using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AI;

namespace InfiniteWorld.VoxelWorld.Contracts
{
    public interface IChunkNavSourceReader
    {
        float ChunkWorldSize { get; }
        void GetLoadedChunkCoords(List<Vector2Int> results);
        bool TryGetChunkNavSourceSnapshot(Vector2Int coord, out ChunkNavSourceSnapshot snapshot);
    }

    public interface IWorldInterestReader
    {
        int InterestVersion { get; }
        void GetInterestPoints(List<WorldInterestPoint> results);
    }

    public interface INavCoverageReader
    {
        bool IsPositionCovered(Vector3 worldPosition);
        void GetCoverageWindows(List<NavCoverageWindowSnapshot> results);
    }

    public readonly struct ChunkNavSourceSnapshot
    {
        public ChunkNavSourceSnapshot(Vector2Int coord, int version, ChunkNavBuildSourceDescriptor[] sources)
        {
            Coord = coord;
            Version = version;
            Sources = sources;
        }

        public Vector2Int Coord { get; }
        public int Version { get; }
        public ChunkNavBuildSourceDescriptor[] Sources { get; }
    }

    public readonly struct ChunkNavBuildSourceDescriptor
    {
        public ChunkNavBuildSourceDescriptor(NavMeshBuildSourceShape shape, Matrix4x4 transform, Vector3 size, Mesh mesh, int area)
        {
            Shape = shape;
            Transform = transform;
            Size = size;
            Mesh = mesh;
            Area = area;
        }

        public NavMeshBuildSourceShape Shape { get; }
        public Matrix4x4 Transform { get; }
        public Vector3 Size { get; }
        public Mesh Mesh { get; }
        public int Area { get; }

        public static ChunkNavBuildSourceDescriptor CreateBox(Matrix4x4 transform, Vector3 size, int area = 0)
        {
            return new ChunkNavBuildSourceDescriptor(NavMeshBuildSourceShape.Box, transform, size, null, area);
        }

        public static ChunkNavBuildSourceDescriptor CreateMesh(Matrix4x4 transform, Mesh mesh, int area = 0)
        {
            return new ChunkNavBuildSourceDescriptor(NavMeshBuildSourceShape.Mesh, transform, Vector3.zero, mesh, area);
        }
    }

    public readonly struct WorldInterestPoint
    {
        public WorldInterestPoint(Vector3 position, float priority, WorldInterestKind kind)
        {
            Position = position;
            Priority = priority;
            Kind = kind;
        }

        public Vector3 Position { get; }
        public float Priority { get; }
        public WorldInterestKind Kind { get; }
    }

    public enum WorldInterestKind
    {
        PlayerActor = 0,
        ActiveNpc = 1,
        SpawnAnchor = 2,
        Other = 3
    }

    public readonly struct NavCoverageWindowSnapshot
    {
        public NavCoverageWindowSnapshot(int id, Bounds bounds, NavCoverageState state, int interestCount)
        {
            Id = id;
            Bounds = bounds;
            State = state;
            InterestCount = interestCount;
        }

        public int Id { get; }
        public Bounds Bounds { get; }
        public NavCoverageState State { get; }
        public int InterestCount { get; }
    }

    public enum NavCoverageState
    {
        Pending = 0,
        Building = 1,
        Ready = 2
    }

    public readonly struct ChunkNavGeometryReadyMessage
    {
        public ChunkNavGeometryReadyMessage(Vector2Int coord, int version)
        {
            Coord = coord;
            Version = version;
        }

        public Vector2Int Coord { get; }
        public int Version { get; }
    }

    public readonly struct ChunkNavGeometryRemovedMessage
    {
        public ChunkNavGeometryRemovedMessage(Vector2Int coord, int version)
        {
            Coord = coord;
            Version = version;
        }

        public Vector2Int Coord { get; }
        public int Version { get; }
    }

    public readonly struct WorldInterestChangedMessage
    {
        public WorldInterestChangedMessage(int version)
        {
            Version = version;
        }

        public int Version { get; }
    }
}