using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using Newtonsoft.Json.Linq;
using Umbraco.Core;
using Umbraco.Core.Exceptions;
using Umbraco.Core.Logging;
using Umbraco.Core.Models;
using Umbraco.Core.Models.Editors;
using Umbraco.Core.PropertyEditors;
using Umbraco.Core.PropertyEditors.Validators;
using Umbraco.Core.Services;

namespace Umbraco.Web.PropertyEditors
{
    /// <summary>
    /// Represents a multiple text string property editor.
    /// </summary>
    [DataEditor(
        Constants.PropertyEditors.Aliases.MultipleTextstring,
        "Repeatable textstrings",
        "multipletextbox",
        ValueType = ValueTypes.Text,
        Group = Constants.PropertyEditors.Groups.Lists,
        Icon = "icon-ordered-list")]
    public class MultipleTextStringPropertyEditor : DataEditor
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="MultipleTextStringPropertyEditor"/> class.
        /// </summary>
        public MultipleTextStringPropertyEditor(ILogger logger)
            : base(logger)
        { }

        /// <inheritdoc />
        protected override IDataValueEditor CreateValueEditor() => new MultipleTextStringPropertyValueEditor(Attribute);

        /// <inheritdoc />
        protected override IConfigurationEditor CreateConfigurationEditor() => new MultipleTextStringConfigurationEditor();

        /// <summary>
        /// Custom value editor so we can format the value for the editor and the database
        /// </summary>
        internal class MultipleTextStringPropertyValueEditor : DataValueEditor
        {
            public MultipleTextStringPropertyValueEditor(DataEditorAttribute attribute)
                : base(attribute)
            { }

            /// <summary>
            /// The value passed in from the editor will be an array of simple objects so we'll need to parse them to get the string
            /// </summary>
            /// <param name="editorValue"></param>
            /// <param name="currentValue"></param>
            /// <returns></returns>
            /// <remarks>
            /// We will also check the pre-values here, if there are more items than what is allowed we'll just trim the end
            /// </remarks>
            public override object FromEditor(ContentPropertyData editorValue, object currentValue)
            {
                var asArray = editorValue.Value as JArray;
                if (asArray == null)
                {
                    return null;
                }

                if (!(editorValue.DataTypeConfiguration is MultipleTextStringConfiguration config))
                    throw new PanicException($"editorValue.DataTypeConfiguration is {editorValue.DataTypeConfiguration.GetType()} but must be {typeof(MultipleTextStringConfiguration)}");
                var max = config.Maximum;

                //The legacy property editor saved this data as new line delimited! strange but we have to maintain that.
                var array = asArray.OfType<JObject>()
                                   .Where(x => x["value"] != null)
                                   .Select(x => x["value"].Value<string>());

                //only allow the max if over 0
                if (max > 0)
                {
                    return string.Join(Environment.NewLine, array.Take(max));
                }

                return string.Join(Environment.NewLine, array);
            }

            /// <summary>
            /// We are actually passing back an array of simple objects instead of an array of strings because in angular a primitive (string) value
            /// cannot have 2 way binding, so to get around that each item in the array needs to be an object with a string.
            /// </summary>
            /// <param name="property"></param>
            /// <param name="dataTypeService"></param>
            /// <param name="culture"></param>
            /// <param name="segment"></param>
            /// <returns></returns>
            /// <remarks>
            /// The legacy property editor saved this data as new line delimited! strange but we have to maintain that.
            /// </remarks>
            public override object ToEditor(Property property, IDataTypeService dataTypeService, string culture = null, string segment = null)
            {
                var val = property.GetValue(culture, segment);
                return val?.ToString().Split(new[] {Environment.NewLine}, StringSplitOptions.RemoveEmptyEntries)
                           .Select(x => JObject.FromObject(new {value = x})) ?? new JObject[] { };
            }

            /// <summary>
            /// A custom FormatValidator is used as for multiple text strings, each string should individually be checked
            /// against the configured regular expression, rather than the JSON representing all the strings as a whole.
            /// </summary>
            public override IValueFormatValidator FormatValidator => new MultipleTextStringFormatValidator();
        }

        internal class MultipleTextStringFormatValidator : IValueFormatValidator
        {
            public IEnumerable<ValidationResult> ValidateFormat(object value, string valueType, string format)
            {
                var asArray = value as JArray;
                if (asArray == null)
                {
                    return Enumerable.Empty<ValidationResult>();
                }

                var textStrings = asArray.OfType<JObject>()
                    .Where(x => x["value"] != null)
                    .Select(x => x["value"].Value<string>());
                var textStringValidator = new RegexValidator();
                foreach (var textString in textStrings)
                {
                    var validationResults = textStringValidator.ValidateFormat(textString, valueType, format).ToList();
                    if (validationResults.Any())
                    {
                        return validationResults;
                    }
                }

                return Enumerable.Empty<ValidationResult>();
            }
        }
    }
}