package com.projectsacrifice.game;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;

import java.util.Arrays;

import org.junit.Test;

public final class VersionedSessionCodecTest {
    @Test
    public void currentSnapshotRoundTripsEveryPuzzleCriticalField() {
        GameSessionSnapshot original = sampleSnapshot();

        VersionedSessionCodec.DecodeResult decoded =
                VersionedSessionCodec.decode(VersionedSessionCodec.encode(original));

        assertEquals(VersionedSessionCodec.Status.RESTORED, decoded.status());
        GameSessionSnapshot restored = decoded.snapshot();
        assertEquals(5, restored.levelNumber());
        assertEquals(12.75f, restored.elapsedSeconds(), 0f);
        assertEquals(2, restored.deaths());
        assertEquals(640f, restored.player().x(), 0f);
        assertFalse(restored.player().alive());
        assertEquals(2, restored.bodies().size());
        assertTrue(restored.bodies().get(0).pinned());
        assertTrue(restored.bodies().get(1).conductive());
        assertTrue(restored.bodies().get(0).crushed());
        assertTrue(restored.bodies().get(1).burned());
        assertEquals(2, restored.objects().size());
        assertEquals(LevelDefinition.PhysicalObjectType.BOX,
                restored.objects().get(0).type());
        assertEquals(3, restored.objects().get(1).mass());
        assertTrue(restored.collectibleFound());
        assertEquals(Arrays.asList(1.25f, 3.5f), restored.platformMotionTimes());
        assertTrue(restored.toggleSignals().get("gate"));
        assertEquals(2.25f, restored.timedSignals().get("clock"), 0f);
        assertTrue(restored.previousSwitchContacts().get("gate@420.0"));
    }

    @Test
    public void legacyV1MigratesWithSafeEmptyEdgeContacts() {
        VersionedSessionCodec.DecodeResult decoded = VersionedSessionCodec.decode(
                VersionedSessionCodec.encodeLegacyV1(sampleSnapshot()));

        assertEquals(VersionedSessionCodec.Status.MIGRATED, decoded.status());
        assertEquals(VersionedSessionCodec.CURRENT_VERSION,
                decoded.snapshot().saveVersion());
        assertTrue(decoded.snapshot().previousSwitchContacts().isEmpty());
        assertEquals(2, decoded.snapshot().bodies().size());
        assertFalse(decoded.snapshot().bodies().get(0).crushed());
        assertFalse(decoded.snapshot().bodies().get(1).burned());
    }

    @Test
    public void legacyV2MigratesWithSafeDefaultCorpseStates() {
        VersionedSessionCodec.DecodeResult decoded = VersionedSessionCodec.decode(
                VersionedSessionCodec.encodeLegacyV2(sampleSnapshot()));

        assertEquals(VersionedSessionCodec.Status.MIGRATED, decoded.status());
        assertTrue(decoded.snapshot().previousSwitchContacts().get("gate@420.0"));
        assertFalse(decoded.snapshot().bodies().get(0).crushed());
        assertFalse(decoded.snapshot().bodies().get(1).burned());
        assertTrue(decoded.snapshot().objects().isEmpty());
    }

    @Test
    public void legacyV3MigratesWithSafeEmptyPhysicalObjectRuntime() {
        VersionedSessionCodec.DecodeResult decoded = VersionedSessionCodec.decode(
                VersionedSessionCodec.encodeLegacyV3(sampleSnapshot()));

        assertEquals(VersionedSessionCodec.Status.MIGRATED, decoded.status());
        assertTrue(decoded.snapshot().bodies().get(0).crushed());
        assertTrue(decoded.snapshot().bodies().get(1).burned());
        assertTrue(decoded.snapshot().objects().isEmpty());
    }

    @Test
    public void legacyV4MigratesWithCollectibleNotInvented() {
        VersionedSessionCodec.DecodeResult decoded = VersionedSessionCodec.decode(
                VersionedSessionCodec.encodeLegacyV4(sampleSnapshot()));

        assertEquals(VersionedSessionCodec.Status.MIGRATED, decoded.status());
        assertEquals(2, decoded.snapshot().objects().size());
        assertFalse(decoded.snapshot().collectibleFound());
    }

    @Test
    public void corruptAndFutureSnapshotsFailClosed() {
        VersionedSessionCodec.DecodeResult corrupt =
                VersionedSessionCodec.decode(new byte[] {1, 2, 3});
        VersionedSessionCodec.DecodeResult future =
                VersionedSessionCodec.decode(VersionedSessionCodec.encodeVersionForTest(99));

        assertEquals(VersionedSessionCodec.Status.CORRUPT, corrupt.status());
        assertNull(corrupt.snapshot());
        assertEquals(VersionedSessionCodec.Status.UNSUPPORTED, future.status());
        assertNull(future.snapshot());
    }

    @Test
    public void productionTeachingLevelSnapshotRoundTrips() {
        GameSessionSnapshot snapshot = GameSessionSnapshot.builder(14)
                .elapsedSeconds(3f)
                .player(new GameSessionSnapshot.PlayerData(
                        130f, 760f, 0f, 0f, true, true,
                        0f, 0f, -1, 1))
                .build();

        VersionedSessionCodec.DecodeResult decoded = VersionedSessionCodec.decode(
                VersionedSessionCodec.encode(snapshot));

        assertEquals(VersionedSessionCodec.Status.RESTORED, decoded.status());
        assertEquals(14, decoded.snapshot().levelNumber());
    }

    private static GameSessionSnapshot sampleSnapshot() {
        return GameSessionSnapshot.builder(5)
                .elapsedSeconds(12.75f)
                .deaths(2)
                .collectibleFound(true)
                .respawnSeconds(0.4f)
                .player(new GameSessionSnapshot.PlayerData(
                        640f, 780f, 120f, -40f, false, false,
                        0.1f, 0.08f, -1, -1))
                .addBody(new GameSessionSnapshot.BodyData(
                        500f, 826f, 72f, 54f, 0f, 0f,
                        false, false, true, true, true, false,
                        -1, "CRUSH"))
                .addBody(new GameSessionSnapshot.BodyData(
                        720f, 826f, 72f, 54f, 0f, 0f,
                        false, true, true, true, false, true,
                        -1, "FIRE"))
                .addObject(new GameSessionSnapshot.ObjectData(
                        LevelDefinition.PhysicalObjectType.BOX,
                        300f, 800f, 80f, 80f, 20f, 0f, 1, true, -1))
                .addObject(new GameSessionSnapshot.ObjectData(
                        LevelDefinition.PhysicalObjectType.COUNTERWEIGHT,
                        700f, 780f, 80f, 100f, 0f, 0f, 3, true, 1))
                .platformMotionTimes(Arrays.asList(1.25f, 3.5f))
                .toggleSignal("gate", true)
                .timedSignal("clock", 2.25f)
                .previousSwitchContact("gate@420.0", true)
                .build();
    }
}