ForgottenWawiTech/Content/Projectiles/FragmentedPrism/FragmentedPrismController.cs

using Microsoft.Xna.Framework;
using Terraria;
using Terraria.Audio;
using Terraria.DataStructures;
using Terraria.ID;
using Terraria.ModLoader;

namespace ForgottenWawiTech.Content.Projectiles.FragmentedPrism
{
    public class FragmentedPrismController : ModProjectile
    {
        public const int ShardCount = 5;
        public const float ChargeTimePerShard = 24f;
        private const float ChargeDecayRate = 3f;
        private const int ShardSpawnDelay = 4;

        public static float MaxChargeTime => ChargeTimePerShard * ShardCount;

        private ref float SpawnTimer => ref Projectile.ai[0];
        private ref float ChargeTimer => ref Projectile.ai[1];
        private ref float LastFiringCount => ref Projectile.localAI[0];

        public override string Texture => "Terraria/Images/Projectile_0";

        public override void SetDefaults()
        {
            Projectile.width = 10;
            Projectile.height = 10;
            Projectile.friendly = false;
            Projectile.hostile = false;
            Projectile.penetrate = -1;
            Projectile.tileCollide = false;
            Projectile.ignoreWater = true;
            Projectile.hide = true;
            Projectile.DamageType = DamageClass.Magic;
        }

        public override void AI()
        {
            Player player = Main.player[Projectile.owner];
            int itemType = ModContent.ItemType<Items.Weapons.Magic.FragmentedPrism>();
            if (!player.active || player.dead || player.HeldItem.type != itemType)
            {
                Projectile.Kill();
                return;
            }

            player.heldProj = Projectile.whoAmI;
            if (player.channel || ChargeTimer > 0f)
            {
                player.itemAnimation = player.itemTime = 2;
                player.SetDummyItemTime(2);
            }

            Projectile.Center = player.Center;
            Projectile.timeLeft = 2;

            if (Main.myPlayer == player.whoAmI)
            {
                SpawnTimer++;
                if (SpawnTimer >= ShardSpawnDelay)
                {
                    SpawnTimer = 0f;
                    TrySpawnShard(player);
                }
            }

            float maxCharge = MaxChargeTime;
            if (player.channel)
            {
                ChargeTimer = MathHelper.Clamp(ChargeTimer + 1f, 0f, maxCharge);
            }
            else
            {
                ChargeTimer = MathHelper.Clamp(ChargeTimer - ChargeDecayRate, 0f, maxCharge);
            }

            int currentFiringCount = (int)MathHelper.Clamp(ChargeTimer / ChargeTimePerShard, 0f, ShardCount);
            if (currentFiringCount > LastFiringCount)
            {
                SoundEngine.PlaySound(SoundID.Item117 with { Volume = 0.45f, Pitch = 0.3f }, player.Center);
                Projectile.netUpdate = true;
            }
            else if (currentFiringCount < LastFiringCount)
            {
                Projectile.netUpdate = true;
            }

            LastFiringCount = currentFiringCount;
        }

        public override void OnKill(int timeLeft)
        {
            if (Main.player[Projectile.owner] is not Player player)
            {
                return;
            }

            for (int i = 0; i < Main.maxProjectiles; i++)
            {
                Projectile other = Main.projectile[i];
                if (other.active && other.owner == Projectile.owner && other.type == ModContent.ProjectileType<FragmentedPrismShard>())
                {
                    other.Kill();
                }
            }
        }

        private void TrySpawnShard(Player player)
        {
            int shardType = ModContent.ProjectileType<FragmentedPrismShard>();
            bool[] occupied = new bool[ShardCount];

            for (int i = 0; i < Main.maxProjectiles; i++)
            {
                Projectile shard = Main.projectile[i];
                if (shard.active && shard.owner == player.whoAmI && shard.type == shardType)
                {
                    int slot = (int)shard.ai[0];
                    if (slot >= 0 && slot < ShardCount)
                    {
                        occupied[slot] = true;
                    }
                }
            }

            IEntitySource source = player.GetSource_ItemUse_WithPotentialAmmo(player.HeldItem, AmmoID.None);
            bool spawnedAny = false;
            for (int index = 0; index < ShardCount; index++)
            {
                if (occupied[index])
                {
                    continue;
                }

                int proj = Projectile.NewProjectile(source, player.Center, Vector2.Zero, shardType, Projectile.damage, Projectile.knockBack, player.whoAmI, index);
                if (Main.projectile.IndexInRange(proj))
                {
                    Main.projectile[proj].originalDamage = Projectile.damage;
                    Main.projectile[proj].ai[1] = MathHelper.TwoPi * (index / (float)ShardCount);
                }
                spawnedAny = true;
            }

            if (spawnedAny)
            {
                SoundEngine.PlaySound(SoundID.Item4 with { Volume = 0.35f, Pitch = -0.3f }, player.Center);
            }
        }
    }
}