using System;
using Content.Server.Alert;
using Content.Shared.Alert;
using Content.Shared.Atmos;
using Content.Shared.Damage;
using Content.Shared.Damage.Components;
using Robust.Shared.GameObjects;
using Robust.Shared.Physics;
using Robust.Shared.Serialization.Manager.Attributes;
using Robust.Shared.ViewVariables;
using Robust.Shared.IoC;
using Robust.Shared.Prototypes;

namespace Content.Server.Temperature.Components
{
    /// <summary>
    /// Handles changing temperature,
    /// informing others of the current temperature,
    /// and taking fire damage from high temperature.
    /// </summary>
    [RegisterComponent]
    public class TemperatureComponent : Component
    {
        /// <inheritdoc />
        public override string Name => "Temperature";

        [DataField("heatDamageThreshold")]
        private float _heatDamageThreshold = default;
        [DataField("coldDamageThreshold")]
        private float _coldDamageThreshold = default;
        [DataField("tempDamageCoefficient")]
        private float _tempDamageCoefficient = 1;
        [DataField("currentTemperature")]
        public float CurrentTemperature { get; set; } = Atmospherics.T20C;
        [DataField("specificHeat")]
        private float _specificHeat = Atmospherics.MinimumHeatCapacity;

        [ViewVariables] public float HeatDamageThreshold => _heatDamageThreshold;
        [ViewVariables] public float ColdDamageThreshold => _coldDamageThreshold;
        [ViewVariables] public float TempDamageCoefficient => _tempDamageCoefficient;
        [ViewVariables] public float SpecificHeat => _specificHeat;
        [ViewVariables] public float HeatCapacity {
            get
            {
                if (Owner.TryGetComponent<IPhysBody>(out var physics))
                {
                    return SpecificHeat * physics.Mass;
                }

                return Atmospherics.MinimumHeatCapacity;
            }
        }

        // TODO PROTOTYPE Replace this datafield variable with prototype references, once they are supported.
        // Also remove Initialize override, if no longer needed.
        [DataField("coldDamageType")]
        private readonly string _coldDamageTypeID = "Cold";
        [ViewVariables(VVAccess.ReadWrite)]
        public DamageTypePrototype ColdDamageType = default!;
        [DataField("hotDamageType")]
        private readonly string _hotDamageTypeID = "Heat";
        [ViewVariables(VVAccess.ReadWrite)]
        public DamageTypePrototype HotDamageType = default!;
        protected override void Initialize()
        {
            base.Initialize();
            ColdDamageType = IoCManager.Resolve<IPrototypeManager>().Index<DamageTypePrototype>(_coldDamageTypeID);
            HotDamageType = IoCManager.Resolve<IPrototypeManager>().Index<DamageTypePrototype>(_hotDamageTypeID);
        }

        public void Update()
        {

            if (Owner.TryGetComponent(out ServerAlertsComponent? status))
            {
                switch (CurrentTemperature)
                {
                    // Cold strong.
                    case <= 260:
                        status.ShowAlert(AlertType.Cold, 3);
                        break;

                    // Cold mild.
                    case <= 280 and > 260:
                        status.ShowAlert(AlertType.Cold, 2);
                        break;

                    // Cold weak.
                    case <= 292 and > 280:
                        status.ShowAlert(AlertType.Cold, 1);
                        break;

                    // Safe.
                    case <= 327 and > 292:
                        status.ClearAlertCategory(AlertCategory.Temperature);
                        break;

                    // Heat weak.
                    case <= 335 and > 327:
                        status.ShowAlert(AlertType.Hot, 1);
                        break;

                    // Heat mild.
                    case <= 345 and > 335:
                        status.ShowAlert(AlertType.Hot, 2);
                        break;

                    // Heat strong.
                    case > 345:
                        status.ShowAlert(AlertType.Hot, 3);
                        break;
                }
            }

            if (!Owner.TryGetComponent(out IDamageableComponent? component)) return;

            if (CurrentTemperature >= _heatDamageThreshold)
            {
                int tempDamage = (int) Math.Floor((CurrentTemperature - _heatDamageThreshold) * _tempDamageCoefficient);
                component.TryChangeDamage(HotDamageType, tempDamage, false);
            }
            else if (CurrentTemperature <= _coldDamageThreshold)
            {
                int tempDamage = (int) Math.Floor((_coldDamageThreshold - CurrentTemperature) * _tempDamageCoefficient);
                component.TryChangeDamage(ColdDamageType, tempDamage, false);
            }
            
        }

        /// <summary>
        /// Forcefully give heat to this component
        /// </summary>
        /// <param name="heatAmount"></param>
        public void ReceiveHeat(float heatAmount)
        {
            CurrentTemperature += heatAmount / HeatCapacity;
        }

        /// <summary>
        /// Forcefully remove heat from this component
        /// </summary>
        /// <param name="heatAmount"></param>
        public void RemoveHeat(float heatAmount)
        {
            CurrentTemperature -= heatAmount / HeatCapacity;
        }

    }
}