using System.Collections.Generic;
using UnityEngine;

public class MateMgr : MonoSingleton<MateMgr>
{
    [SerializeField] MateSkillCutSceneView skillCutSceneView;
    [SerializeField] MateSkillCoolTimeView skillCoolTimeView;

    bool isInitialized;

    Dictionary<uint, IVMate> mateInstanceGroup;
    SlotGroup<IVMate> settedMates;

    int currentMateSlotIndex;
    IVMate activeMate;

    List<IHasBuff> activeSynergies = new();

    public SlotGroup<IVMate> SettedMates => settedMates;
    public IVMate ActiveMate => activeMate;

    public void Init()
    {
        if (isInitialized) return;

        mateInstanceGroup = new();
        foreach (var id in MateDataGroup.Instance.MateIDs)
        {
            if (!MateDataGroup.Instance.TryGetMateData(id, out var mate)) continue;

            var instance = Instantiate(mate.Prefab);
            instance.SetData(mate);

            instance.gameObject.SetActive(false);
            mateInstanceGroup.Add(mate.ID, instance);
        }

        settedMates = new SlotGroup<IVMate>(GameProperty.Instance.MateMaxCount);
        foreach (var row in MateDataGroup.Instance.GetMateDataMatrix(MateData.CompareBySettedSlotIndex))
        {
            settedMates.GetEmptySlots(out var emptySlots);
            foreach (var mate in row)
            {
                if(emptySlots.Count == 0) break;

                if(mate.IsSetted)
                {
                    SetMateAt(mate.ID, mate.SettedSlotIndex);
                    emptySlots.RemoveAt(0);
                }
            }
        }

        isInitialized = true;
    }

    private void Update()
    {
        if(!isInitialized || BattleMgr.Instance.BattlePause) return;

        for(int i = 0; i < settedMates.SlotCount; i++)
        {
            var currentSlot = settedMates.GetSlot(i);

            if(!currentSlot.IsEmpty)
                currentSlot.item.UpdateSkillCoolTime();
        }

        if (activeMate is null) return;

        if (IsSafeToChangeCurrentMate() && activeMate.Skill.IsInCoolTime)
        {
            for (int i = currentMateSlotIndex + 1; true; i++)
            {
                int nextIndex = i % settedMates.SlotCount;
                if (nextIndex == currentMateSlotIndex) break;

                var slot = settedMates.GetSlot(nextIndex);
                if (!slot.IsEmpty)
                {
                    if(!slot.item.Skill.IsInCoolTime)
                        ChangeActiveMate(slot.item, slot.slotIndex);
                    break;
                }
            }
        }

        if (activeMate.CastSkill())
        {
            skillCutSceneView.Show();
        }
    }

    private void ChangeActiveMate(IVMate target, int slotIndex)
    {
        var player = BattleMgr.Instance.GetPlayer();

        Transform spawnTrans = null;
        Vector2 lookDir = player.LookDirection;

        if (activeMate != null && activeMate != target)
        {
            spawnTrans = activeMate.transform;
            lookDir = activeMate.LookDirection;
            activeMate.Dispose();
        }

        currentMateSlotIndex = slotIndex;
        activeMate = target;
        activeMate.Spawn(player, lookDir, spawnTrans);

        skillCutSceneView.SetMate(activeMate);
    }

    public bool IsSafeToChangeCurrentMate() => activeMate?.IsSafeChange ?? true;

    public void SetMateAt(uint id, int slotIndex)
    {
        Debug.Assert(slotIndex >= 0 && slotIndex < GameProperty.Instance.MateMaxCount, "Invalid spawn position index");

        if (!mateInstanceGroup.TryGetValue(id, out var targetMate) || settedMates.TryGetSlot(targetMate, out SlotGroup<IVMate>.Slot _)) return;

        if (settedMates.TryGetItem(slotIndex, out IVMate existedMate))
        {
            existedMate.Data.RemoveSlotIndex();
            existedMate.Dispose();
            settedMates.ClearSlot(slotIndex);

            if(activeMate == existedMate)
                activeMate = null;
        }

        settedMates[slotIndex] = targetMate;
        targetMate.Data.SetSlotIndex(slotIndex);

        if (activeMate is null)
            ChangeActiveMate(targetMate, slotIndex);

        RefreshSynergies();

        skillCoolTimeView?.SetMateAt(settedMates.GetSlot(slotIndex));
    }

    public void RemoveMateAt(int slotIndex)
    {
        Debug.Assert(slotIndex >= 0 && slotIndex < GameProperty.Instance.MateMaxCount, "Invalid spawn position index");

        if (!settedMates.TryGetItem(slotIndex, out IVMate existedMate)) return;

        existedMate.Data.RemoveSlotIndex();
        existedMate.Dispose();
        settedMates.ClearSlot(slotIndex);

        if (activeMate == existedMate)
        {
            for(int i = currentMateSlotIndex + 1; true; i++)
            {
                int nextIndex = i % settedMates.SlotCount;
                if (nextIndex == currentMateSlotIndex)
                {
                    currentMateSlotIndex = -1;
                    activeMate = null;
                    break;
                }

                var slot = settedMates.GetSlot(nextIndex);

                if(!slot.IsEmpty)
                {
                    ChangeActiveMate(slot.item, slot.slotIndex);
                    break;
                }
            }
        }

        RefreshSynergies();

        skillCoolTimeView?.RemoveMateAt(slotIndex);
    }

    public void SetAcitveMateToFirst()
    {
        for(int i = 0; i < settedMates.SlotCount; i++)
        {
            var slot = settedMates.GetSlot(i);
            if(!slot.IsEmpty)
            {
                currentMateSlotIndex = i;
                activeMate = slot.item;
                skillCutSceneView?.SetMate(activeMate);
                break;
            }
        }
    }

    public void EndAllSettedMateSkillCool()
    {
        settedMates.LoopValidSlot((mate) =>
        {
            mate.Skill.EndCoolTime();
            return true;
        });
    }

    private void RefreshSynergies()
    {
        foreach (var synergy in activeSynergies)
        {
            GamePlayBuffMgr.Instance.RemoveBuffs(synergy.Buffs);
        }
        activeSynergies.Clear();

        _RefreshSynergies(settedMates.ConvertAll((mate) => mate.Data.Nationality), MateDataGroup.Instance.NationalitySynergies);
        _RefreshSynergies(settedMates.ConvertAll((mate) => mate.Data.Grade), MateDataGroup.Instance.GradeSynergies);
        _RefreshSynergies(settedMates.ConvertAll((mate) => mate.Data.Property), MateDataGroup.Instance.DestinySynergies);

        foreach (var synergy in activeSynergies)
        {
            GamePlayBuffMgr.Instance.AddBuffs(synergy.Buffs);
        }
    }

    private void _RefreshSynergies<T>(IReadOnlyList<T> toCheck, IReadOnlyList<SynergyData<T>> synergyDatas)
    {
        foreach (var synergyData in synergyDatas)
        {
            if (synergyData.CheckCondition(toCheck))
            {
                activeSynergies.Add(synergyData);
            }
        }
    }
}