using System;
using AibisDream.Utility;
using UnityEngine;

namespace AibisDream
{
    public class EngineSystem : MonoBehaviour
    {
        [SerializeField] private float oilDownRatio;
        [SerializeField] private float oilUpRatio;
        [SerializeField] private float acceleratedSpeed;
        [SerializeField] private float resistance;
        [SerializeField] private float airMaxRatio;
        [SerializeField] private float airMinRatio;
        [SerializeField] private float baseAirMax;
        [SerializeField] public int maxLevel;

        private EngineData _engineData;

        public event Action<EngineData> UpdateDashboard;

        private void OnEnable()
        {
            _engineData = new EngineData();
        }

        private void Update()
        {
            // 更新部分按时间自然计算的指标
            DataAutoChange();
            // 更新看板
            UpdateDashboard?.Invoke(_engineData);
        }

        private void DataAutoChange()
        {
            // 自然减速
            _engineData.OilChange(-oilDownRatio);
            _engineData.CalcAir(airMaxRatio, airMinRatio, baseAirMax);
            // 推算速度
            _engineData.CalcSpeed(acceleratedSpeed, resistance);
        }

        /// <summary>
        /// 加速过程
        /// </summary>
        public void AddOil()
        {
            _engineData.OilChange(oilUpRatio);
        }

        public void SubtractAirLevel()
        {
            _engineData.SubtractAirLevel();
        }

        public void AddAirLevel()
        {
            _engineData.AddAirLevel();
        }
    }

    public struct EngineData
    {
        public float curSpeed;
        public float curOil;
        public float curAir;
        public float curAirMin;
        public float curAirMax;

        public int curAirLevel;

        public void OilChange(float oilChangeRatio)
        {
            curOil = CommonUtil.LimitedAdd(curOil, oilChangeRatio * Time.deltaTime, 1f, 0f);
        }

        public void CalcSpeed(float acceleratedSpeed, float resistance)
        {
            var addNum = InAirLevel()
                ? (curOil * acceleratedSpeed - curSpeed * resistance) * Time.deltaTime
                : -curSpeed * resistance * Time.deltaTime;

            curSpeed = CommonUtil.LimitedAdd(curSpeed, addNum, 1f, 0f);
        }

        public void CalcAir(float airMaxRatio, float airMinRatio, float baseAirMax)
        {
            curAir = curOil;

            curAirMax = curSpeed * (curAirLevel + 1) * airMaxRatio + baseAirMax;
            curAirMin = curSpeed * (curAirLevel + 1) * airMinRatio;
        }

        public void AddAirLevel()
        {
            curAirLevel += 1;
            if (curAirLevel > 5)
            {
                curAirLevel = 4;
            }

            if (curAirLevel < 0)
            {
                curAirLevel = 0;
            }
        }

        public void SubtractAirLevel()
        {
            curAirLevel -= 1;
            if (curAirLevel > 5)
            {
                curAirLevel = 4;
            }

            if (curAirLevel < 0)
            {
                curAirLevel = 0;
            }
        }

        private bool InAirLevel()
        {
            return curAir <= curAirMax && curAir >= curAirMin;
        }
    }
}