using System.Collections.Generic;
using System.Linq;
using BumpCombat.Defense;
using BumpCombat.Defense.Comparison;
using NUnit.Framework;

namespace BumpCombat.PlayModeTests
{
    public sealed class Defense25DPersonalMissionPlayModeTests
    {
        private readonly List<int> openPortalIds = new();
        private readonly List<Defense25DPersonalMissionSpawnRequest> spawnedRequests = new();
        private readonly List<string> queuedRewardTokens = new();
        private Defense25DPersonalMissions missions;
        private bool runCanAcceptMissions;
        private bool allowRewardQueue;
        private int nextSpawnId;

        [SetUp]
        public void SetUp()
        {
            openPortalIds.Clear();
            spawnedRequests.Clear();
            queuedRewardTokens.Clear();
            runCanAcceptMissions = true;
            allowRewardQueue = true;
            nextSpawnId = 100;
            missions = new Defense25DPersonalMissions();
            missions.Bind(
                new[] { 3, 6, 3 },
                () => runCanAcceptMissions,
                () => openPortalIds,
                SpawnTargets,
                QueueReward);
            missions.Reset(7, 12345);
        }

        [Test]
        public void StartRequiresEnoughOpenPortalsAndRejectsConcurrentMission()
        {
            openPortalIds.AddRange(new[] { 2, 0, 2 });

            Assert.That(missions.CanStart(1, out string reason), Is.False);
            Assert.That(reason, Does.Contain("3"));
            Assert.That(missions.TryStart(1), Is.False);
            Assert.That(spawnedRequests, Is.Empty);

            openPortalIds.AddRange(new[] { 1, 3 });
            Assert.That(missions.TryStart(1), Is.True);
            Assert.That(spawnedRequests, Has.Count.EqualTo(3));
            Assert.That(spawnedRequests.Select(request => request.PortalId).Distinct().Count(), Is.EqualTo(3));
            Assert.That(spawnedRequests.All(request =>
                request.RunGeneration == 7
                && request.MissionId == 1
                && request.MissionInstanceId == 1
                && request.Source == Defense25DSpawnSource.PersonalMission), Is.True);
            Assert.That(missions.TryStart(2), Is.False);
        }

        [Test]
        public void MissionTargetsAreThreeSixAndThreeAndOnlyDeathsQueueOneReward()
        {
            for (int missionId = 1; missionId <= 3; missionId++)
            {
                openPortalIds.Clear();
                for (int portalId = 0; portalId < 6; portalId++)
                    openPortalIds.Add(portalId);

                int firstSpawnIndex = spawnedRequests.Count;
                Assert.That(missions.TryStart(missionId), Is.True);
                int targetCount = new[] { 3, 6, 3 }[missionId - 1];
                IReadOnlyList<int> targetIds = missions.States[missionId - 1].TargetSpawnIds;
                Assert.That(targetIds, Has.Count.EqualTo(targetCount));

                for (int i = 0; i < targetIds.Count - 1; i++)
                {
                    Assert.That(missions.ResolveTarget(7, targetIds[i], Defense25DSpawnSource.PersonalMission,
                        missionId, missions.States[missionId - 1].MissionInstanceId, DefenseEnemyResolution.Death), Is.True);
                    Assert.That(missions.States[missionId - 1].Status, Is.EqualTo(Defense25DPersonalMissionStatus.Active));
                }

                Assert.That(missions.ResolveTarget(7, targetIds[targetIds.Count - 1],
                    Defense25DSpawnSource.PersonalMission, missionId,
                    missions.States[missionId - 1].MissionInstanceId, DefenseEnemyResolution.Death), Is.True);
                Assert.That(missions.States[missionId - 1].Status, Is.EqualTo(Defense25DPersonalMissionStatus.RewardPending));
                Assert.That(missions.ResolveTarget(7, targetIds[0], DefenseEnemyResolution.Death), Is.False);
                Assert.That(queuedRewardTokens, Has.Count.EqualTo(missionId));
                Assert.That(queuedRewardTokens[missionId - 1], Is.EqualTo($"personal-mission:7:{missionId}"));
                if (missionId < 3)
                    Assert.That(missions.TryStart(missionId + 1), Is.False);
                Assert.That(missions.TryCompleteReward(7, missions.States[missionId - 1].MissionInstanceId), Is.True);
                Assert.That(missions.States[missionId - 1].Status, Is.EqualTo(Defense25DPersonalMissionStatus.Completed));
                Assert.That(missions.TryCompleteReward(7, missions.States[missionId - 1].MissionInstanceId), Is.False);
                Assert.That(spawnedRequests.Skip(firstSpawnIndex).Take(targetCount)
                    .Select(request => request.PortalId).Distinct().Count(), Is.EqualTo(targetCount));
            }
        }

        [Test]
        public void RewardQueueFailureStaysPendingUntilQueuedAndChoiceIsConfirmed()
        {
            openPortalIds.AddRange(Enumerable.Range(0, 3));
            Assert.That(missions.TryStart(1), Is.True);
            Defense25DPersonalMissionState mission = missions.States[0];
            allowRewardQueue = false;

            foreach (int spawnId in mission.TargetSpawnIds)
                Assert.That(missions.ResolveTarget(7, spawnId, DefenseEnemyResolution.Death), Is.True);

            Assert.That(mission.Status, Is.EqualTo(Defense25DPersonalMissionStatus.RewardPending));
            Assert.That(mission.RewardQueued, Is.False);
            Assert.That(queuedRewardTokens, Is.Empty);
            Assert.That(missions.TryCompleteReward(7, mission.MissionInstanceId), Is.False);

            allowRewardQueue = true;
            Assert.That(missions.TryQueuePendingReward(7, mission.MissionInstanceId), Is.True);
            Assert.That(queuedRewardTokens, Has.Count.EqualTo(1));
            Assert.That(missions.TryQueuePendingReward(7, mission.MissionInstanceId), Is.False);
            Assert.That(mission.Status, Is.EqualTo(Defense25DPersonalMissionStatus.RewardPending));
            Assert.That(missions.TryStart(2), Is.False);
            Assert.That(missions.TryCompleteReward(7, mission.MissionInstanceId), Is.True);
            Assert.That(mission.Status, Is.EqualTo(Defense25DPersonalMissionStatus.Completed));
        }

        [Test]
        public void ArrivalFailsImmediatelyAndDoesNotResolveRemainingEnemiesOrReward()
        {
            openPortalIds.AddRange(Enumerable.Range(0, 3));
            Assert.That(missions.TryStart(1), Is.True);
            IReadOnlyList<int> targets = missions.States[0].TargetSpawnIds;

            Assert.That(missions.ResolveTarget(7, targets[0], DefenseEnemyResolution.Arrival), Is.True);
            Assert.That(missions.States[0].Status, Is.EqualTo(Defense25DPersonalMissionStatus.Failed));
            Assert.That(missions.States[0].RemainingTargetCount, Is.EqualTo(2));
            Assert.That(missions.ResolveTarget(7, targets[1], DefenseEnemyResolution.Death), Is.True);
            Assert.That(missions.States[0].RemainingTargetCount, Is.EqualTo(1));
            Assert.That(queuedRewardTokens, Is.Empty);
        }

        [Test]
        public void UnownedGlobalEliteAndBossSummonIdsCannotCountAsMissionTargets()
        {
            openPortalIds.AddRange(Enumerable.Range(0, 3));
            Assert.That(missions.TryStart(1), Is.True);
            Defense25DPersonalMissionState mission = missions.States[0];
            int globalEliteId = mission.TargetSpawnIds[0];
            int bossSummonId = mission.TargetSpawnIds[1];

            Assert.That(missions.ResolveTarget(7, globalEliteId, Defense25DSpawnSource.GlobalElite,
                1, mission.MissionInstanceId, DefenseEnemyResolution.Death), Is.False);
            Assert.That(missions.ResolveTarget(7, bossSummonId, Defense25DSpawnSource.BossSummon,
                1, mission.MissionInstanceId, DefenseEnemyResolution.Death), Is.False);
            Assert.That(missions.States[0].RemainingTargetCount, Is.EqualTo(3));
            Assert.That(queuedRewardTokens, Is.Empty);
            Assert.That(spawnedRequests.All(request => request.Source == Defense25DSpawnSource.PersonalMission), Is.True);
        }

        [Test]
        public void ResetClearsMissionOwnershipAndRejectsStaleGenerationCallbacks()
        {
            openPortalIds.AddRange(Enumerable.Range(0, 3));
            Assert.That(missions.TryStart(1), Is.True);
            int staleSpawnId = missions.States[0].TargetSpawnIds[0];

            missions.Reset(8, 54321);

            Assert.That(missions.Generation, Is.EqualTo(8));
            Assert.That(missions.States.All(state => state.Status == Defense25DPersonalMissionStatus.Available), Is.True);
            Assert.That(missions.ResolveTarget(7, staleSpawnId, DefenseEnemyResolution.Death), Is.False);
            Assert.That(missions.TryCompleteReward(7, 1), Is.False);
            Assert.That(queuedRewardTokens, Is.Empty);

            Assert.That(missions.TryStart(1), Is.True);
            Assert.That(missions.States[0].MissionInstanceId, Is.EqualTo(1));
            Assert.That(missions.States[0].TargetSpawnIds[0], Is.Not.EqualTo(staleSpawnId));
        }

        private bool SpawnTargets(
            IReadOnlyList<Defense25DPersonalMissionSpawnRequest> requests,
            out IReadOnlyList<int> spawnIds)
        {
            var ids = new List<int>(requests.Count);
            foreach (Defense25DPersonalMissionSpawnRequest request in requests)
            {
                spawnedRequests.Add(request);
                ids.Add(nextSpawnId++);
            }

            spawnIds = ids;
            return true;
        }

        private bool QueueReward(string token)
        {
            if (!allowRewardQueue)
                return false;

            queuedRewardTokens.Add(token);
            return true;
        }
    }
}