ForgottenWawiTech/Content/NPCs/OriginalNiko/Niko.cs

using Terraria;
using Terraria.ID;
using Terraria.ModLoader;
using Microsoft.Xna.Framework;
using Terraria.Chat;
using Terraria.Localization;

namespace ForgottenWawiTech.Content.NPCs.OriginalNiko
{
    [AutoloadBossHead]
    public class Niko : ModNPC
    {
        public override void SetStaticDefaults()
        {
            // DisplayName.SetDefault("Original Niko");
            Main.npcFrameCount[NPC.type] = 1;
        }

        public override void SetDefaults()
        {
            NPC.width = 40;
            NPC.height = 40;
            NPC.damage = 1786;
            NPC.defense = 290;
            NPC.lifeMax = 1000000;
            NPC.HitSound = SoundID.NPCHit1;
            NPC.DeathSound = SoundID.NPCDeath1;
            NPC.knockBackResist = 0f;
            NPC.boss = true;
            NPC.aiStyle = -1;
            NPC.value = Item.buyPrice(0, 1, 0, 0);
        }

        public override void AI()
        {
            // Phased behaviour for Niko:
            // Phase 0: initial/dummy AI until 50% HP
            // Phase 1: invulnerable for ~1 minute (dialogue opportunity)
            // Phase 2: dummy AI until 30% HP
            // Phase 3: spawn other bosses (Lyyka, Neptune, Lexy) if they are undefeated, then move to Phase 4

            NPC.TargetClosest(false);
            Player target = Main.player[NPC.target];
            if (!target.active || target.dead)
            {
                NPC.timeLeft = 300;
                return;
            }

            int phase = (int)NPC.ai[0];
            int flags = (int)NPC.ai[1]; // bit0=Lyyka spawned, bit1=Neptune spawned, bit2=Lexy spawned
            int timer = (int)NPC.ai[2];

            // Simple dummy movement helper
            void DoDummyMovement(float speed)
            {
                Vector2 dir = target.Center - NPC.Center;
                if (dir.Length() > 8f)
                {
                    dir.Normalize();
                    NPC.velocity = Vector2.Lerp(NPC.velocity, dir * speed, 0.02f);
                }
            }

            // Phase 0: initial until 50% HP
            if (phase == 0)
            {
                DoDummyMovement(3f);
                if (NPC.life <= NPC.lifeMax / 2)
                {
                    // Enter invulnerable phase
                    NPC.ai[0] = 1;
                    NPC.ai[2] = 0; // reset timer
                    NPC.dontTakeDamage = true;
                    NPC.netUpdate = true;

                    string announce = "Niko envelopes themself in a strange silence...";
                    if (Main.netMode != NetmodeID.MultiplayerClient)
                        Main.NewText(announce, 200, 100, 255);
                    else
                        ChatHelper.BroadcastChatMessage(NetworkText.FromLiteral(announce), new Color(200, 100, 255));
                }
            }

            // Phase 1: invulnerable waiting (~1 minute) for dialogue
            else if (phase == 1)
            {
                NPC.ai[2]++;
                // Idle drift
                NPC.velocity *= 0.98f;

                // Periodic short dialogue during invulnerable phase
                int t = (int)NPC.ai[2];
                if (t == 120)
                {
                    string line = "...silence stretches, an uneasy calm.";
                    if (Main.netMode != NetmodeID.MultiplayerClient)
                        Main.NewText(line, 200, 120, 255);
                    else
                        ChatHelper.BroadcastChatMessage(NetworkText.FromLiteral(line), new Color(200, 120, 255));
                }
                else if (t == 900)
                {
                    string line = "Niko: You think you've seen everything?";
                    if (Main.netMode != NetmodeID.MultiplayerClient)
                        Main.NewText(line, 220, 160, 255);
                    else
                        ChatHelper.BroadcastChatMessage(NetworkText.FromLiteral(line), new Color(220, 160, 255));
                }
                else if (t == 2100)
                {
                    string line = "Niko: There's more yet to come...";
                    if (Main.netMode != NetmodeID.MultiplayerClient)
                        Main.NewText(line, 200, 140, 255);
                    else
                        ChatHelper.BroadcastChatMessage(NetworkText.FromLiteral(line), new Color(200, 140, 255));
                }

                // After approx 60 seconds (3600 ticks), end invulnerability
                if (NPC.ai[2] >= 3600)
                {
                    NPC.dontTakeDamage = false;
                    NPC.ai[0] = 2;
                    NPC.netUpdate = true;

                    string announce = "Niko's barrier fades... the battle resumes.";
                    if (Main.netMode != NetmodeID.MultiplayerClient)
                        Main.NewText(announce, 255, 150, 100);
                    else
                        ChatHelper.BroadcastChatMessage(NetworkText.FromLiteral(announce), new Color(255, 150, 100));
                }
            }

            // Phase 2: dummy AI after invul until 30% HP
            else if (phase == 2)
            {
                DoDummyMovement(4f);
                if (NPC.life <= (int)(NPC.lifeMax * 0.3f))
                {
                    NPC.ai[0] = 3; // go to spawn phase
                    NPC.netUpdate = true;
                }
            }

            // Phase 3: spawn other bosses if undefeated
            else if (phase == 3)
            {
                // Spawn Lyyka if undefeated and not already spawned
                if (!WorldDefeatedBosses.Lyyka && (flags & 1) == 0)
                {
                    flags |= 1;
                    string announceL = "Lyyka is called to the fray!";
                }

                // Spawn Neptune if undefeated and not already spawned
                if (!WorldDefeatedBosses.Neptune && (flags & 2) == 0)
                {
                    flags |= 2;
                    string announceN = "The waves answer Niko's call: Neptune arrives!";
                }

                // Spawn Lexy if undefeated and not already spawned
                if (!WorldDefeatedBosses.Lexy && (flags & 4) == 0)
                {
                    flags |= 4;
                    string announceX = "Lexy emerges to twist the battlefield!";
                }

                // Save flags and move to final phase
                NPC.ai[1] = flags;
                NPC.ai[0] = 4;
                NPC.netUpdate = true;
            }

            // Phase 4+: final behaviour (dummy)
            else
            {
                DoDummyMovement(5f);
            }
        }

        public override void OnKill()
        {
            // Spawn NikoNPC when killed
/*             if (Main.netMode != NetmodeID.MultiplayerClient)
            {
                NPC.NewNPC(NPC.GetSource_Death(), (int)NPC.Center.X, (int)NPC.Center.Y, ModContent.NPCType<NikoNPC>());
            }
            else
            {
                NetMessage.SendData(MessageID.SpawnNPC, number: ModContent.NPCType<NikoNPC>(), number2: NPC.whoAmI);
            } */
            // Set a world flag or similar to indicate Niko has been defeated
            WorldDefeatedBosses.Niko = true;
            // Immediate sync of world flags
            WorldDefeatedBosses.Sync(ModContent.GetInstance<ForgottenWawiTech>());
        }
    }
}