DeathMod

using SoulHarvest.Common;
using Microsoft.Xna.Framework;
using System;
using System.IO;
using Terraria;
using Terraria.ID;
using Terraria.ModLoader;

namespace SoulHarvest.Projectiles;

/// <summary>
/// Server-authoritative, persistent Void tear shared by the Void special,
/// passives and ultimate. It damages along the visible opening and pulls normal
/// enemies toward the closest point on that opening.
/// </summary>
public sealed class ReaperVoidRiftProjectile : ModProjectile
{
    private SickleCombatSnapshot snapshot;
    private float riftLength;
    private float riftWidth;
    private float pullRadius;
    private int lifetime;
    private int seed;
    private int age;
    private bool configured;
    private bool serverAuthorized;

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

    internal static int Spawn(Terraria.DataStructures.IEntitySource source, int owner,
        in SickleCombatSnapshot snapshot, Vector2 center, Vector2 direction,
        float length, float width, int lifetime, float pullRadius,
        float damageMultiplier, int phase, int actionId)
    {
        if (Main.netMode == NetmodeID.MultiplayerClient)
            return -1;

        direction = direction.SafeNormalize(Vector2.UnitX);
        int index = Projectile.NewProjectile(source, center, direction,
            ModContent.ProjectileType<ReaperVoidRiftProjectile>(),
            Math.Max(1, (int)Math.Round(snapshot.Damage * damageMultiplier)),
            snapshot.Knockback * 0.18f, owner);
        if (index < 0 || index >= Main.maxProjectiles)
            return -1;

        Projectile projectile = Main.projectile[index];
        projectile.originalDamage = snapshot.Damage;
        projectile.CritChance = 0;
        int stableSeed = unchecked(actionId * 486187739 + phase * 16777619 + owner * 31);
        if (projectile.ModProjectile is ReaperVoidRiftProjectile rift)
            rift.Configure(snapshot, length, width, lifetime, pullRadius, stableSeed);
        projectile.GetGlobalProjectile<MyGlobalProjectile>().ConfigureReaperProjectile(
            projectile, snapshot, ReaperHitKind.DamageOverTime, phase,
            direction.ToRotation(), actionId);
        projectile.localNPCHitCooldown = 16;
        ReaperProjectileHelper.SyncNewProjectile(projectile);
        return index;
    }

    public override void SetDefaults()
    {
        Projectile.width = 4;
        Projectile.height = 4;
        Projectile.friendly = true;
        Projectile.hostile = false;
        Projectile.tileCollide = false;
        Projectile.ignoreWater = true;
        Projectile.penetrate = -1;
        Projectile.timeLeft = 180;
        Projectile.netImportant = true;
        Projectile.DamageType = DamageClass.Melee;
        Projectile.usesLocalNPCImmunity = true;
        Projectile.localNPCHitCooldown = 16;
    }

    public override bool ShouldUpdatePosition() => false;

    public override bool? CanDamage()
        => configured && age >= 5 && Projectile.timeLeft > 18 ? null : false;

    public override void AI()
    {
        if (Main.netMode == NetmodeID.Server && !serverAuthorized)
        {
            Projectile.Kill();
            return;
        }
        if (!configured)
            return;

        age++;
        Projectile.rotation = Projectile.velocity.ToRotation();
        if (Main.netMode != NetmodeID.MultiplayerClient)
            PullNearbyEnemies();
    }

    public override bool? Colliding(Rectangle projHitbox, Rectangle targetHitbox)
    {
        Vector2 axis = Projectile.velocity.SafeNormalize(Vector2.UnitX);
        Vector2 start = Projectile.Center - axis * riftLength * 0.5f;
        Vector2 end = Projectile.Center + axis * riftLength * 0.5f;
        float collisionPoint = 0f;
        return Collision.CheckAABBvLineCollision(targetHitbox.TopLeft(), targetHitbox.Size(),
            start, end, Math.Max(3f, riftWidth * 0.72f), ref collisionPoint);
    }

    public override bool PreDraw(ref Color lightColor)
    {
        if (!configured || Main.dedServ)
            return false;

        float reveal = Smooth01(age / 13f);
        float fade = Smooth01(Projectile.timeLeft / 40f);
        float breathing = 0.96f + (float)Math.Sin((age + seed * 0.001f) * 0.11f) * 0.04f;
        ReaperVoidBackdropRenderer.DrawPersistentRift(Main.spriteBatch, Projectile.Center,
            Projectile.velocity, riftLength, riftWidth * breathing, seed,
            reveal, fade);
        return false;
    }

    public override void SendExtraAI(BinaryWriter writer)
    {
        writer.Write(configured);
        if (!configured)
            return;
        snapshot.Write(writer);
        writer.Write(riftLength);
        writer.Write(riftWidth);
        writer.Write(pullRadius);
        writer.Write((short)Math.Clamp(lifetime, 1, short.MaxValue));
        writer.Write(seed);
        writer.Write((short)Math.Clamp(age, 0, short.MaxValue));
    }

    public override void ReceiveExtraAI(BinaryReader reader)
    {
        bool incomingConfigured = reader.ReadBoolean();
        if (!incomingConfigured)
        {
            if (Main.netMode != NetmodeID.Server)
                configured = false;
            return;
        }

        SickleCombatSnapshot incomingSnapshot = SickleCombatSnapshot.Read(reader);
        float incomingLength = reader.ReadSingle();
        float incomingWidth = reader.ReadSingle();
        float incomingPullRadius = reader.ReadSingle();
        int incomingLifetime = reader.ReadInt16();
        int incomingSeed = reader.ReadInt32();
        int incomingAge = reader.ReadInt16();
        if (Main.netMode == NetmodeID.Server)
            return;

        snapshot = incomingSnapshot;
        riftLength = incomingLength;
        riftWidth = incomingWidth;
        pullRadius = incomingPullRadius;
        lifetime = incomingLifetime;
        seed = incomingSeed;
        age = incomingAge;
        configured = true;
    }

    private void Configure(in SickleCombatSnapshot value, float length, float width,
        int activeLifetime, float attractionRadius, int shapeSeed)
    {
        snapshot = value;
        riftLength = MathHelper.Clamp(length, 32f, 2600f);
        riftWidth = MathHelper.Clamp(width, 4f, 190f);
        pullRadius = MathHelper.Clamp(attractionRadius, 0f, 820f);
        lifetime = Math.Clamp(activeLifetime, 30, 600);
        seed = shapeSeed;
        age = 0;
        configured = true;
        serverAuthorized = Main.netMode != NetmodeID.MultiplayerClient;
        Projectile.timeLeft = lifetime;
    }

    private void PullNearbyEnemies()
    {
        if (pullRadius <= 1f || age < 5 || Projectile.timeLeft <= 18)
            return;

        Vector2 axis = Projectile.velocity.SafeNormalize(Vector2.UnitX);
        Vector2 start = Projectile.Center - axis * riftLength * 0.5f;
        Vector2 end = Projectile.Center + axis * riftLength * 0.5f;
        Vector2 segment = end - start;
        float segmentLengthSquared = Math.Max(1f, segment.LengthSquared());
        foreach (NPC npc in Main.ActiveNPCs)
        {
            if (!npc.CanBeChasedBy(Projectile) || npc.boss || npc.realLife >= 0)
                continue;

            float amount = MathHelper.Clamp(Vector2.Dot(npc.Center - start, segment)
                / segmentLengthSquared, 0f, 1f);
            Vector2 closest = Vector2.Lerp(start, end, amount);
            Vector2 toRift = closest - npc.Center;
            float distance = toRift.Length();
            if (distance <= 2f || distance >= pullRadius)
                continue;

            float influence = 1f - distance / pullRadius;
            float maximumSpeed = MathHelper.Lerp(1.2f, 6.2f, influence);
            Vector2 desired = toRift / distance * maximumSpeed;
            npc.velocity = Vector2.Lerp(npc.velocity, desired, 0.035f + influence * 0.09f);
            if (Main.netMode == NetmodeID.Server && Main.GameUpdateCount % 10 == 0)
                npc.netUpdate = true;
        }
    }

    private static float Smooth01(float value)
    {
        value = MathHelper.Clamp(value, 0f, 1f);
        return value * value * (3f - 2f * value);
    }
}