using System;
using System.Globalization;
using System.Linq;
using System.Net.Http.Formatting;
using Umbraco.Core;
using Umbraco.Core.Events;
using Umbraco.Web.Models.Trees;
using Umbraco.Web.WebApi;
using Umbraco.Web.WebApi.Filters;
using Umbraco.Core.Models;

namespace Umbraco.Web.Trees
{
    /// <summary>
    /// A base controller reference for non-attributed trees (un-registered). Developers should inherit from
    /// TreeController.
    /// </summary>
    [AngularJsonOnlyConfiguration]
    public abstract class TreeControllerBase : UmbracoAuthorizedApiController
    {
        /// <summary>
        /// The method called to render the contents of the tree structure
        /// </summary>
        /// <param name="id"></param>
        /// <param name="queryStrings">
        /// All of the query string parameters passed from jsTree
        /// </param>
        /// <remarks>
        /// We are allowing an arbitrary number of query strings to be pased in so that developers are able to persist custom data from the front-end
        /// to the back end to be used in the query for model data.
        /// </remarks>
        protected abstract TreeNodeCollection GetTreeNodes(string id, FormDataCollection queryStrings);

        /// <summary>
        /// Returns the menu structure for the node
        /// </summary>
        /// <param name="id"></param>
        /// <param name="queryStrings"></param>
        /// <returns></returns>
        protected abstract MenuItemCollection GetMenuForNode(string id, FormDataCollection queryStrings);

        /// <summary>
        /// The name to display on the root node
        /// </summary>
        public abstract string RootNodeDisplayName { get; }

        /// <summary>
        /// Gets the current tree alias from the attribute assigned to it.
        /// </summary>
        public abstract string TreeAlias { get; }

        /// <summary>
        /// Returns the root node for the tree
        /// </summary>
        /// <param name="queryStrings"></param>
        /// <returns></returns>
        [HttpQueryStringFilter("queryStrings")]
        public TreeNode GetRootNode(FormDataCollection queryStrings)
        {
            if (queryStrings == null) queryStrings = new FormDataCollection("");
            var node = CreateRootNode(queryStrings);

            //add the tree alias to the root
            node.AdditionalData["treeAlias"] = TreeAlias;

            AddQueryStringsToAdditionalData(node, queryStrings);

            //check if the tree is searchable and add that to the meta data as well
            if (this is ISearchableTree)
            {
                node.AdditionalData.Add("searchable", "true");
            }

            //now update all data based on some of the query strings, like if we are running in dialog mode           
            if (IsDialog(queryStrings))
            {
                node.RoutePath = "#";
            }

            OnRootNodeRendering(this, new TreeNodeRenderingEventArgs(node, queryStrings));

            return node;
        }

        /// <summary>
        /// The action called to render the contents of the tree structure
        /// </summary>
        /// <param name="id"></param>
        /// <param name="queryStrings">
        /// All of the query string parameters passed from jsTree
        /// </param>
        /// <returns>JSON markup for jsTree</returns>        
        /// <remarks>
        /// We are allowing an arbitrary number of query strings to be pased in so that developers are able to persist custom data from the front-end
        /// to the back end to be used in the query for model data.
        /// </remarks>
        [HttpQueryStringFilter("queryStrings")]
        public TreeNodeCollection GetNodes(string id, FormDataCollection queryStrings)
        {
            if (queryStrings == null) queryStrings = new FormDataCollection("");
            var nodes = GetTreeNodes(id, queryStrings);

            foreach (var node in nodes)
            {
                AddQueryStringsToAdditionalData(node, queryStrings);
            }

            //now update all data based on some of the query strings, like if we are running in dialog mode            
            if (IsDialog((queryStrings)))
            {
                foreach (var node in nodes)
                {
                    node.RoutePath = "#";
                }
            }

            //raise the event
            OnTreeNodesRendering(this, new TreeNodesRenderingEventArgs(nodes, queryStrings));

            return nodes;
        }

        /// <summary>
        /// The action called to render the menu for a tree node
        /// </summary>
        /// <param name="id"></param>
        /// <param name="queryStrings"></param>
        /// <returns></returns>
        [HttpQueryStringFilter("queryStrings")]
        public MenuItemCollection GetMenu(string id, FormDataCollection queryStrings)
        {
            if (queryStrings == null) queryStrings = new FormDataCollection("");
            var menu = GetMenuForNode(id, queryStrings);
            //raise the event
            OnMenuRendering(this, new MenuRenderingEventArgs(id, menu, queryStrings));
            return menu;
        }

        /// <summary>
        /// Helper method to create a root model for a tree
        /// </summary>
        /// <returns></returns>
        protected virtual TreeNode CreateRootNode(FormDataCollection queryStrings)
        {
            var rootNodeAsString = Constants.System.Root.ToString(CultureInfo.InvariantCulture);
            var currApp = queryStrings.GetValue<string>(TreeQueryStringParameters.Application);

            var node = new TreeNode(
                rootNodeAsString,
                null, //this is a root node, there is no parent
                Url.GetTreeUrl(GetType(), rootNodeAsString, queryStrings),
                Url.GetMenuUrl(GetType(), rootNodeAsString, queryStrings))
                {
                    HasChildren = true,
                    RoutePath = currApp,
                    Name = RootNodeDisplayName
                };

            return node;
        }

        #region Create TreeNode methods

        /// <summary>
        /// Helper method to create tree nodes
        /// </summary>
        /// <param name="id"></param>
        /// <param name="parentId"></param>
        /// <param name="queryStrings"></param>
        /// <param name="title"></param>
        /// <returns></returns>
        public TreeNode CreateTreeNode(string id, string parentId, FormDataCollection queryStrings, string title)
        {
            var jsonUrl = Url.GetTreeUrl(GetType(), id, queryStrings);
            var menuUrl = Url.GetMenuUrl(GetType(), id, queryStrings);
            var node = new TreeNode(id, parentId, jsonUrl, menuUrl) { Name = title };
            return node;
        }

        /// <summary>
        /// Helper method to create tree nodes
        /// </summary>
        /// <param name="id"></param>
        /// <param name="parentId"></param>
        /// <param name="queryStrings"></param>
        /// <param name="title"></param>
        /// <param name="icon"></param>
        /// <returns></returns>
        public TreeNode CreateTreeNode(string id, string parentId, FormDataCollection queryStrings, string title, string icon)
        {
            var jsonUrl = Url.GetTreeUrl(GetType(), id, queryStrings);
            var menuUrl = Url.GetMenuUrl(GetType(), id, queryStrings);
            var node = new TreeNode(id, parentId, jsonUrl, menuUrl) { Name = title, Icon = icon };
            return node;
        }

        /// <summary>
        /// Helper method to create tree nodes
        /// </summary>
        /// <param name="id"></param>
        /// <param name="parentId"></param>
        /// <param name="queryStrings"></param>
        /// <param name="title"></param>
        /// <param name="routePath"></param>
        /// <param name="icon"></param>
        /// <returns></returns>
        public TreeNode CreateTreeNode(string id, string parentId, FormDataCollection queryStrings, string title, string icon, string routePath)
        {
            var jsonUrl = Url.GetTreeUrl(GetType(), id, queryStrings);
            var menuUrl = Url.GetMenuUrl(GetType(), id, queryStrings);
            var node = new TreeNode(id, parentId, jsonUrl, menuUrl) { Name = title, RoutePath = routePath, Icon = icon };
            return node;
        }

        /// <summary>
        /// Helper method to create tree nodes and automatically generate the json url
        /// </summary>
        /// <param name="id"></param>
        /// <param name="parentId"></param>
        /// <param name="queryStrings"></param>
        /// <param name="title"></param>
        /// <param name="icon"></param>
        /// <param name="hasChildren"></param>
        /// <returns></returns>
        public TreeNode CreateTreeNode(string id, string parentId, FormDataCollection queryStrings, string title, string icon, bool hasChildren)
        {
            var treeNode = CreateTreeNode(id, parentId, queryStrings, title, icon);
            treeNode.HasChildren = hasChildren;
            return treeNode;
        }

        /// <summary>
        /// Helper method to create tree nodes and automatically generate the json url
        /// </summary>
        /// <param name="id"></param>
        /// <param name="parentId"></param>
        /// <param name="queryStrings"></param>
        /// <param name="title"></param>
        /// <param name="routePath"></param>
        /// <param name="hasChildren"></param>
        /// <param name="icon"></param>
        /// <returns></returns>
        public TreeNode CreateTreeNode(string id, string parentId, FormDataCollection queryStrings, string title, string icon, bool hasChildren, string routePath)
        {
            var treeNode = CreateTreeNode(id, parentId, queryStrings, title, icon);
            treeNode.HasChildren = hasChildren;
            treeNode.RoutePath = routePath;
            return treeNode;
        }

        #endregion

        /// <summary>
        /// The AdditionalData of a node is always populated with the query string data, this method performs this
        /// operation and ensures that special values are not inserted or that duplicate keys are not added.
        /// </summary>
        /// <param name="node"></param>
        /// <param name="queryStrings"></param>
        protected void AddQueryStringsToAdditionalData(TreeNode node, FormDataCollection queryStrings)
        {
            foreach (var q in queryStrings.Where(x => node.AdditionalData.ContainsKey(x.Key) == false))
            {
                node.AdditionalData.Add(q.Key, q.Value);
            }
        }

        /// <summary>
        /// If the request is for a dialog mode tree
        /// </summary>
        /// <param name="queryStrings"></param>
        /// <returns></returns>
        protected bool IsDialog(FormDataCollection queryStrings)
        {
            return queryStrings.GetValue<bool>(TreeQueryStringParameters.IsDialog);
        }

        /// <summary>
        /// An event that allows developers to modify the tree node collection that is being rendered
        /// </summary>
        /// <remarks>
        /// Developers can add/remove/replace/insert/update/etc... any of the tree items in the collection.
        /// </remarks>
        public static event TypedEventHandler<TreeControllerBase, TreeNodesRenderingEventArgs> TreeNodesRendering;

        private static void OnTreeNodesRendering(TreeControllerBase instance, TreeNodesRenderingEventArgs e)
        {
            var handler = TreeNodesRendering;
            if (handler != null) handler(instance, e);
        }

        /// <summary>
        /// An event that allows developer to modify the root tree node that is being rendered
        /// </summary>
        public static event TypedEventHandler<TreeControllerBase, TreeNodeRenderingEventArgs> RootNodeRendering;

        private static void OnRootNodeRendering(TreeControllerBase instance, TreeNodeRenderingEventArgs e)
        {
            var handler = RootNodeRendering;
            if (handler != null) handler(instance, e);
        }

        /// <summary>
        /// An event that allows developers to modify the meun that is being rendered
        /// </summary>
        /// <remarks>
        /// Developers can add/remove/replace/insert/update/etc... any of the tree items in the collection.
        /// </remarks>
        public static event TypedEventHandler<TreeControllerBase, MenuRenderingEventArgs> MenuRendering;

        private static void OnMenuRendering(TreeControllerBase instance, MenuRenderingEventArgs e)
        {
            var handler = MenuRendering;
            if (handler != null) handler(instance, e);
        }
    }
}