using GameCore.ECS;
using GameCore.ECS.Interfaces;
using GameCore.Input;
using GameCore.Math;
using GameCore.Physics;
using GameCore.Player;

namespace GameCore.AI;

public class AIPathfindingSystem : ISystem
{
    private const float WaypointReachThreshold = 0.5f;

    public void Update(World world, float deltaTime)
    {
        var entities = world.GetEntitiesWith<AIComponent>();
        foreach (var entity in entities)
        {
            if (world.GetComponent<PlayerComponent>(entity) != null) continue;

            var ai = world.GetComponent<AIComponent>(entity);
            var input = world.GetComponent<InputStateComponent>(entity);
            var pos = world.GetComponent<PositionComponent>(entity);
            if (ai == null || input == null || pos == null) continue;

            input.MoveDirection = Vector3.Zero;
            Vector3? targetPosition = null;

            switch (ai.CurrentState)
            {
                case AIState.Chase:
                    targetPosition = ai.LastKnownTargetPosition;
                    world.Logger.Debug($"AI Entity {entity.Id} chasing target at {targetPosition}");
                    break;
                case AIState.Patrol:
                    var patrol = world.GetComponent<PatrolComponent>(entity);
                    if (patrol == null || patrol.PatrolPoints.Count == 0)
                    {
                        ai.CurrentState = AIState.Idle;
                        world.Logger.Debug($"AI Entity {entity.Id} has no patrol points, switching to Idle state.");
                        continue;
                    }

                    targetPosition = patrol.PatrolPoints[patrol.CurrentPatrolIndex];
                    var horizontalDiff = new Vector3(targetPosition.Value.X - pos.Position.X, 0f,
                        targetPosition.Value.Z - pos.Position.Z);
                    var distanceToPatrolPoint = horizontalDiff.Length();

                    if (distanceToPatrolPoint < WaypointReachThreshold)
                    {
                        patrol.CurrentPatrolIndex++;
                        if (patrol.CurrentPatrolIndex >= patrol.PatrolPoints.Count)
                            patrol.CurrentPatrolIndex = patrol.IsLooping ? 0 : patrol.PatrolPoints.Count - 1;
                        targetPosition = patrol.PatrolPoints[patrol.CurrentPatrolIndex];
                        world.Logger.Debug(
                            $"AI Entity {entity.Id} reached patrol point, moving to next point at {targetPosition}");
                    }

                    break;
                case AIState.Idle:
                case AIState.Attack:
                    world.Logger.Debug($"AI Entity {entity.Id} is in state {ai.CurrentState}, not moving.");
                    continue;
            }

            if (targetPosition == null)
            {
                world.Logger.Debug($"AI Entity {entity.Id} has no target position.");
                continue;
            }

            var path = world.WorldQuery.GetPath(pos.Position, targetPosition.Value);
            world.Logger.Debug($"Path for AI Entity {entity.Id}: {string.Join(" -> ", path)}");

            if (path.Count > 0)
            {
                var nextWaypoint = path[0];
                var horizontalDiffToWaypoint =
                    new Vector3(nextWaypoint.X - pos.Position.X, 0f, nextWaypoint.Z - pos.Position.Z);
                if (horizontalDiffToWaypoint.Length() < 0.1f && path.Count > 1)
                {
                    nextWaypoint = path[1];
                    world.Logger.Debug($"AI Entity {entity.Id} skipping first waypoint, moving to {nextWaypoint}");
                }

                var directionVector = nextWaypoint - pos.Position;
                input.MoveDirection = new Vector3(directionVector.X, 0f, directionVector.Z).Normalize();
                world.Logger.Debug(
                    $"AI Entity {entity.Id} moving towards waypoint at {nextWaypoint} with direction {input.MoveDirection}");
            }
            else
            {
                world.Logger.Debug($"AI Entity {entity.Id} has no path.");
            }
        }
    }
}