//! Types for the [`m.room.history_visibility`] event.
//!
//! [`m.room.history_visibility`]: https://spec.matrix.org/v1.2/client-server-api/#mroomhistory_visibility

use ruma_macros::EventContent;
use serde::{Deserialize, Serialize};

use crate::{events::EmptyStateKey, serde::StringEnum, PrivOwnedStr};

/// The content of an `m.room.history_visibility` event.
///
/// This event controls whether a member of a room can see the events that happened in a room from
/// before they joined.
#[derive(Clone, Debug, Deserialize, Serialize, EventContent)]
#[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
#[ruma_event(type = "m.room.history_visibility", kind = State, state_key_type = EmptyStateKey)]
pub struct RoomHistoryVisibilityEventContent {
    /// Who can see the room history.
    #[ruma_event(skip_redaction)]
    pub history_visibility: HistoryVisibility,
}

impl RoomHistoryVisibilityEventContent {
    /// Creates a new `RoomHistoryVisibilityEventContent` with the given policy.
    pub fn new(history_visibility: HistoryVisibility) -> Self {
        Self { history_visibility }
    }
}

impl RoomHistoryVisibilityEvent {
    /// Obtain the history visibility, regardless of whether this event is redacted.
    pub fn history_visibility(&self) -> &HistoryVisibility {
        match self {
            Self::Original(ev) => &ev.content.history_visibility,
            Self::Redacted(ev) => &ev.content.history_visibility,
        }
    }
}

impl SyncRoomHistoryVisibilityEvent {
    /// Obtain the history visibility, regardless of whether this event is redacted.
    pub fn history_visibility(&self) -> &HistoryVisibility {
        match self {
            Self::Original(ev) => &ev.content.history_visibility,
            Self::Redacted(ev) => &ev.content.history_visibility,
        }
    }
}

/// Who can see a room's history.
#[doc = include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/src/doc/string_enum.md"))]
#[derive(Clone, Debug, PartialEq, Eq, StringEnum)]
#[ruma_enum(rename_all = "snake_case")]
#[non_exhaustive]
pub enum HistoryVisibility {
    /// Previous events are accessible to newly joined members from the point they were invited
    /// onwards.
    ///
    /// Events stop being accessible when the member's state changes to something other than
    /// *invite* or *join*.
    Invited,

    /// Previous events are accessible to newly joined members from the point they joined the room
    /// onwards.
    /// Events stop being accessible when the member's state changes to something other than
    /// *join*.
    Joined,

    /// Previous events are always accessible to newly joined members.
    ///
    /// All events in the room are accessible, even those sent when the member was not a part of
    /// the room.
    Shared,

    /// All events while this is the `HistoryVisibility` value may be shared by any participating
    /// homeserver with anyone, regardless of whether they have ever joined the room.
    WorldReadable,

    #[doc(hidden)]
    _Custom(PrivOwnedStr),
}

impl HistoryVisibility {
    /// Creates a string slice from this `HistoryVisibility`.
    pub fn as_str(&self) -> &str {
        self.as_ref()
    }
}