// memio's tests indirectly cover alloc/free; the direct row here pins
// the FFI shape under lib/os itself so future bindings refactors can't
// quietly drift.
//
// getenv env contract (ww ships no setenv primitive, deliberately):
//
//   WW_TEST_GETENV     = "hello-world"
//   WW_TEST_EMPTY      = ""           (set, but value is empty)
//   WW_TEST_NOT_SET    unset
//
// The rows that need a var PRESENT skip loudly when it is absent, so
// the suite passes bare; the arranged leg (env constructed per row,
// rows asserted `ok`, not SKIP) is test/libenv/libenv_test.ww.
//
// Don't `use io;` here — lib/os and lib/io both export read/write/
// close as C symbols that collide under the driver's flat-scope
// concat (task #17). os alone is sufficient: getenv + alloc/free are
// the only primitives needed.

package os_test;

import os;
import rt;
import test;



fn streq(a: str, b: str) bool = {
	if (a.len != b.len) { return false; };
	let i: i32 = 0;
	for (i < a.len) {
		if (a[i] != b[i]) { return false; };
		i += 1;
	};
	return true;
};

fn ostestwait(pid: i32, status: *i32) i32 = {
	for (true) {
		let r: i32 = os.wait4(pid, status, 0i32, nil: *void);
		if (r != -4i32) { return r; };
	};
	return -1;
};

@test fn test_getenv_set() void = {
	let r = os.getenv("WW_TEST_GETENV");
	match (r) {
	case void => test.skip("WW_TEST_GETENV unset (arranged leg: test/libenv)");
	case let s: str => {
		assert(!(!streq(s, "hello-world")));
	};
	};
};

// POSIX permits an env var with an empty value (`name=` in environ).
// getenv must return the empty str, NOT void — void is reserved for
// "name not present at all".

@test fn test_getenv_empty() void = {
	let r = os.getenv("WW_TEST_EMPTY");
	match (r) {
	case void => test.skip("WW_TEST_EMPTY unset (arranged leg: test/libenv)");
	case let s: str => {
		assert(!(s.len != 0));
	};
	};
};

@test fn test_getenv_unset() void = {
	let r = os.getenv("WW_TEST_NOT_SET");
	match (r) {
	case void => {};
	case let s: str => abort();
	};
};

// Probes that "WW_TEST_GETEN" (a prefix of WW_TEST_GETENV) doesn't
// match. Without the explicit `entry[name.len] == '='` check in
// getenv, a naive prefix matcher would return the value of any
// longer-named var that starts with the queried name. The row's
// premise is that the longer var exists, so it skips with it.

@test fn test_getenv_prefix_no_match() void = {
	match (os.getenv("WW_TEST_GETENV")) {
	case void => test.skip("WW_TEST_GETENV unset (arranged leg: test/libenv)");
	case let s: str => {};
	};
	let r = os.getenv("WW_TEST_GETEN");
	match (r) {
	case void => {};
	case let s: str => abort();
	};
};

// getenvs() is public API (task #28) and the single env walker getenv
// routes through. getenv's cases exercise the walk transitively, but
// none asserts the []str RETURN shape — its count or "NAME=VALUE" entry
// text. This row pins both: the slice must be non-empty, and every
// expected entry must appear verbatim (name, '=', value duped intact).
// Fails if getenvs miscounts (len 0 → the inner search finds nothing)
// or dups the wrong bytes (off-by-one truncation → no streq match).
// The "WW_TEST_EMPTY=" row also pins the empty-value entry text.

@test fn test_getenvs_entries() void = {
	let env: []str = os.getenvs();
	assert(!(env.len == 0));
	match (os.getenv("WW_TEST_GETENV")) {
	case void => test.skip("WW_TEST_GETENV unset (arranged leg: test/libenv)");
	case let s: str => {};
	};
	match (os.getenv("WW_TEST_EMPTY")) {
	case void => test.skip("WW_TEST_EMPTY unset (arranged leg: test/libenv)");
	case let s: str => {};
	};
	let want: [2]str = ["WW_TEST_GETENV=hello-world", "WW_TEST_EMPTY="];
	let w: i32 = 0;
	for (w < 2) {
		let found: bool = false;
		let i: i32 = 0;
		for (i < env.len) {
			if (streq(env[i], want[w])) { found = true; };
			i += 1;
		};
		assert(found);
		w += 1;
	};
};

// Direct round-trip. Write-then-read-back proves the returned page is
// dereferenceable. A miscompiled binding (wrong arg order, wrong ABI,
// etc.) would either fault or return zero here.

@test fn test_alloc_free_roundtrip() void = {
	let p: []u8 = alloc([], 4096u64)!;
	p.len = 4096;
	p[0] = 90u8;		// 0x5a
	p[4095] = 165u8;	// 0xa5
	assert(!(p[0] != 90u8));
	assert(!(p[4095] != 165u8));
	os.free(p.ptr: *void, 4096u64);
};

@test fn test_pipe_roundtrip() void = {
	let fds: [2]i32;
	assert(!(os.pipe(&fds) != 0));
	let want: [1]u8 = [90u8];
	let got: [1]u8;
	assert(!(os.write(fds[1], &want[0], 1u64) != 1i64));
	assert(!(os.read(fds[0], &got[0], 1u64) != 1i64));
	assert(!(got[0] != want[0]));
	assert(!(os.close(fds[0]) != 0));
	assert(!(os.close(fds[1]) != 0));
};

@test fn test_pipe2_exec_hold() void = {
	let aa: []str = os.args();
	if (len(aa) < 3 || !streq(aa[2], "pipe2-cloexec-helper")) { return; };
	let b: [1]u8 = [1u8];
	assert(!(os.write(101i32, &b[0], 1u64) != 1i64));
	os.close(101i32);
	assert(!(os.read(100i32, &b[0], 1u64) != 1i64));
	os.close(100i32);
};

@test fn test_pipe2_cloexec() void = {
	let fds: [2]i32;
	assert(!(os.pipe2(&fds, os.O_CLOEXEC) != 0));
	let hold: [2]i32;
	if (os.pipe(&hold) != 0) {
		os.close(fds[0]); os.close(fds[1]);
		abort();
	};
	let ready: [2]i32;
	if (os.pipe(&ready) != 0) {
		os.close(fds[0]); os.close(fds[1]);
		os.close(hold[0]); os.close(hold[1]);
		abort();
	};
	let pid: i32 = os.fork();
	if (pid < 0) {
		os.close(fds[0]); os.close(fds[1]);
		os.close(hold[0]); os.close(hold[1]);
		os.close(ready[0]); os.close(ready[1]);
		abort();
	};
	if (pid == 0) {
		os.close(fds[0]);
		os.close(hold[1]);
		os.close(ready[0]);
		if (os.dup2(hold[0], 100i32) != 100i32) { os.exit(120); };
		if (os.dup2(ready[1], 101i32) != 101i32) { os.exit(121); };
		os.close(hold[0]);
		os.close(ready[1]);
		let aa: []str = os.args();
		if (len(aa) == 0) { os.exit(122); };
		let av: [4]*u8 = [aa[0].ptr, "test_pipe2_exec_hold\0".ptr,
		    "pipe2-cloexec-helper\0".ptr, nil: *u8];
		os.execve(aa[0], &av[0], nil: **u8);
		let mark: [1]u8 = ['E'];
		for (true) {
			let wr: i64 = os.write(fds[1], &mark[0], 1u64);
			if (wr == 1i64) { break; };
			if (wr != -4i64) { os.exit(123); };
		};
		os.close(fds[1]);
		os.exit(124);
	};
	os.close(fds[1]);
	os.close(hold[0]);
	os.close(ready[1]);
	let b: [1]u8;
	let rr: i64 = 0;
	for (true) {
		rr = os.read(ready[0], &b[0], 1u64);
		if (rr != -4i64) { break; };
	};
	if (rr != 1i64) {
		os.close(fds[0]); os.close(hold[1]); os.close(ready[0]);
		os.kill(pid, os.SIGKILL);
		let failedstatus: i32 = 0;
		ostestwait(pid, &failedstatus);
		abort();
	};
	os.close(ready[0]);
	for (true) {
		rr = os.read(fds[0], &b[0], 1u64);
		if (rr != -4i64) { break; };
	};
	os.close(fds[0]);
	let release: [1]u8 = [1u8];
	let wr: i64 = os.write(hold[1], &release[0], 1u64);
	os.close(hold[1]);
	let status: i32 = 0;
	let r: i32 = ostestwait(pid, &status);
	assert(!(wr != 1i64));
	assert(!(r != pid));
	assert(os.wifexited(status));
	assert(!(os.wexitstatus(status) != 0));
	assert(!(rr != 0i64));
};

@test fn test_wait_status_decode() void = {
	let exited: i32 = 7i32 << 8i32;
	assert(os.wifexited(exited));
	assert(!os.wifsignaled(exited));
	assert(!(os.wexitstatus(exited) != 7));
	assert(!(os.wtermsig(exited) != 0));

	let signaled: i32 = os.SIGKILL | 128i32;
	assert(!os.wifexited(signaled));
	assert(os.wifsignaled(signaled));
	assert(!(os.wtermsig(signaled) != os.SIGKILL));
	assert(!os.wifsignaled(127i32));
	assert(!(os.WNOHANG != 1));
};

@test fn test_wait4_nohang_normal_exit() void = {
	let gate: [2]i32;
	assert(!(os.pipe(&gate) != 0));
	let pid: i32 = os.fork();
	assert(!(pid < 0));
	if (pid == 0) {
		os.close(gate[1]);
		let b: [1]u8;
		if (os.read(gate[0], &b[0], 1u64) != 1i64) { os.exit(120); };
		os.close(gate[0]);
		os.exit(7);
	};
	os.close(gate[0]);
	let status: i32 = 0;
	let r: i32 = os.wait4(pid, &status, os.WNOHANG, nil: *void);
	if (r != 0) {
		os.close(gate[1]);
		if (r < 0) {
			os.kill(pid, os.SIGKILL);
			ostestwait(pid, &status);
		};
		abort();
	};
	let b: [1]u8 = [1u8];
	assert(!(os.write(gate[1], &b[0], 1u64) != 1i64));
	os.close(gate[1]);
	r = ostestwait(pid, &status);
	assert(!(r != pid));
	assert(os.wifexited(status));
	assert(!(os.wexitstatus(status) != 7));
};

@test fn test_process_group_signal() void = {
	let hold: [2]i32;
	assert(!(os.pipe(&hold) != 0));
	let pid: i32 = os.fork();
	assert(!(pid < 0));
	if (pid == 0) {
		os.close(hold[1]);
		if (os.setpgid(0i32, 0i32) != 0) { os.exit(120); };
		let b: [1]u8;
		os.read(hold[0], &b[0], 1u64);
		os.exit(120);
	};
	os.close(hold[0]);
	let pg: i32 = os.setpgid(pid, pid);
	if (pg != 0) {
		os.close(hold[1]);
		os.kill(pid, os.SIGKILL);
		let failedstatus: i32 = 0;
		ostestwait(pid, &failedstatus);
		abort();
	};
	let kr: i32 = os.kill(-pid, os.SIGTERM);
	os.close(hold[1]);
	if (kr != 0) {
		os.kill(pid, os.SIGKILL);
		let failedstatus: i32 = 0;
		ostestwait(pid, &failedstatus);
		abort();
	};
	let status: i32 = 0;
	let r: i32 = ostestwait(pid, &status);
	assert(!(r != pid));
	assert(os.wifsignaled(status));
	assert(!(os.wtermsig(status) != os.SIGTERM));
};

@test fn test_process_group_term_escalation() void = {
	let ready: [2]i32;
	assert(!(os.pipe(&ready) != 0));
	let hold: [2]i32;
	if (os.pipe(&hold) != 0) {
		os.close(ready[0]);
		os.close(ready[1]);
		abort();
	};
	let pid: i32 = os.fork();
	if (pid < 0) {
		os.close(ready[0]); os.close(ready[1]);
		os.close(hold[0]); os.close(hold[1]);
		abort();
	};
	if (pid == 0) {
		os.close(ready[0]);
		os.close(hold[1]);
		if (os.setpgid(0i32, 0i32) != 0) { os.exit(120); };
		let mask: u64 = 1u64 << ((os.SIGTERM - 1): u64);
		if (os.sigprocmask(os.SIG_BLOCK, &mask, nil: *u64) != 0) {
			os.exit(121);
		};
		let b: [1]u8 = [1u8];
		if (os.write(ready[1], &b[0], 1u64) != 1i64) { os.exit(122); };
		os.close(ready[1]);
		os.read(hold[0], &b[0], 1u64);
		os.exit(123);
	};
	os.close(ready[1]);
	os.close(hold[0]);
	let pg: i32 = os.setpgid(pid, pid);
	if (pg != 0) {
		os.close(ready[0]); os.close(hold[1]);
		os.kill(pid, os.SIGKILL);
		let failedstatus: i32 = 0;
		ostestwait(pid, &failedstatus);
		abort();
	};
	let b: [1]u8;
	if (os.read(ready[0], &b[0], 1u64) != 1i64) {
		os.close(ready[0]); os.close(hold[1]);
		os.kill(-pid, os.SIGKILL);
		let failedstatus: i32 = 0;
		ostestwait(pid, &failedstatus);
		abort();
	};
	os.close(ready[0]);
	if (os.kill(-pid, os.SIGTERM) != 0) {
		os.close(hold[1]);
		os.kill(-pid, os.SIGKILL);
		let failedstatus: i32 = 0;
		ostestwait(pid, &failedstatus);
		abort();
	};
	let status: i32 = 0;
	let r: i32 = os.wait4(pid, &status, os.WNOHANG, nil: *void);
	if (r != 0) {
		os.close(hold[1]);
		if (r < 0) {
			os.kill(-pid, os.SIGKILL);
			ostestwait(pid, &status);
		};
		abort();
	};
	let kr: i32 = os.kill(-pid, os.SIGKILL);
	os.close(hold[1]);
	if (kr != 0) {
		os.kill(pid, os.SIGKILL);
		ostestwait(pid, &status);
		abort();
	};
	r = ostestwait(pid, &status);
	assert(!(r != pid));
	assert(os.wifsignaled(status));
	assert(!(os.wtermsig(status) != os.SIGKILL));
	assert(!(os.SIG_UNBLOCK != 1));
	assert(!(os.SIG_SETMASK != 2));
};

@test fn test_chdir_child() void = {
	let pid: i32 = os.fork();
	assert(!(pid < 0));
	if (pid == 0) {
		if (os.chdir("/") != 0) { os.exit(120); };
		let buf: [8]u8;
		let n: i64 = os.getcwd(&buf[0], size([8]u8));
		if (n != 2i64 || buf[0] != '/' || buf[1] != 0u8) {
			os.exit(121);
		};
		os.exit(0);
	};
	let status: i32 = 0;
	assert(!(ostestwait(pid, &status) != pid));
	assert(os.wifexited(status));
	assert(!(os.wexitstatus(status) != 0));
};

@test fn test_signalfd_nonblocking() void = {
	let mask: u64 = 1u64 << ((os.SIGINT - 1): u64);
	let oldmask: u64 = 0u64;
	assert(!(os.sigprocmask(os.SIG_BLOCK, &mask, &oldmask) != 0));
	let fd: i32 = os.signalfd(-1i32, &mask,
	    os.SFD_CLOEXEC | os.SFD_NONBLOCK);
	if (fd < 0) {
		os.sigprocmask(os.SIG_SETMASK, &oldmask, nil: *u64);
		abort();
	};
	if (os.kill(os.getpid(), os.SIGINT) != 0) {
		os.close(fd);
		os.sigprocmask(os.SIG_SETMASK, &oldmask, nil: *u64);
		abort();
	};
	let info: [128]u8;
	let n: i64 = 0i64;
	for (true) {
		n = os.read(fd, &info[0], size([128]u8));
		if (n != -4i64 && n != -11i64) { break; };
	};
	let cr: i32 = os.close(fd);
	let mr: i32 = os.sigprocmask(os.SIG_SETMASK, &oldmask, nil: *u64);
	assert(!(n != size([128]u8): i64));
	assert(!(info[0] != os.SIGINT: u8));
	assert(!(info[1] != 0u8 || info[2] != 0u8 || info[3] != 0u8));
	assert(!(cr != 0));
	assert(!(mr != 0));
	assert(!(os.SFD_CLOEXEC != os.O_CLOEXEC));
	assert(!(os.SFD_NONBLOCK != os.O_NONBLOCK));
};