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

[RequireComponent(typeof(CharacterController))]
[RequireComponent(typeof(AudioSource))]
public class PlayerController : MonoBehaviour
{
    public float walkSpeed;
    public float runSpeed;
    private Vector3 movement;
    private CharacterController characterController;
    private AudioSource audioSource;

    public GameObject FPSCamera;
    private Vector3 moveDir = Vector3.zero;

    private float gravity = 9.8f;
    public float jumpPower;
    public AudioClip jumpSound;

    // ★追加（足音）
    private float runStepLengthen = 0.7f;
    private float stepInterval = 10f;
    private float stepCycle;
    private float nextStep;
    private float speed;
    private bool isWalking;
    public AudioClip stepSound;

    private void Start()
    {
        characterController = GetComponent<CharacterController>();
        audioSource = GetComponent<AudioSource>();
    }

    private void Update()
    {
        PlayerMove();

        // ★追加（足音）
        ProgressStepCycle(speed);
    }

    void PlayerMove()
    {
        float moveH = Input.GetAxis("Horizontal");
        float moveV = Input.GetAxis("Vertical");
        movement = new Vector3(moveH, 0, moveV);

        Vector3 desiredMove = FPSCamera.transform.forward * movement.z + FPSCamera.transform.right * movement.x;
        moveDir.x = desiredMove.x * 5f;
        moveDir.z = desiredMove.z * 5f;

        if (Input.GetKey(KeyCode.LeftShift))
        {
            characterController.Move(moveDir * Time.deltaTime * runSpeed);

            // ★追加（足音）
            isWalking = false;
            speed = runSpeed;
        }
        else
        {
            characterController.Move(moveDir * Time.deltaTime * walkSpeed);

            // ★追加（足音）
            isWalking = true;
            speed = walkSpeed;
        }

        if (characterController.isGrounded)
        {
            if (Input.GetKeyDown(KeyCode.Space))
            {
                moveDir.y = jumpPower;
                audioSource.clip = jumpSound;
                audioSource.Play();
            }
        }
        else
        {
            moveDir.y -= gravity * Time.deltaTime;
        }
    }

    // ★追加（足音）
    void PlayStepSound()
    {
        // ジャンプ中は足音を発生させない。
        if(!characterController.isGrounded)
        {
            return;
        }

        audioSource.clip = stepSound;
        audioSource.PlayOneShot(audioSource.clip);
    }

    // ★追加（足音）
    // ステップサイクル
    void ProgressStepCycle(float speed)
    {
        if(characterController.velocity.sqrMagnitude > 0 && (movement.x != 0 || movement.z != 0))
        {
            // 三項演算子（プログラミングテクニック）
            stepCycle += (characterController.velocity.magnitude + (speed * (isWalking ? 1f : runStepLengthen))) * Time.deltaTime;
        }

        if(!(stepCycle > nextStep))
        {
            return;
        }

        // 足音の発生間隔・・・＞歩く時は間隔が長い。走る時は短い。
        nextStep = stepCycle + stepInterval;
        PlayStepSound();
    }
}