using System.Linq;
using Content.Server.Atmos.Monitor.Components;
using Content.Server.Atmos.EntitySystems;
using Content.Server.Atmos.Piping.EntitySystems;
using Content.Server.Atmos.Piping.Components;
using Content.Server.DeviceNetwork;
using Content.Server.DeviceNetwork.Components;
using Content.Server.DeviceNetwork.Systems;
using Content.Server.Power.Components;
using Content.Server.Power.EntitySystems;
using Content.Shared.Atmos;
using Content.Shared.Atmos.Monitor;
using Content.Shared.Tag;
using Robust.Server.GameObjects;
using Robust.Shared.Audio;
using Robust.Shared.Player;
using Robust.Shared.Prototypes;

namespace Content.Server.Atmos.Monitor.Systems
{
    // AtmosMonitorSystem. Grabs all the AtmosAlarmables connected
    // to it via local APC net, and starts sending updates of the
    // current atmosphere. Monitors fire (which always triggers as
    // a danger), and atmos (which triggers based on set thresholds).
    public sealed class AtmosMonitorSystem : EntitySystem
    {
        [Dependency] private readonly AtmosphereSystem _atmosphereSystem = default!;
        [Dependency] private readonly AtmosDeviceSystem _atmosDeviceSystem = default!;
        [Dependency] private readonly DeviceNetworkSystem _deviceNetSystem = default!;
        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;

        // Commands
        public const string AtmosMonitorSetThresholdCmd = "atmos_monitor_set_threshold";

        // Packet data
        public const string AlertTypes = "atmos_monitor_alert_types";

        public const string AtmosMonitorThresholdData = "atmos_monitor_threshold_data";

        public const string AtmosMonitorThresholdDataType = "atmos_monitor_threshold_type";

        public const string AtmosMonitorThresholdGasType = "atmos_monitor_threshold_gas";

        public override void Initialize()
        {
            SubscribeLocalEvent<AtmosMonitorComponent, ComponentInit>(OnAtmosMonitorInit);
            SubscribeLocalEvent<AtmosMonitorComponent, ComponentStartup>(OnAtmosMonitorStartup);
            SubscribeLocalEvent<AtmosMonitorComponent, AtmosDeviceUpdateEvent>(OnAtmosUpdate);
            SubscribeLocalEvent<AtmosMonitorComponent, TileFireEvent>(OnFireEvent);
            SubscribeLocalEvent<AtmosMonitorComponent, PowerChangedEvent>(OnPowerChangedEvent);
            SubscribeLocalEvent<AtmosMonitorComponent, BeforePacketSentEvent>(BeforePacketRecv);
            SubscribeLocalEvent<AtmosMonitorComponent, DeviceNetworkPacketEvent>(OnPacketRecv);
        }

        private void OnAtmosMonitorInit(EntityUid uid, AtmosMonitorComponent component, ComponentInit args)
        {
            if (component.TemperatureThresholdId != null)
                component.TemperatureThreshold = new(_prototypeManager.Index<AtmosAlarmThreshold>(component.TemperatureThresholdId));

            if (component.PressureThresholdId != null)
                component.PressureThreshold = new(_prototypeManager.Index<AtmosAlarmThreshold>(component.PressureThresholdId));

            if (component.GasThresholdIds != null)
            {
                component.GasThresholds = new();
                foreach (var (gas, id) in component.GasThresholdIds)
                    if (_prototypeManager.TryIndex<AtmosAlarmThreshold>(id, out var gasThreshold))
                        component.GasThresholds.Add(gas, new(gasThreshold));
            }
        }

        private void OnAtmosMonitorStartup(EntityUid uid, AtmosMonitorComponent component, ComponentStartup args)
        {
            if (!HasComp<ApcPowerReceiverComponent>(uid)
                && TryComp<AtmosDeviceComponent>(uid, out var atmosDeviceComponent))
            {
                _atmosDeviceSystem.LeaveAtmosphere(atmosDeviceComponent);
                return;
            }
        }

        private void BeforePacketRecv(EntityUid uid, AtmosMonitorComponent component, BeforePacketSentEvent args)
        {
            if (!component.NetEnabled) args.Cancel();
        }

        private void OnPacketRecv(EntityUid uid, AtmosMonitorComponent component, DeviceNetworkPacketEvent args)
        {
            // sync the internal 'last alarm state' from
            // the other alarms, so that we can calculate
            // the highest network alarm state at any time
            if (!args.Data.TryGetValue(DeviceNetworkConstants.Command, out string? cmd))
            {
                return;
            }

            switch (cmd)
            {
                case AtmosDeviceNetworkSystem.RegisterDevice:
                    component.RegisteredDevices.Add(args.SenderAddress);
                    break;
                case AtmosAlarmableSystem.ResetAll:
                    Reset(uid);
                    // Don't clear alarm states here.
                    break;
                case AtmosMonitorSetThresholdCmd:
                    if (args.Data.TryGetValue(AtmosMonitorThresholdData, out AtmosAlarmThreshold? thresholdData)
                        && args.Data.TryGetValue(AtmosMonitorThresholdDataType, out AtmosMonitorThresholdType? thresholdType))
                    {
                        args.Data.TryGetValue(AtmosMonitorThresholdGasType, out Gas? gas);
                        SetThreshold(uid, thresholdType.Value, thresholdData, gas);
                    }

                    break;
                case AtmosDeviceNetworkSystem.SyncData:
                    var payload = new NetworkPayload();
                    payload.Add(DeviceNetworkConstants.Command, AtmosDeviceNetworkSystem.SyncData);
                    if (component.TileGas != null)
                    {
                        var gases = new Dictionary<Gas, float>();
                        foreach (var gas in Enum.GetValues<Gas>())
                        {
                            gases.Add(gas, component.TileGas.GetMoles(gas));
                        }

                        payload.Add(AtmosDeviceNetworkSystem.SyncData, new AtmosSensorData(
                            component.TileGas.Pressure,
                            component.TileGas.Temperature,
                            component.TileGas.TotalMoles,
                            component.LastAlarmState,
                            gases,
                            component.PressureThreshold ?? new(),
                            component.TemperatureThreshold ?? new(),
                            component.GasThresholds ?? new()
                        ));
                    }

                    _deviceNetSystem.QueuePacket(uid, args.SenderAddress, payload);
                    break;
            }
        }

        private void OnPowerChangedEvent(EntityUid uid, AtmosMonitorComponent component, PowerChangedEvent args)
        {
            if (TryComp<AtmosDeviceComponent>(uid, out var atmosDeviceComponent))
            {
                if (!args.Powered)
                {
                    if (atmosDeviceComponent.JoinedGrid != null)
                    {
                        _atmosDeviceSystem.LeaveAtmosphere(atmosDeviceComponent);
                        component.TileGas = null;
                    }
                }
                else if (args.Powered)
                {
                    if (atmosDeviceComponent.JoinedGrid == null)
                    {
                        _atmosDeviceSystem.JoinAtmosphere(atmosDeviceComponent);
                        var air = _atmosphereSystem.GetContainingMixture(uid, true);
                        component.TileGas = air;
                    }

                    Alert(uid, component.LastAlarmState);
                }
            }
        }

        private void OnFireEvent(EntityUid uid, AtmosMonitorComponent component, ref TileFireEvent args)
        {
            if (!this.IsPowered(uid, EntityManager))
                return;

            // if we're monitoring for atmos fire, then we make it similar to a smoke detector
            // and just outright trigger a danger event
            //
            // somebody else can reset it :sunglasses:
            if (component.MonitorFire
                && component.LastAlarmState != AtmosMonitorAlarmType.Danger)
            {
                component.TrippedThresholds.Add(AtmosMonitorThresholdType.Temperature);
                Alert(uid, AtmosMonitorAlarmType.Danger, null, component); // technically???
            }

            // only monitor state elevation so that stuff gets alarmed quicker during a fire,
            // let the atmos update loop handle when temperature starts to reach different
            // thresholds and different states than normal -> warning -> danger
            if (component.TemperatureThreshold != null
                && component.TemperatureThreshold.CheckThreshold(args.Temperature, out var temperatureState)
                && temperatureState > component.LastAlarmState)
            {
                component.TrippedThresholds.Add(AtmosMonitorThresholdType.Temperature);
                Alert(uid, AtmosMonitorAlarmType.Danger, null, component);
            }
        }

        private void OnAtmosUpdate(EntityUid uid, AtmosMonitorComponent component, AtmosDeviceUpdateEvent args)
        {
            if (!this.IsPowered(uid, EntityManager))
                return;

            // can't hurt
            // (in case something is making AtmosDeviceUpdateEvents
            // outside the typical device loop)
            if (!TryComp<AtmosDeviceComponent>(uid, out var atmosDeviceComponent)
                || atmosDeviceComponent.JoinedGrid == null)
                return;

            // if we're not monitoring atmos, don't bother
            if (component.TemperatureThreshold == null
                && component.PressureThreshold == null
                && component.GasThresholds == null)
                return;

            UpdateState(uid, component.TileGas, component);
        }

        // Update checks the current air if it exceeds thresholds of
        // any kind.
        //
        // If any threshold exceeds the other, that threshold
        // immediately replaces the current recorded state.
        //
        // If the threshold does not match the current state
        // of the monitor, it is set in the Alert call.
        private void UpdateState(EntityUid uid, GasMixture? air, AtmosMonitorComponent? monitor = null)
        {
            if (air == null) return;

            if (!Resolve(uid, ref monitor)) return;

            AtmosMonitorAlarmType state = AtmosMonitorAlarmType.Normal;
            HashSet<AtmosMonitorThresholdType> alarmTypes = new(monitor.TrippedThresholds);

            if (monitor.TemperatureThreshold != null
                && monitor.TemperatureThreshold.CheckThreshold(air.Temperature, out var temperatureState))
            {
                if (temperatureState > state)
                {
                    state = temperatureState;
                    alarmTypes.Add(AtmosMonitorThresholdType.Temperature);
                }
                else if (temperatureState == AtmosMonitorAlarmType.Normal)
                {
                    alarmTypes.Remove(AtmosMonitorThresholdType.Temperature);
                }
            }

            if (monitor.PressureThreshold != null
                && monitor.PressureThreshold.CheckThreshold(air.Pressure, out var pressureState)
                )
            {
                if (pressureState > state)
                {
                    state = pressureState;
                    alarmTypes.Add(AtmosMonitorThresholdType.Pressure);
                }
                else if (pressureState == AtmosMonitorAlarmType.Normal)
                {
                    alarmTypes.Remove(AtmosMonitorThresholdType.Pressure);
                }
            }

            if (monitor.GasThresholds != null)
            {
                var tripped = false;
                foreach (var (gas, threshold) in monitor.GasThresholds)
                {
                    var gasRatio = air.GetMoles(gas) / air.TotalMoles;
                    if (threshold.CheckThreshold(gasRatio, out var gasState)
                        && gasState > state)
                    {
                        state = gasState;
                        tripped = true;
                    }
                }

                if (tripped)
                {
                    alarmTypes.Add(AtmosMonitorThresholdType.Gas);
                }
                else
                {
                    alarmTypes.Remove(AtmosMonitorThresholdType.Gas);
                }
            }

            // if the state of the current air doesn't match the last alarm state,
            // we update the state
            if (state != monitor.LastAlarmState || !alarmTypes.SetEquals(monitor.TrippedThresholds))
            {
                Alert(uid, state, alarmTypes, monitor);
            }
        }

        /// <summary>
        ///     Alerts the network that the state of a monitor has changed.
        /// </summary>
        /// <param name="state">The alarm state to set this monitor to.</param>
        /// <param name="alarms">The alarms that caused this alarm state.</param>
        public void Alert(EntityUid uid, AtmosMonitorAlarmType state, HashSet<AtmosMonitorThresholdType>? alarms = null, AtmosMonitorComponent? monitor = null)
        {
            if (!Resolve(uid, ref monitor)) return;

            monitor.LastAlarmState = state;
            monitor.TrippedThresholds = alarms ?? monitor.TrippedThresholds;

            BroadcastAlertPacket(monitor);

            // TODO: Central system that grabs *all* alarms from wired network
        }

        /// <summary>
        ///     Resets a single monitor's alarm.
        /// </summary>
        private void Reset(EntityUid uid)
        {
            Alert(uid, AtmosMonitorAlarmType.Normal);
        }

        /// <summary>
        ///	Broadcasts an alert packet to all devices on the network,
        ///	which consists of the current alarm types,
        ///	the highest alarm currently cached by this monitor,
        ///	and the current alarm state of the monitor (so other
        ///	alarms can sync to it).
        /// </summary>
        /// <remarks>
        ///	Alarmables use the highest alarm to ensure that a monitor's
        ///	state doesn't override if the alarm is lower. The state
        ///	is synced between monitors the moment a monitor sends out an alarm,
        ///	or if it is explicitly synced (see ResetAll/Sync).
        /// </remarks>
        private void BroadcastAlertPacket(AtmosMonitorComponent monitor, TagComponent? tags = null)
        {
            if (!monitor.NetEnabled) return;

            if (!Resolve(monitor.Owner, ref tags))
            {
                return;
            }

            var payload = new NetworkPayload
            {
                [DeviceNetworkConstants.Command] = AtmosAlarmableSystem.AlertCmd,
                [DeviceNetworkConstants.CmdSetState] = monitor.LastAlarmState,
                [AtmosAlarmableSystem.AlertSource] = tags.Tags,
                [AtmosAlarmableSystem.AlertTypes] = monitor.TrippedThresholds
            };

            foreach (var addr in monitor.RegisteredDevices)
            {
                _deviceNetSystem.QueuePacket(monitor.Owner, addr, payload);
            }
        }

        /// <summary>
        ///     Set a monitor's threshold.
        /// </summary>
        /// <param name="type">The type of threshold to change.</param>
        /// <param name="threshold">Threshold data.</param>
        /// <param name="gas">Gas, if applicable.</param>
        public void SetThreshold(EntityUid uid, AtmosMonitorThresholdType type, AtmosAlarmThreshold threshold, Gas? gas = null, AtmosMonitorComponent? monitor = null)
        {
            if (!Resolve(uid, ref monitor)) return;

            switch (type)
            {
                case AtmosMonitorThresholdType.Pressure:
                    monitor.PressureThreshold = threshold;
                    break;
                case AtmosMonitorThresholdType.Temperature:
                    monitor.TemperatureThreshold = threshold;
                    break;
                case AtmosMonitorThresholdType.Gas:
                    if (gas == null || monitor.GasThresholds == null) return;
                    monitor.GasThresholds[(Gas) gas] = threshold;
                    break;
            }

        }
    }
}