using NUnit.Framework;
using ProjectM.Server;
using ProjectM.Simulation;
using Unity.Core;
using Unity.Entities;
using Unity.NetCode;

namespace ProjectM.Tests
{
    /// <summary>
    /// Plain-Entities EditMode tests for the server-only <see cref="InventoryDepositSystem"/> — the RPC that
    /// moves a player's PERSONAL inventory into the shared ledger. Mirrors RegionTransitSystemTests' seeding:
    /// a ResourceLedger singleton, a mock connection (NetworkId), a player (GhostOwner + InventorySlot +
    /// PlayerTag), and an InventoryDepositRequest + ReceiveRpcCommandRequest. Pins: a specific-item deposit
    /// moves the clamped amount; ItemId 0 deposits everything and empties the bag; an unresolvable connection
    /// moves nothing; the request is consumed either way.
    /// </summary>
    public class InventoryDepositSystemTests
    {
        static (World world, SimulationSystemGroup group, Entity ledger) MakeWorld(string name)
        {
            var world = new World(name);
            var group = world.GetOrCreateSystemManaged<SimulationSystemGroup>();
            group.AddSystemToUpdateList(world.GetOrCreateSystem<InventoryDepositSystem>());
            group.SortSystems();
            world.SetTime(new TimeData(elapsedTime: 0f, deltaTime: 1f / 60f));
            var em = world.EntityManager;
            var ledger = em.CreateEntity(typeof(ResourceLedger));
            em.AddBuffer<StorageEntry>(ledger);
            return (world, group, ledger);
        }

        static Entity MakeConnection(EntityManager em, int networkId)
        {
            var e = em.CreateEntity();
            em.AddComponentData(e, new NetworkId { Value = networkId });
            return e;
        }

        static Entity MakePlayer(EntityManager em, int networkId, params (ushort id, int count)[] items)
        {
            var e = em.CreateEntity();
            em.AddComponentData(e, new GhostOwner { NetworkId = networkId });
            em.AddComponent<PlayerTag>(e);
            var bag = em.AddBuffer<InventorySlot>(e);
            foreach (var it in items)
                bag.Add(new InventorySlot { ItemId = it.id, Count = it.count });
            return e;
        }

        static void MakeRequest(EntityManager em, ushort itemId, int count, Entity conn)
        {
            var e = em.CreateEntity();
            em.AddComponentData(e, new InventoryDepositRequest { ItemId = itemId, Count = count });
            em.AddComponentData(e, new ReceiveRpcCommandRequest { SourceConnection = conn });
        }

        static int LedgerCount(EntityManager em, Entity ledger, ushort itemId)
        {
            var buf = em.GetBuffer<StorageEntry>(ledger);
            for (int i = 0; i < buf.Length; i++)
                if (buf[i].ItemId == itemId) return buf[i].Count;
            return 0;
        }

        static int InvCount(EntityManager em, Entity player, ushort itemId)
        {
            var buf = em.GetBuffer<InventorySlot>(player);
            return InventoryMath.CountOf(buf, itemId);
        }

        [Test]
        public void Deposit_Specific_Item_Moves_Clamped_Amount_To_Ledger()
        {
            var (world, group, ledger) = MakeWorld("DepositSpecific");
            using (world)
            {
                var em = world.EntityManager;
                var conn = MakeConnection(em, 1);
                var player = MakePlayer(em, 1, (ResourceId.Ore, 30));
                MakeRequest(em, ResourceId.Ore, 20, conn);

                group.Update();

                Assert.AreEqual(10, InvCount(em, player, ResourceId.Ore), "20 of 30 Ore moved out of the bag.");
                Assert.AreEqual(20, LedgerCount(em, ledger, ResourceId.Ore), "20 Ore landed in the shared ledger.");
                using var q = em.CreateEntityQuery(typeof(InventoryDepositRequest));
                Assert.AreEqual(0, q.CalculateEntityCount(), "The request is consumed.");
            }
        }

        [Test]
        public void Deposit_All_Empties_Bag_Into_Ledger()
        {
            var (world, group, ledger) = MakeWorld("DepositAll");
            using (world)
            {
                var em = world.EntityManager;
                var conn = MakeConnection(em, 1);
                var player = MakePlayer(em, 1, (ResourceId.Ore, 30), (ResourceId.Aether, 5));
                MakeRequest(em, itemId: 0, count: 0, conn); // 0 = deposit all

                group.Update();

                Assert.AreEqual(0, InvCount(em, player, ResourceId.Ore), "Deposit-all empties the bag.");
                Assert.AreEqual(0, InvCount(em, player, ResourceId.Aether));
                Assert.AreEqual(30, LedgerCount(em, ledger, ResourceId.Ore));
                Assert.AreEqual(5, LedgerCount(em, ledger, ResourceId.Aether));
            }
        }

        [Test]
        public void Deposit_From_Unresolvable_Connection_Moves_Nothing()
        {
            var (world, group, ledger) = MakeWorld("DepositUnknown");
            using (world)
            {
                var em = world.EntityManager;
                var player = MakePlayer(em, 1, (ResourceId.Ore, 30));
                MakeRequest(em, ResourceId.Ore, 20, Entity.Null); // no NetworkId on Entity.Null

                group.Update();

                Assert.AreEqual(30, InvCount(em, player, ResourceId.Ore), "An unresolvable sender moves nothing.");
                Assert.AreEqual(0, LedgerCount(em, ledger, ResourceId.Ore));
                using var q = em.CreateEntityQuery(typeof(InventoryDepositRequest));
                Assert.AreEqual(0, q.CalculateEntityCount(), "The request is still consumed.");
            }
        }
    }
}