1;
	}
	unlink(comb);
	char tmp[320];
	snprintf(tmp, sizeof tmp, "%s.s", stem); unlink(tmp);
	snprintf(tmp, sizeof tmp, "%s.o", stem); unlink(tmp);
	unlink(stem);
	return rc;
}

/* modfn_run — `<drv> run <fixture>` and assert exit 6 (#30). The fixture's
 * main returns `aa() + aa.helper()` = 1 + 5: the bare `aa()` must resolve to
 * the fn (1) and the qualified `aa.helper()` to the module member (5). A
 * mis-resolution that still compiled would run to a different code; this
 * pins the resolved TARGETS, not just acceptance. */
static int
modfn_run(const char *bin, const char *drv, const char *fixture, const char *what)
{
	char cmd[4096];
	snprintf(cmd, sizeof cmd, "%s/%s run %s > /dev/null 2>&1", bin, drv, fixture);
	int rc = runwait(cmd);
	if (rc != 6) {
		fprintf(stderr, "910 FAIL: %s run %s exited %d (expected 6 — bare fn "
		    "+ qualified module resolution)\n", drv, what, rc);
		return 1;
	}
	return 0;
}

int
main(void)
{
	const char *bin = absbin();
	if (!bin) { fprintf(stderr, "910 FAIL: getcwd\n"); return 1; }

	if (run_fixture(bin, "w6c", "ww") != 0) return 1;
	for (size_t i = 0; i < sizeof rejects / sizeof rejects[0]; i++)
		if (reject(bin, "w6c", rejects[i].fixture, rejects[i].what) != 0)
			return 1;
	if (nondrop(bin, "w6c") != 0) return 1;
	if (reject_plain(bin, "w6c", "test/wcc/data/attest_undefbody.ww",
	    "undefined symbol in @test body") != 0) return 1;
	if (linkfail(bin, "w6c") != 0) return 1;

	/* #23 — top-level duplicate-decl reject (one row per kind: all four
	 * route through installtop, so each deserves its own pin) + legal
	 * cross-package control + the builtin-redecl carve-out accept. */
	if (reject_plain(bin, "w6c", "test/wcc/data/dup_fn.ww",
	    "same-module duplicate fn") != 0) return 1;
	if (reject_plain(bin, "w6c", "test/wcc/data/dup_type.ww",
	    "same-module duplicate type") != 0) return 1;
	if (reject_plain(bin, "w6c", "test/wcc/data/dup_def.ww",
	    "same-module duplicate def") != 0) return 1;
	if (reject_plain(bin, "w6c", "test/wcc/data/dup_let.ww",
	    "same-module duplicate let") != 0) return 1;
	if (accept(bin, "w6c", "test/wcc/data/dup_xpkg_ok.ww",
	    "cross-package same-name") != 0) return 1;
	if (accept(bin, "w6c", "test/wcc/data/builtin_redecl_ok.ww",
	    "builtin nomem redecl (carve-out)") != 0) return 1;
	/* #30 — a top-level fn whose leaf matches an imported module name
	 * coexists with the module bareword (different namespaces). Accept
	 * proves both the bare `aa()` (fn) and qualified `aa.helper()`
	 * (module) resolve; a mis-resolution would fail to compile. Both
	 * decl orders are pinned (use-before-value AND value-before-use): the
	 * order-dependence is exactly what regresses silently — cstage is
	 * order-independent, wwstage closes both directions via the symmetric
	 * promotes in installtop + installdecl's N_USE arm. */
	if (accept(bin, "w6c", "test/wcc/data/modfn_coexist_ok.ww",
	    "fn named like imported module (use-before-value)") != 0) return 1;
	if (accept(bin, "w6c", "test/wcc/data/modfn_coexist_vbu_ok.ww",
	    "fn named like imported module (value-before-use)") != 0) return 1;
	/* runtime-resolve: both orders run to exit 6 (bare fn=1 + module
	 * member=5), pinning the resolved targets on the cstage driver. */
	if (modfn_run(bin, "ww", "test/wcc/data/modfn_coexist_ok.ww",
	    "use-before-value") != 0) return 1;
	if (modfn_run(bin, "ww", "test/wcc/data/modfn_coexist_vbu_ok.ww",
	    "value-before-use") != 0) return 1;
	if (collide_run(bin, "w6c", "ww") != 0) return 1;

	printf("@test -T: run ok + user-main and bad-signature rejected + "
	    "non-T @test drop + checked-body + dangling-call link-fail (#6) + "
	    "dup fn/type/def/let reject + xpkg + builtin-redecl accept + "
	    "modfn coexist (#30) + fn-run collision (#23)\n");
	return 0;
}