namespace System.Web.Mvc {
    using System;
    using System.Collections.Generic;
    using System.Diagnostics.CodeAnalysis;
    using System.Web.Script.Serialization;

    public class FormContext {

        private readonly Dictionary<string, FieldValidationMetadata> _fieldValidators = new Dictionary<string, FieldValidationMetadata>();
        private readonly Dictionary<string, bool> _renderedFields = new Dictionary<string, bool>();

        public IDictionary<string, FieldValidationMetadata> FieldValidators {
            get {
                return _fieldValidators;
            }
        }

        public string FormId {
            get;
            set;
        }

        public bool ReplaceValidationSummary {
            get;
            set;
        }

        public string ValidationSummaryId {
            get;
            set;
        }

        [SuppressMessage("Microsoft.Design", "CA1024:UsePropertiesWhereAppropriate", Justification = "Performs a potentially time-consuming conversion.")]
        public string GetJsonValidationMetadata() {
            JavaScriptSerializer serializer = new JavaScriptSerializer();

            SortedDictionary<string, object> dict = new SortedDictionary<string, object>() {
                { "Fields", FieldValidators.Values },
                { "FormId", FormId }
            };
            if (!String.IsNullOrEmpty(ValidationSummaryId)) {
                dict["ValidationSummaryId"] = ValidationSummaryId;
            }
            dict["ReplaceValidationSummary"] = ReplaceValidationSummary;

            return serializer.Serialize(dict);
        }

        public FieldValidationMetadata GetValidationMetadataForField(string fieldName) {
            return GetValidationMetadataForField(fieldName, false /* createIfNotFound */);
        }

        public FieldValidationMetadata GetValidationMetadataForField(string fieldName, bool createIfNotFound) {
            if (String.IsNullOrEmpty(fieldName)) {
                throw Error.ParameterCannotBeNullOrEmpty("fieldName");
            }

            FieldValidationMetadata metadata;
            if (!FieldValidators.TryGetValue(fieldName, out metadata)) {
                if (createIfNotFound) {
                    metadata = new FieldValidationMetadata() {
                        FieldName = fieldName
                    };
                    FieldValidators[fieldName] = metadata;
                }
            }
            return metadata;
        }

        public bool RenderedField(string fieldName) {
            bool result;
            _renderedFields.TryGetValue(fieldName, out result);
            return result;
        }

        public void RenderedField(string fieldName, bool value) {
            _renderedFields[fieldName] = value;
        }
    }
}