//! D-Bus standard interfaces.
//!
//! The D-Bus specification defines the message bus messages and some standard interfaces that may
//! be useful across various D-Bus applications. This module provides their proxy.

use enumflags2::{bitflags, BitFlags};
use serde::{Deserialize, Serialize};
use serde_repr::{Deserialize_repr, Serialize_repr};
use static_assertions::assert_impl_all;
use std::collections::HashMap;
use zbus_names::{
    BusName, InterfaceName, OwnedBusName, OwnedInterfaceName, OwnedUniqueName, UniqueName,
    WellKnownName,
};
use zvariant::{
    DeserializeDict, ObjectPath, Optional, OwnedObjectPath, OwnedValue, SerializeDict, Type, Value,
};

use crate::{dbus_interface, dbus_proxy, DBusError, MessageHeader, ObjectServer, SignalContext};

#[rustfmt::skip]
macro_rules! gen_introspectable_proxy {
    ($gen_async:literal, $gen_blocking:literal) => {
        /// Proxy for the `org.freedesktop.DBus.Introspectable` interface.
        #[dbus_proxy(
            interface = "org.freedesktop.DBus.Introspectable",
            default_path = "/",
            gen_async = $gen_async,
            gen_blocking = $gen_blocking,
        )]
        trait Introspectable {
            /// Returns an XML description of the object, including its interfaces (with signals and
            /// methods), objects below it in the object path tree, and its properties.
            fn introspect(&self) -> Result<String>;
        }
    };
}

gen_introspectable_proxy!(true, false);
assert_impl_all!(IntrospectableProxy<'_>: Send, Sync, Unpin);

/// Server-side implementation for the `org.freedesktop.DBus.Introspectable` interface.
/// This interface is implemented automatically for any object registered to the
/// [ObjectServer](crate::ObjectServer).
pub(crate) struct Introspectable;

#[dbus_interface(name = "org.freedesktop.DBus.Introspectable")]
impl Introspectable {
    async fn introspect(
        &self,
        #[zbus(object_server)] server: &ObjectServer,
        #[zbus(header)] header: MessageHeader<'_>,
    ) -> Result<String> {
        let path = header.path()?.ok_or(crate::Error::MissingField)?;
        let root = server.root().read().await;
        let node = root
            .get_child(path)
            .ok_or_else(|| Error::UnknownObject(format!("Unknown object '{}'", path)))?;

        Ok(node.introspect().await)
    }
}

#[rustfmt::skip]
macro_rules! gen_properties_proxy {
    ($gen_async:literal, $gen_blocking:literal) => {
        /// Proxy for the `org.freedesktop.DBus.Properties` interface.
        #[dbus_proxy(
            interface = "org.freedesktop.DBus.Properties",
            gen_async = $gen_async,
            gen_blocking = $gen_blocking,
        )]
        trait Properties {
            /// Get a property value.
            async fn get(
                &self,
                interface_name: InterfaceName<'_>,
                property_name: &str,
            ) -> Result<OwnedValue>;

            /// Set a property value.
            async fn set(
                &self,
                interface_name: InterfaceName<'_>,
                property_name: &str,
                value: &Value<'_>,
            ) -> Result<()>;

            /// Get all properties.
            async fn get_all(
                &self,
                interface_name: InterfaceName<'_>,
            ) -> Result<HashMap<String, OwnedValue>>;

            #[dbus_proxy(signal)]
            async fn properties_changed(
                &self,
                interface_name: InterfaceName<'_>,
                changed_properties: HashMap<&str, Value<'_>>,
                invalidated_properties: Vec<&str>,
            ) -> Result<()>;
        }
    };
}

gen_properties_proxy!(true, false);
assert_impl_all!(PropertiesProxy<'_>: Send, Sync, Unpin);

/// Server-side implementation for the `org.freedesktop.DBus.Properties` interface.
/// This interface is implemented automatically for any object registered to the
/// [ObjectServer](crate::ObjectServer).
pub struct Properties;

assert_impl_all!(Properties: Send, Sync, Unpin);

#[dbus_interface(name = "org.freedesktop.DBus.Properties")]
impl Properties {
    async fn get(
        &self,
        interface_name: InterfaceName<'_>,
        property_name: &str,
        #[zbus(object_server)] server: &ObjectServer,
        #[zbus(header)] header: MessageHeader<'_>,
    ) -> Result<OwnedValue> {
        let path = header.path()?.ok_or(crate::Error::MissingField)?;
        let root = server.root().read().await;
        let iface = root
            .get_child(path)
            .and_then(|node| node.interface_lock(interface_name.as_ref()))
            .ok_or_else(|| {
                Error::UnknownInterface(format!("Unknown interface '{}'", interface_name))
            })?;

        let res = iface.read().await.get(property_name).await;
        res.unwrap_or_else(|| {
            Err(Error::UnknownProperty(format!(
                "Unknown property '{}'",
                property_name
            )))
        })
    }

    async fn set(
        &self,
        interface_name: InterfaceName<'_>,
        property_name: &str,
        value: Value<'_>,
        #[zbus(object_server)] server: &ObjectServer,
        #[zbus(header)] header: MessageHeader<'_>,
        #[zbus(signal_context)] ctxt: SignalContext<'_>,
    ) -> Result<()> {
        let path = header.path()?.ok_or(crate::Error::MissingField)?;
        let root = server.root().read().await;
        let iface = root
            .get_child(path)
            .and_then(|node| node.interface_lock(interface_name.as_ref()))
            .ok_or_else(|| {
                Error::UnknownInterface(format!("Unknown interface '{}'", interface_name))
            })?;

        match iface.read().await.set(property_name, &value, &ctxt) {
            zbus::DispatchResult::RequiresMut => {}
            zbus::DispatchResult::NotFound => {
                return Err(Error::UnknownProperty(format!(
                    "Unknown property '{}'",
                    property_name
                )));
            }
            zbus::DispatchResult::Async(f) => {
                return f.await.map_err(Into::into);
            }
        }
        let res = iface
            .write()
            .await
            .set_mut(property_name, &value, &ctxt)
            .await;
        res.unwrap_or_else(|| {
            Err(Error::UnknownProperty(format!(
                "Unknown property '{}'",
                property_name
            )))
        })
    }

    async fn get_all(
        &self,
        interface_name: InterfaceName<'_>,
        #[zbus(object_server)] server: &ObjectServer,
        #[zbus(header)] header: MessageHeader<'_>,
    ) -> Result<HashMap<String, OwnedValue>> {
        let path = header.path()?.ok_or(crate::Error::MissingField)?;
        let root = server.root().read().await;
        let iface = root
            .get_child(path)
            .and_then(|node| node.interface_lock(interface_name.as_ref()))
            .ok_or_else(|| {
                Error::UnknownInterface(format!("Unknown interface '{}'", interface_name))
            })?;

        let res = iface.read().await.get_all().await;
        Ok(res)
    }

    /// Emits the `org.freedesktop.DBus.Properties.PropertiesChanged` signal.
    #[dbus_interface(signal)]
    #[rustfmt::skip]
    pub async fn properties_changed(
        ctxt: &SignalContext<'_>,
        interface_name: InterfaceName<'_>,
        changed_properties: &HashMap<&str, &Value<'_>>,
        invalidated_properties: &[&str],
    ) -> zbus::Result<()>;
}

/// The type returned by the [`ObjectManagerProxy::get_managed_objects`] method.
pub type ManagedObjects =
    HashMap<OwnedObjectPath, HashMap<OwnedInterfaceName, HashMap<String, OwnedValue>>>;

#[rustfmt::skip]
macro_rules! gen_object_manager_proxy {
    ($gen_async:literal, $gen_blocking:literal) => {
        /// Proxy for the `org.freedesktop.DBus.ObjectManager` interface.
        ///
        /// **NB:** Changes to properties on existing interfaces are not reported using this interface.
        /// Please use [`PropertiesProxy::receive_properties_changed`] to monitor changes to properties on
        /// objects.
        #[dbus_proxy(
            interface = "org.freedesktop.DBus.ObjectManager",
            gen_async = $gen_async,
            gen_blocking = $gen_blocking,
        )]
        trait ObjectManager {
            /// The return value of this method is a dict whose keys are object paths. All returned object
            /// paths are children of the object path implementing this interface, i.e. their object paths
            /// start with the ObjectManager's object path plus '/'.
            ///
            /// Each value is a dict whose keys are interfaces names. Each value in this inner dict is the
            /// same dict that would be returned by the org.freedesktop.DBus.Properties.GetAll() method for
            /// that combination of object path and interface. If an interface has no properties, the empty
            /// dict is returned.
            fn get_managed_objects(&self) -> Result<ManagedObjects>;

            /// This signal is emitted when either a new object is added or when an existing object gains
            /// one or more interfaces. The `interfaces_and_properties` argument contains a map with the
            /// interfaces and properties (if any) that have been added to the given object path.
            #[dbus_proxy(signal)]
            fn interfaces_added(
                &self,
                object_path: ObjectPath<'_>,
                interfaces_and_properties: HashMap<&str, HashMap<&str, Value<'_>>>,
            ) -> Result<()>;

            /// This signal is emitted whenever an object is removed or it loses one or more interfaces.
            /// The `interfaces` parameters contains a list of the interfaces that were removed.
            #[dbus_proxy(signal)]
            fn interfaces_removed(
                &self,
                object_path: ObjectPath<'_>,
                interfaces: Vec<&str>,
            ) -> Result<()>;
        }
    };
}

gen_object_manager_proxy!(true, false);
assert_impl_all!(ObjectManagerProxy<'_>: Send, Sync, Unpin);

/// Service-side [Object Manager][om] interface implementation.
///
/// The recommended path to add this interface at is the path form of the well-known name of a D-Bus
/// service, or below. For example, if a D-Bus service is available at the well-known name
/// `net.example.ExampleService1`, this interface should typically be registered at
/// `/net/example/ExampleService1`, or below (to allow for multiple object managers in a service).
///
/// It is supported, but not recommended, to add this interface at the root path, `/`.
///
/// When added to an `ObjectServer`, `InterfacesAdded` signal is emitted for all the objects under
/// the `path` its added at. You can use this fact to minimize the signal emissions by populating
/// the entire (sub)tree under `path` before registering an object manager.
///
/// [om]: https://dbus.freedesktop.org/doc/dbus-specification.html#standard-interfaces-objectmanager
#[derive(Debug, Clone)]
pub struct ObjectManager;

#[dbus_interface(name = "org.freedesktop.DBus.ObjectManager")]
impl ObjectManager {
    async fn get_managed_objects(
        &self,
        #[zbus(object_server)] server: &ObjectServer,
        #[zbus(header)] header: MessageHeader<'_>,
    ) -> Result<ManagedObjects> {
        let path = header.path()?.ok_or(crate::Error::MissingField)?;
        let root = server.root().read().await;
        let node = root
            .get_child(path)
            .ok_or_else(|| Error::UnknownObject(format!("Unknown object '{}'", path)))?;

        Ok(node.get_managed_objects().await)
    }

    /// This signal is emitted when either a new object is added or when an existing object gains
    /// one or more interfaces. The `interfaces_and_properties` argument contains a map with the
    /// interfaces and properties (if any) that have been added to the given object path.
    #[dbus_interface(signal)]
    pub async fn interfaces_added(
        ctxt: &SignalContext<'_>,
        object_path: &ObjectPath<'_>,
        interfaces_and_properties: &HashMap<InterfaceName<'_>, HashMap<&str, Value<'_>>>,
    ) -> zbus::Result<()>;

    /// This signal is emitted whenever an object is removed or it loses one or more interfaces.
    /// The `interfaces` parameters contains a list of the interfaces that were removed.
    #[dbus_interface(signal)]
    pub async fn interfaces_removed(
        ctxt: &SignalContext<'_>,
        object_path: &ObjectPath<'_>,
        interfaces: &[InterfaceName<'_>],
    ) -> zbus::Result<()>;
}

#[rustfmt::skip]
macro_rules! gen_peer_proxy {
    ($gen_async:literal, $gen_blocking:literal) => {
        /// Proxy for the `org.freedesktop.DBus.Peer` interface.
        #[dbus_proxy(
            interface = "org.freedesktop.DBus.Peer",
            gen_async = $gen_async,
            gen_blocking = $gen_blocking,
        )]
        trait Peer {
            /// On receipt, an application should do nothing other than reply as usual. It does not matter
            /// which object path a ping is sent to.
            fn ping(&self) -> Result<()>;

            /// An application should reply the containing a hex-encoded UUID representing the identity of
            /// the machine the process is running on. This UUID must be the same for all processes on a
            /// single system at least until that system next reboots. It should be the same across reboots
            /// if possible, but this is not always possible to implement and is not guaranteed. It does not
            /// matter which object path a GetMachineId is sent to.
            fn get_machine_id(&self) -> Result<String>;
        }
    };
}

gen_peer_proxy!(true, false);
assert_impl_all!(PeerProxy<'_>: Send, Sync, Unpin);

pub(crate) struct Peer;

/// Server-side implementation for the `org.freedesktop.DBus.Peer` interface.
/// This interface is implemented automatically for any object registered to the
/// [ObjectServer](crate::ObjectServer).
#[dbus_interface(name = "org.freedesktop.DBus.Peer")]
impl Peer {
    fn ping(&self) {}

    fn get_machine_id(&self) -> Result<String> {
        let mut id = match std::fs::read_to_string("/var/lib/dbus/machine-id") {
            Ok(id) => id,
            Err(e) => {
                if let Ok(id) = std::fs::read_to_string("/etc/machine-id") {
                    id
                } else {
                    return Err(Error::IOError(format!(
                        "Failed to read from /var/lib/dbus/machine-id or /etc/machine-id: {}",
                        e
                    )));
                }
            }
        };

        let len = id.trim_end().len();
        id.truncate(len);
        Ok(id)
    }
}

#[rustfmt::skip]
macro_rules! gen_monitoring_proxy {
    ($gen_async:literal, $gen_blocking:literal) => {
        /// Proxy for the `org.freedesktop.DBus.Monitoring` interface.
        #[dbus_proxy(
            interface = "org.freedesktop.DBus.Monitoring",
            gen_async = $gen_async,
            gen_blocking = $gen_blocking,
        )]
        trait Monitoring {
            /// Converts the connection into a monitor connection which can be used as a
            /// debugging/monitoring tool.
            fn become_monitor(&self, n1: &[&str], n2: u32) -> Result<()>;
        }
    };
}

gen_monitoring_proxy!(true, false);
assert_impl_all!(MonitoringProxy<'_>: Send, Sync, Unpin);

#[rustfmt::skip]
macro_rules! gen_stats_proxy {
    ($gen_async:literal, $gen_blocking:literal) => {
        /// Proxy for the `org.freedesktop.DBus.Stats` interface.
        #[dbus_proxy(
            interface = "org.freedesktop.DBus.Debug.Stats",
            gen_async = $gen_async,
            gen_blocking = $gen_blocking,
        )]
        trait Stats {
            /// GetStats (undocumented)
            fn get_stats(&self) -> Result<Vec<HashMap<String, OwnedValue>>>;

            /// GetConnectionStats (undocumented)
            fn get_connection_stats(&self, n1: &str) -> Result<Vec<HashMap<String, OwnedValue>>>;

            /// GetAllMatchRules (undocumented)
            fn get_all_match_rules(&self) -> Result<Vec<HashMap<String, Vec<String>>>>;
        }
    };
}

gen_stats_proxy!(true, false);
assert_impl_all!(StatsProxy<'_>: Send, Sync, Unpin);

/// The flags used by the bus [`request_name`] method.
///
/// [`request_name`]: struct.DBusProxy.html#method.request_name
#[bitflags]
#[repr(u32)]
#[derive(Type, Debug, PartialEq, Eq, Copy, Clone, Serialize, Deserialize)]
pub enum RequestNameFlags {
    /// If an application A specifies this flag and succeeds in becoming the owner of the name, and
    /// another application B later calls [`request_name`] with the [`ReplaceExisting`] flag, then
    /// application A will lose ownership and receive a `org.freedesktop.DBus.NameLost` signal, and
    /// application B will become the new owner. If [`AllowReplacement`] is not specified by
    /// application A, or [`ReplaceExisting`] is not specified by application B, then application B
    /// will not replace application A as the owner.
    ///
    /// [`ReplaceExisting`]: enum.RequestNameFlags.html#variant.ReplaceExisting
    /// [`AllowReplacement`]: enum.RequestNameFlags.html#variant.AllowReplacement
    /// [`request_name`]: struct.DBusProxy.html#method.request_name
    AllowReplacement = 0x01,
    /// Try to replace the current owner if there is one. If this flag is not set the application
    /// will only become the owner of the name if there is no current owner. If this flag is set,
    /// the application will replace the current owner if the current owner specified
    /// [`AllowReplacement`].
    ///
    /// [`AllowReplacement`]: enum.RequestNameFlags.html#variant.AllowReplacement
    ReplaceExisting = 0x02,
    ///  Without this flag, if an application requests a name that is already owned, the application
    ///  will be placed in a queue to own the name when the current owner gives it up. If this flag
    ///  is given, the application will not be placed in the queue, the request for the name will
    ///  simply fail. This flag also affects behavior when an application is replaced as name owner;
    ///  by default the application moves back into the waiting queue, unless this flag was provided
    ///  when the application became the name owner.
    DoNotQueue = 0x04,
}

assert_impl_all!(RequestNameFlags: Send, Sync, Unpin);

/// The return code of the [`request_name`] method.
///
/// [`request_name`]: struct.DBusProxy.html#method.request_name
#[repr(u32)]
#[derive(Deserialize_repr, Serialize_repr, Type, Debug, PartialEq, Eq)]
pub enum RequestNameReply {
    /// The caller is now the primary owner of the name, replacing any previous owner. Either the
    /// name had no owner before, or the caller specified [`ReplaceExisting`] and the current owner
    /// specified [`AllowReplacement`].
    ///
    /// [`ReplaceExisting`]: enum.RequestNameFlags.html#variant.ReplaceExisting
    /// [`AllowReplacement`]: enum.RequestNameFlags.html#variant.AllowReplacement
    PrimaryOwner = 0x01,
    /// The name already had an owner, [`DoNotQueue`] was not specified, and either the current
    /// owner did not specify [`AllowReplacement`] or the requesting application did not specify
    /// [`ReplaceExisting`].
    ///
    /// [`DoNotQueue`]: enum.RequestNameFlags.html#variant.DoNotQueue
    /// [`ReplaceExisting`]: enum.RequestNameFlags.html#variant.ReplaceExisting
    /// [`AllowReplacement`]: enum.RequestNameFlags.html#variant.AllowReplacement
    InQueue = 0x02,
    /// The name already has an owner, [`DoNotQueue`] was specified, and either [`AllowReplacement`]
    /// was not specified by the current owner, or [`ReplaceExisting`] was not specified by the
    /// requesting application.
    ///
    /// [`DoNotQueue`]: enum.RequestNameFlags.html#variant.DoNotQueue
    /// [`ReplaceExisting`]: enum.RequestNameFlags.html#variant.ReplaceExisting
    /// [`AllowReplacement`]: enum.RequestNameFlags.html#variant.AllowReplacement
    Exists = 0x03,
    /// The application trying to request ownership of a name is already the owner of it.
    AlreadyOwner = 0x04,
}

assert_impl_all!(RequestNameReply: Send, Sync, Unpin);

/// The return code of the [`release_name`] method.
///
/// [`release_name`]: struct.DBusProxy.html#method.release_name
#[repr(u32)]
#[derive(Deserialize_repr, Serialize_repr, Type, Debug, PartialEq, Eq)]
pub enum ReleaseNameReply {
    /// The caller has released their claim on the given name. Either the caller was the primary
    /// owner of the name, and the name is now unused or taken by somebody waiting in the queue for
    /// the name, or the caller was waiting in the queue for the name and has now been removed from
    /// the queue.
    Released = 0x01,
    /// The given name does not exist on this bus.
    NonExistent = 0x02,
    /// The caller was not the primary owner of this name, and was also not waiting in the queue to
    /// own this name.
    NotOwner = 0x03,
}

assert_impl_all!(ReleaseNameReply: Send, Sync, Unpin);

/// Credentials of a process connected to a bus server.
///
/// If unable to determine certain credentials (for instance, because the process is not on the same
/// machine as the bus daemon, or because this version of the bus daemon does not support a
/// particular security framework), or if the values of those credentials cannot be represented as
/// documented here, then those credentials are omitted.
///
/// **Note**: unknown keys, in particular those with "." that are not from the specification, will
/// be ignored. Use your own implementation or contribute your keys here, or in the specification.
#[derive(Debug, DeserializeDict, PartialEq, Eq, SerializeDict, Type)]
#[zvariant(signature = "a{sv}")]
pub struct ConnectionCredentials {
    /// The numeric Unix user ID, as defined by POSIX
    #[zvariant(rename = "UnixUserID")]
    pub unix_user_id: Option<u32>,

    /// The numeric Unix group IDs (including both the primary group and the supplementary groups),
    /// as defined by POSIX, in numerically sorted order. This array is either complete or absent:
    /// if the message bus is able to determine some but not all of the caller's groups, or if one
    /// of the groups is not representable in a UINT32, it must not add this credential to the
    /// dictionary.
    #[zvariant(rename = "UnixGroupIDs")]
    pub unix_group_ids: Option<Vec<u32>>,

    /// The numeric process ID, on platforms that have this concept. On Unix, this is the process ID
    /// defined by POSIX.
    #[zvariant(rename = "ProcessID")]
    pub process_id: Option<u32>,

    /// The Windows security identifier in its string form, e.g.
    /// `S-1-5-21-3623811015-3361044348-30300820-1013` for a domain or local computer user or
    /// "S-1-5-18` for the LOCAL_SYSTEM user.
    #[zvariant(rename = "WindowsSID")]
    pub windows_sid: Option<String>,

    /// On Linux systems, the security label that would result from the SO_PEERSEC getsockopt call.
    /// The array contains the non-zero bytes of the security label in an unspecified
    /// ASCII-compatible encoding, followed by a single zero byte.
    ///
    /// For example, the SELinux context `system_u:system_r:init_t:s0` (a string of length 27) would
    /// be encoded as 28 bytes ending with `':', 's', '0', '\x00'`
    ///
    /// On SELinux systems this is the SELinux context, as output by `ps -Z` or `ls -Z`. Typical values
    /// might include `system_u:system_r:init_t:s0`,
    /// `unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023`, or
    /// `unconfined_u:unconfined_r:chrome_sandbox_t:s0-s0:c0.c1023`.
    ///
    /// On Smack systems, this is the Smack label. Typical values might include `_`, `*`, `User`,
    /// `System` or `System::Shared`.
    ///
    /// On AppArmor systems, this is the AppArmor context, a composite string encoding the AppArmor
    /// label (one or more profiles) and the enforcement mode. Typical values might include
    /// `unconfined`, `/usr/bin/firefox (enforce)` or `user1 (complain)`.
    #[zvariant(rename = "LinuxSecurityLabel")]
    pub linux_security_label: Option<Vec<u8>>,
}

#[rustfmt::skip]
macro_rules! gen_dbus_proxy {
    ($gen_async:literal, $gen_blocking:literal) => {
        /// Proxy for the `org.freedesktop.DBus` interface.
        #[dbus_proxy(
            interface = "org.freedesktop.DBus",
            gen_async = $gen_async,
            gen_blocking = $gen_blocking,
        )]
        trait DBus {
            /// Adds a match rule to match messages going through the message bus
            fn add_match(&self, rule: &str) -> Result<()>;

            /// Returns auditing data used by Solaris ADT, in an unspecified binary format.
            fn get_adt_audit_session_data(&self, bus_name: BusName<'_>) -> Result<Vec<u8>>;

            /// Returns as many credentials as possible for the process connected to the server.
            fn get_connection_credentials(
                &self,
                bus_name: BusName<'_>,
            ) -> Result<ConnectionCredentials>;

            /// Returns the security context used by SELinux, in an unspecified format.
            #[dbus_proxy(name = "GetConnectionSELinuxSecurityContext")]
            fn get_connection_selinux_security_context(
                &self,
                bus_name: BusName<'_>,
            ) -> Result<Vec<u8>>;

            /// Returns the Unix process ID of the process connected to the server.
            #[dbus_proxy(name = "GetConnectionUnixProcessID")]
            fn get_connection_unix_process_id(&self, bus_name: BusName<'_>) -> Result<u32>;

            /// Returns the Unix user ID of the process connected to the server.
            fn get_connection_unix_user(&self, bus_name: BusName<'_>) -> Result<u32>;

            /// Gets the unique ID of the bus.
            fn get_id(&self) -> Result<String>;

            /// Returns the unique connection name of the primary owner of the name given.
            fn get_name_owner(&self, name: BusName<'_>) -> Result<OwnedUniqueName>;

            /// Returns the unique name assigned to the connection.
            fn hello(&self) -> Result<OwnedUniqueName>;

            /// Returns a list of all names that can be activated on the bus.
            fn list_activatable_names(&self) -> Result<Vec<OwnedBusName>>;

            /// Returns a list of all currently-owned names on the bus.
            fn list_names(&self) -> Result<Vec<OwnedBusName>>;

            /// List the connections currently queued for a bus name.
            fn list_queued_owners(&self, name: WellKnownName<'_>) -> Result<Vec<OwnedUniqueName>>;

            /// Checks if the specified name exists (currently has an owner).
            fn name_has_owner(&self, name: BusName<'_>) -> Result<bool>;

            /// Ask the message bus to release the method caller's claim to the given name.
            fn release_name(&self, name: WellKnownName<'_>) -> Result<ReleaseNameReply>;

            /// Reload server configuration.
            fn reload_config(&self) -> Result<()>;

            /// Removes the first rule that matches.
            fn remove_match(&self, rule: &str) -> Result<()>;

            /// Ask the message bus to assign the given name to the method caller.
            fn request_name(
                &self,
                name: WellKnownName<'_>,
                flags: BitFlags<RequestNameFlags>,
            ) -> Result<RequestNameReply>;

            /// Tries to launch the executable associated with a name (service
            /// activation), as an explicit request.
            fn start_service_by_name(&self, name: WellKnownName<'_>, flags: u32) -> Result<u32>;

            /// This method adds to or modifies that environment when activating services.
            fn update_activation_environment(&self, environment: HashMap<&str, &str>)
                -> Result<()>;

            /// This signal indicates that the owner of a name has
            /// changed. It's also the signal to use to detect the appearance
            /// of new names on the bus.
            #[dbus_proxy(signal)]
            fn name_owner_changed(
                &self,
                name: BusName<'_>,
                old_owner: Optional<UniqueName<'_>>,
                new_owner: Optional<UniqueName<'_>>,
            );

            /// This signal is sent to a specific application when it loses ownership of a name.
            #[dbus_proxy(signal)]
            fn name_lost(&self, name: BusName<'_>);

            /// This signal is sent to a specific application when it gains ownership of a name.
            #[dbus_proxy(signal)]
            fn name_acquired(&self, name: BusName<'_>);

            /// This property lists abstract “features” provided by the message bus, and can be used by
            /// clients to detect the capabilities of the message bus with which they are communicating.
            #[dbus_proxy(property)]
            fn features(&self) -> Result<Vec<String>>;

            /// This property lists interfaces provided by the `/org/freedesktop/DBus` object, and can be
            /// used by clients to detect the capabilities of the message bus with which they are
            /// communicating. Unlike the standard Introspectable interface, querying this property does not
            /// require parsing XML. This property was added in version 1.11.x of the reference
            /// implementation of the message bus.
            ///
            /// The standard `org.freedesktop.DBus` and `org.freedesktop.DBus.Properties` interfaces are not
            /// included in the value of this property, because their presence can be inferred from the fact
            /// that a method call on `org.freedesktop.DBus.Properties` asking for properties of
            /// `org.freedesktop.DBus` was successful. The standard `org.freedesktop.DBus.Peer` and
            /// `org.freedesktop.DBus.Introspectable` interfaces are not included in the value of this
            /// property either, because they do not indicate features of the message bus implementation.
            #[dbus_proxy(property)]
            fn interfaces(&self) -> Result<Vec<OwnedInterfaceName>>;
        }
    };
}

gen_dbus_proxy!(true, false);
assert_impl_all!(DBusProxy<'_>: Send, Sync, Unpin);

/// Errors from <https://gitlab.freedesktop.org/dbus/dbus/-/blob/master/dbus/dbus-protocol.h>
#[derive(Debug, DBusError, PartialEq)]
#[dbus_error(prefix = "org.freedesktop.DBus.Error", impl_display = true)]
#[allow(clippy::upper_case_acronyms)]
pub enum Error {
    /// Unknown or fall-through ZBus error.
    #[dbus_error(zbus_error)]
    ZBus(zbus::Error),

    /// A generic error; "something went wrong" - see the error message for more.
    Failed(String),

    /// There was not enough memory to complete an operation.
    NoMemory(String),

    /// The bus doesn't know how to launch a service to supply the bus name you wanted.
    ServiceUnknown(String),

    /// The bus name you referenced doesn't exist (i.e. no application owns it).
    NameHasNoOwner(String),

    /// No reply to a message expecting one, usually means a timeout occurred.
    NoReply(String),

    /// Something went wrong reading or writing to a socket, for example.
    IOError(String),

    /// A D-Bus bus address was malformed.
    BadAddress(String),

    /// Requested operation isn't supported (like ENOSYS on UNIX).
    NotSupported(String),

    /// Some limited resource is exhausted.
    LimitsExceeded(String),

    /// Security restrictions don't allow doing what you're trying to do.
    AccessDenied(String),

    /// Authentication didn't work.
    AuthFailed(String),

    /// Unable to connect to server (probably caused by ECONNREFUSED on a socket).
    NoServer(String),

    /// Certain timeout errors, possibly ETIMEDOUT on a socket.
    /// Note that `TimedOut` is used for message reply timeouts.
    Timeout(String),

    /// No network access (probably ENETUNREACH on a socket).
    NoNetwork(String),

    /// Can't bind a socket since its address is in use (i.e. EADDRINUSE).
    AddressInUse(String),

    /// The connection is disconnected and you're trying to use it.
    Disconnected(String),

    /// Invalid arguments passed to a method call.
    InvalidArgs(String),

    /// Missing file.
    FileNotFound(String),

    /// Existing file and the operation you're using does not silently overwrite.
    FileExists(String),

    /// Method name you invoked isn't known by the object you invoked it on.
    UnknownMethod(String),

    /// Object you invoked a method on isn't known.
    UnknownObject(String),

    /// Interface you invoked a method on isn't known by the object.
    UnknownInterface(String),

    /// Property you tried to access isn't known by the object.
    UnknownProperty(String),

    /// Property you tried to set is read-only.
    PropertyReadOnly(String),

    /// Certain timeout errors, e.g. while starting a service.
    TimedOut(String),

    /// Tried to remove or modify a match rule that didn't exist.
    MatchRuleNotFound(String),

    /// The match rule isn't syntactically valid.
    MatchRuleInvalid(String),

    /// While starting a new process, the exec() call failed.
    #[dbus_error(name = "Spawn.ExecFailed")]
    SpawnExecFailed(String),

    /// While starting a new process, the fork() call failed.
    #[dbus_error(name = "Spawn.ForkFailed")]
    SpawnForkFailed(String),

    /// While starting a new process, the child exited with a status code.
    #[dbus_error(name = "Spawn.ChildExited")]
    SpawnChildExited(String),

    /// While starting a new process, the child exited on a signal.
    #[dbus_error(name = "Spawn.ChildSignaled")]
    SpawnChildSignaled(String),

    /// While starting a new process, something went wrong.
    #[dbus_error(name = "Spawn.Failed")]
    SpawnFailed(String),

    /// We failed to setup the environment correctly.
    #[dbus_error(name = "Spawn.FailedToSetup")]
    SpawnFailedToSetup(String),

    /// We failed to setup the config parser correctly.
    #[dbus_error(name = "Spawn.ConfigInvalid")]
    SpawnConfigInvalid(String),

    /// Bus name was not valid.
    #[dbus_error(name = "Spawn.ServiceNotValid")]
    SpawnServiceNotValid(String),

    /// Service file not found in system-services directory.
    #[dbus_error(name = "Spawn.ServiceNotFound")]
    SpawnServiceNotFound(String),

    /// Permissions are incorrect on the setuid helper.
    #[dbus_error(name = "Spawn.PermissionsInvalid")]
    SpawnPermissionsInvalid(String),

    /// Service file invalid (Name, User or Exec missing).
    #[dbus_error(name = "Spawn.FileInvalid")]
    SpawnFileInvalid(String),

    /// There was not enough memory to complete the operation.
    #[dbus_error(name = "Spawn.NoMemory")]
    SpawnNoMemory(String),

    /// Tried to get a UNIX process ID and it wasn't available.
    UnixProcessIdUnknown(String),

    /// A type signature is not valid.
    InvalidSignature(String),

    /// A file contains invalid syntax or is otherwise broken.
    InvalidFileContent(String),

    /// Asked for SELinux security context and it wasn't available.
    SELinuxSecurityContextUnknown(String),

    /// Asked for ADT audit data and it wasn't available.
    AdtAuditDataUnknown(String),

    /// There's already an object with the requested object path.
    ObjectPathInUse(String),

    /// The message meta data does not match the payload. e.g. expected number of file descriptors
    /// were not sent over the socket this message was received on.
    InconsistentMessage(String),

    /// The message is not allowed without performing interactive authorization, but could have
    /// succeeded if an interactive authorization step was allowed.
    InteractiveAuthorizationRequired(String),

    /// The connection is not from a container, or the specified container instance does not exist.
    NotContainer(String),
}

assert_impl_all!(Error: Send, Sync, Unpin);

/// Alias for a `Result` with the error type [`zbus::fdo::Error`].
///
/// [`zbus::fdo::Error`]: enum.Error.html
pub type Result<T> = std::result::Result<T, Error>;

#[cfg(test)]
mod tests {
    use crate::{fdo, DBusError, Error, Message};
    use futures_util::StreamExt;
    use ntest::timeout;
    use std::{convert::TryInto, future::ready};
    use test_log::test;
    use tokio::runtime;
    use zbus_names::WellKnownName;

    #[test]
    fn error_from_zerror() {
        let m = Message::method(Some(":1.2"), None::<()>, "/", None::<()>, "foo", &()).unwrap();
        let m = Message::method_error(
            None::<()>,
            &m,
            "org.freedesktop.DBus.Error.TimedOut",
            &("so long"),
        )
        .unwrap();
        let e: Error = m.into();
        let e: fdo::Error = e.try_into().unwrap();
        assert_eq!(e, fdo::Error::TimedOut("so long".to_string()),);
        assert_eq!(e.name(), "org.freedesktop.DBus.Error.TimedOut");
        assert_eq!(e.description(), Some("so long"));
    }

    #[test]
    #[timeout(15000)]
    fn signal() {
        // Multi-threaded scheduler.
        runtime::Runtime::new().unwrap().block_on(test_signal());

        // single-threaded scheduler.
        runtime::Builder::new_current_thread()
            .enable_io()
            .build()
            .unwrap()
            .block_on(test_signal());
    }

    async fn test_signal() {
        let conn = crate::Connection::session().await.unwrap();
        let proxy = fdo::DBusProxy::new(&conn).await.unwrap();

        // Register a well-known name with the session bus and ensure we get the appropriate
        // signals called for that.
        let well_known = "org.freedesktop.zbus.FdoSignalStreamTest";
        let unique_name = conn.unique_name().unwrap();
        let owner_change_stream =
            proxy
                .receive_name_owner_changed()
                .await
                .unwrap()
                .filter(|signal| {
                    let args = signal.args().unwrap();

                    if args.name() != well_known {
                        // Meant for the other testcase then
                        return ready(false);
                    }
                    assert_eq!(*args.new_owner().as_ref().unwrap(), *unique_name);

                    ready(true)
                });

        let name_acquired_stream = proxy
            .receive_name_acquired()
            .await
            .unwrap()
            .filter(|signal| {
                let args = signal.args().unwrap();
                // `NameAcquired` is emitted twice, first when the unique name is assigned on
                // connection and secondly after we ask for a specific name.
                ready(args.name() == well_known)
            });
        let mut stream = owner_change_stream.zip(name_acquired_stream);

        let well_known: WellKnownName<'static> = well_known.try_into().unwrap();
        proxy
            .request_name(
                well_known.as_ref(),
                fdo::RequestNameFlags::ReplaceExisting.into(),
            )
            .await
            .unwrap();

        let (name_owner_changed, name_acquired) = stream.next().await.unwrap();
        assert_eq!(name_owner_changed.args().unwrap().name(), &well_known);
        assert_eq!(
            *name_owner_changed
                .args()
                .unwrap()
                .new_owner()
                .as_ref()
                .unwrap(),
            *unique_name
        );
        assert_eq!(name_acquired.args().unwrap().name(), &well_known);

        let result = proxy.release_name(well_known.as_ref()).await.unwrap();
        assert_eq!(result, fdo::ReleaseNameReply::Released);

        let result = proxy.release_name(well_known).await.unwrap();
        assert_eq!(result, fdo::ReleaseNameReply::NonExistent);

        let _stream = proxy
            .receive_features_changed()
            .await
            .filter_map(|changed| async move {
                let v = changed.get().await.ok();
                dbg!(v)
            });
    }
}