/*
 * 911_continue_run — runtime + byte-id net for #138: `continue` in a
 * loop with a post-step (3-clause C-style `for (init; cond; post)` OR
 * Hare-range `for (let x .. xs)` with its implicit `i+=1`) must run
 * the post-step BEFORE re-testing the cond / bound. Pre-fix the
 * continue-target was the loop top, which SKIPPED the post-step → the
 * value that triggered continue never advanced → infinite loop.
 *
 * Pre-fix BOTH STAGES emitted identical buggy asm (`JMP loop_top` for
 * continue, post-step JMP'd over) — cs==ww byte-id held → 990-997 gate
 * was BLIND to the miscompile. Found by impl-strconv-fold2 during the
 * fold-3 decimal.ha port: leftshift_newdigits uses `for (let i: u32 =
 * 0u32; i < n; i += 1u32) { ... else if (d.digits[i]==p5[i]) continue;
 * ... }`; pre-fix that path infinite-looped at the first equal digit.
 *
 * Fix (both stages): allocate a dedicated `post` (3-clause) / `rpost`
 * (range) label; continue jumps to that label; the label emits before
 * the post-step; fall-through naturally hits it too. For 1-clause `for
 * (cond)` with no post-step, the cont-target stays = loop-top
 * (unchanged from pre-#138, byte-id preserved on the corpus's
 * 1-clause shape).
 *
 * Rows cover the 3 shapes the fix targets PLUS a 1-clause regression
 * row asserting the byte-id surface for the 1-clause path is
 * unchanged. cstage `ww build` + run for runtime; w6c vs w6c_ww `.s`
 * cmp for rule-10 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;
}

struct row { const char *label; const char *src; int want_exit; };

static const struct row rows[] = {
	/* The lead's repro: 3-clause for with continue. Pre-fix infinite
	 * loop on i=2; post-fix count=4 (i=0,1,3,4 all increment count). */
	{ "for3_skip_one",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let count: i32 = 0;\n"
	  "	for (let i: i32 = 0; i < 5; i += 1) {\n"
	  "		if (i == 2) { continue; };\n"
	  "		count += 1;\n"
	  "	};\n"
	  "	return count;\n"
	  "};\n", 4 },
	/* Two skips: continue must advance i correctly each time. count
	 * over i=0,2,4 only (skip 1 and 3); 3 hits × 10 = 30. */
	{ "for3_skip_two",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let c: i32 = 0;\n"
	  "	for (let i: i32 = 0; i < 5; i += 1) {\n"
	  "		if (i == 1) { continue; };\n"
	  "		if (i == 3) { continue; };\n"
	  "		c += 10;\n"
	  "	};\n"
	  "	return c;\n"
	  "};\n", 30 },
	/* Hare-range form `for (let x .. xs)`. Continue must run the
	 * implicit `i+=1` increment. Pre-fix infinite-loop on first
	 * matching element; post-fix sum over non-skipped values. xs =
	 * [10, 20, 30, 40, 50]; skip 30; sum = 10+20+40+50 = 120. */
	{ "range_skip",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let xs: [5]i32 = [10, 20, 30, 40, 50];\n"
	  "	let sum: i32 = 0;\n"
	  "	for (let v .. xs) {\n"
	  "		if (v == 30) { continue; };\n"
	  "		sum += v;\n"
	  "	};\n"
	  "	return sum;\n"
	  "};\n", 120 },
	/* 1-clause `for (cond)` with continue. No post-step, so cont-
	 * target stays = loop-top. Pre-#138 emission must be byte-id
	 * preserved — this is the bootstrap shape. Manual post-step
	 * inside the body. count over i=0,1,3,4 (skip i=2) → 4. */
	{ "for1_continue_byteid",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let count: i32 = 0;\n"
	  "	let i: i32 = 0;\n"
	  "	for (i < 5) {\n"
	  "		let cur: i32 = i;\n"
	  "		i += 1;\n"
	  "		if (cur == 2) { continue; };\n"
	  "		count += 1;\n"
	  "	};\n"
	  "	return count;\n"
	  "};\n", 4 },
	{ NULL, NULL, 0 }
};

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

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

		char tmpdir[64];
		snprintf(tmpdir, sizeof tmpdir, "/tmp/wwcont_%d_d_%d",
		    getpid(), i);
		mkdir(tmpdir, 0755);

		/* Build with 5s timeout — pre-fix the buggy rows infinite-
		 * looped; post-fix all rows must exit cleanly under it. */
		char cmd[2048];
		snprintf(cmd, sizeof cmd, "cd %s && %s/ww build %s",
		    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';

		/* timeout wrapper: pre-fix bug = infinite loop; want clean
		 * exit. exit 124 = timeout/hang. */
		char rcmd[256];
		snprintf(rcmd, sizeof rcmd, "timeout 5 %s", outbin);
		int got = runwait(rcmd);
		if (got != rows[i].want_exit) {
			fprintf(stderr, "row[%s]: cstage exit %d, want %d "
			    "(124 = timeout / pre-fix infinite loop)\n",
			    rows[i].label, got, rows[i].want_exit);
			fail++;
		}
		unlink(outbin); rmdir(tmpdir);

		char cs_s[64], ws_s[64];
		snprintf(cs_s, sizeof cs_s, "/tmp/wwcont_%d_%d_cs.s",
		    getpid(), i);
		snprintf(ws_s, sizeof ws_s, "/tmp/wwcont_%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 continue tests failed\n", fail, n);
		return 1;
	}
	printf("continue: %d/%d ok (cstage run + cs==ww byte-id)\n",
	    n, n);
	return 0;
}