/*
 * 989_m1usehint_run — M1 (#40): the cgen mangle-hint must be MODULE-scoped,
 * not unit-global. When two directory-packages in the same compilation unit
 * export the same leaf fn (a.math and b.math both `export fn pick`), and two
 * referencing modules each `import <X>.math` aliasing `math`, every
 * `math.pick()` call must mangle to the package its OWN module imported —
 * not to whichever `use` the file-global hint collected first.
 *
 * Pre-#40 the hint (use_hint / usehint) was file-global first-match: both
 * modules' `math.pick()` resolved to the same package, so one call landed
 * the wrong body and returned the wrong value — IDENTICALLY on both stages
 * (a byte-id-green #263-class miscompile). Gate-visible: each module's call
 * has a distinct expected value, so a mis-route changes the runtime exit.
 *
 *   row              | proves
 *   -----------------+--------------------------------------------------
 *   leaf_collision   | two same-leaf exported fns; each module's qualified
 *                    |   call mangles to its OWN import (111 / 222) -> 0
 *   collision_diff   | same, with mismatched signatures — the checker's
 *                    |   curmod-preferenced resolve agrees with the hint
 *                    |   (pick(int) vs pick()) -> 0
 *
 * Plus a byte-id gate: cstage.s == wwstage.s on the leaf_collision unit
 * (rule-10).
 */
#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;
}

struct file { const char *path; const char *content; };

struct row {
	const char *label;
	struct file files[6];	/* {NULL,NULL}-terminated package files */
	const char *root;	/* root main.ww content */
	int want_exit;
};

static const struct row rows[] = {
	{ "leaf_collision",
	  { { "a/math/math.ww",
	      "package math;\n"
	      "export fn pick() int = { return 111; };\n" },
	    { "b/math/math.ww",
	      "package math;\n"
	      "export fn pick() int = { return 222; };\n" },
	    { "one/one.ww",
	      "package one;\n"
	      "import a.math;\n"
	      "export fn getone() int = { return math.pick(); };\n" },
	    { "two/two.ww",
	      "package two;\n"
	      "import b.math;\n"
	      "export fn gettwo() int = { return math.pick(); };\n" },
	    { NULL, NULL } },
	  "package main;\n"
	  "import one;\n"
	  "import two;\n"
	  "export fn main() int = {\n"
	  "	if (one.getone() != 111) { return 1; };\n"
	  "	if (two.gettwo() != 222) { return 2; };\n"
	  "	return 0;\n"
	  "};\n",
	  0 },

	{ "collision_diff",
	  { { "a/math/math.ww",
	      "package math;\n"
	      "export fn pick(x: int) int = { return x + 100; };\n" },
	    { "b/math/math.ww",
	      "package math;\n"
	      "export fn pick() int = { return 222; };\n" },
	    { "one/one.ww",
	      "package one;\n"
	      "import a.math;\n"
	      "export fn getone() int = { return math.pick(11); };\n" },
	    { "two/two.ww",
	      "package two;\n"
	      "import b.math;\n"
	      "export fn gettwo() int = { return math.pick(); };\n" },
	    { NULL, NULL } },
	  "package main;\n"
	  "import one;\n"
	  "import two;\n"
	  "export fn main() int = {\n"
	  "	if (one.getone() != 111) { return 1; };\n"
	  "	if (two.gettwo() != 222) { return 2; };\n"
	  "	return 0;\n"
	  "};\n",
	  0 },
};

/* write_file — create `dir/rel` in an already-owned package tree. */
static int
write_file(const char *dir, const char *rel, const char *content, int *acquired)
{
	char path[512];
	*acquired = 0;
	snprintf(path, sizeof path, "%s/%s", dir, rel);
	FILE *f = fopen(path, "wb");
	if (!f) return -1;
	*acquired = 1;
	int rc = fputs(content, f) == EOF ? -1 : 0;
	if (fclose(f) != 0) rc = -1;
	return rc;
}

struct layout_owned {
	int root, a, amath, b, bmath, one, two;
	int files[6], mainfile;
};

/* Remove exactly the files and semantic directories acquired for one row. */
static int
cleanup_layout(const char *dir, const struct row *r, int byteid,
    const struct layout_owned *owned, const int started[2])
{
	char path[512], cmd[1024];
	int fail = 0;
	if (byteid) {
		const char *tags[] = { "cstage", "wwstage" };
		for (int i = 0; i < 2; i++) {
			if (!started[i]) continue;
			snprintf(path, sizeof path, "%s/%s.sepwork", dir, tags[i]);
			snprintf(cmd, sizeof cmd, "rm -rf '%s'", path);
			if (runwait(cmd) != 0) fail = 1;
			snprintf(path, sizeof path, "%s/%s", dir, tags[i]);
			if (unlink(path) != 0 && access(path, F_OK) == 0) fail = 1;
			snprintf(path, sizeof path, "%s/%s.s", dir, tags[i]);
			if (unlink(path) != 0 && access(path, F_OK) == 0) fail = 1;
		}
	} else {
		if (started[0]) {
			snprintf(path, sizeof path, "%s/main.sepwork", dir);
			snprintf(cmd, sizeof cmd, "rm -rf '%s'", path);
			if (runwait(cmd) != 0) fail = 1;
			snprintf(path, sizeof path, "%s/main", dir);
			if (unlink(path) != 0 && access(path, F_OK) == 0) fail = 1;
		}
	}
	if (owned->mainfile) {
		snprintf(path, sizeof path, "%s/main.ww", dir);
		if (unlink(path) != 0 && access(path, F_OK) == 0) fail = 1;
	}
	for (int k = 0; r->files[k].path; k++) {
		if (!owned->files[k]) continue;
		snprintf(path, sizeof path, "%s/%s", dir, r->files[k].path);
		if (unlink(path) != 0 && access(path, F_OK) == 0) fail = 1;
	}
	if (owned->amath) {
		snprintf(path, sizeof path, "%s/a/math", dir);
		if (rmdir(path) != 0 && access(path, F_OK) == 0) fail = 1;
	}
	if (owned->a) {
		snprintf(path, sizeof path, "%s/a", dir);
		if (rmdir(path) != 0 && access(path, F_OK) == 0) fail = 1;
	}
	if (owned->bmath) {
		snprintf(path, sizeof path, "%s/b/math", dir);
		if (rmdir(path) != 0 && access(path, F_OK) == 0) fail = 1;
	}
	if (owned->b) {
		snprintf(path, sizeof path, "%s/b", dir);
		if (rmdir(path) != 0 && access(path, F_OK) == 0) fail = 1;
	}
	if (owned->one) {
		snprintf(path, sizeof path, "%s/one", dir);
		if (rmdir(path) != 0 && access(path, F_OK) == 0) fail = 1;
	}
	if (owned->two) {
		snprintf(path, sizeof path, "%s/two", dir);
		if (rmdir(path) != 0 && access(path, F_OK) == 0) fail = 1;
	}
	if (owned->root && rmdir(dir) != 0) fail = 1;
	return fail ? -1 : 0;
}

/* layout — acquire and lay out the row's package tree + root under `dir`. */
static int
layout(const char *dir, const struct row *r, struct layout_owned *owned)
{
	char path[512];
	memset(owned, 0, sizeof *owned);
	if (mkdir(dir, 0755) != 0) return -1;
	owned->root = 1;
	snprintf(path, sizeof path, "%s/a", dir);
	if (mkdir(path, 0755) != 0) goto fail;
	owned->a = 1;
	snprintf(path, sizeof path, "%s/a/math", dir);
	if (mkdir(path, 0755) != 0) goto fail;
	owned->amath = 1;
	snprintf(path, sizeof path, "%s/b", dir);
	if (mkdir(path, 0755) != 0) goto fail;
	owned->b = 1;
	snprintf(path, sizeof path, "%s/b/math", dir);
	if (mkdir(path, 0755) != 0) goto fail;
	owned->bmath = 1;
	snprintf(path, sizeof path, "%s/one", dir);
	if (mkdir(path, 0755) != 0) goto fail;
	owned->one = 1;
	snprintf(path, sizeof path, "%s/two", dir);
	if (mkdir(path, 0755) != 0) goto fail;
	owned->two = 1;
	for (int k = 0; r->files[k].path; k++)
		if (write_file(dir, r->files[k].path, r->files[k].content,
		    &owned->files[k]) != 0)
			goto fail;
	if (write_file(dir, "main.ww", r->root, &owned->mainfile) != 0) goto fail;
	return 0;

fail:
	{
		int started[2] = { 0, 0 };
		if (cleanup_layout(dir, r, 0, owned, started) != 0)
			fprintf(stderr, "m1usehint_run: temporary cleanup failed during setup\n");
	}
	return -1;
}

/* run_build — build+run the row's root via `driver`; return the binary's
 * exit code, or -1 on a build failure. */
static int
run_build(const char *driver, const struct row *r, int i, int *cleanup_failed)
{
	char dir[64], cmd[2048];
	struct layout_owned owned;
	int started[2] = { 0, 0 };
	*cleanup_failed = 0;
	snprintf(dir, sizeof dir, "/tmp/m1usehint_%d_%d", getpid(), i);
	if (layout(dir, r, &owned) != 0) return -2;

	/* #93 sep layout: `-o main` emits per-unit asm under
	 * main.sepwork/ (each dir-pkg in its own <pkgpath>.s); binary stays
	 * <dir>/main. The whole tree is removed below. */
	snprintf(cmd, sizeof cmd,
	    "cd '%s' && %s build -o main "
	    "main.ww 2>/dev/null", dir, driver);
	started[0] = 1;
	int brc = runwait(cmd);

	int got = -1;
	if (brc == 0) {
		char outbin[128];
		snprintf(outbin, sizeof outbin, "%s/main", dir);
		got = runwait(outbin);
	}
	if (cleanup_layout(dir, r, 0, &owned, started) != 0) {
		*cleanup_failed = 1;
	}
	return brc == 0 ? got : -1;
}

/* byteid — build the leaf_collision unit with both drivers and cmp the
 * concatenated per-package .s (rule 10). Returns 0 on byte-identical. */
static int
byteid(const char *cdrv, const char *wdrv, const struct row *r,
    int *cleanup_failed)
{
	char dir[64], cmd[2048];
	char cstem[128], wstem[128], cs[160], ws[160];
	struct layout_owned owned;
	int started[2] = { 0, 0 };
	*cleanup_failed = 0;
	snprintf(dir, sizeof dir, "/tmp/m1usehint_bid_%d", getpid());
	if (layout(dir, r, &owned) != 0) return -1;
	snprintf(cstem, sizeof cstem, "%s/cstage", dir);
	snprintf(wstem, sizeof wstem, "%s/wwstage", dir);
	snprintf(cs, sizeof cs, "%s.s", cstem);
	snprintf(ws, sizeof ws, "%s.s", wstem);

	/* #93 sep layout: each stage emits per-unit asm under <stem>.sepwork/
	 * (a.math.s, b.math.s, one.s, two.s, __root.s). The rule-10 byte-id
	 * gate concats each tree's per-unit *.s (sorted glob order is
	 * deterministic) into a flat <stem>.s and cmps the two. */
	int rc = -1;
	snprintf(cmd, sizeof cmd,
	    "cd '%s' && %s build -o '%s' "
	    "main.ww 2>/dev/null && cat '%s.sepwork/'*.s > '%s'",
	    dir, cdrv, cstem, cstem, cs);
	started[0] = 1;
	int cb = runwait(cmd);
	snprintf(cmd, sizeof cmd,
	    "cd '%s' && %s build -o '%s' "
	    "main.ww 2>/dev/null && cat '%s.sepwork/'*.s > '%s'",
	    dir, wdrv, wstem, wstem, ws);
	started[1] = 1;
	int wb = runwait(cmd);
	if (cb == 0 && wb == 0) {
		snprintf(cmd, sizeof cmd, "cmp -s '%s' '%s'", cs, ws);
		rc = runwait(cmd);
	} else {
		fprintf(stderr, "m1usehint_run: byte-id build failed "
		    "(cstage=%d wwstage=%d)\n", cb, wb);
	}
	if (cleanup_layout(dir, r, 1, &owned, started) != 0) {
		*cleanup_failed = 1;
	}
	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 cdrv[1024], wdrv[1024];
	snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
	snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);

	struct { const char *name; const char *drv; 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].drv, X_OK) != 0) {
			fprintf(stderr, "m1usehint_run: skip %s (no %s)\n",
			    drivers[d].name, drivers[d].drv);
			continue;
		}
		for (int i = 0; i < n; i++) {
			total++;
			int cleanfail = 0;
			int got = run_build(drivers[d].drv, &rows[i], i,
			    &cleanfail);
			if (got != rows[i].want_exit) {
				fprintf(stderr, "m1usehint_run[%s][%s]: exit=%d "
				    "want=%d\n", drivers[d].name, rows[i].label,
				    got, rows[i].want_exit);
				fail++;
			}
			if (cleanfail) {
				fprintf(stderr, "m1usehint_run[%s][%s]: temporary cleanup "
				    "failed\n", drivers[d].name, rows[i].label);
				fail++;
			}
		}
	}

	/* rule-10 byte-id gate on the leaf_collision unit. */
	if (access(wdrv, X_OK) == 0) {
		total++;
		int cleanfail = 0;
		if (byteid(cdrv, wdrv, &rows[0], &cleanfail) != 0) {
			fprintf(stderr, "m1usehint_run: cstage.s != wwstage.s "
			    "(byte-id break)\n");
			fail++;
		}
		if (cleanfail) {
			fprintf(stderr, "m1usehint_run: byte-id temporary cleanup "
			    "failed\n");
			fail++;
		}
	}

	if (fail) {
		fprintf(stderr, "m1usehint_run: %d/%d failed\n", fail, total);
		return 1;
	}
	printf("m1usehint_run: %d/%d ok\n", total, total);
	return 0;
}