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

public class GameScene : MonoBehaviour {
    public static GameScene instance;
    // Objects
    public GameObject tankPlayer;
    public GameObject tankEnemy;
    public GameObject bullet;
    // Text fields
    public Text playerHealthText;
    public Text enemyHealthText;
    public Text scoreText;
    // Game variables
    int playerHealth = 100;
    int enemyHealth = 100;
    int playerDeath;
    int enemyDeath;
    // Input
    bool goUp;
    bool goDown;
    // Fields for interpolating the movement of an enemy
    Queue<Vector2> posEnemyBuffer = new Queue<Vector2>();
    bool bufferReady;
    int frame;
    int stepToNewPoint;
    Vector2 step;

    void Start() {
        Application.targetFrameRate = 30;
        if (instance == null) instance = this; // creating singleton
        UpdateVievHealth();
        UpdateScore();
        float timeRepeat = 1f / 30f;
        InvokeRepeating("MovePlayer", 0f, timeRepeat);
        InvokeRepeating("MoveEnemy", timeRepeat, timeRepeat);
        InvokeRepeating("SendPosition", timeRepeat, timeRepeat);
    }


    ////////////////////////
    // Methods for the tank of this device
    ////////////////////////

    // player tank movement when pushing buttons
    void MovePlayer() {
        if (playerHealth > 0) {
            if (goUp || goDown) {
                int direction = goUp ? 1 : -1;
                Vector2 vector = tankPlayer.transform.position;
                vector.y = Mathf.Clamp(vector.y + 10 * Time.deltaTime * direction, -2.8f, 2.8f);
                tankPlayer.transform.position = vector;
            }
        }
    }

    // wrapping a player’s tank position into an array of bytes and transferring this array to an enemy device
    void SendPosition() {
        byte[] position = new byte[9];
        byte[] posX = new byte[4];
        byte[] posY = new byte[4];
        posX = NetworkManager.instance.FloatToBytes(tankPlayer.transform.position.x);
        posY = NetworkManager.instance.FloatToBytes(tankPlayer.transform.position.y);
        position[0] = 0;
        position[1] = posX[0];
        position[2] = posX[1];
        position[3] = posX[2];
        position[4] = posX[3];
        position[5] = posY[0];
        position[6] = posY[1];
        position[7] = posY[2];
        position[8] = posY[3];
        NetworkManager.instance.WriteMessage(position); // message transfer
    }

    // delay between shots
    IEnumerator ShotPlayer() {
        while (true) {
            if (playerHealth > 0) {
                Vector2 vector = tankPlayer.transform.position;
                vector.x += 1;
                GameObject newBullet = Instantiate(bullet, vector, Quaternion.identity);
                newBullet.GetComponent<Rigidbody2D>().AddForce(Vector2.right * 100);
                NetworkManager.instance.WriteMessage(new byte[1] { (byte)1 }); // message transfer
            }
            yield return new WaitForSeconds(0.3f);
        }
    }

    // the reduction of the HP of the enemy tank and the destruction of the tank when the HP is equal to zero
    public void HitByEnemy() {
        if (enemyHealth > 20) {
            enemyHealth -= 20;
            NetworkManager.instance.WriteMessage(new byte[2] { (byte)2, (byte)enemyHealth }); // message transfer
            UpdateVievHealth();
        }
        else if (enemyHealth == 20) {
            enemyHealth = 0;
            NetworkManager.instance.WriteMessage(new byte[1] { (byte)3 }); // message transfer
            UpdateVievHealth();
            tankEnemy.transform.position = new Vector2(3.256f, 20);
            Invoke("ReturnEnemyToStartingPosion", 1f);
            enemyDeath++;
            UpdateScore();
        }
    }

    // the return of the enemy’s tank to the starting position a second after its destruction
    void ReturnEnemyToStartingPosion() {
        tankEnemy.transform.position = new Vector2(3.256f, 0);
        enemyHealth = 100;
        NetworkManager.instance.WriteMessage(new byte[1] { (byte)4 }); // message transfer
        posEnemyBuffer.Clear();
        UpdateVievHealth();
    }


    /////////////////////////////
    // Commands from another device
    /////////////////////////////

    // If the buffer is not empty, then the movement of the enemy tank begins.
    // tank movement
    void MoveEnemy() {
        if (enemyHealth > 0) {
            if (posEnemyBuffer.Count > 0) tankEnemy.transform.position = posEnemyBuffer.Dequeue();
        }
    }

    // The resulting positions are converted from an array of bytes to coordinates of type Vector2 and added to the buffer.
    public void PutInBufferPosition(byte[] position) {
        Vector2 currentPosition;
        byte[] posX = new byte[4];
        byte[] posY = new byte[4];
        posX[0] = position[1];
        posX[1] = position[2];
        posX[2] = position[3];
        posX[3] = position[4];
        posY[0] = position[5];
        posY[1] = position[6];
        posY[2] = position[7];
        posY[3] = position[8];
        currentPosition.x = -NetworkManager.instance.BytesToFloat(posX);
        currentPosition.y = NetworkManager.instance.BytesToFloat(posY);
        posEnemyBuffer.Enqueue(currentPosition);
    }

    // shot of an enemy tank
    public void ShotEnemy() {
        Vector2 vector = tankEnemy.transform.position;
        vector.x -= 1;
        GameObject newBullet = Instantiate(bullet, vector, Quaternion.identity);
        newBullet.GetComponent<Rigidbody2D>().AddForce(-Vector2.right * 100);
    }

    // hitting the player's tank
    public void HitByPlayer(byte health) {
        playerHealth = (int)health;
        UpdateVievHealth();
    }

    // player tank destruction
    public void DestroyTankPlayer() {
        tankPlayer.transform.position = new Vector2(-3.256f, 20);
        playerHealth = 0;
        playerDeath++;
        UpdateVievHealth();
        UpdateScore();
    }

    // the return of the player’s tank to the starting position
    public void ReturnPlayerToStartingPosion() {
        tankPlayer.transform.position = new Vector2(-3.256f, 0);
        frame = 0;
        playerHealth = 100;
        UpdateVievHealth();
    }


    // View
    void UpdateVievHealth() {
        playerHealthText.text = playerHealth + "%";
        enemyHealthText.text = enemyHealth + "%";
    }
    void UpdateScore() {
        scoreText.text = playerDeath + ":" + enemyDeath;
    }
    // Input
    public void UpButtonPointerDown() {
        goUp = true;
    }
    public void UpButtonPointerUp() {
        goUp = false;
    }
    public void DownButtonPointerDown() {
        goDown = true;
    }
    public void DownButtonPointerUp() {
        goDown = false;
    }
    public void ShotButtonPointerDown() {
        StartCoroutine("ShotPlayer");
    }
    public void ShotButtonPointerUp() {
        StopCoroutine("ShotPlayer");
    }
    public void ExitScene() {
        NetworkManager.instance.ExitGameScene();
    }
}