using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web.Mvc;

namespace EnVisage.Models.ValidationAttributes
{
    public class ValidationAttributeBase : ValidationAttribute
    {
        protected List<ModelMetadata> GetMetadata(ModelMetadata metadata, ControllerContext context)
        {
            if (metadata == null || context == null)
                return new List<ModelMetadata>();

            var _metadata = new List<ModelMetadata>();

            if (metadata.Container != null)
            {
                var containerProperties = ModelMetadataProviders.Current.GetMetadataForProperties(metadata.Container, metadata.ContainerType).ToList();
                if (containerProperties != null && containerProperties.Count > 0)
                    _metadata.AddRange(containerProperties);
            }

            if (metadata.Container != null && context.Controller.ViewData.Model != null && metadata.ContainerType != context.Controller.ViewData.Model.GetType())
            {
                var modelProperties = ModelMetadataProviders.Current.GetMetadataForProperties(context.Controller.ViewData.Model, context.Controller.ViewData.Model.GetType()).ToList();
                if (modelProperties != null)
                {
                    var missingProperties = modelProperties.FindAll(x => _metadata.All(s => s.PropertyName != x.PropertyName));
                    if (missingProperties != null && missingProperties.Count > 0)
                        _metadata.AddRange(modelProperties);
                }
            }

            return _metadata;
        }

        protected object GetPropertyValue(string propertyName, ModelMetadata metadata, ControllerContext context)
        {
            var properties = GetMetadata(metadata, context);
            if (properties == null || properties.Count <= 0)
                return null;

            var property = properties.FirstOrDefault(x => x.PropertyName == propertyName);
            if (property == null)
                return null;

            return property.Model;
        }
    }
}