using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Events;
using exprivia.ui;

public class VariablesViewDelegate : MonoBehaviour, IDataViewDelegate {
    public GameObject itemPrefab;
    public Color selectionColor = Color.cyan;

    public Text selVarDescText;

    private Color unselectionColor = Color.black;
    private Dictionary<string, IDataViewItem> selection = new Dictionary<string, IDataViewItem>();

    //bool isFirst = true;
    public IDataView variablesDataView;

    public int selectedVariableIndex = -1;

    [Serializable]
    public class VariableSelectionEvent : UnityEvent<int> { }
    public VariableSelectionEvent OnVariableSelected = new VariableSelectionEvent();

    public void LoadViewItem(IDataSourceType data, IDataViewItem item) {
    }

    public void UnloadViewItem(IDataSourceType data, IDataViewItem item) {
    }

    public void OnItemAdded(IDataSourceType data, IDataViewItem item) {
        if ((data as VariablesDataSourceType).initiallySelected)
        {
            variablesDataView.SelectItem(item);
        }
    }

    public void OnSelectionChanged(List<IDataViewItem> selection) {
    }

    public void OnItemRemoved(IDataSourceType data, IDataViewItem item) {
    }

    public void OnItemSelected(IDataSourceType data, IDataViewItem item) {
        item.GetGameObject().GetComponent<Image>().color = selectionColor;
        string id = data.UniqueId();
        if (!selection.ContainsKey(id))
            selection.Add(id, item);

        VariablesViewItem vi = item as VariablesViewItem;
        selVarDescText.text = vi.variableDescription;

        selectedVariableIndex = vi.variableIndex;
        OnVariableSelected.Invoke(selectedVariableIndex);
    }

    public void OnItemUnselected(IDataSourceType data, IDataViewItem item) {
        item.GetGameObject().GetComponent<Image>().color = unselectionColor;
        selection.Remove(data.UniqueId());
    }

    public IDataViewItem CreateViewItem(IDataSourceType data) {
        GameObject item = Instantiate(itemPrefab);
        unselectionColor = item.GetComponent<Image>().color;
        VariablesViewItem viewItem = exprivia.Utils.GetOrAddComponent<VariablesViewItem>(item);
        VariablesDataSourceType variableData = (VariablesDataSourceType)data;
        viewItem.Setup(variableData);
        return viewItem;
    }
}