using System.Linq;
using System.Numerics;
using Content.Server._CP14.Demiplane;
using Content.Server._CP14.Demiplane.Components;
using Content.Server.Destructible;
using Content.Server.Station.Systems;
using Content.Shared._CP14.Demiplane.Components;
using Content.Shared._CP14.Demiplane.Prototypes;
using Content.Shared._CP14.DemiplaneTraveling;
using Content.Shared.Damage;
using Content.Shared.Destructible;
using Content.Shared.Popups;
using Content.Shared.Pulling.Events;
using Content.Shared.UserInterface;
using Robust.Server.GameObjects;
using Robust.Shared.Audio.Systems;
using Robust.Shared.Prototypes;
using Robust.Shared.Random;

namespace Content.Server._CP14.DemiplaneTraveling;

public sealed partial class CP14StationDemiplaneMapSystem : CP14SharedStationDemiplaneMapSystem
{
    [Dependency] private readonly UserInterfaceSystem _userInterface = default!;
    [Dependency] private readonly StationSystem _station = default!;
    [Dependency] private readonly IPrototypeManager _proto = default!;
    [Dependency] private readonly IRobustRandom _random = default!;
    [Dependency] private readonly CP14DemiplaneSystem _demiplane = default!;
    [Dependency] private readonly SharedAudioSystem _audio = default!;
    [Dependency] private readonly SharedPopupSystem _popup = default!;
    [Dependency] private readonly DestructibleSystem _destructible = default!;
    [Dependency] private readonly DamageableSystem _damageable = default!;

    public override void Initialize()
    {
        base.Initialize();

        SubscribeLocalEvent<CP14StationDemiplaneMapComponent, MapInitEvent>(OnMapInit);

        SubscribeLocalEvent<CP14DemiplaneNavigationMapComponent, CP14DemiplaneMapEjectMessage>(DemiplaneEjectAttempt);
        SubscribeLocalEvent<CP14DemiplaneNavigationMapComponent, CP14DemiplaneMapRevokeMessage>(DemiplaneRevokeAttempt);

        SubscribeLocalEvent<CP14DemiplaneNavigationMapComponent, BeforeActivatableUIOpenEvent>(OnBeforeActivatableUiOpen);
        SubscribeLocalEvent<CP14DemiplaneMapNodeBlockerComponent, ComponentShutdown>(OnNodeBlockerShutdown);

        SubscribeLocalEvent<CP14DemiplaneCoreComponent, MapInitEvent>(OnCoreInit);
        SubscribeLocalEvent<CP14DemiplaneCoreComponent, DestructionEventArgs>(OnCoreShutdown);
    }

    private void OnCoreShutdown(Entity<CP14DemiplaneCoreComponent> ent, ref DestructionEventArgs args)
    {
        if (TryComp<CP14DemiplaneComponent>(ent.Comp.Demiplane, out var demiplane))
        {
            _demiplane.StartDestructDemiplane((ent.Comp.Demiplane.Value, demiplane));
        }

        var query = EntityQueryEnumerator<CP14StationDemiplaneMapComponent>();
        while (query.MoveNext(out var uid, out var stationMap))
        {
            if (stationMap.Nodes.TryGetValue(ent.Comp.Position, out var node))
            {
                node.Completed = true;
            }
        }
    }

    private void OnCoreInit(Entity<CP14DemiplaneCoreComponent> core, ref MapInitEvent args)
    {
        core.Comp.Demiplane = Transform(core).MapUid;
        if (!TryComp<CP14DemiplaneMapNodeBlockerComponent>(core.Comp.Demiplane, out var demiBlocker))
            return;

        core.Comp.Station = demiBlocker.Station;
        core.Comp.Position = demiBlocker.Position;

        EnsureComp<CP14DemiplaneMapNodeBlockerComponent>(core, out var coreBlocker);

        coreBlocker.Position = core.Comp.Position;
        coreBlocker.Station = core.Comp.Station;
        coreBlocker.IncreaseNodeDifficulty = 0;
    }

    private void OnNodeBlockerShutdown(Entity<CP14DemiplaneMapNodeBlockerComponent> ent, ref ComponentShutdown args)
    {
        if (!TryComp<CP14StationDemiplaneMapComponent>(ent.Comp.Station, out var stationMap))
            return;

        if (!stationMap.Nodes.TryGetValue(ent.Comp.Position, out var node))
            return;

        if (ent.Comp.IncreaseNodeDifficulty == 0)
            return;

        node.AdditionalLevel += ent.Comp.IncreaseNodeDifficulty;
        GenerateNodeData(node, clearOldModifiers: true);
    }

    private void DemiplaneEjectAttempt(Entity<CP14DemiplaneNavigationMapComponent> ent, ref CP14DemiplaneMapEjectMessage args)
    {
        var station = _station.GetOwningStation(ent, Transform(ent));

        if (!TryComp<CP14StationDemiplaneMapComponent>(station, out var stationMap))
            return;

        if (!stationMap.Nodes.TryGetValue(args.Position, out var node))
            return;

        if (!node.InFrontierZone)
            return;

        //Eject!
        var key = SpawnAttachedTo(ent.Comp.KeyProto, Transform(ent).Coordinates);
        _audio.PlayPvs(ent.Comp.EjectSound, Transform(key).Coordinates);

        if (TryComp<CP14DemiplaneDataComponent>(key, out var demiData))
        {
            demiData.Location = node.LocationConfig;
            demiData.SelectedModifiers.AddRange(node.Modifiers);
        }

        EnsureComp<CP14DemiplaneMapNodeBlockerComponent>(key, out var blockerComp);
        blockerComp.Position = args.Position;
        blockerComp.Station = station;
    }

    private void DemiplaneRevokeAttempt(Entity<CP14DemiplaneNavigationMapComponent> ent, ref CP14DemiplaneMapRevokeMessage args)
    {
        var station = _station.GetOwningStation(ent, Transform(ent));

        var query = EntityQueryEnumerator<CP14DemiplaneMapNodeBlockerComponent>();
        while (query.MoveNext(out var uid, out var blocker))
        {
            if (blocker.Station != station)
                continue;

            if (blocker.Position != args.Position)
                continue;

            if (!TryComp<CP14StationDemiplaneMapComponent>(station, out var demiStation))
                continue;

            if (!demiStation.Nodes.TryGetValue(args.Position, out var node))
                continue;

            SpawnAttachedTo("CP14ImpactEffectMagicSplitting", Transform(ent).Coordinates);

            //If it's a demiplane, initiate closure. If not, just delete it.
            if (TryComp<CP14DemiplaneComponent>(uid, out var demiplane))
            {
                _demiplane.StartDestructDemiplane((uid, demiplane));
                _popup.PopupEntity(Loc.GetString("cp14-demiplane-revoke-map"), ent);
            }
            else
            {
                SpawnAttachedTo("CP14ImpactEffectMagicSplitting", Transform(uid).Coordinates);
                _popup.PopupEntity(Loc.GetString("cp14-demiplane-revoke-item"), ent);
                _popup.PopupEntity(Loc.GetString("cp14-demiplane-revoke-item"), uid);
                _damageable.TryChangeDamage(uid, ent.Comp.RevokeDamage, true);
                _destructible.DestroyEntity(uid);
            }
        }
    }

    private void OnBeforeActivatableUiOpen(Entity<CP14DemiplaneNavigationMapComponent> ent,
        ref BeforeActivatableUIOpenEvent args)
    {
        var station = _station.GetOwningStation(ent, Transform(ent));

        if (!TryComp<CP14StationDemiplaneMapComponent>(station, out var stationMap))
            return;

        UpdateNodesStatus((station.Value, stationMap));

        _userInterface.SetUiState(ent.Owner,
            CP14DemiplaneMapUiKey.Key,
            new CP14DemiplaneMapUiState(stationMap.Nodes, stationMap.Edges));
    }

    private void OnMapInit(Entity<CP14StationDemiplaneMapComponent> ent, ref MapInitEvent args)
    {
        GenerateDemiplaneMap(ent);
    }

    private void GenerateDemiplaneMap(Entity<CP14StationDemiplaneMapComponent> ent)
    {
        ent.Comp.Nodes.Clear();
        ent.Comp.Edges.Clear();

        var allSpecials = _proto.EnumeratePrototypes<CP14SpecialDemiplanePrototype>().ToList();
        _random.Shuffle(allSpecials);

        var grid = new Dictionary<Vector2i, CP14DemiplaneMapNode>();

        //Spawn start room at 0 0
        var startPos = new Vector2i(0, 0);
        var startNode = new CP14DemiplaneMapNode(0, startPos, true);
        grid[startPos] = startNode;

        //Spawn special rooms
        var specialCount = _random.Next(ent.Comp.Specials.Min, ent.Comp.Specials.Max + 1);
        var placedSpecials = 0;
        var specialPositions = new List<Vector2i>();

        foreach (var special in allSpecials)
        {
            if (placedSpecials >= specialCount)
                break;

            var specialLevel = special.Levels.Next(_random);

            var possiblePositions = new List<Vector2i>();
            for (var x = -specialLevel; x <= specialLevel; x++)
            {
                var y = specialLevel - Math.Abs(x);
                if (y != 0)
                    possiblePositions.Add(new Vector2i(x, y));
                possiblePositions.Add(new Vector2i(x, -y));
            }

            _random.Shuffle(possiblePositions);

            var specialPos = new Vector2i(0, 0);
            foreach (var pos in possiblePositions)
            {
                if (!grid.ContainsKey(pos))
                {
                    specialPos = pos;
                    break;
                }
            }

            if (grid.ContainsKey(specialPos))
                continue;

            var specialNode = new CP14DemiplaneMapNode(
                specialLevel,
                new Vector2(specialPos.X, specialPos.Y),
                false,
                locationConfig: special.Location,
                modifiers: [..special.Modifiers]
            );
            grid[specialPos] = specialNode;
            specialPositions.Add(specialPos);
            placedSpecials++;
        }

        // Build meandering paths to each special room and add edges
        foreach (var specialPos in specialPositions)
        {
            var current = startPos;

            while (current != specialPos)
            {
                var delta = specialPos - current;
                var options = new List<Vector2i>();

                if (delta.X != 0)
                    options.Add(new Vector2i(Math.Sign(delta.X), 0));
                if (delta.Y != 0)
                    options.Add(new Vector2i(0, Math.Sign(delta.Y)));

                // Add the possibility of a "mistaken" step to the side
                if (_random.Prob(0.3f)) // 30% chance to take a side step
                {
                    if (delta.X != 0 && delta.Y != 0)
                    {
                        options.Add(new Vector2i(0, Math.Sign(delta.Y)) * -1);
                        options.Add(new Vector2i(Math.Sign(delta.X), 0) * -1);
                    }
                }

                _random.Shuffle(options);
                var step = options[0];
                var next = current + step;

                if (!grid.TryGetValue(next, out var nextNode))
                {
                    nextNode = new CP14DemiplaneMapNode(Math.Abs(next.X) + Math.Abs(next.Y),
                        new Vector2(next.X, next.Y),
                        false);
                    grid[next] = nextNode;
                }

                ent.Comp.Edges.Add((current, next));

                current = next;
            }
        }

        //Fill nodes with random data
        foreach (var node in grid.Values)
        {
            GenerateNodeData(node);
        }

        // Random visual offset
        foreach (var node in grid.Values)
        {
            var x = node.UiPosition.X + _random.NextFloat(-0.2f, 0.2f);
            var y = node.UiPosition.Y + _random.NextFloat(-0.2f, 0.2f);
            node.UiPosition = new Vector2(x, y);
        }

        //Add all rooms into component
        ent.Comp.Nodes = grid;
    }

    private void GenerateNodeData(CP14DemiplaneMapNode node, bool clearOldModifiers = false)
    {
        if (node.Level == 0)
            return;

        var location = _demiplane.GenerateDemiplaneLocation(node.Level);
        node.LocationConfig ??= location;

        var limits = new Dictionary<ProtoId<CP14DemiplaneModifierCategoryPrototype>, float>
        {
            { "Danger", (node.Level + node.AdditionalLevel) * 0.2f },
            { "GhostRoleDanger", 1f },
            { "Reward", Math.Max(node.Level * 0.2f, 0.5f) },
            { "Ore", Math.Max(node.Level * 0.2f, 0.5f) },
            { "Fun", 1f },
            { "Weather", 1f },
            { "MapLight", 1f },
        };
        var mods = _demiplane.GenerateDemiplaneModifiers(node.Level, location, limits);

        if (clearOldModifiers)
            node.Modifiers.Clear();
        foreach (var mod in mods)
        {
            node.Modifiers.Add(mod);
        }
    }

    private void UpdateNodesStatus(Entity<CP14StationDemiplaneMapComponent> ent)
    {
        foreach (var node in ent.Comp.Nodes)
        {
            node.Value.InFrontierZone = NodeInFronrierZone(ent.Comp.Nodes, ent.Comp.Edges, node.Key);
            node.Value.InUsing = false;
        }

        var query = EntityQueryEnumerator<CP14DemiplaneMapNodeBlockerComponent>();
        while (query.MoveNext(out var uid, out var blocker))
        {
            if (!TryComp<CP14StationDemiplaneMapComponent>(blocker.Station, out var stationMap))
                continue;

            if (!stationMap.Nodes.TryGetValue(blocker.Position, out var node))
                continue;

            node.InUsing = true;
        }
    }
}