using ProjectM.Simulation;
using Unity.CharacterController;
using Unity.Entities;
using UnityEngine;

namespace ProjectM.Authoring
{
    /// <summary>
    /// Authoring for the kinematic-character half of the player ghost (M5b: Unity Character Controller). Added
    /// to the SAME prefab GameObject as <c>PlayerAuthoring</c> + the GhostAuthoringComponent (multiple bakers
    /// per GameObject is supported; both resolve the same Entity). The baker calls
    /// <see cref="KinematicCharacterUtilities.BakeCharacter"/>, which adds the CC runtime components/buffers
    /// (KinematicCharacterProperties, KinematicCharacterBody, StoredKinematicCharacterData, the four CC
    /// buffers, kinematic PhysicsVelocity/PhysicsMass, PhysicsGravityFactor, CharacterInterpolation) and bakes
    /// the GameObject's CapsuleCollider into a PhysicsCollider. We then add our
    /// <see cref="CharacterComponent"/> + <see cref="CharacterControl"/>.
    /// <para>
    /// IMPORTANT: BakeCharacter aborts (logs an error, adds nothing) if the GameObject has a Rigidbody and
    /// requires uniform (1,1,1) scale — so the M5 Rigidbody MUST be removed from the prefab (the M5
    /// CapsuleCollider stays — it is what gets baked into the character's PhysicsCollider).
    /// </para>
    /// </summary>
    [DisallowMultipleComponent]
    public class PlayerCharacterAuthoring : MonoBehaviour
    {
        [Tooltip("Sharpness of ground velocity smoothing (higher = snappier).")]
        public float GroundedMovementSharpness = 15f;

        public AuthoringKinematicCharacterProperties CharacterProperties = AuthoringKinematicCharacterProperties.GetDefault();

        private class PlayerCharacterBaker : Baker<PlayerCharacterAuthoring>
        {
            public override void Bake(PlayerCharacterAuthoring authoring)
            {
                // Top-down planar character: no gravity (handled in the processor), stay on the plane.
                var props = authoring.CharacterProperties;
                props.SnapToGround = false;       // no floor entity to snap to; planar
                props.EvaluateGrounding = true;   // floor/obstacle contact still reads as grounded
                props.InterpolatePosition = true; // smooth fixed-step position for presentation
                props.InterpolateRotation = false; // rotation owned by PlayerAimSystem
                props.SimulateDynamicBody = false; // players don't physically shove each other (keep simple)

                KinematicCharacterUtilities.BakeCharacter(this, authoring.gameObject, props);

                var entity = GetEntity(TransformUsageFlags.Dynamic | TransformUsageFlags.WorldSpace);

                AddComponent(entity, new CharacterComponent
                {
                    GroundedMovementSharpness = authoring.GroundedMovementSharpness,
                    StepAndSlopeHandling = BasicStepAndSlopeHandlingParameters.GetDefault(),
                });
                AddComponent(entity, new CharacterControl());
            }
        }
    }
}