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

namespace ProjectM.Tests
{
    /// <summary>
    /// Pins Step 13 — <see cref="MetaSpendSystem"/>: the Staging-gated Aether→tier purchase with DR-014 in-loop
    /// ledger atomicity (two same-tick barely-enough purchases → exactly ONE succeeds), the TotalOf pre-check
    /// (Withdraw clamps, it never rejects), the ABSOLUTE-value modifier upsert on every live class member (R-F1/2),
    /// tier bump-or-append on the director record, the SaveRequest flag, and the reject paths (wrong class mask,
    /// MaxTier cap, non-Staging lifecycle) — with requests always consumed.
    /// </summary>
    public class MetaSpendSystemTests
    {
        static (World world, SimulationSystemGroup group) MakeWorld()
        {
            var world = new World("MetaSpendTest");
            var group = world.GetOrCreateSystemManaged<SimulationSystemGroup>();
            group.AddSystemToUpdateList(world.GetOrCreateSystem<MetaSpendSystem>());
            group.SortSystems();
            world.SetTime(new TimeData(elapsedTime: 0f, deltaTime: 1f / 60f));
            return (world, group);
        }

        static Entity MakeDirector(EntityManager em, byte lifecycle, int aether)
        {
            var dir = em.CreateEntity(typeof(RunInfo), typeof(ResourceLedger), typeof(SaveRequest),
                typeof(MetaUpgradeCatalog));
            em.SetComponentData(dir, new RunInfo { Lifecycle = lifecycle });
            em.SetComponentData(dir, new MetaUpgradeCatalog { Value = MetaCatalogData.BuildDefault() });
            var ledger = em.AddBuffer<StorageEntry>(dir);
            if (aether > 0) ledger.Add(new StorageEntry { ItemId = ResourceId.Aether, Count = aether });
            em.AddBuffer<MetaTierState>(dir);
            return dir;
        }

        static Entity MakePlayer(EntityManager em, int networkId, byte classId)
        {
            var conn = em.CreateEntity(typeof(NetworkId));
            em.SetComponentData(conn, new NetworkId { Value = networkId });
            var player = em.CreateEntity(typeof(PlayerTag), typeof(GhostOwner), typeof(PlayerClass));
            em.SetComponentData(player, new GhostOwner { NetworkId = networkId });
            em.SetComponentData(player, new PlayerClass { ClassId = classId });
            em.AddBuffer<StatModifier>(player);
            em.AddComponentData(player, new ConnRef { Conn = conn });
            return player;
        }

        /// <summary>Test-only pointer so a request can be issued from the player's own connection.</summary>
        struct ConnRef : IComponentData { public Entity Conn; }

        static void SendRequest(EntityManager em, Entity player, byte upgradeId)
        {
            var conn = em.GetComponentData<ConnRef>(player).Conn;
            var req = em.CreateEntity(typeof(MetaSpendRequest), typeof(ReceiveRpcCommandRequest));
            em.SetComponentData(req, new MetaSpendRequest { UpgradeId = upgradeId });
            em.SetComponentData(req, new ReceiveRpcCommandRequest { SourceConnection = conn });
        }

        static int PendingRequests(EntityManager em)
        {
            var q = em.CreateEntityQuery(typeof(MetaSpendRequest));
            int n = q.CalculateEntityCount();
            q.Dispose();
            return n;
        }

        static float MetaModValue(EntityManager em, Entity player, byte upgradeId, out int rowCount)
        {
            var mods = em.GetBuffer<StatModifier>(player, true);
            float value = 0f;
            rowCount = 0;
            for (int i = 0; i < mods.Length; i++)
                if (mods[i].SourceId == Tuning.MetaSourceIdBase + upgradeId) { value = mods[i].Value; rowCount++; }
            return value;
        }

        [Test]
        public void Purchase_BumpsTier_Withdraws_UpsertsAllClassMembers_FlagsSave()
        {
            var (world, group) = MakeWorld();
            var em = world.EntityManager;
            var dir = MakeDirector(em, RunLifecycle.Staging, 25);
            var warriorA = MakePlayer(em, 1, ClassTraits.WarriorClass);
            var warriorB = MakePlayer(em, 2, ClassTraits.WarriorClass);   // classmate: shared per-class pool
            var ranger = MakePlayer(em, 3, ClassTraits.RangerClass);      // other class: untouched

            SendRequest(em, warriorA, 1); // Reinforced Frame: BaseCost 10, +15/tier
            group.Update();

            var record = em.GetBuffer<MetaTierState>(dir, true);
            Assert.AreEqual(1, MetaMath.TierOf(record, ClassTraits.WarriorClass, 1), "tier bumped to 1");
            Assert.AreEqual(15, StorageMath.TotalOf(em.GetBuffer<StorageEntry>(dir, true), ResourceId.Aether),
                "cost 10 withdrawn from 25");
            Assert.AreEqual(15f, MetaModValue(em, warriorA, 1, out int rowsA), 1e-3f, "buyer modifier = 15 * tier1");
            Assert.AreEqual(1, rowsA);
            Assert.AreEqual(15f, MetaModValue(em, warriorB, 1, out _), 1e-3f, "live classmate upserted too (R-F2)");
            Assert.AreEqual(0f, MetaModValue(em, ranger, 1, out int rowsR), 1e-3f, "other class untouched");
            Assert.AreEqual(0, rowsR);
            Assert.AreEqual(1, em.GetComponentData<SaveRequest>(dir).Pending, "purchase flags the autosave");
            Assert.AreEqual(0, PendingRequests(em), "request consumed");
            world.Dispose();
        }

        [Test]
        public void TwoSameTick_BarelyEnough_ExactlyOneSucceeds()
        {
            var (world, group) = MakeWorld();
            var em = world.EntityManager;
            var dir = MakeDirector(em, RunLifecycle.Staging, 10); // ids 1 and 4 BOTH cost 10 at tier 0
            var warrior = MakePlayer(em, 1, ClassTraits.WarriorClass);

            SendRequest(em, warrior, 1);
            SendRequest(em, warrior, 4);
            group.Update();

            var record = em.GetBuffer<MetaTierState>(dir, true);
            int bought = MetaMath.TierOf(record, ClassTraits.WarriorClass, 1)
                       + MetaMath.TierOf(record, ClassTraits.WarriorClass, 4);
            Assert.AreEqual(1, bought, "in-loop atomicity: barely-enough Aether buys exactly ONE (DR-014)");
            Assert.AreEqual(0, StorageMath.TotalOf(em.GetBuffer<StorageEntry>(dir, true), ResourceId.Aether),
                "the single cost fully drained the ledger — and never went negative (TotalOf pre-check)");
            Assert.AreEqual(0, PendingRequests(em), "both requests consumed");
            world.Dispose();
        }

        [Test]
        public void SecondPurchase_AbsoluteUpsert_SingleRow_RampedCost()
        {
            var (world, group) = MakeWorld();
            var em = world.EntityManager;
            var dir = MakeDirector(em, RunLifecycle.Staging, 30); // tier1 = 10, tier2 = 10 + 1*5 = 15
            var warrior = MakePlayer(em, 1, ClassTraits.WarriorClass);

            SendRequest(em, warrior, 1);
            group.Update();
            SendRequest(em, warrior, 1);
            group.Update();

            var record = em.GetBuffer<MetaTierState>(dir, true);
            Assert.AreEqual(2, MetaMath.TierOf(record, ClassTraits.WarriorClass, 1), "tier 2 owned");
            Assert.AreEqual(1, record.Length, "record row BUMPED in place, not duplicated");
            Assert.AreEqual(30f, MetaModValue(em, warrior, 1, out int rows), 1e-3f,
                "ABSOLUTE upsert: 15 * tier2 (R-F1)");
            Assert.AreEqual(1, rows, "one modifier row — an incremental append would double-count in recompute");
            Assert.AreEqual(5, StorageMath.TotalOf(em.GetBuffer<StorageEntry>(dir, true), ResourceId.Aether),
                "linear ramp: 30 - 10 - 15");
            world.Dispose();
        }

        [Test]
        public void Rejects_WrongClassMask_MaxTierCap_NonStaging()
        {
            var (world, group) = MakeWorld();
            var em = world.EntityManager;
            var dir = MakeDirector(em, RunLifecycle.Staging, 999);
            var warrior = MakePlayer(em, 1, ClassTraits.WarriorClass);

            // (a) Ranger-masked upgrade requested by a Warrior — dropped, nothing withdrawn.
            SendRequest(em, warrior, 7); // Ranger's Longshot (mask 2)
            group.Update();
            Assert.AreEqual(999, StorageMath.TotalOf(em.GetBuffer<StorageEntry>(dir, true), ResourceId.Aether),
                "class-mask reject leaves the ledger untouched");

            // (b) at MaxTier — dropped. Fleet Stride (id 4) MaxTier 3.
            var record = em.GetBuffer<MetaTierState>(dir);
            record.Add(new MetaTierState { ClassId = ClassTraits.WarriorClass, UpgradeId = 4, Tier = 3 });
            SendRequest(em, warrior, 4);
            group.Update();
            Assert.AreEqual(3, MetaMath.TierOf(em.GetBuffer<MetaTierState>(dir, true), ClassTraits.WarriorClass, 4),
                "MaxTier cap holds");
            Assert.AreEqual(999, StorageMath.TotalOf(em.GetBuffer<StorageEntry>(dir, true), ResourceId.Aether));

            // (c) mid-run — dropped (N4: the shop is a between-runs surface).
            em.SetComponentData(dir, new RunInfo { Lifecycle = RunLifecycle.InRoom });
            SendRequest(em, warrior, 1);
            group.Update();
            Assert.AreEqual(0, MetaMath.TierOf(em.GetBuffer<MetaTierState>(dir, true), ClassTraits.WarriorClass, 1),
                "non-Staging purchase dropped");
            Assert.AreEqual(999, StorageMath.TotalOf(em.GetBuffer<StorageEntry>(dir, true), ResourceId.Aether));
            Assert.AreEqual(0, PendingRequests(em), "every request consumed, accepted or not");
            world.Dispose();
        }
    }
}