/*
 * 782_strict_package — #24a strict-package gate, BOTH stages (w6c + w6c_ww).
 *
 * Every primary section must open with a `package` clause; a missing clause
 * on the first real decl is a hard error ("missing package clause"). An
 * imported (`//ww:module <path>`) or sep primary-reset region carries its
 * identity out-of-band and is exempt; an in-section `package` clause then
 * ASSERTS — its leaf must equal the path's last component ("package <x>
 * does not match import path <p>"). A bare `//ww:module-reset` opens a fresh
 * primary section that must itself re-declare a clause.
 *
 * Rule-10: every row runs on cstage `w6c` AND wwstage `w6c_ww`; both must
 * agree (accept/reject identically; diagnostic text differs by stage —
 * cstage `errorf` carries a position, wwstage `errmsg` is terser — so the
 * check is on a shared substring, not the whole line). Reject rows feed RAW
 * source: the `package` clause IS the unit under test, so there is no
 * auto-prepend here (unlike the migrated codegen fixtures).
 */
#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
file_contains(const char *path, const char *needle)
{
	FILE *f = fopen(path, "r");
	if (!f) return 0;
	char line[4096];
	int found = 0;
	while (fgets(line, sizeof line, f))
		if (strstr(line, needle)) { found = 1; break; }
	fclose(f);
	return found;
}

struct row {
	const char *label;
	const char *src;
	int accept;		/* 1 = must compile clean; 0 = must reject */
	const char *diag;	/* reject: required stderr substring (NULL on accept) */
};

static const struct row rows[] = {
	/* 1: a `package main;` executable section. */
	{ "pkg_main_accept",
	  "package main;\nexport fn main() i32 = { return 0; };\n",
	  1, NULL },
	/* 2: no clause → hard error on the first decl. */
	{ "no_clause_reject",
	  "export fn main() i32 = { return 0; };\n",
	  0, "missing package clause" },
	/* 3: imported region — the clause leaf matches the path leaf. */
	{ "module_leaf_match_accept",
	  "//ww:module foo\npackage foo;\nexport fn x() i32 = { return 0; };\n",
	  1, NULL },
	/* 4: imported region — the clause leaf mismatches the path. */
	{ "module_leaf_mismatch_reject",
	  "//ww:module foo\npackage bar;\nexport fn x() i32 = { return 0; };\n",
	  0, "does not match import path" },
	/* 5: a comment-only file declares nothing, so no clause is required. */
	{ "comment_only_accept",
	  "// just a comment, no decls\n",
	  1, NULL },
	/* 6: a bare `//ww:module-reset` opens a fresh primary section; the
	 * clause-less second section is rejected (the #84/#24a boundary). */
	{ "reset_second_section_reject",
	  "package main;\nexport fn a() i32 = { return 0; };\n"
	  "//ww:module-reset\nexport fn b() i32 = { return 0; };\n",
	  0, "missing package clause" },
	{ NULL, NULL, 0, NULL },
};

/* Compile r->src with `stage` (a w6c-family binary); verify accept/reject
 * and, on reject, the diagnostic substring. Returns 0 on success. */
static int
check_stage(const char *stage, const char *tag, const struct row *r,
    const char *tmpdir)
{
	char src[256], sout[256], errf[256], cmd[2048];
	snprintf(src,  sizeof src,  "%s/sp_%s.ww", tmpdir, r->label);
	snprintf(sout, sizeof sout, "%s/sp_%s.s",  tmpdir, r->label);
	snprintf(errf, sizeof errf, "%s/sp_%s.err", tmpdir, r->label);

	FILE *f = fopen(src, "wb");
	if (!f) { fprintf(stderr, "782 FAIL: write %s\n", src); return 1; }
	fputs(r->src, f);
	fclose(f);

	snprintf(cmd, sizeof cmd, "%s -o %s %s 2>%s", stage, sout, src, errf);
	int rc = runwait(cmd);

	if (r->accept) {
		if (rc != 0) {
			fprintf(stderr, "782 FAIL: [%s][%s] expected ACCEPT, "
			    "rejected (rc=%d)\n", r->label, tag, rc);
			return 1;
		}
		return 0;
	}
	if (rc == 0) {
		fprintf(stderr, "782 FAIL: [%s][%s] expected REJECT, "
		    "accepted\n", r->label, tag);
		return 1;
	}
	if (!file_contains(errf, r->diag)) {
		fprintf(stderr, "782 FAIL: [%s][%s] rejected but no `%s` "
		    "on stderr\n", r->label, tag, r->diag);
		return 1;
	}
	return 0;
}

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 cs[1100], ww[1100], tmpdir[64], rmcmd[160];
	snprintf(cs, sizeof cs, "%s/w6c", bin);
	snprintf(ww, sizeof ww, "%s/w6c_ww", bin);
	snprintf(tmpdir, sizeof tmpdir, "/tmp/sp782_%d", getpid());
	mkdir(tmpdir, 0755);
	snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir);

	/* wwstage twin is gated on its presence (rule 14 / 993 pattern). */
	int have_ww = (access(ww, X_OK) == 0);

	int fail = 0;
	for (int i = 0; rows[i].label; i++) {
		fail += check_stage(cs, "cs", &rows[i], tmpdir);
		if (have_ww)
			fail += check_stage(ww, "ww", &rows[i], tmpdir);
	}

	runwait(rmcmd);
	if (fail) {
		fprintf(stderr, "782: %d check(s) failed\n", fail);
		return 1;
	}
	printf("strict_package: 6 rows (accept/reject + leaf-assert + bare-reset) "
	    "agree on cstage w6c%s (#24a)\n", have_ww ? " and wwstage w6c_ww" : "");
	return 0;
}