using System;
using UnityEngine;
using UnityEngine.UI;
using UnityExplorer.UI.Panels;

namespace UnityExplorer.UI.Inspectors
{
    public abstract class InspectorBase
    {
        public object Target;
        public bool IsActive { get; private set; }

        public abstract string TabLabel { get; }

        internal bool m_pendingDestroy;

        public InspectorBase(object target)
        {
            Target = target;

            if (Target.IsNullOrDestroyed(false))
            {
                Destroy();
                return;
            }

            AddInspectorTab(this);
        }

        public virtual void SetActive()
        {
            this.IsActive = true;
            Content?.SetActive(true);
        }

        public virtual void SetInactive()
        {
            this.IsActive = false;
            Content?.SetActive(false);
        }

        public virtual void Update()
        {
            if (Target.IsNullOrDestroyed(false))
            {
                Destroy();
                return;
            }

            m_tabText.text = TabLabel;
        }

        public virtual void Destroy()
        {
            m_pendingDestroy = true;

            GameObject tabGroup = m_tabButton?.transform.parent.gameObject;

            if (tabGroup)
                GameObject.Destroy(tabGroup);

            int thisIndex = -1;
            if (InspectorManager.ActiveInspectors.Contains(this))
            {
                thisIndex = InspectorManager.ActiveInspectors.IndexOf(this);
                InspectorManager.ActiveInspectors.Remove(this);
            }

            if (ReferenceEquals(InspectorManager.m_activeInspector, this))
            {
                InspectorManager.UnsetInspectorTab();

                if (InspectorManager.ActiveInspectors.Count > 0)
                {
                    var prevTab = InspectorManager.ActiveInspectors[thisIndex > 0 ? thisIndex - 1 : 0];
                    InspectorManager.SetInspectorTab(prevTab);
                }
            }
        }

        #region UI

        public abstract GameObject Content { get; set; }
        public Button m_tabButton;
        public Text m_tabText;

        public void AddInspectorTab(InspectorBase parent)
        {
            var tabContent = InspectorPanel.Instance.NavbarHolder;

            var tabGroupObj = UIFactory.CreateHorizontalGroup(tabContent, "TabObject", true, true, true, true);
            UIFactory.SetLayoutElement(tabGroupObj, minWidth: 185, flexibleWidth: 0);
            tabGroupObj.AddComponent<Mask>();

            m_tabButton = UIFactory.CreateButton(tabGroupObj,
                "TabButton",
                "",
                () => { InspectorManager.SetInspectorTab(parent); });

            UIFactory.SetLayoutElement(m_tabButton.gameObject, minWidth: 165, flexibleWidth: 0);

            m_tabText = m_tabButton.GetComponentInChildren<Text>();
            m_tabText.horizontalOverflow = HorizontalWrapMode.Overflow;
            m_tabText.alignment = TextAnchor.MiddleLeft;

            var closeBtn = UIFactory.CreateButton(tabGroupObj,
                "CloseButton",
                "X",
                parent.Destroy,
                new Color(0.2f, 0.2f, 0.2f, 1));

            UIFactory.SetLayoutElement(closeBtn.gameObject, minWidth: 20, flexibleWidth: 0);

            var closeBtnText = closeBtn.GetComponentInChildren<Text>();
            closeBtnText.color = new Color(1, 0, 0, 1);
        }

        public virtual void OnPanelResized() { }

        #endregion
    }
}