using System.Collections.Generic;
using System.Threading;
using Code.OfficeGame.BattleMode.Actions;
using Cysharp.Threading.Tasks;
using UnityEngine;

namespace Code.OfficeGame.BattleMode.Timeline
{
    public class BattleTimeline
    {
        public const int TicksPerSecond = 60;
        public const float TickDelta = 1f / TicksPerSecond;

        public int CurrentBattleFrame { get; private set; }

        private List<EntityTimelineActor> _entities;

        public async UniTask RunBattleLoopAsync(List<EntityTimelineActor> entities, CancellationToken ct)
        {
            _entities = entities;
            
            CurrentBattleFrame = 0;

            await DecideActions(_entities, ct);

            while (!IsBattleOver() && !ct.IsCancellationRequested)
            {
                List<EntityTimelineActor> entitiesNeedOrders = await PlayTimelineUntilPause(ct);

                await DecideActions(entitiesNeedOrders, ct);
            }
        }

        private async UniTask DecideActions(List<EntityTimelineActor> entityActionMakers, CancellationToken ct)
        {
            foreach (var entity in entityActionMakers)
            {
                Debug.Log($"Deciding action for {entity.name}");
                await entity.DecideAction(ct);
            }
        }

        private async UniTask<List<EntityTimelineActor>> PlayTimelineUntilPause(CancellationToken ct)
        {
            float accumulator = 0f;
            var readyEntities = new List<EntityTimelineActor>();

            while (readyEntities.Count == 0 && !ct.IsCancellationRequested)
            {
                await UniTask.Yield(PlayerLoopTiming.Update, ct);

                accumulator += Time.unscaledDeltaTime;

                while (accumulator >= TickDelta)
                {
                    accumulator -= TickDelta;
                    SimulateSingleFrame(readyEntities);

                    if (readyEntities.Count > 0) return readyEntities;
                }
            }

            return readyEntities;
        }

        private void SimulateSingleFrame(List<EntityTimelineActor> outReadyEntities)
        {
            CurrentBattleFrame++;
            
            foreach (var entity in _entities)
            {
                entity.CurrentAction.Tick(TickDelta);
            }

            foreach (var entity in _entities)
            {
                entity.animator.Update(TickDelta);
            }

            Physics.Simulate(TickDelta);
            Physics.SyncTransforms();
            
            foreach (var entity in _entities)
            {
                if (entity.Finished)
                {
                    outReadyEntities.Add(entity);
                }
            }
        }

        private bool IsBattleOver() => false;
    }
}