// Copyright (C) Stichting Deltares 2025. All rights reserved.
// 
// This file is part of the application DAM - UI.
// 
// DAM - UI is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
// 
// All names, logos, and references to "Deltares" are registered trademarks of
// Stichting Deltares and remain full property of Stichting Deltares at all times.
// All rights reserved.

using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;
using Deltares.Standard.IO.DtoAssembler;

namespace Deltares.Standard;

/// <summary>
/// Base class for a data transfer collection assembler
/// </summary>
/// <typeparam name="T">The type of class to be assembled</typeparam>
public abstract class DtoCollectionAssembler<TDomainObject> : IDtoCollectionAssembler<TDomainObject>
    where TDomainObject : new()
{
    /// <summary>
    /// Holds a reference to the entity assembler
    /// </summary>
    private readonly DtoAssembler<TDomainObject> entityAssembler;

    public DtoCollectionAssembler(DtoAssembler<TDomainObject> entityAssembler, string elementName)
    {
        this.entityAssembler = entityAssembler;
        ElementName = elementName;
    }

    /// <summary>
    /// Creates a domain object collection from an xml document
    /// </summary>
    /// <param name="dtoObjColl"></param>
    /// <returns></returns>
    public IEnumerable<TDomainObject> CreateDomainObjectCollection(string xmlString)
    {
        XDocument doc = XDocument.Parse(xmlString);

        // assemble the collection
        return CreateDomainObjectCollection(doc);
    }

    /// <summary>
    /// Creates a domain object collection from an xml document
    /// </summary>
    /// <param name="dtoObjColl"></param>
    /// <returns></returns>
    public IEnumerable<TDomainObject> CreateDomainObjectCollection(XDocument doc)
    {
        IEnumerable<XElement> dto = from x in doc.Descendants()
                                    where x.Name.LocalName == EntityAssembler.ElementName && x.Parent.Name.LocalName == ElementName
                                    select x;

        // assemble the collection
        return CreateDomainObjectCollection(dto);
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="dtoObjColl"></param>
    /// <returns></returns>
    public IEnumerable<TDomainObject> CreateDomainObjectCollection(IEnumerable<XElement> dtoObjColl)
    {
        return dtoObjColl.ToDomainObjectIterator(entityAssembler);
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="domainObjColl"></param>
    /// <returns></returns>
    public XElement CreateDataTransferObject(IEnumerable<TDomainObject> domainObjColl, XNamespace elementNamespace)
    {
        XElement el = CreateDataTransferObject(domainObjColl);
        var nel = new XElement(elementNamespace + ElementName);
        el.Name = nel.Name;

        return el;
    }

    #region IDtoCollectionAssembler<TDomainObject> Members

    /// <summary>
    /// Gets the entity assembler
    /// </summary>
    public IDtoAssembler<TDomainObject> EntityAssembler
    {
        get
        {
            return entityAssembler;
        }
    }

    /// <summary>
    /// Gets or sets the xml element name
    /// </summary>
    public string ElementName { get; }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="dtoObjColl"></param>
    /// <returns></returns>
    public virtual IEnumerable<TDomainObject> CreateDomainObjectCollection(XElement dtoSequenceElement)
    {
        IEnumerable<XElement> dto = from x in dtoSequenceElement.Descendants()
                                    where x.Name.LocalName == EntityAssembler.ElementName && x.Parent.Name.LocalName == ElementName
                                    select x;

        return dto.ToDomainObjectIterator(entityAssembler);
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="domainObjColl"></param>
    /// <returns></returns>
    public virtual XElement CreateDataTransferObject(IEnumerable<TDomainObject> domainObjColl)
    {
        if (!ElementName.HasValidStringValue())
        {
            throw new DtoAssemblerException("There is no element name specified");
        }

        if (entityAssembler == null)
        {
            // TODO: need to support serialization based on reflection
        }

        // is there a schema attached to the assembler so we can 
        // validate the collection?
        XDocument schema = entityAssembler.Schema;
        if (schema != null)
        {
            if (entityAssembler == null)
            {
                // TODO: need to support serialization based on reflection
            }
            else
            {
                // get the collection rules (min and max requirements) (if any)
                var collRules = from x in schema.Descendants()
                                where x.Name.LocalName == "element" && x.Attribute("name").Value == entityAssembler.ElementName
                                select new
                                {
                                    MinOccurs = x.AttributeAs<string>("minOccurs") == "unbounded" ? 0 : x.AttributeAs<int>("minOccurs"),
                                    MaxOccurs = x.AttributeAs<string>("maxOccurs") == "unbounded" ? -1 : x.AttributeAs<int>("maxOccurs")
                                };

                if (collRules.Any())
                {
                    var rules = collRules.Single();
                    // validate the min and max values of the collection according to the xsd
                    int count = domainObjColl.Count();
                    if (domainObjColl == null || (count == 0 && rules.MinOccurs > 0)
                                              || (count > 0 & rules.MaxOccurs >= 0 && count > rules.MaxOccurs))
                    {
                        throw new CollectionRequirementsNotSatisfiedException(ElementName, EntityAssembler.ElementName, domainObjColl);
                    }
                }
            }
        }
        else if (domainObjColl == null)
        {
            return null; // Use empty sequence instead?
        }

        return new XElement(ElementName, domainObjColl.ToDtoIterator(entityAssembler).ToArray());
    }

    #endregion
}