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

public class SelectorBehavior : MonoBehaviour
{

    #region private fields
    List<Transform> transports;
    int columnCount;
    Image playerPanelImage;
    Text playerPanelText;
    Transform currentTransport;
    object selectionLock;
    private bool _selected;
    private Image _gameObjectImage;
    #endregion

    #region private properties
    int GetCurrentTransportIndex
    {
        get
        {
            return transports != null && currentTransport != null ? transports.IndexOf(currentTransport) : -1;
        }
    }

    private DateTime lastInput;

    bool IsSpawned
    {
        get { return lastInput == null || (DateTime.Now - lastInput).Milliseconds < InputDelay; }
    }

    Transform CurrentTransport
    {
        get { return currentTransport; }
        set
        {
            lock (selectionLock)
            {
                currentTransport = value;
                AlignSelectorWithTransport(currentTransport);
                UpdatePlayerUIElements();
            }
        }
    }

    public bool Selected
    {
        get
        {
            return _selected;
        }
        set
        {
            _selected = value;
            lastInput = DateTime.Now;
            SelectedChanged();
        }
    }

    #endregion

    #region public fields		
    public bool Player2;
    public int InputDelay = 200;
    public int Padding;
    public Transform TransportsPanel;
    public Transform PlayerPanel;
    public Sprite SelectorImage;
    public Color SelectorColor;
    public Sprite SelectionImage;
    public string HorizontalAxisName;
    public string VerticalAxisName;
    public string SubmitButtonName;
    public string CancelButtonName;
    #endregion

    #region Behavior overrided methods
    // Use this for initialization
    void Start()
    {
        selectionLock = new object();
        lastInput = DateTime.Now.AddSeconds(1.5);
        //3E00FFFF
        InitGameObjectImage();
    }
    private void OnRenderObject()
    {
        if (transports == null) InitializedTransportsList();
        if (PlayerPanel != null)
        {
            if (playerPanelImage == null && playerPanelText == null)
            {
                playerPanelImage = PlayerPanel.GetChild(0).gameObject.GetComponent<Image>(); ;
                playerPanelText = PlayerPanel.GetChild(1).gameObject.GetComponent<Text>();
                UpdatePlayerUIElements();
            }
        }
    }

    void Update()
    {
        HandleInputs();
    }
    #endregion

    private void InitGameObjectImage()
    {
        _gameObjectImage = transform.GetChild(0).gameObject.GetComponent<Image>();
        if (_gameObjectImage != null)
        {
            _gameObjectImage.sprite = SelectorImage;
            _gameObjectImage.color = SelectorColor;
        }
    }

    private void InitializedTransportsList()
    {
        if (TransportsPanel != null)
        {
            transports = new List<Transform>();
            for (int i = 0; i < TransportsPanel.childCount; i++)
                transports.Add(TransportsPanel.GetChild(i));
            columnCount = TransportsPanel.GetComponent<GridLayoutGroup>().constraintCount;
            CurrentTransport = transports[Player2 ? transports.Count / 2 : 0];
        }
    }

    #region Ui

    private void AlignSelectorWithTransport(Transform transport)
    {
        if (transport != null)
        {
            transform.SetPositionAndRotation(transport.position, transform.rotation);
            var temp = transport.GetComponent<RectTransform>();
            transform.gameObject.GetComponent<RectTransform>().sizeDelta = new Vector2(temp.sizeDelta.x + 2 * Padding, temp.sizeDelta.y + 2 * Padding);
        }
    }

    private void UpdatePlayerUIElements()
    {
        if (CurrentTransport != null)
        {

            if (playerPanelImage != null)
            {
                playerPanelImage.sprite = CurrentTransport.GetChild(0).gameObject.GetComponent<Image>().sprite;
                playerPanelImage.preserveAspect = true;
            }
            if (playerPanelText != null)
                playerPanelText.text = currentTransport.gameObject.name;

        }
    }
    #endregion

    // Update is called once per frame
    private void HandleInputs()
    {
        if (IsSpawned || transports == null || LaunchGameScript.Current.Launching) return;
        if (!string.IsNullOrEmpty(VerticalAxisName) && !Selected)
        {
            var verticalAxis = Input.GetAxis(VerticalAxisName);
            if (Math.Abs(verticalAxis) == 1)
            {
                bool? move = IsPositiveMove(verticalAxis);
                if (move.HasValue)
                {
                    MoveVertical(move.Value);
                }
            }
        }
        if (!string.IsNullOrEmpty(HorizontalAxisName) && !Selected)
        {
            var horizontalAxis = Input.GetAxis(HorizontalAxisName);
            if (Math.Abs(horizontalAxis) == 1)
            {
                bool? move = IsPositiveMove(horizontalAxis);
                if (move.HasValue)
                {
                    MoveHorizontal(move.Value);
                }
            }
        }
        if (!string.IsNullOrEmpty(SubmitButtonName))
        {
            if (Input.GetButton(SubmitButtonName))
            {
                Selected = true;
            }
        }
        if (!string.IsNullOrEmpty(CancelButtonName))
        {
            if (Input.GetButton(CancelButtonName))
            {
                if (Selected)
                    Selected = false;
                else if (StartupScript.Current != null)
                    StartupScript.Current.Display(0, 1);
            }
        }
    }

    #region Move selector
    private static bool? IsPositiveMove(float axis)
    {
        bool? move = null;
        if (axis == 1) move = true;
        else if (axis == -1) move = false;
        return move;
    }
    private void MoveVertical(bool positive)
    {
        var value = GetCurrentTransportIndex;
        if (value - (transports.Count / 2) >= 0)
            value -= (transports.Count / 2);
        else value += (transports.Count / 2);
        //var value = GetCurrentTransportIndex;
        //if (positive) value += 1;
        //else value -= 1;
        //if (value > transports.Count - 1) value -= transports.Count - 1;
        lastInput = DateTime.Now;
        CurrentTransport = transports[value];
    }

    private void MoveHorizontal(bool positive)
    {
        var value = GetCurrentTransportIndex;

        if (positive) value++;
        else value--;
        if (value < 0) value = transports.Count - 1;
        if (value > transports.Count - 1) value = 0;

        lastInput = DateTime.Now;
        CurrentTransport = transports[value];
    }
    #endregion

    private void SelectedChanged()
    {
        if (_gameObjectImage == null) return;
        _gameObjectImage.sprite = Selected ? SelectionImage : SelectorImage;
        LaunchGameScript.Current.SelectionChanged();
    }

}