BattleSystem.cs

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



public enum BattleState { START, PLAYERTURN, ENEMYTURN, WON, LOST }
public class BattleSystem : MonoBehaviour
{

    public GameObject playerPrefab;
    public GameObject enemyPrefab;

    public Transform playerBattleStation;
    public Transform enemyBattleStation;

    Unit playerUnit;
    Unit enemyUnit;

    public Animator animator;


    public Text dialogueText;

    public BattleHUD playerHUD;
    public BattleHUD enemyHUD;

    public BattleState state; 

    void Start()
    {
        state = BattleState.START;
        StartCoroutine(SetupBattle());
    }

    IEnumerator SetupBattle ()
    {
        GameObject playerGO = Instantiate(playerPrefab, playerBattleStation);
        playerUnit = playerGO.GetComponent<Unit>();

        GameObject enemyGO = Instantiate(enemyPrefab, enemyBattleStation);
        enemyUnit = enemyGO.GetComponent<Unit>();

        dialogueText.text = "A hostile " + enemyUnit.unitName + " approaches...";

        playerHUD.SetHUD(playerUnit);
        enemyHUD.SetHUD(enemyUnit);

        yield return new WaitForSeconds(.5f);

        state = BattleState.PLAYERTURN;
        StartCoroutine(PlayerTurn());
    }

    IEnumerator PlayerAttack()
    {
        //Damage enemy
        bool isDead = enemyUnit.TakeDamage(playerUnit.damage);
        enemyHUD.SetHP(enemyUnit.currentHP);
        yield return new WaitForSeconds(1.0f);
        dialogueText.text = "The attack is successful!";
        state = BattleState.ENEMYTURN;

        yield return new WaitForSeconds(2f);

        //check if enemy dead
        if (isDead)
        {
            state = BattleState.WON;
            EndBattle();
        }

        else
        {
            state = BattleState.ENEMYTURN;
            StartCoroutine(EnemyTurn());
        }
       
    }

    IEnumerator EnemyTurn()
    {
        dialogueText.text = enemyUnit.unitName + "'s turn";
        yield return new WaitForSeconds(1.5f);

        dialogueText.text = enemyUnit.unitName + " attacks!";

        yield return new WaitForSeconds(2f);

        bool isDead = playerUnit.TakeDamage(enemyUnit.damage);
        playerHUD.SetHP(playerUnit.currentHP);

        yield return new WaitForSeconds(.5f);

        if (isDead)
        {
            state = BattleState.LOST;
        }
        else
        {
            state = BattleState.PLAYERTURN;
            
            PlayerTurn();
        }
    }

    void EndBattle()
    {
        //change state
        if (state == BattleState.WON)
         {
            dialogueText.text = "You won";
             }
             
        else if (state == BattleState.LOST)
             {
            dialogueText.text = "You lost";
             }
          
    }


        IEnumerator PlayerTurn()
    {
        
        dialogueText.text = "Choose an action:";
        yield return new WaitForSeconds(.5f);
    }


    IEnumerator PlayerHeal()
    {
        yield return new WaitForSeconds(.5f);
        playerUnit.Heal(5);
        playerHUD.SetHP(playerUnit.currentHP);
        yield return new WaitForSeconds(.01f);
        dialogueText.text = "You feel renewed strength!";
        state = BattleState.ENEMYTURN;
        yield return new WaitForSeconds(1f);
        StartCoroutine(EnemyTurn());
        



    }
    public void OnAttackButton()
    {
        if (state != BattleState.PLAYERTURN)
            return;

        StartCoroutine(PlayerAttack());
    }

    public void OnHealButton()
    {
        if (state != BattleState.PLAYERTURN)
            return;

        StartCoroutine(PlayerHeal());
    }
}