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

[RequireComponent(typeof(NavMeshAgent), typeof(Animator))]
public class NPCController : MonoBehaviour
{
    public enum NPCState { Walking, Drinking, Golfing, Ragdolled }
    
    [Header("Current State")]
    public NPCState currentState = NPCState.Walking;

    [Header("Wander Settings")]
    public float wanderRadius = 15f;
    [Tooltip("How long they stand still to drink or play golf.")]
    public float minActionTime = 3f;
    public float maxActionTime = 7f;

    [Header("Impact & Physics")]
    [Tooltip("How violently they get thrown when hit by a car.")]
    public float hitForceMultiplier = 1.2f;

    private NavMeshAgent agent;
    private Animator anim;
    
    private Rigidbody[] ragdollBodies;
    private Collider[] ragdollColliders;
    private Collider mainCollider;

    void Start()
    {
        agent = GetComponent<NavMeshAgent>();
        anim = GetComponent<Animator>();
        mainCollider = GetComponent<Collider>();

        // Find all ragdoll bones generated by Unity's Ragdoll Wizard
        ragdollBodies = GetComponentsInChildren<Rigidbody>();
        ragdollColliders = GetComponentsInChildren<Collider>();

        // Disable ragdoll physics on spawn so they can walk normally
        foreach (Rigidbody rb in ragdollBodies)
        {
            // Skip the root if it has a rigidbody
            if (rb.gameObject == this.gameObject) continue; 
            rb.isKinematic = true;
        }
        foreach (Collider col in ragdollColliders)
        {
            if (col.gameObject == this.gameObject) continue;
            col.enabled = false;
        }

        StartCoroutine(BehaviorRoutine());
    }

    void Update()
    {
        if (currentState == NPCState.Ragdolled) return;

        // Pass the movement speed to the Animator (Make sure you have a "Speed" float parameter in your Animator!)
        if (anim != null)
        {
            anim.SetFloat("Speed", agent.velocity.magnitude);
        }
    }

    private IEnumerator BehaviorRoutine()
    {
        while (currentState != NPCState.Ragdolled)
        {
            if (currentState == NPCState.Walking)
            {
                // Pick a random spot on the golf course
                Vector3 randomDir = Random.insideUnitSphere * wanderRadius;
                randomDir += transform.position;
                
                if (NavMesh.SamplePosition(randomDir, out NavMeshHit hit, wanderRadius, NavMesh.AllAreas))
                {
                    agent.SetDestination(hit.position);
                }

                // Wait until they reach the destination
                while (agent.pathPending || agent.remainingDistance > 0.5f)
                {
                    if (currentState == NPCState.Ragdolled) yield break;
                    yield return null;
                }

                // Reached destination! Pick a random action
                int action = Random.Range(0, 3);
                if (action == 0) currentState = NPCState.Walking; // Just keep walking
                else if (action == 1) currentState = NPCState.Drinking;
                else currentState = NPCState.Golfing;
            }
            else if (currentState == NPCState.Drinking)
            {
                // Play drink animation
                if (anim != null) anim.SetTrigger("Drink");
                
                yield return new WaitForSeconds(Random.Range(minActionTime, maxActionTime));
                currentState = NPCState.Walking;
            }
            else if (currentState == NPCState.Golfing)
            {
                // Play golf swing animation
                if (anim != null) anim.SetTrigger("GolfSwing");
                
                yield return new WaitForSeconds(Random.Range(minActionTime, maxActionTime));
                currentState = NPCState.Walking;
            }

            yield return null;
        }
    }

    // Detect if a car crashes into them
    private void OnCollisionEnter(Collision collision)
    {
        if (currentState == NPCState.Ragdolled) return;

        // If hit with enough speed (e.g. a car)
        if (collision.relativeVelocity.magnitude > 4f)
        {
            Vector3 impactPoint = collision.GetContact(0).point;
            EnableRagdoll(collision.relativeVelocity, impactPoint);
        }
    }

    // Also support triggers just in case your car uses trigger hitboxes
    private void OnTriggerEnter(Collider other)
    {
        if (currentState == NPCState.Ragdolled) return;

        Rigidbody otherRb = other.GetComponentInParent<Rigidbody>();
        if (otherRb != null && otherRb.linearVelocity.magnitude > 4f)
        {
            EnableRagdoll(otherRb.linearVelocity, transform.position);
        }
    }

    private void EnableRagdoll(Vector3 impactVelocity, Vector3 impactPoint)
    {
        currentState = NPCState.Ragdolled;

        // Turn off AI and Animations
        if (agent != null) agent.enabled = false;
        if (anim != null) anim.enabled = false;
        if (mainCollider != null) mainCollider.enabled = false;

        StopAllCoroutines();

        // Calculate how hard they get thrown
        // Add a little upward force so they fly through the air!
        Vector3 force = (impactVelocity + Vector3.up * 3f) * hitForceMultiplier;

        // Turn ON the ragdoll colliders
        foreach (Collider col in ragdollColliders)
        {
            if (col.gameObject != this.gameObject) col.enabled = true;
        }

        // Turn ON the ragdoll physics and apply the crash force
        foreach (Rigidbody rb in ragdollBodies)
        {
            if (rb.gameObject != this.gameObject)
            {
                rb.isKinematic = false;
                rb.useGravity = true;
                
                // VelocityChange ignores the mass of the bone, guaranteeing they fly away violently
                rb.AddForceAtPosition(force, impactPoint, ForceMode.VelocityChange);
            }
        }
    }
}