using Disco.Data.Repository;
using Disco.Models.UI.Device;
using Disco.Services.Interop.ActiveDirectory;
using Disco.Services.Plugins;
using Disco.Services.Plugins.Features.UIExtension;
using System;
using System.Text;
using System.Web.Mvc;

namespace Disco.Plugins.ADCompare.Features
{
    [PluginFeature(Id = "ADCompareDeviceUI", Name = "Device Page - AD Compare")]
    public class DeviceUIExtension : UIExtensionFeature<DeviceShowModel>
    {
        public override void Initialize(DiscoDataContext Database)
        {
            Register();
        }

        public override UIExtensionResult ExecuteAction(ControllerContext context, DeviceShowModel model)
        {
            var device = model.Device;
            if (device == null || string.IsNullOrEmpty(device.DeviceDomainId))
                return Nothing();

            var html = new StringBuilder();

            // Wrapper div with unique ID for relocation
            html.Append("<div id='adcompare-device-panel'>");
            html.Append("<div class='form-group' style='margin-top:15px;'>");
            html.Append("<h4 style='border-bottom:1px solid #ddd;padding-bottom:5px;'>");
            html.Append("<i class='fa fa-exchange'></i> AD Compare</h4>");

            try
            {
                var adAccount = ActiveDirectory.RetrieveADMachineAccount(
                    device.DeviceDomainId,
                    new[] { "managedBy", "lastLogonTimestamp" });

                if (adAccount == null)
                {
                    html.Append("<div class='alert alert-danger'>");
                    html.Append("<i class='fa fa-times-circle'></i> Computer not found in Active Directory");
                    html.Append("</div>");
                }
                else
                {
                    var managedByDN = adAccount.GetPropertyValue<string>("managedBy");
                    var discoAssignedUser = device.AssignedUserId;
                    var hasManagedBy = !string.IsNullOrEmpty(managedByDN);
                    var hasAssignment = !string.IsNullOrEmpty(discoAssignedUser);

                    string managedByDisplayName = hasManagedBy ? ExtractCNFromDN(managedByDN) : null;

                    string assignedUserDN = null;
                    if (hasAssignment)
                    {
                        try
                        {
                            var assignedUserAD = ActiveDirectory.RetrieveADUserAccount(discoAssignedUser);
                            if (assignedUserAD != null)
                                assignedUserDN = assignedUserAD.DistinguishedName;
                        }
                        catch { }
                    }

                    bool isMatch = false;
                    if (!hasAssignment && !hasManagedBy)
                        isMatch = true;
                    else if (hasAssignment && hasManagedBy && assignedUserDN != null)
                        isMatch = string.Equals(assignedUserDN, managedByDN, StringComparison.OrdinalIgnoreCase);

                    html.Append("<table class='table table-condensed' style='margin-bottom:10px;'>");

                    if (isMatch)
                    {
                        html.Append("<tr class='success'><td colspan='2'>");
                        html.Append("<i class='fa fa-check-circle'></i> <strong>Managed By matches Assigned User</strong>");
                        html.Append("</td></tr>");
                    }
                    else
                    {
                        html.Append("<tr class='warning'><td colspan='2'>");
                        html.Append("<i class='fa fa-exclamation-triangle'></i> <strong>Managed By does NOT match Assigned User</strong>");
                        html.Append("</td></tr>");
                    }

                    html.Append("<tr><td style='width:180px;'><strong>Disco Assigned User</strong></td><td>");
                    if (hasAssignment)
                    {
                        html.Append(Encode(discoAssignedUser));
                        if (device.AssignedUser != null)
                        {
                            html.Append(" <span class='text-muted'>(");
                            html.Append(Encode(device.AssignedUser.DisplayName));
                            html.Append(")</span>");
                        }
                    }
                    else
                    {
                        html.Append("<em class='text-muted'>Not assigned</em>");
                    }
                    html.Append("</td></tr>");

                    html.Append("<tr><td><strong>AD Managed By</strong></td><td>");
                    if (hasManagedBy)
                    {
                        html.Append(Encode(managedByDisplayName ?? managedByDN));
                    }
                    else
                    {
                        html.Append("<em class='text-muted'>Empty</em>");
                    }
                    html.Append("</td></tr>");

                    var lastLogonTicks = adAccount.GetPropertyValue<long>("lastLogonTimestamp");
                    html.Append("<tr><td><strong>Last Login</strong></td><td>");
                    if (lastLogonTicks > 0)
                    {
                        try
                        {
                            var lastLogon = DateTime.FromFileTime(lastLogonTicks);
                            var ago = DateTime.Now.Subtract(lastLogon);
                            html.Append(Encode(lastLogon.ToString("dd/MM/yyyy hh:mm tt")));
                            html.Append(" <span class='text-muted'>(");
                            html.Append(FormatTimeAgo(ago));
                            html.Append(")</span>");
                        }
                        catch
                        {
                            html.Append("<em class='text-muted'>Unable to parse</em>");
                        }
                    }
                    else
                    {
                        html.Append("<em class='text-muted'>Never</em>");
                    }
                    html.Append("</td></tr>");

                    if (adAccount.IsDisabled)
                    {
                        html.Append("<tr class='danger'><td><strong>AD Status</strong></td><td>");
                        html.Append("<i class='fa fa-ban'></i> <strong>Disabled</strong>");
                        html.Append("</td></tr>");
                    }

                    html.Append("</table>");
                }
            }
            catch (Exception ex)
            {
                html.Append("<div class='alert alert-warning'>");
                html.Append("<i class='fa fa-exclamation-triangle'></i> AD lookup error: ");
                html.Append(Encode(ex.Message));
                html.Append("</div>");
            }

            html.Append("</div>"); // form-group
            html.Append("</div>"); // wrapper

            // Script to relocate panel under the user assignment section
            html.Append("<script type='text/javascript'>");
            html.Append("$(function(){");
            html.Append("var p=$('#adcompare-device-panel');");
            html.Append("var t=$('#Device_Show_User').closest('.status');");
            html.Append("if(t.length){p.insertAfter(t);}");
            html.Append("else{p.prependTo('#Device_Show_Details > div:first');}");
            html.Append("});");
            html.Append("</script>");

            return Literal(html.ToString());
        }

        private string ExtractCNFromDN(string dn)
        {
            if (string.IsNullOrEmpty(dn)) return null;
            if (dn.StartsWith("CN=", StringComparison.OrdinalIgnoreCase))
            {
                var commaIndex = dn.IndexOf(',');
                if (commaIndex > 3) return dn.Substring(3, commaIndex - 3);
                return dn.Substring(3);
            }
            return dn;
        }

        private string Encode(string value)
        {
            if (string.IsNullOrEmpty(value)) return "";
            return System.Web.HttpUtility.HtmlEncode(value);
        }

        private string FormatTimeAgo(TimeSpan span)
        {
            if (span.TotalDays >= 365)
                return string.Format("{0} year(s) ago", (int)(span.TotalDays / 365));
            if (span.TotalDays >= 30)
                return string.Format("{0} month(s) ago", (int)(span.TotalDays / 30));
            if (span.TotalDays >= 1)
                return string.Format("{0} day(s) ago", (int)span.TotalDays);
            if (span.TotalHours >= 1)
                return string.Format("{0} hour(s) ago", (int)span.TotalHours);
            return "Just now";
        }
    }
}