using BansheeGz.BGDatabase;
using UnityEngine;

public class EventListenersDemo : MonoBehaviour
{
    void Start() => AddListeners();
    private void OnDestroy() => RemoveListeners();
    private void AddListeners()
    {
        //get target objects
        var meta = BGRepo.I["MyTable"];
        var field = meta.GetField("name");
        var entity = meta.GetEntity(0);

        //listen to some field change
        field.ValueChanged += FieldChanged;

        //listen to particular entity (row)
        meta.AddEntityUpdatedListener(entity.Id, EntityUpdated);
        meta.AddEntityDeletedListener(entity.Id, EntityDeleted);

        //listen to all entities (rows) of particular table (meta)
        meta.AnyEntityUpdated += SomeEntityUpdated;
        meta.AnyEntityAdded += SomeEntityAdded;
        meta.AnyEntityBeforeDeleted += SomeEntityBeforeDeleted;
        meta.AnyEntityDeleted += SomeEntityDeleted;
        
        //listen to batch events (any table). See BatchEventExample method below for more information
        BGRepo.I.Events.OnBatchUpdate += BatchUpdate;

        //listen on any change events (any table)
        BGRepo.I.Events.OnAnyChange += AnyChange;
    }

    //always match adding listeners with removing listeners to prevent memory leak
    private void RemoveListeners()
    {
        //get target objects
        var meta = BGRepo.I["MyTable"];
        var field = meta.GetField("name");
        var entity = meta.GetEntity(0);
        
        meta.RemoveEntityUpdatedListener(entity.Id, EntityUpdated);
        meta.RemoveEntityDeletedListener(entity.Id, EntityDeleted);
        
        meta.AnyEntityUpdated -= SomeEntityUpdated;
        meta.AnyEntityAdded -= SomeEntityAdded;
        meta.AnyEntityBeforeDeleted -= SomeEntityBeforeDeleted;
        meta.AnyEntityDeleted -= SomeEntityDeleted;
        
        field.ValueChanged -= FieldChanged;
        
        BGRepo.I.Events.OnBatchUpdate -= BatchUpdate;
        
        BGRepo.I.Events.OnAnyChange -= AnyChange;
    }

    //------------------------------------------------
    //            Field changed
    //------------------------------------------------
    private void FieldChanged(object sender, BGEventArgsField e)
    {
        if (e is BGEventArgsFieldWithValue<string> ev) Debug.Log($"The field {ev.Field.Name} for entity {ev.Entity.Name} was changed {ev.OldValue} -> {ev.NewValue}");
        else Debug.Log($"The field value was changed, entity={e.Entity.Name}");
    }
    //------------------------------------------------
    //             any entity (row)
    //------------------------------------------------
    private void SomeEntityUpdated(object sender, BGEventArgsAnyEntityUpdated e)
    {
        if (e is BGEventArgsAnyEntityUpdatedWithValue ev) Debug.Log($"The field {ev.GetField().Name} for entity {ev.Entity.Name} was changed {ev.GetOldValue()} -> {ev.GetNewValue()}");
        else Debug.Log("The entity Updated " + e.Entity.Name);  
    } 
    private void SomeEntityAdded(object sender, BGEventArgsAnyEntity e) => Debug.Log($"The entity is added {e.Entity.Id}");
    private void SomeEntityBeforeDeleted(object sender, BGEventArgsAnyEntity e)=> Debug.Log($"The entity is about to be deleted {e.Entity.Id}");
    private void SomeEntityDeleted(object sender, BGEventArgsAnyEntity e) => Debug.Log($"The entity is deleted {e.Entity.Id}");
    //------------------------------------------------
    //             particular (provided) entity (row)
    //------------------------------------------------
    private void EntityDeleted(object sender, BGEventArgsEntity e) => Debug.Log($"The Entity was deleted {e.Entity.Id}");
    private void EntityUpdated(object sender, BGEventArgsEntityUpdated e) => Debug.Log($"The Entity was updated {e.Entity.Name}");
    
    //------------------------------------------------
    //            Batch update
    //------------------------------------------------
    private void BatchUpdate(object sender, BGEventArgsBatch e) => Debug.Log($"Batch update. Use WasEntitiesAdded/WasEntitiesDeleted/WasEntitiesUpdated methods to find out if entities were modified");

    //this method provide example how batch event is fired
    private void BatchEventExample()
    {
        BGRepo.I.Events.Batch(() =>
        {
            //all individual events inside this method will be disabled. One batch event will be fired when this action is executed
            //update all "name" field values for the first table
            BGRepo.I.GetMeta(0).ForEachEntity(entity => entity.Name += " [Updated]");
        });
    }


    //------------------------------------------------
    //            Any change
    //------------------------------------------------
    private void AnyChange(object sender, BGEventArgsAnyChange e) => Debug.Log($"Some change was made to the database");

}