using Insight.Domain.Interfaces;
using Insight.Domain.Network;
using Insight.Domain.Network.Agent.Messages;
using System.Management;
using System.Runtime.Versioning;

namespace Insight.Agent.Network.Handlers;

[SupportedOSPlatform("windows")]
public class UserHandler : IMessageHandler<AgentSession>
{
    public async ValueTask HandleAsync<TMessage>(AgentSession sender, TMessage message, CancellationToken cancellationToken) where TMessage : IMessage
    {
        switch (message)
        {
            case InventoryRequest:
                {
                    var result = new Collection<User>();
                    result.AddRange(GetUsers());

                    await sender.SendAsync(result, cancellationToken);
                    break;
                }
        }
    }

    private static List<User> GetUsers()
    {
        var users = QueryUsers();
        var groups = GetGroups();
        var usergrouping = QueryUserGroupMaps();

        foreach (var u in users)
        {
            u.Groups = [];

            foreach (var ug in usergrouping.Where(ug => ug.UserDomain == u.Domain && ug.UserName == u.Name))
            {
                var grps = groups.Where(g => g.Domain == ug.GroupDomain && g.Name == ug.GroupName);

                if (grps is not null)
                {
                    u.Groups.AddRange(grps);
                }
            }
        }

        return users;
    }

    private static List<Group> GetGroups()
    {
        using var searcher = new ManagementObjectSearcher
        {
            Scope = new ManagementScope(@"root\cimv2"),
            Query = new ObjectQuery("select sid, domain, name, description, localaccount from win32_group")
        };

        if (searcher.TryGet(out var collection) is false)
        {
            searcher.Query = new ObjectQuery("select * from win32_group");

            if (searcher.TryGet(out collection) is false) throw new InvalidOperationException("WMI Collection NULL");
        }

        var groups = new List<Group>();

        using (collection)
        {
            foreach (ManagementObject @object in collection.Cast<ManagementObject>())
            {
                var group = new Group();

                var properties = @object.GetPropertyHashes();

                group.Sid = @object.GetValue<string>(properties, "sid")?.Trim();
                group.Domain = @object.GetValue<string>(properties, "domain")?.Trim();
                group.Name = @object.GetValue<string>(properties, "name")?.Trim();
                group.Description = @object.GetValue<string>(properties, "description")?.Trim();
                group.LocalAccount = @object.GetValue<bool>(properties, "localaccount");

                groups.Add(group);
            }
        }

        return [.. groups.OrderBy(x => x.Name)];
    }

    private static List<User> QueryUsers()
    {
        using var searcher = new ManagementObjectSearcher
        {
            Scope = new ManagementScope(@"root\cimv2"),
            Query = new ObjectQuery("select sid, name, fullname, description, domain, localaccount, disabled, lockout, status, passwordchangeable, passwordexpires, passwordrequired from win32_useraccount")
        };

        if (searcher.TryGet(out var collection) is false)
        {
            searcher.Query = new ObjectQuery("select * from win32_useraccount");

            if (searcher.TryGet(out collection) is false) throw new InvalidOperationException("WMI Collection NULL");
        }

        var users = new List<User>();

        using (collection)
        {
            foreach (ManagementObject @object in collection.Cast<ManagementObject>())
            {
                var user = new User();

                var properties = @object.GetPropertyHashes();

                user.Sid = @object.GetValue<string>(properties, "sid")?.Trim();
                user.Name = @object.GetValue<string>(properties, "name")?.Trim();
                user.FullName = @object.GetValue<string>(properties, "fullname")?.Trim();
                user.Description = @object.GetValue<string>(properties, "description")?.Trim();
                user.Domain = @object.GetValue<string>(properties, "domain")?.Trim();
                user.LocalAccount = @object.GetValue<bool>(properties, "localaccount");
                user.Disabled = @object.GetValue<bool>(properties, "disabled");
                user.Lockout = @object.GetValue<bool>(properties, "lockout");
                user.Status = @object.GetValue<string>(properties, "status")?.Trim();
                user.PasswordChangeable = @object.GetValue<bool>(properties, "passwordchangeable");
                user.PasswordExpires = @object.GetValue<bool>(properties, "passwordexpires");
                user.PasswordRequired = @object.GetValue<bool>(properties, "passwordrequired");

                users.Add(user);
            }
        }

        return users;
    }

    private static List<UserGroupMap> QueryUserGroupMaps()
    {
        using var searcher = new ManagementObjectSearcher
        {
            Scope = new ManagementScope(@"root\cimv2"),
            Query = new ObjectQuery("select groupcomponent, partcomponent from win32_groupuser")
        };

        if (searcher.TryGet(out var collection) is false)
        {
            searcher.Query = new ObjectQuery("select * from win32_groupuser");

            if (searcher.TryGet(out collection) is false) throw new InvalidOperationException("WMI Collection NULL");
        }

        var usergroups = new List<UserGroupMap>();

        using (collection)
        {
            foreach (ManagementObject @object in collection.Cast<ManagementObject>())
            {
                var usergroup = new UserGroupMap();

                var properties = @object.GetPropertyHashes();

                var raw = @object.GetValue<string>(properties, "groupcomponent");
                var split = raw?.Split(".Domain=")[1]?.Split(",Name=");

                if (split is not null && split.Length > 1)
                {
                    usergroup.GroupDomain = split[0].TrimStart('"').TrimEnd('"');
                    usergroup.GroupName = split[1].TrimStart('"').TrimEnd('"');
                }

                raw = @object.GetValue<string>(properties, "partcomponent");
                split = raw?.Split(".Domain=")[1]?.Split(",Name=");

                if (split is not null && split.Length > 1)
                {
                    usergroup.UserDomain = split[0].TrimStart('"').TrimEnd('"');
                    usergroup.UserName = split[1].TrimStart('"').TrimEnd('"');
                }

                usergroups.Add(usergroup);
            }
        }

        return usergroups;
    }

    private class UserGroupMap
    {
        public string? GroupDomain { get; set; }
        public string? GroupName { get; set; }

        public string? UserDomain { get; set; }
        public string? UserName { get; set; }
    }
}