hytale-gravity-flip/src/test/java/com/mythlane/gravityflip/physics/FallDamageGuardTest.java

package com.mythlane.gravityflip.physics;

import com.hypixel.hytale.math.shape.Box;
import com.hypixel.hytale.math.vector.Vector3d;
import com.mythlane.gravityflip.region.GravityFlipRegion;
import org.junit.jupiter.api.Test;

import java.util.UUID;

import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;

/** Pure-data tests for {@link FallDamageGuard} — entry, in-region, exit, grace-window, re-entry. */
class FallDamageGuardTest {

    @Test
    void notInRegionReturnsFalse() {
        FallDamageGuard guard = new FallDamageGuard();
        assertFalse(guard.shouldSuppressFallDamage(UUID.randomUUID(), 1000L));
    }

    @Test
    void inRegionFallDamageTrueReturnsFalse() {
        FallDamageGuard guard = new FallDamageGuard();
        UUID uuid = UUID.randomUUID();
        GravityFlipRegion region = region(true, 2500);
        guard.markInRegion(uuid, region);
        assertFalse(guard.shouldSuppressFallDamage(uuid, 1000L));
    }

    @Test
    void inRegionFallDamageFalseReturnsTrue() {
        FallDamageGuard guard = new FallDamageGuard();
        UUID uuid = UUID.randomUUID();
        GravityFlipRegion region = region(false, 2500);
        guard.markInRegion(uuid, region);
        assertTrue(guard.shouldSuppressFallDamage(uuid, 1000L));
    }

    @Test
    void afterExitWithinGraceReturnsTrue() {
        FallDamageGuard guard = new FallDamageGuard();
        UUID uuid = UUID.randomUUID();
        GravityFlipRegion region = region(false, 2500);
        guard.markInRegion(uuid, region);
        long t0 = 1000L;
        guard.markExit(uuid, region, t0);
        assertTrue(guard.shouldSuppressFallDamage(uuid, t0 + 2499));
    }

    @Test
    void afterExitBeyondGraceReturnsFalse() {
        FallDamageGuard guard = new FallDamageGuard();
        UUID uuid = UUID.randomUUID();
        GravityFlipRegion region = region(false, 2500);
        guard.markInRegion(uuid, region);
        long t0 = 1000L;
        guard.markExit(uuid, region, t0);
        assertFalse(guard.shouldSuppressFallDamage(uuid, t0 + 2501));
    }

    @Test
    void reEntryAfterExitResetsTracking() {
        FallDamageGuard guard = new FallDamageGuard();
        UUID uuid = UUID.randomUUID();
        GravityFlipRegion region = region(false, 2500);
        guard.markInRegion(uuid, region);
        guard.markExit(uuid, region, 1000L);
        guard.markInRegion(uuid, region);
        assertTrue(guard.shouldSuppressFallDamage(uuid, 1500L));
    }

    @Test
    void fallDamageTrueRegionNeverSuppressesEvenDuringGrace() {
        FallDamageGuard guard = new FallDamageGuard();
        UUID uuid = UUID.randomUUID();
        GravityFlipRegion suppressed = region(false, 2500);
        GravityFlipRegion allowed = region(true, 2500);
        guard.markInRegion(uuid, suppressed);
        guard.markExit(uuid, suppressed, 1000L);
        guard.markInRegion(uuid, allowed);
        assertFalse(guard.shouldSuppressFallDamage(uuid, 1500L));
    }

    private static GravityFlipRegion region(boolean fallDamage, int graceMs) {
        GravityFlipRegion r = new GravityFlipRegion(
                "t", new Box(new Vector3d(0, 0, 0), new Vector3d(1, 1, 1)), true);
        r.setFallDamage(fallDamage);
        r.setGracePeriodMs(graceMs);
        return r;
    }
}