using System.Linq;
using System.Numerics;
using Content.Server.Gateway.Components;
using Content.Server.Parallax;
using Content.Server.Procedural;
using Content.Shared.Dataset;
using Content.Shared.Movement.Components;
using Content.Shared.Parallax.Biomes;
using Content.Shared.Physics;
using Content.Shared.Procedural;
using Content.Shared.Salvage;
using Robust.Shared.Map;
using Robust.Shared.Map.Components;
using Robust.Shared.Physics.Collision.Shapes;
using Robust.Shared.Physics.Components;
using Robust.Shared.Physics.Systems;
using Robust.Shared.Prototypes;
using Robust.Shared.Random;
using Robust.Shared.Timing;
using Robust.Shared.Utility;

namespace Content.Server.Gateway.Systems;

/// <summary>
/// Generates gateway destinations regularly and indefinitely that can be chosen from.
/// </summary>
public sealed class GatewayGeneratorSystem : EntitySystem
{
    [Dependency] private readonly IGameTiming _timing = default!;
    [Dependency] private readonly IMapManager _mapManager = default!;
    [Dependency] private readonly IPrototypeManager _protoManager = default!;
    [Dependency] private readonly IRobustRandom _random = default!;
    [Dependency] private readonly ITileDefinitionManager _tileDefManager = default!;
    [Dependency] private readonly BiomeSystem _biome = default!;
    [Dependency] private readonly DungeonSystem _dungeon = default!;
    [Dependency] private readonly FixtureSystem _fixtures = default!;
    [Dependency] private readonly GatewaySystem _gateway = default!;
    [Dependency] private readonly MetaDataSystem _metadata = default!;
    [Dependency] private readonly SharedMapSystem _maps = default!;
    [Dependency] private readonly SharedPhysicsSystem _physics = default!;

    [ValidatePrototypeId<DatasetPrototype>]
    private const string PlanetNames = "names_borer";

    // TODO:
    // Fix shader some more
    // Show these in UI
    // Use regular mobs for thingo.

    // Use salvage mission params
    // Add the funny song
    // Put salvage params in the UI

    // Re-use salvage config stuff for the RNG
    // Have it in the UI like expeditions.

    // Also add weather coz it's funny.

    // Add songs (incl. the downloaded one) to the ambient music playlist for planet probably.
    // Copy most of salvage mission spawner

    public override void Initialize()
    {
        base.Initialize();
        SubscribeLocalEvent<GatewayGeneratorComponent, EntityUnpausedEvent>(OnGeneratorUnpaused);
        SubscribeLocalEvent<GatewayGeneratorComponent, MapInitEvent>(OnGeneratorMapInit);
        SubscribeLocalEvent<GatewayGeneratorComponent, ComponentShutdown>(OnGeneratorShutdown);
        SubscribeLocalEvent<GatewayGeneratorDestinationComponent, AttemptGatewayOpenEvent>(OnGeneratorAttemptOpen);
        SubscribeLocalEvent<GatewayGeneratorDestinationComponent, GatewayOpenEvent>(OnGeneratorOpen);
    }

    private void OnGeneratorShutdown(EntityUid uid, GatewayGeneratorComponent component, ComponentShutdown args)
    {
        foreach (var genUid in component.Generated)
        {
            if (Deleted(genUid))
                continue;

            QueueDel(genUid);
        }
    }

    private void OnGeneratorUnpaused(Entity<GatewayGeneratorComponent> ent, ref EntityUnpausedEvent args)
    {
        ent.Comp.NextUnlock += args.PausedTime;
    }

    private void OnGeneratorMapInit(EntityUid uid, GatewayGeneratorComponent generator, MapInitEvent args)
    {
        for (var i = 0; i < 3; i++)
        {
            GenerateDestination(uid, generator);
        }

        Dirty(uid, generator);
    }

    private void GenerateDestination(EntityUid uid, GatewayGeneratorComponent? generator = null)
    {
        if (!Resolve(uid, ref generator))
            return;

        var tileDef = _tileDefManager["FloorSteel"];
        const int MaxOffset = 256;
        var tiles = new List<(Vector2i Index, Tile Tile)>();
        var seed = _random.Next();
        var random = new Random(seed);
        var mapId = _mapManager.CreateMap();
        var mapUid = _mapManager.GetMapEntityId(mapId);
        var origin = new Vector2i(random.Next(-MaxOffset, MaxOffset), random.Next(-MaxOffset, MaxOffset));
        var restriction = AddComp<RestrictedRangeComponent>(mapUid);
        restriction.Origin = origin;
        _biome.EnsurePlanet(mapUid, _protoManager.Index<BiomeTemplatePrototype>("Continental"), seed);

        var grid = Comp<MapGridComponent>(mapUid);

        for (var x = -2; x <= 2; x++)
        {
            for (var y = -2; y <= 2; y++)
            {
                tiles.Add((new Vector2i(x, y) + origin, new Tile(tileDef.TileId, variant: random.NextByte(tileDef.Variants))));
            }
        }

        // Clear area nearby as a sort of landing pad.
        _maps.SetTiles(mapUid, grid, tiles);

        var gatewayName = SharedSalvageSystem.GetFTLName(_protoManager.Index<DatasetPrototype>(PlanetNames), seed);

        _metadata.SetEntityName(mapUid, gatewayName);
        var originCoords = new EntityCoordinates(mapUid, origin);

        var genDest = AddComp<GatewayGeneratorDestinationComponent>(mapUid);
        genDest.Origin = origin;
        genDest.Seed = seed;
        genDest.Generator = uid;

        // Enclose the area
        var boundaryUid = Spawn(null, originCoords);
        var boundaryPhysics = AddComp<PhysicsComponent>(boundaryUid);
        var cShape = new ChainShape();
        // Don't need it to be a perfect circle, just need it to be loosely accurate.
        cShape.CreateLoop(Vector2.Zero, restriction.Range + 1f, false, count: 4);
        _fixtures.TryCreateFixture(
            boundaryUid,
            cShape,
            "boundary",
            collisionLayer: (int) (CollisionGroup.HighImpassable | CollisionGroup.Impassable | CollisionGroup.LowImpassable),
            body: boundaryPhysics);
        _physics.WakeBody(boundaryUid, body: boundaryPhysics);
        AddComp<BoundaryComponent>(boundaryUid);

        // Create the gateway.
        var gatewayUid = SpawnAtPosition(generator.Proto, originCoords);
        var gatewayComp = Comp<GatewayComponent>(gatewayUid);
        _gateway.SetDestinationName(gatewayUid, FormattedMessage.FromMarkup($"[color=#D381C996]{gatewayName}[/color]"), gatewayComp);
        _gateway.SetEnabled(gatewayUid, true, gatewayComp);
        generator.Generated.Add(mapUid);
    }

    private void OnGeneratorAttemptOpen(Entity<GatewayGeneratorDestinationComponent> ent, ref AttemptGatewayOpenEvent args)
    {
        if (ent.Comp.Loaded || args.Cancelled)
            return;

        if (!TryComp(ent.Comp.Generator, out GatewayGeneratorComponent? generatorComp))
            return;

        if (generatorComp.NextUnlock + _metadata.GetPauseTime(ent.Owner) <= _timing.CurTime)
            return;

        args.Cancelled = true;
    }

    private void OnGeneratorOpen(Entity<GatewayGeneratorDestinationComponent> ent, ref GatewayOpenEvent args)
    {
        if (ent.Comp.Loaded)
            return;

        if (TryComp(ent.Comp.Generator, out GatewayGeneratorComponent? generatorComp))
        {
            generatorComp.NextUnlock = _timing.CurTime + generatorComp.UnlockCooldown;
            _gateway.UpdateAllGateways();
            // Generate another destination to keep them going.
            GenerateDestination(ent.Comp.Generator);
        }

        if (!TryComp(args.MapUid, out MapGridComponent? grid))
            return;

        ent.Comp.Locked = false;
        ent.Comp.Loaded = true;

        // Do dungeon
        var seed = ent.Comp.Seed;
        var origin = ent.Comp.Origin;
        var random = new Random(seed);
        var dungeonDistance = random.Next(3, 6);
        var dungeonRotation = _dungeon.GetDungeonRotation(seed);
        var dungeonPosition = (origin + dungeonRotation.RotateVec(new Vector2i(0, dungeonDistance))).Floored();

        _dungeon.GenerateDungeon(_protoManager.Index<DungeonConfigPrototype>("Experiment"), args.MapUid, grid, dungeonPosition, seed);

        // TODO: Dungeon mobs + loot.

        // Do markers on the map.
        if (TryComp(ent.Owner, out BiomeComponent? biomeComp) && generatorComp != null)
        {
            // - Loot
            var lootLayers = generatorComp.LootLayers.ToList();

            for (var i = 0; i < generatorComp.LootLayerCount; i++)
            {
                var layerIdx = random.Next(lootLayers.Count);
                var layer = lootLayers[layerIdx];
                lootLayers.RemoveSwap(layerIdx);

                _biome.AddMarkerLayer(biomeComp, layer.Id);
            }

            // - Mobs
            var mobLayers = generatorComp.MobLayers.ToList();

            for (var i = 0; i < generatorComp.MobLayerCount; i++)
            {
                var layerIdx = random.Next(mobLayers.Count);
                var layer = mobLayers[layerIdx];
                mobLayers.RemoveSwap(layerIdx);

                _biome.AddMarkerLayer(biomeComp, layer.Id);
            }
        }
    }
}