using EnVisage.Code;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Web.Mvc;

namespace EnVisage.Models.ValidationAttributes.NonProjectTime
{
    public class NPTimeEffectiveDateAttribute : ValidationAttributeBase, IClientValidatable
    {
        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
        {
            if (value == null)
                return ValidationResult.Success;

            var propertyId = validationContext.ObjectType.GetProperty("Id");
            var propertyPermanent = validationContext.ObjectType.GetProperty("Permanent");
            var propertyPermanentOld = validationContext.ObjectType.GetProperty("PermanentOld");
            var propertyStartDate = validationContext.ObjectType.GetProperty("NonProjectTimeStartDate");
            var propertyStartDateOld = validationContext.ObjectType.GetProperty("NonProjectTimeStartDateOld");

            if (propertyId != null && propertyPermanent != null && propertyPermanentOld != null && propertyStartDate != null && propertyStartDateOld != null)
            {
                var id = ((Guid?)propertyId.GetValue(validationContext.ObjectInstance) ?? Guid.Empty);
                var permanentOld = ((bool?)propertyPermanentOld.GetValue(validationContext.ObjectInstance) ?? false);
                var permanent = ((bool?)propertyPermanent.GetValue(validationContext.ObjectInstance) ?? false);
                var startDateOld = ((DateTime?)propertyStartDateOld.GetValue(validationContext.ObjectInstance) ?? DateTime.MinValue);
                var startDate = ((DateTime?)propertyStartDate.GetValue(validationContext.ObjectInstance) ?? DateTime.MinValue);
                var effectiveDate = ((DateTime?)value ?? DateTime.MinValue);

                // if user edits permanent np time the effective date is required
                var isValid = !(id != Guid.Empty && permanent && permanentOld && startDateOld > startDate && effectiveDate != startDate);
                if (isValid)
                    return ValidationResult.Success;
            }

            return new ValidationResult(ErrorMessage);
        }

        public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
        {
            var rule = new ModelClientValidationRule
            {
                ErrorMessage = ErrorMessage,
                ValidationType = "nptimeeffectivedate"
            };

            var id = ((Guid?)GetPropertyValue("Id", metadata, context) ?? Guid.Empty);
            var permanentOld = ((bool?)GetPropertyValue("PermanentOld", metadata, context) ?? false);
            var startDateOld = ((DateTime?)GetPropertyValue("NonProjectTimeStartDateOld", metadata, context));

            rule.ValidationParameters["id"] = id.ToString();
            rule.ValidationParameters["permanentold"] = Convert.ToInt32(permanentOld);
            rule.ValidationParameters["permanent"] = "Permanent";
            rule.ValidationParameters["startdateold"] = startDateOld.HasValue ? Utils.ConvertToUnixDate(startDateOld.Value) : 0;
            rule.ValidationParameters["startdate"] = "NonProjectTimeStartDate";

            yield return rule;
        }
    }
}