using UnityEngine;
using System.Collections;
 
[RequireComponent (typeof(Rigidbody))]
[RequireComponent (typeof(BoxCollider))]
 
public class PlayerController : MonoBehaviour {
    //Player movement variables
    public float playerSpeed = 2.5f;
    public float playerSpeedWalk = 1.5f;
    public float playerSpeedRun = 4.5f;
    public float maxVelocityChange = 10.0f;
    public float jumpHeight = 1.0f;
    public bool canJump = true;
    private bool grounded = false;
 
    //World variables
    public float gravity = 10.0f;
    public bool canPickUpItems = true;
    public bool isPlayerHoldingItem = false;
 
    //Components and GameObjects
    public GameObject hands;
    public GameObject itemNearPlayer;
    public GameObject itemInHands;
    public GameObject worldObject;
    public Collider playerCollider;
 
    //Awake
    void Awake() {
        rigidbody.freezeRotation = true;
        rigidbody.useGravity = false;
    }
 
    //FixedUpdate
    void FixedUpdate() {
        if (grounded) {
            //Get movement ready
            Vector3 targetVelocity = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
            targetVelocity = transform.TransformDirection(targetVelocity);
 
            //Set the speed based on if the player should be walking, sprinting, or walking slowly.
            if (Input.GetButton("Walk")) {
                targetVelocity *= playerSpeedWalk;
            }
            else if (Input.GetButton("Run")) {
                targetVelocity *= playerSpeedRun;
            }
            else {
                targetVelocity *= playerSpeed;
            }
 
            //Move the player
            Vector3 velocity = rigidbody.velocity;
            Vector3 velocityChange = (targetVelocity - velocity);
            velocityChange.x = Mathf.Clamp(velocityChange.x, -maxVelocityChange, maxVelocityChange);
            velocityChange.z = Mathf.Clamp(velocityChange.z, -maxVelocityChange, maxVelocityChange);
            velocityChange.y = 0;
            rigidbody.AddForce(velocityChange, ForceMode.VelocityChange);
 
            //Jumping
            if (canJump && Input.GetButtonDown("Jump")) {
                rigidbody.velocity = new Vector3(velocity.x, CalculateJumpVerticalSpeed(), velocity.z);
            }
        }
 
        //The "Use" key
        if (Input.GetButtonDown("Use")) {
            //See if the player needs to pick up an item
            if (!isPlayerHoldingItem && canPickUpItems) {
                PickUpItem(itemNearPlayer);
            }
        }
 
        //Drop the held item
        if (Input.GetButtonDown("Drop")) {
            if (isPlayerHoldingItem) {
                DropItem(itemInHands);
            }
        }
 
        //Gravity
        rigidbody.AddForce(new Vector3(0, -gravity * rigidbody.mass, 0));
        grounded = false;
    }
 
    float CalculateJumpVerticalSpeed() {
        //Get speed from jumpHeight and gravity
        return Mathf.Sqrt(2 * jumpHeight * gravity);
    }
 
    void OnCollisionStay(Collision collision) {
        //A lot of messy annoying code to make jumping not suck
        //TODO: Clean this part up and make it work a bit better.
        grounded = true;
        Vector3 bottom = this.gameObject.transform.TransformDirection(-Vector3.up);
        Vector3 forwardtest = this.gameObject.transform.TransformDirection(Vector3.forward);
 
        if (Physics.Raycast(this.gameObject.transform.position, bottom, 1)) {
            canJump = true;
        }
        if (Physics.Raycast(this.gameObject.transform.position, forwardtest, 0.5f)) {
            canJump = false;
        }
        else {
            canJump = true;
        }
    }
 
    void OnTriggerEnter(Collider trigger) {
        //Set the itemNearPlayer variable so the item can be picked up
        itemNearPlayer = trigger.gameObject.transform.parent.gameObject;
    }
 
    public void PickUpItem(GameObject item) {
            //Pick the item up
            itemInHands = item;
            Physics.IgnoreCollision(playerCollider, item.gameObject.GetComponent<BoxCollider>(), true);
            item.transform.Find("Pickup").gameObject.GetComponent<SphereCollider>().enabled = false;
            item.transform.parent = hands.transform;
            item.rigidbody.isKinematic = true;
            item.transform.position = hands.transform.position;
            item.transform.rotation = hands.transform.rotation;
            canPickUpItems = false;
            isPlayerHoldingItem = true;
    }
 
    public void DropItem(GameObject item) {
            //Drop the held item
            Physics.IgnoreCollision(playerCollider, item.gameObject.GetComponent<BoxCollider>(), false);
            item.rigidbody.isKinematic = false;
            item.transform.parent = worldObject.transform;
            item.transform.Find("Pickup").gameObject.GetComponent<SphereCollider>().enabled = true;
            canPickUpItems = true;
            isPlayerHoldingItem = false;
    }
}