Physics

package com.example.tests;

import com.frotty27.hrtk.api.annotation.HytaleSuite;
import com.frotty27.hrtk.api.annotation.WorldTest;
import com.frotty27.hrtk.api.annotation.Tag;
import com.frotty27.hrtk.api.annotation.DisplayName;
import com.frotty27.hrtk.api.annotation.Order;
import com.frotty27.hrtk.api.assert_.HytaleAssert;
import com.frotty27.hrtk.api.assert_.PhysicsAssert;
import com.frotty27.hrtk.api.context.WorldTestContext;
import com.frotty27.hrtk.api.lifecycle.IsolationStrategy;

@HytaleSuite(value = "Physics Surface Tests", isolation = IsolationStrategy.DEDICATED_WORLD)
@Tag("physics")
public class PhysicsSurfaceTests {

    @WorldTest
    @Order(1)
    @DisplayName("Spawned entity on solid ground is stationary")
    void spawnedEntityIsStationary(WorldTestContext ctx) {
        // Build a solid floor first, then spawn on top of it.
        ctx.fillRegion(-5, 63, -5, 5, 63, 5, "Rock_Sandstone");
        Object entity = ctx.spawnNPC("Kweebec_Sapling", 0, 64, 0);
        ctx.waitTicks(5);

        Object store = ctx.getStore();

        // assertOnGround checks the grounded flag on the physics component.
        PhysicsAssert.assertOnGround(store, entity);

        // assertStationary checks that the entity's speed is below the tolerance.
        // A small tolerance (0.01) accounts for floating-point imprecision.
        PhysicsAssert.assertStationary(store, entity, 0.01);
    }

    @WorldTest
    @Order(2)
    @DisplayName("Read velocity components from a moving entity")
    void readVelocityFromEntity(WorldTestContext ctx) {
        ctx.fillRegion(-5, 63, -5, 5, 63, 5, "Rock_Sandstone");
        Object entity = ctx.spawnNPC("Trork_Warrior", 0, 64, 0);
        ctx.waitTicks(2);

        Object store = ctx.getStore();

        // getVelocity returns a double array [vx, vy, vz].
        double[] velocity = ctx.getVelocity(store, entity);
        HytaleAssert.assertNotNull("Velocity should not be null", velocity);
        HytaleAssert.assertEquals(3, velocity.length);
    }

    @WorldTest
    @Order(3)
    @DisplayName("Entity in air is detected as not on ground")
    void entityInAirDetected(WorldTestContext ctx) {
        // Spawn the entity high above the ground with no floor beneath.
        Object entity = ctx.spawnNPC("Kweebec_Sapling", 0, 200, 0);
        ctx.waitTicks(1);

        Object store = ctx.getStore();

        // The entity is falling - it should be detected as in the air.
        PhysicsAssert.assertInAir(store, entity);
    }

    @WorldTest
    @Order(4)
    @DisplayName("Apply a force and verify the entity gains speed")
    void applyForceGivesSpeed(WorldTestContext ctx) {
        ctx.fillRegion(-5, 63, -5, 5, 63, 5, "Rock_Sandstone");
        Object entity = ctx.spawnNPC("Trork_Warrior", 0, 64, 0);
        ctx.waitTicks(2);

        Object store = ctx.getStore();

        // Apply a horizontal force impulse in the +X direction.
        ctx.addForce(store, entity, 5.0, 0.0, 0.0);
        ctx.waitTicks(1);

        // After the force is applied, the entity's speed should be above zero.
        double speed = ctx.getSpeed(store, entity);
        HytaleAssert.assertTrue(
            "Speed should be greater than zero after force application",
            speed > 0.0
        );
    }

    @WorldTest
    @Order(5)
    @DisplayName("Set velocity directly and verify it was applied")
    void setVelocityDirectly(WorldTestContext ctx) {
        ctx.fillRegion(-5, 63, -5, 5, 63, 5, "Rock_Sandstone");
        Object entity = ctx.spawnNPC("Kweebec_Sapling", 0, 64, 0);
        ctx.waitTicks(2);

        Object store = ctx.getStore();

        // setVelocity overrides the current velocity with exact values.
        ctx.setVelocity(store, entity, 1.0, 2.0, 3.0);
        ctx.waitTicks(1);

        // Verify the velocity was set. Note: gravity and friction will have
        // modified the values slightly by the time we read them one tick later.
        PhysicsAssert.assertVelocity(store, entity, 1.0, 2.0, 3.0, 1.0);
    }

    @WorldTest
    @Order(6)
    @DisplayName("Verify speed assertion with tolerance")
    void speedAssertionWithTolerance(WorldTestContext ctx) {
        ctx.fillRegion(-5, 63, -5, 5, 63, 5, "Rock_Sandstone");
        Object entity = ctx.spawnNPC("Outlander_Hunter", 0, 64, 0);
        ctx.waitTicks(5);

        Object store = ctx.getStore();

        // A stationary entity should have speed near 0.
        PhysicsAssert.assertSpeed(store, entity, 0.0, 0.1);
    }
}