using System.Globalization;
using System.Linq;
using System.Runtime.Serialization;

namespace Umbraco.Web.Models.Trees
{
    /// <summary>
    /// A tree node that represents various types of root nodes
    /// </summary>
    /// <remarks>
    /// <para>
    /// A <see cref="TreeRootNode"/> represents:
    /// * The root node for a section containing a single tree
    /// * The root node for a section containing multiple sub-trees
    /// * The root node for a section containing groups of multiple sub-trees
    /// * The group node in a section containing groups of multiple sub-trees
    /// </para>
    /// <para>
    /// This is required to return the tree data for a given section. Some sections may only contain one tree which means it's section
    /// root should also display a menu, whereas other sections have multiple trees and the section root shouldn't display a menu.
    /// </para>
    /// <para>
    /// The root node also contains an explicit collection of children.
    /// </para>
    /// </remarks>
    [DataContract(Name = "node", Namespace = "")]
    public sealed class TreeRootNode : TreeNode
    {
        private static readonly string RootId = Core.Constants.System.Root.ToString(CultureInfo.InvariantCulture);
        private bool _isGroup;
        private bool _alwaysShow;

        /// <summary>
        /// Creates a group node for grouped multiple trees
        /// </summary>
        /// <param name="children"></param>
        /// <returns></returns>
        public static TreeRootNode CreateGroupNode(TreeNodeCollection children, string section)
        {
            var sectionRoot = new TreeRootNode(RootId, string.Empty, string.Empty)
            {
                IsGroup = true,
                Children = children,
                RoutePath = section
            };

            return sectionRoot;
        }

        /// <summary>
        /// Creates a section root node for grouped multiple trees
        /// </summary>
        /// <param name="children"></param>
        /// <returns></returns>
        public static TreeRootNode CreateGroupedMultiTreeRoot(TreeNodeCollection children)
        {
            var sectionRoot = new TreeRootNode(RootId, string.Empty, string.Empty)
            {
                IsContainer = true,
                Children = children,
                ContainsGroups = true
            };

            return sectionRoot;
        }

        /// <summary>
        /// Creates a section root node for non-grouped multiple trees
        /// </summary>
        /// <param name="children"></param>
        /// <returns></returns>
        public static TreeRootNode CreateMultiTreeRoot(TreeNodeCollection children)
        {
            var sectionRoot = new TreeRootNode(RootId, string.Empty, string.Empty)
            {
                IsContainer = true,
                Children = children
            };

            return sectionRoot;
        }

        /// <summary>
        /// Creates a section root node for a section with a single tree
        /// </summary>
        /// <param name="nodeId"></param>
        /// <param name="getChildNodesUrl"></param>
        /// <param name="menuUrl"></param>
        /// <param name="title"></param>
        /// <param name="children"></param>
        /// <param name="alwaysShowRootNode"></param>
        /// <returns></returns>
        public static TreeRootNode CreateSingleTreeRoot(string nodeId, string getChildNodesUrl, string menuUrl, string title, TreeNodeCollection children, bool alwaysShowRootNode = false)
        {
            return new TreeRootNode(nodeId, getChildNodesUrl, menuUrl)
            {
                Children = children,
                Name = title,               
                _alwaysShow = alwaysShowRootNode
            };
        }

        /// <summary>
        /// Private constructor
        /// </summary>
        /// <param name="nodeId"></param>
        /// <param name="getChildNodesUrl"></param>
        /// <param name="menuUrl"></param>
        private TreeRootNode(string nodeId, string getChildNodesUrl, string menuUrl)
            : base(nodeId, null, getChildNodesUrl, menuUrl)
        {
            //default to false
            IsContainer = false;
        }

        /// <summary>
        /// Will be true if this is a multi-tree section root node (i.e. contains other trees)
        /// </summary>
        [DataMember(Name = "isContainer")]
        public bool IsContainer { get; private set; }

        /// <summary>
        /// True if this is a group root node
        /// </summary>
        [DataMember(Name = "isGroup")]
        public bool IsGroup
        {
            get => _isGroup;
            private set
            {
                //if a group is true then it is also a container
                _isGroup = value;
                IsContainer = true;
            }
        }

        /// <summary>
        /// True if this root node contains group root nodes
        /// </summary>
        [DataMember(Name = "containsGroups")]
        public bool ContainsGroups { get; private set; }

        /// <summary>
        /// The node's children collection
        /// </summary>
        [DataMember(Name = "children")]
        public TreeNodeCollection Children { get; private set; }

        /// <summary>
        /// Returns true if there are any children
        /// </summary>
        /// <remarks>
        /// This is used in the UI to configure a full screen section/app
        /// </remarks>
        [DataMember(Name = "containsTrees")]
        public bool ContainsTrees => Children.Count > 0 || _alwaysShow;
    }
}