//! Types for the *m.room.history_visibility* event.

use ruma_events_macros::EventContent;
use ruma_serde::StringEnum;
use serde::{Deserialize, Serialize};

use crate::StateEvent;

/// This event controls whether a member of a room can see the events that happened in a room
/// from before they joined.
pub type HistoryVisibilityEvent = StateEvent<HistoryVisibilityEventContent>;

/// The payload for `HistoryVisibilityEvent`.
#[derive(Clone, Debug, Deserialize, Serialize, EventContent)]
#[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
#[ruma_event(type = "m.room.history_visibility", kind = State)]
pub struct HistoryVisibilityEventContent {
    /// Who can see the room history.
    #[ruma_event(skip_redaction)]
    pub history_visibility: HistoryVisibility,
}

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

/// Who can see a room's history.
///
/// This type can hold an arbitrary string. To check for formats that are not available as a
/// documented variant here, use its string representation, obtained through `.as_str()`.
#[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(String),
}

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