using System;
using System.Web;
using umbraco.presentation.LiveEditing;
using umbraco.BasePages;
using umbraco.cms.businesslogic.web;

namespace umbraco.presentation
{
    /// <summary>
    /// Class that encapsulates Umbraco information of a specific HTTP request.
    /// </summary>
    public class UmbracoContext
    {
        private HttpContext m_HttpContext;

        /// <summary>
        /// Gets the current Umbraco Context.
        /// </summary>
        public static UmbracoContext Current
        {
            get
            {
                return (UmbracoContext)HttpContext.Current.Items["UmbracoContext"];
            }

            set
            {
                if (Current != null)
                    throw new ApplicationException("The current httpContext can only be set once during a request.");

                HttpContext.Current.Items["UmbracoContext"] = value;
            }
        }

        /// <summary>
        /// Gets the current page ID, or <c>null</c> if no page ID is available (e.g. a custom page).
        /// </summary>
        public virtual int? PageId
        {
            get
            {
                try
                {
                    return int.Parse(m_HttpContext.Items["pageID"].ToString());
                }
                catch
                {
                    return null;
                }
            }
        }

        /// <summary>
        /// Determines whether the current user has the specified permission on the current page.
        /// </summary>
        /// <param name="permissionToken">The permission token.</param>
        /// <returns>
        /// 	<c>true</c> if the user has permission; otherwise, <c>false</c>.
        /// </returns>
        public virtual bool HasPermission(char permissionToken)
        {
            int? pageId = UmbracoContext.Current.PageId;
            return pageId.HasValue
                    && UmbracoEnsuredPage.CurrentUser != null
                    && UmbracoEnsuredPage.CurrentUser.GetPermissions(new Document(pageId.Value).Path)
                        .Contains(permissionToken.ToString());
        }

        /// <summary>
        /// Gets the current Live Editing Context.
        /// </summary>
        public virtual ILiveEditingContext LiveEditingContext
        {
            get
            {
                ILiveEditingContext value = (ILiveEditingContext)m_HttpContext.Items["LiveEditingContext"];
                if (value == null)
                {
                    LiveEditingContext = value = new DefaultLiveEditingContext();
                }
                return value;
            }

            set
            {
                m_HttpContext.Items["LiveEditingContext"] = value;
            }
        }

        /// <summary>
        /// Creates a new Umbraco context.
        /// </summary>
        /// <param name="httpContext">The HTTP context on which the Umbraco context operates.</param>
        public UmbracoContext(HttpContext httpContext)
        {
            m_HttpContext = httpContext;
        }

        /// <summary>
        /// Gets the response for the current context
        /// </summary>
        /// <value>The response.</value>
        public HttpResponse Response
        {
            get
            {
                return this.m_HttpContext.Response;
            }
        }

        /// <summary>
        /// Gets the request for the current context
        /// </summary>
        /// <value>The request.</value>
        public HttpRequest Request
        {
            get
            {
                return this.m_HttpContext.Request;
            }
        }
    }
}