use std::collections::{BTreeMap, BTreeSet};

use axum::extract::State;
use conduwuit::{Result, Server};
use ruma::{
	RoomVersionId,
	api::{
		OAuthClientScope,
		client::discovery::get_capabilities::{
			self,
			v3::{
				AdminCapability, Capabilities, GetLoginTokenCapability, ProfileFieldsCapability,
				RoomVersionStability, RoomVersionsCapability, ThirdPartyIdChangesCapability,
			},
		},
	},
	assign,
};
use serde_json::json;

use crate::Ruma;

/// # `GET /_matrix/client/v3/capabilities`
///
/// Get information on the supported feature set and other relevant capabilities
/// of this server.
pub(crate) async fn get_capabilities_route(
	State(services): State<crate::State>,
	body: Ruma<get_capabilities::v3::Request>,
) -> Result<get_capabilities::v3::Response> {
	let sender_user = body.identity.expect_sender_user()?;

	let available: BTreeMap<RoomVersionId, RoomVersionStability> =
		Server::available_room_versions().collect();

	let mut capabilities = Capabilities::default();
	capabilities.room_versions = RoomVersionsCapability::new(
		services.server.config.default_room_version.clone(),
		available,
	);

	// Only allow 3pid changes if SMTP is configured
	capabilities.thirdparty_id_changes =
		ThirdPartyIdChangesCapability::new(services.threepid.email_requirement().may_change());

	capabilities.get_login_token =
		GetLoginTokenCapability::new(services.server.config.login_via_existing_session);

	capabilities.forget_forced_upon_leave.enabled =
		services.server.config.forget_forced_upon_leave;

	if services.users.is_admin(sender_user).await {
		capabilities.account_moderation.lock = true;
		capabilities.account_moderation.suspend = true;

		capabilities.admin =
			AdminCapability::new(BTreeSet::from_iter([OAuthClientScope::ServerAdministration]));
	}

	capabilities.profile_fields = Some(
		assign!(ProfileFieldsCapability::new(true), { disallowed: Some(services.oidc.restricted_profile_fields()) }),
	);

	capabilities.set(
		"org.matrix.msc4174.webpush",
		json!({ "enabled": true, "vapid": services.pusher.webpush_vapid_public_key() }),
	)?;

	Ok(get_capabilities::v3::Response::new(capabilities))
}