ForgottenWawiTech/Content/Projectiles/Avali/AvaliHuntingDrone.cs

using Microsoft.Xna.Framework;
using Terraria;
using Terraria.Audio;
using Terraria.ID;
using Terraria.ModLoader;
using ForgottenWawiTech.Content.Players;

namespace ForgottenWawiTech.Content.Projectiles.Avali
{
    public class AvaliHuntingDrone : ModProjectile
    {
        private const float OrbitSpeed = 0.045f;
        private const float OrbitRadius = 96f;
        private const int ShootCooldown = 28;
        private const float TargetRange = 920f;
        private const float ShotSpeed = 19.5f;

        public override void SetStaticDefaults()
        {
            ProjectileID.Sets.MinionSacrificable[Type] = false;
            ProjectileID.Sets.MinionTargettingFeature[Type] = true;
        }

        public override void SetDefaults()
        {
            Projectile.width = 26;
            Projectile.height = 26;
            Projectile.friendly = false;
            Projectile.minion = true;
            Projectile.penetrate = -1;
            Projectile.tileCollide = false;
            Projectile.ignoreWater = true;
            Projectile.DamageType = DamageClass.Summon;
            Projectile.netImportant = true;
            Projectile.timeLeft = 2;
            Projectile.minionSlots = 0f;
            Projectile.damage = 0;
        }

        public override void AI()
        {
            Player owner = Main.player[Projectile.owner];
            AvaliVanguardPlayer modPlayer = owner.GetModPlayer<AvaliVanguardPlayer>();
            if (!owner.active || owner.dead || !modPlayer.HuntingDronesActive)
            {
                Projectile.Kill();
                return;
            }

            Projectile.timeLeft = 2;

            float index = Projectile.ai[0];
            float total = Projectile.ai[1];
            if (total <= 0f)
            {
                total = 3f;
            }

            float rotation = (Main.GameUpdateCount * OrbitSpeed) + index * MathHelper.TwoPi / total;
            Vector2 offset = rotation.ToRotationVector2() * OrbitRadius;
            Projectile.Center = owner.Center + offset;
            Projectile.velocity = owner.velocity;
            Projectile.rotation = (owner.Center - Projectile.Center).ToRotation() + MathHelper.PiOver2;

            Lighting.AddLight(Projectile.Center, 0.35f, 0.6f, 1f);

            if (Projectile.owner == Main.myPlayer)
            {
                Projectile.localAI[0]++;
                if (Projectile.localAI[0] >= ShootCooldown)
                {
                    Projectile.localAI[0] = 0f;
                    NPC target = AcquireTarget(owner, Projectile.Center, TargetRange);
                    if (target != null)
                    {
                        Vector2 velocity = (target.Center - Projectile.Center).SafeNormalize(Vector2.UnitY) * ShotSpeed;
                        int damage = AvaliVanguardPlayer.GetDroneBaseDamage(owner);
                        var source = Projectile.GetSource_FromAI();
                        Projectile.NewProjectile(
                            source,
                            Projectile.Center,
                            velocity,
                            ModContent.ProjectileType<AvaliHuntingDroneShot>(),
                            damage,
                            2f,
                            owner.whoAmI);
                        SoundEngine.PlaySound(SoundID.Item12 with { Volume = 0.6f }, Projectile.Center);
                        Projectile.netUpdate = true;
                    }
                }
            }
        }

        private static NPC AcquireTarget(Player owner, Vector2 center, float range)
        {
            if (owner.HasMinionAttackTargetNPC)
            {
                NPC target = Main.npc[owner.MinionAttackTargetNPC];
                if (target.CanBeChasedBy())
                {
                    return target;
                }
            }

            NPC closest = null;
            float squaredRange = range * range;
            for (int i = 0; i < Main.maxNPCs; i++)
            {
                NPC npc = Main.npc[i];
                if (!npc.active || npc.friendly || npc.dontTakeDamage || npc.life <= 0)
                {
                    continue;
                }

                float distance = Vector2.DistanceSquared(npc.Center, center);
                if (distance <= squaredRange && Collision.CanHitLine(center, 0, 0, npc.Center, 0, 0))
                {
                    squaredRange = distance;
                    closest = npc;
                }
            }

            return closest;
        }
    }
}