//! [POST /_matrix/client/r0/register](https://matrix.org/docs/spec/client_server/r0.4.0.html#post-matrix-client-r0-register)

use ruma_api::ruma_api;
use ruma_identifiers::UserId;
use serde::{Deserialize, Serialize};

ruma_api! {
    metadata {
        description: "Register an account on this homeserver.",
        method: POST,
        name: "register",
        path: "/_matrix/client/r0/register",
        rate_limited: true,
        requires_authentication: false,
    }

    request {
        /// If true, the server binds the email used for authentication
        /// to the Matrix ID with the ID Server.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub bind_email: Option<bool>,
        /// The desired password for the account.
        ///
        /// Should only be empty for guest accounts.
        // TODO: the spec says nothing about when it is actually required.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub password: Option<String>,
        /// local part of the desired Matrix ID.
        ///
        /// If omitted, the homeserver MUST generate a Matrix ID local part.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub username: Option<String>,
        /// ID of the client device.
        ///
        /// If this does not correspond to a known client device, a new device will be created.
        /// The server will auto-generate a device_id if this is not specified.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub device_id: Option<String>,
        /// A display name to assign to the newly-created device.
        ///
        /// Ignored if `device_id` corresponds to a known device.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub initial_device_display_name: Option<String>,
        /// Additional authentication information for the user-interactive authentication API.
        ///
        /// Note that this information is not used to define how the registered user should be
        /// authenticated, but is instead used to authenticate the register call itself.
        /// It should be left empty, or omitted, unless an earlier call returned an response
        /// with status code 401.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub auth: Option<AuthenticationData>,
        /// Kind of account to register
        ///
        /// Defaults to `User` if ommited.
        #[ruma_api(query)]
        #[serde(skip_serializing_if = "Option::is_none")]
        pub kind: Option<RegistrationKind>,
    }

    response {
        /// An access token for the account.
        ///
        /// This access token can then be used to authorize other requests.
        pub access_token: String,
        /// The hostname of the homeserver on which the account has been registered.
        pub home_server: String,
        /// The fully-qualified Matrix ID that has been registered.
        pub user_id: UserId,
        /// ID of the registered device.
        ///
        /// Will be the same as the corresponding parameter in the request, if one was specified.
        pub device_id: String,
    }
}

/// Additional authentication information for the user-interactive authentication API.
#[derive(Clone, Debug, Deserialize, Serialize)]
pub struct AuthenticationData {
    /// The login type that the client is attempting to complete.
    #[serde(rename = "type")]
    kind: String,
    /// The value of the session key given by the homeserver.
    session: Option<String>,
}

/// The kind of account being registered.
#[derive(Copy, Clone, Debug, Deserialize, Serialize)]
#[serde(rename_all = "snake_case")]
pub enum RegistrationKind {
    /// A guest account
    ///
    /// These accounts may have limited permissions and may not be supported by all servers.
    Guest,
    /// A regular user account
    User,
}
