// Copyright (c) Umbraco.
// See LICENSE for more details.

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using Umbraco.Cms.Core.Hosting;
using Umbraco.Cms.Core.IO;
using Umbraco.Cms.Core.Models;
using Umbraco.Cms.Core.Models.Blocks;
using Umbraco.Cms.Core.Models.Editors;
using Umbraco.Cms.Core.Serialization;
using Umbraco.Cms.Core.Services;
using Umbraco.Cms.Core.Strings;
using Umbraco.Extensions;

namespace Umbraco.Cms.Core.PropertyEditors
{
    /// <summary>
    /// Abstract class for block editor based editors
    /// </summary>
    public abstract class BlockEditorPropertyEditor : DataEditor
    {
        public const string ContentTypeKeyPropertyKey = "contentTypeKey";
        public const string UdiPropertyKey = "udi";

        public BlockEditorPropertyEditor(
            IDataValueEditorFactory dataValueEditorFactory,
            PropertyEditorCollection propertyEditors)
            : base(dataValueEditorFactory)
            => PropertyEditors = propertyEditors;

        private PropertyEditorCollection PropertyEditors { get; }

        #region Value Editor

        protected override IDataValueEditor CreateValueEditor() => DataValueEditorFactory.Create<BlockEditorPropertyValueEditor>(Attribute);

        internal class BlockEditorPropertyValueEditor : DataValueEditor, IDataValueReference
        {
            private readonly PropertyEditorCollection _propertyEditors;
            private readonly IDataTypeService _dataTypeService;
            private readonly ILogger<BlockEditorPropertyValueEditor> _logger;
            private readonly BlockEditorValues _blockEditorValues;

            public BlockEditorPropertyValueEditor(
                DataEditorAttribute attribute,
                PropertyEditorCollection propertyEditors,
                IDataTypeService dataTypeService,
                IContentTypeService contentTypeService,
                ILocalizedTextService textService,
                ILogger<BlockEditorPropertyValueEditor> logger,
                IShortStringHelper shortStringHelper,
                IJsonSerializer jsonSerializer,
                IIOHelper ioHelper,
                IPropertyValidationService propertyValidationService)
                : base(textService, shortStringHelper, jsonSerializer, ioHelper, attribute)
            {
                _propertyEditors = propertyEditors;
                _dataTypeService = dataTypeService;
                _logger = logger;

                _blockEditorValues = new BlockEditorValues(new BlockListEditorDataConverter(), contentTypeService, _logger);
                Validators.Add(new BlockEditorValidator(propertyValidationService, _blockEditorValues,contentTypeService));
                Validators.Add(new MinMaxValidator(_blockEditorValues, textService));
            }

            public IEnumerable<UmbracoEntityReference> GetReferences(object value)
            {
                var rawJson = value == null ? string.Empty : value is string str ? str : value.ToString();

                var result = new List<UmbracoEntityReference>();
                var blockEditorData = _blockEditorValues.DeserializeAndClean(rawJson);
                if (blockEditorData == null)
                    return Enumerable.Empty<UmbracoEntityReference>();

                // loop through all content and settings data
                foreach (var row in blockEditorData.BlockValue.ContentData.Concat(blockEditorData.BlockValue.SettingsData))
                {
                    foreach (var prop in row.PropertyValues)
                    {
                        var propEditor = _propertyEditors[prop.Value.PropertyType.PropertyEditorAlias];

                        var valueEditor = propEditor?.GetValueEditor();
                        if (!(valueEditor is IDataValueReference reference)) continue;

                        var val = prop.Value.Value?.ToString();

                        var refs = reference.GetReferences(val);

                        result.AddRange(refs);
                    }
                }

                return result;
            }

            #region Convert database // editor

            // note: there is NO variant support here

            /// <summary>
            /// Ensure that sub-editor values are translated through their ToEditor methods
            /// </summary>
            /// <param name="property"></param>
            /// <param name="dataTypeService"></param>
            /// <param name="culture"></param>
            /// <param name="segment"></param>
            /// <returns></returns>
            public override object ToEditor(IProperty property, string culture = null, string segment = null)
            {
                var val = property.GetValue(culture, segment);
                var valEditors = new Dictionary<int, IDataValueEditor>();

                BlockEditorData blockEditorData;
                try
                {
                    blockEditorData = _blockEditorValues.DeserializeAndClean(val);
                }
                catch (JsonSerializationException)
                {
                    // if this occurs it means the data is invalid, shouldn't happen but has happened if we change the data format.
                    return string.Empty;
                }

                if (blockEditorData == null)
                    return string.Empty;

                foreach (var row in blockEditorData.BlockValue.ContentData)
                {
                    foreach (var prop in row.PropertyValues)
                    {
                        // create a temp property with the value
                        // - force it to be culture invariant as the block editor can't handle culture variant element properties
                        prop.Value.PropertyType.Variations = ContentVariation.Nothing;
                        var tempProp = new Property(prop.Value.PropertyType);
                        tempProp.SetValue(prop.Value.Value);

                        var propEditor = _propertyEditors[prop.Value.PropertyType.PropertyEditorAlias];
                        if (propEditor == null)
                        {
                            // NOTE: This logic was borrowed from Nested Content and I'm unsure why it exists.
                            // if the property editor doesn't exist I think everything will break anyways?
                            // update the raw value since this is what will get serialized out
                            row.RawPropertyValues[prop.Key] = tempProp.GetValue()?.ToString();
                            continue;
                        }

                        var dataType = _dataTypeService.GetDataType(prop.Value.PropertyType.DataTypeId);
                        if (dataType == null)
                        {
                            // deal with weird situations by ignoring them (no comment)
                            row.PropertyValues.Remove(prop.Key);
                            _logger.LogWarning(
                                "ToEditor removed property value {PropertyKey} in row {RowId} for property type {PropertyTypeAlias}",
                                prop.Key, row.Key, property.PropertyType.Alias);
                            continue;
                        }

                        if (!valEditors.TryGetValue(dataType.Id, out var valEditor))
                        {
                            var tempConfig = dataType.Configuration;
                            valEditor = propEditor.GetValueEditor(tempConfig);

                            valEditors.Add(dataType.Id, valEditor);
                        }

                        var convValue = valEditor.ToEditor(tempProp);

                        // update the raw value since this is what will get serialized out
                        row.RawPropertyValues[prop.Key] = convValue;
                    }
                }

                // return json convertable object
                return blockEditorData.BlockValue;
            }

            /// <summary>
            /// Ensure that sub-editor values are translated through their FromEditor methods
            /// </summary>
            /// <param name="editorValue"></param>
            /// <param name="currentValue"></param>
            /// <returns></returns>
            public override object FromEditor(ContentPropertyData editorValue, object currentValue)
            {
                if (editorValue.Value == null || string.IsNullOrWhiteSpace(editorValue.Value.ToString()))
                    return null;

                BlockEditorData blockEditorData;
                try
                {
                    blockEditorData = _blockEditorValues.DeserializeAndClean(editorValue.Value);
                }
                catch (JsonSerializationException)
                {
                    // if this occurs it means the data is invalid, shouldn't happen but has happened if we change the data format.
                    return string.Empty;
                }

                if (blockEditorData == null || blockEditorData.BlockValue.ContentData.Count == 0)
                    return string.Empty;

                foreach (var row in blockEditorData.BlockValue.ContentData)
                {
                    foreach (var prop in row.PropertyValues)
                    {
                        // Fetch the property types prevalue
                        var propConfiguration = _dataTypeService.GetDataType(prop.Value.PropertyType.DataTypeId).Configuration;

                        // Lookup the property editor
                        var propEditor = _propertyEditors[prop.Value.PropertyType.PropertyEditorAlias];
                        if (propEditor == null) continue;

                        // Create a fake content property data object
                        var contentPropData = new ContentPropertyData(prop.Value.Value, propConfiguration);

                        // Get the property editor to do it's conversion
                        var newValue = propEditor.GetValueEditor().FromEditor(contentPropData, prop.Value.Value);

                        // update the raw value since this is what will get serialized out
                        row.RawPropertyValues[prop.Key] = newValue;
                    }
                }

                // return json
                return JsonConvert.SerializeObject(blockEditorData.BlockValue);
            }

            #endregion
        }

        /// <summary>
        /// Validates the min/max of the block editor
        /// </summary>
        private class MinMaxValidator : IValueValidator
        {
            private readonly BlockEditorValues _blockEditorValues;
            private readonly ILocalizedTextService _textService;

            public MinMaxValidator(BlockEditorValues blockEditorValues, ILocalizedTextService textService)
            {
                _blockEditorValues = blockEditorValues;
                _textService = textService;
            }

            public IEnumerable<ValidationResult> Validate(object value, string valueType, object dataTypeConfiguration)
            {
                var blockConfig = (BlockListConfiguration)dataTypeConfiguration;
                if (blockConfig == null) yield break;

                var validationLimit = blockConfig.ValidationLimit;
                if (validationLimit == null) yield break;

                var blockEditorData = _blockEditorValues.DeserializeAndClean(value);

                if ((blockEditorData == null && validationLimit.Min.HasValue && validationLimit.Min > 0)
                    || (blockEditorData != null && validationLimit.Min.HasValue && blockEditorData.Layout.Count() < validationLimit.Min))
                {
                    yield return new ValidationResult(
                        _textService.Localize("validation", "entriesShort", new[]
                        {
                            validationLimit.Min.ToString(),
                            (validationLimit.Min - blockEditorData.Layout.Count()).ToString()
                        }),
                        new[] { "minCount" });
                }

                if (blockEditorData != null && validationLimit.Max.HasValue && blockEditorData.Layout.Count() > validationLimit.Max)
                {
                    yield return new ValidationResult(
                        _textService.Localize("validation", "entriesExceed", new[]
                        {
                            validationLimit.Max.ToString(),
                            (blockEditorData.Layout.Count() - validationLimit.Max).ToString()
                        }),
                        new[] { "maxCount" });
                }
            }
        }

        internal class BlockEditorValidator : ComplexEditorValidator
        {
            private readonly BlockEditorValues _blockEditorValues;
            private readonly IContentTypeService _contentTypeService;

            public BlockEditorValidator(IPropertyValidationService propertyValidationService, BlockEditorValues blockEditorValues, IContentTypeService contentTypeService)
                : base(propertyValidationService)
            {
                _blockEditorValues = blockEditorValues;
                _contentTypeService = contentTypeService;
            }

            protected override IEnumerable<ElementTypeValidationModel> GetElementTypeValidation(object value)
            {
                var blockEditorData = _blockEditorValues.DeserializeAndClean(value);
                if (blockEditorData != null)
                {
                    // There is no guarantee that the client will post data for every property defined in the Element Type but we still
                    // need to validate that data for each property especially for things like 'required' data to work.
                    // Lookup all element types for all content/settings and then we can populate any empty properties.
                    var allElements = blockEditorData.BlockValue.ContentData.Concat(blockEditorData.BlockValue.SettingsData).ToList();
                    var allElementTypes = _contentTypeService.GetAll(allElements.Select(x => x.ContentTypeKey).ToArray()).ToDictionary(x => x.Key);

                    foreach (var row in allElements)
                    {
                        if (!allElementTypes.TryGetValue(row.ContentTypeKey, out var elementType))
                            throw new InvalidOperationException($"No element type found with key {row.ContentTypeKey}");

                        // now ensure missing properties
                        foreach (var elementTypeProp in elementType.CompositionPropertyTypes)
                        {
                            if (!row.PropertyValues.ContainsKey(elementTypeProp.Alias))
                            {
                                // set values to null
                                row.PropertyValues[elementTypeProp.Alias] = new BlockItemData.BlockPropertyValue(null, elementTypeProp);
                                row.RawPropertyValues[elementTypeProp.Alias] = null;
                            }
                        }

                        var elementValidation = new ElementTypeValidationModel(row.ContentTypeAlias, row.Key);
                        foreach (var prop in row.PropertyValues)
                        {
                            elementValidation.AddPropertyTypeValidation(
                                new PropertyTypeValidationModel(prop.Value.PropertyType, prop.Value.Value));
                        }
                        yield return elementValidation;
                    }
                }
            }
        }

        /// <summary>
        /// Used to deserialize json values and clean up any values based on the existence of element types and layout structure
        /// </summary>
        internal class BlockEditorValues
        {
            private readonly Lazy<Dictionary<Guid, IContentType>> _contentTypes;
            private readonly BlockEditorDataConverter _dataConverter;
            private readonly ILogger _logger;

            public BlockEditorValues(BlockEditorDataConverter dataConverter, IContentTypeService contentTypeService, ILogger logger)
            {
                _contentTypes = new Lazy<Dictionary<Guid, IContentType>>(() => contentTypeService.GetAll().ToDictionary(c => c.Key));
                _dataConverter = dataConverter;
                _logger = logger;
            }

            private IContentType GetElementType(BlockItemData item)
            {
                _contentTypes.Value.TryGetValue(item.ContentTypeKey, out var contentType);
                return contentType;
            }

            public BlockEditorData DeserializeAndClean(object propertyValue)
            {
                if (propertyValue == null || string.IsNullOrWhiteSpace(propertyValue.ToString()))
                    return null;

                var blockEditorData = _dataConverter.Deserialize(propertyValue.ToString());

                if (blockEditorData.BlockValue.ContentData.Count == 0)
                {
                    // if there's no content ensure there's no settings too
                    blockEditorData.BlockValue.SettingsData.Clear();
                    return null;
                }

                var contentTypePropertyTypes = new Dictionary<string, Dictionary<string, IPropertyType>>();

                // filter out any content that isn't referenced in the layout references
                foreach (var block in blockEditorData.BlockValue.ContentData.Where(x => blockEditorData.References.Any(r => r.ContentUdi == x.Udi)))
                {
                    ResolveBlockItemData(block, contentTypePropertyTypes);
                }
                // filter out any settings that isn't referenced in the layout references
                foreach (var block in blockEditorData.BlockValue.SettingsData.Where(x => blockEditorData.References.Any(r => r.SettingsUdi == x.Udi)))
                {
                    ResolveBlockItemData(block, contentTypePropertyTypes);
                }

                // remove blocks that couldn't be resolved
                blockEditorData.BlockValue.ContentData.RemoveAll(x => x.ContentTypeAlias.IsNullOrWhiteSpace());
                blockEditorData.BlockValue.SettingsData.RemoveAll(x => x.ContentTypeAlias.IsNullOrWhiteSpace());

                return blockEditorData;
            }

            private bool ResolveBlockItemData(BlockItemData block, Dictionary<string, Dictionary<string, IPropertyType>> contentTypePropertyTypes)
            {
                var contentType = GetElementType(block);
                if (contentType == null)
                    return false;

                // get the prop types for this content type but keep a dictionary of found ones so we don't have to keep re-looking and re-creating
                // objects on each iteration.
                if (!contentTypePropertyTypes.TryGetValue(contentType.Alias, out var propertyTypes))
                    propertyTypes = contentTypePropertyTypes[contentType.Alias] = contentType.CompositionPropertyTypes.ToDictionary(x => x.Alias, x => x);

                var propValues = new Dictionary<string, BlockItemData.BlockPropertyValue>();

                // find any keys that are not real property types and remove them
                foreach (var prop in block.RawPropertyValues.ToList())
                {
                    // doesn't exist so remove it
                    if (!propertyTypes.TryGetValue(prop.Key, out var propType))
                    {
                        block.RawPropertyValues.Remove(prop.Key);
                        _logger.LogWarning("The property {PropertyKey} for block {BlockKey} was removed because the property type {PropertyTypeAlias} was not found on {ContentTypeAlias}",
                            prop.Key, block.Key, prop.Key, contentType.Alias);
                    }
                    else
                    {
                        // set the value to include the resolved property type
                        propValues[prop.Key] = new BlockItemData.BlockPropertyValue(prop.Value, propType);
                    }
                }

                block.ContentTypeAlias = contentType.Alias;
                block.PropertyValues = propValues;

                return true;
            }
        }

        #endregion

    }
}