// timetest — exercises lib/time. Run with `out/bin/ww run
// lib/time/timetest.ww`. Same `signalled`-then-fail()-with-+10
// pattern as fmttest / logtest / stattest so a non-zero exit
// pinpoints the offending scenario.

package time;

import os;
import time;

let signalled: i32 = 0;

fn fail() void = { os.exit(signalled + 10); };

// ---- constants: load-bearing names + values ----------------------------
//
// Without these multipliers every caller would re-derive 1e9 in
// place. The values themselves are nailed down by Hare's
// ref/hare/time/duration.ha:9-18.

@test fn constants() void = {
	if ((time.nanosecond:  i64) !=          1i64) { fail(); };
	if ((time.microsecond: i64) !=       1000i64) { fail(); };
	if ((time.millisecond: i64) !=    1000000i64) { fail(); };
	if ((time.second:      i64) != 1000000000i64) { fail(); };

	// "Roundtrip" check: derived multiples land on the canonical
	// nanosecond count. Catches a future re-derivation drift.
	if (5i64 * (time.second: i64)      != 5000000000i64) { fail(); };
	if (3i64 * (time.millisecond: i64) !=    3000000i64) { fail(); };
	if (7i64 * (time.microsecond: i64) !=       7000i64) { fail(); };
};

// ---- now(monotonic) is monotonic across two calls ----------------------

@test fn nowmonotonic() void = {
	let a = time.now(time.clock.monotonic);
	let b = time.now(time.clock.monotonic);
	// Two back-to-back calls — b can equal a (same ns tick) but
	// must never precede it.
	if (time.compare(a, b) > 0i8) { fail(); };
};

// ---- now(realtime) returns a post-2020 epoch ---------------------------
//
// Sanity check that the syscall plumbing actually lands real bytes
// in the instant. 2020-01-01 UTC = 1577836800 unix seconds; any
// past-2020 wall clock satisfies this. (CI / test machines running
// pre-2020 would fail here; acceptable trade for catching a
// zero-init / wrong-slot regression.)

@test fn nowrealtime() void = {
	let t = time.now(time.clock.realtime);
	if (t.sec < 1577836800i64) { fail(); };
	if (t.nsec < 0i64) { fail(); };
	if (t.nsec >= 1000000000i64) { fail(); };
};

// ---- add: zero duration is identity ------------------------------------

@test fn addzero() void = {
	let a: time.instant;
	a.sec = 100i64; a.nsec = 500i64;
	let r = time.add(a, 0i64);
	if (r.sec != 100i64) { fail(); };
	if (r.nsec != 500i64) { fail(); };
};

// ---- add: positive duration, no carry ----------------------------------

@test fn addpos_nocarry() void = {
	let a: time.instant;
	a.sec = 10i64; a.nsec = 100i64;
	let r = time.add(a, 200i64);
	if (r.sec != 10i64) { fail(); };
	if (r.nsec != 300i64) { fail(); };
};

// ---- add: positive duration, carries into next second ------------------

@test fn addpos_carry() void = {
	let a: time.instant;
	a.sec = 10i64; a.nsec = 999999900i64;
	let r = time.add(a, 200i64);
	if (r.sec != 11i64)  { fail(); };
	if (r.nsec != 100i64) { fail(); };
};

// ---- add: full-second duration -----------------------------------------

@test fn addpos_fullsecond() void = {
	let a: time.instant;
	a.sec = 5i64; a.nsec = 0i64;
	let r = time.add(a, (time.second: i64) * 3i64);
	if (r.sec != 8i64) { fail(); };
	if (r.nsec != 0i64) { fail(); };
};

// ---- add: negative duration, no borrow ---------------------------------

@test fn addneg_noborrow() void = {
	let a: time.instant;
	a.sec = 10i64; a.nsec = 500i64;
	let r = time.add(a, -100i64);
	if (r.sec != 10i64)  { fail(); };
	if (r.nsec != 400i64) { fail(); };
};

// ---- add: negative duration, borrows from previous second --------------

@test fn addneg_borrow() void = {
	let a: time.instant;
	a.sec = 10i64; a.nsec = 100i64;
	let r = time.add(a, -200i64);
	if (r.sec != 9i64) { fail(); };
	if (r.nsec != 999999900i64) { fail(); };
};

// ---- diff: simple subtraction ------------------------------------------

@test fn diffsimple() void = {
	let a: time.instant; a.sec = 10i64; a.nsec = 100i64;
	let b: time.instant; b.sec = 12i64; b.nsec = 300i64;
	let d: i64 = time.diff(a, b): i64;
	// b - a = 2.0000002 sec = 2_000_000_200 ns
	if (d != 2000000200i64) { fail(); };
};

// ---- diff: reversed sign -----------------------------------------------

@test fn diffneg() void = {
	let a: time.instant; a.sec = 12i64; a.nsec = 300i64;
	let b: time.instant; b.sec = 10i64; b.nsec = 100i64;
	let d: i64 = time.diff(a, b): i64;
	if (d != -2000000200i64) { fail(); };
};

// ---- compare: -1 / 0 / +1 ladder ---------------------------------------

@test fn comparelt() void = {
	let a: time.instant; a.sec = 1i64; a.nsec = 0i64;
	let b: time.instant; b.sec = 2i64; b.nsec = 0i64;
	if (time.compare(a, b) != -1i8) { fail(); };
};

@test fn comparegt() void = {
	let a: time.instant; a.sec = 2i64; a.nsec = 0i64;
	let b: time.instant; b.sec = 1i64; b.nsec = 0i64;
	if (time.compare(a, b) != 1i8) { fail(); };
};

@test fn compareeq() void = {
	let a: time.instant; a.sec = 5i64; a.nsec = 42i64;
	let b: time.instant; b.sec = 5i64; b.nsec = 42i64;
	if (time.compare(a, b) != 0i8) { fail(); };
};

@test fn comparensec_only() void = {
	let a: time.instant; a.sec = 5i64; a.nsec = 100i64;
	let b: time.instant; b.sec = 5i64; b.nsec = 200i64;
	if (time.compare(a, b) != -1i8) { fail(); };
	if (time.compare(b, a) !=  1i8) { fail(); };
};

export fn main() i32 = {
	signalled = 1;  constants();
	signalled = 2;  nowmonotonic();
	signalled = 3;  nowrealtime();
	signalled = 4;  addzero();
	signalled = 5;  addpos_nocarry();
	signalled = 6;  addpos_carry();
	signalled = 7;  addpos_fullsecond();
	signalled = 8;  addneg_noborrow();
	signalled = 9;  addneg_borrow();
	signalled = 10; diffsimple();
	signalled = 11; diffneg();
	signalled = 12; comparelt();
	signalled = 13; comparegt();
	signalled = 14; compareeq();
	signalled = 15; comparensec_only();
	return 0;
};