//! Endpoints for event searches.

/// [POST /_matrix/client/r0/search](https://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-client-r0-search)
pub mod search_events {
    use ruma_events::collections::all::Event;
    use ruma_identifiers::{EventId, RoomId, UserId};

    use r0::filter::RoomEventFilter;
    use r0::profile::get_profile::Response as UserProfile;

    use std::collections::HashMap;

    /// This API endpoint's body parameters.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct BodyParams {
        /// Describes which categories to search in and their criteria.
        pub search_categories: Categories,
    }

    /// Categories of events that can be searched for.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct Categories {
        /// Criteria for searching a category of events.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub room_events: Option<Criteria>
    }

    /// Criteria for searching a category of events.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct Criteria {
        /// Configures whether any context for the events returned are included in the response.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub event_context: Option<EventContext>,
        /// A `Filter` to apply to the search.
        // TODO: "timeline" key might need to be included.
        // See https://github.com/matrix-org/matrix-doc/issues/598.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub filter: Option<RoomEventFilter>,
        /// Requests that the server partitions the result set based on the provided list of keys.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub groupings: Option<Groupings>,
        /// Requests the server return the current state for each room returned.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub include_state: Option<bool>,
        /// The keys to search for. Defaults to all keys.
        #[serde(skip_serializing_if = "Vec::is_empty")]
        #[serde(default)]
        pub keys: Vec<SearchKeys>,
        /// The order in which to search for results.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub order_by: Option<OrderBy>,
        /// The string to search events for.
        pub search_term: String,
    }


    /// Details about this API endpoint.
    #[derive(Clone, Copy, Debug)]
    pub struct Endpoint;

    /// Configures whether any context for the events returned are included in the response.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct EventContext {
        /// How many events after the result are returned.
        pub after_limit: u64,
        /// How many events before the result are returned.
        pub before_limit: u64,
        /// Requests that the server returns the historic profile information for the users that
        /// sent the events that were returned.
        pub include_profile: bool,
    }

    /// Context for search results, if requested.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct EventContextResult {
        /// Pagination token for the end of the chunk.
        pub end: String,
        /// Events just after the result.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub events_after: Option<Vec<Event>>,
        /// Events just before the result.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub events_before: Option<Vec<Event>>,
        /// The historic profile information of the users that sent the events returned.
        // TODO: Not sure this is right. https://github.com/matrix-org/matrix-doc/issues/773
        #[serde(skip_serializing_if = "Option::is_none")]
        pub profile_info: Option<HashMap<UserId, UserProfile>>,
        /// Pagination token for the start of the chunk.
        pub start: String,
    }

    /// A grouping for partioning the result set.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct Grouping {
        /// The key within events to use for this grouping.
        pub key: GroupingKey
    }

    /// The key within events to use for this grouping.
    #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, PartialEq, Serialize)]
    pub enum GroupingKey {
        /// `room_id`
        #[serde(rename="room_id")]
        RoomId,
        /// `sender`
        #[serde(rename="sender")]
        Sender,
    }

    /// Requests that the server partitions the result set based on the provided list of keys.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct Groupings {
        /// List of groups to request.
        pub group_by: Vec<Grouping>,
    }

    /// The keys to search for.
    #[derive(Clone, Copy, Debug, Deserialize, Serialize)]
    pub enum SearchKeys {
        /// content.body
        #[serde(rename="content.body")]
        ContentBody,
        /// content.name
        #[serde(rename="content.name")]
        ContentName,
        /// content.topic
        #[serde(rename="content.topic")]
        ContentTopic,
    }

    /// The order in which to search for results.
    #[derive(Clone, Copy, Debug, Deserialize, Serialize)]
    pub enum OrderBy {
        /// Prioritize events by a numerical ranking of how closely they matched the search
        /// criteria.
        #[serde(rename="rank")]
        Rank,
        /// Prioritize recent events.
        #[serde(rename="recent")]
        Recent,
    }

    /// This API endpoint's query string parameters.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct QueryParams {
        /// The point to return events from.
        ///
        /// If given, this should be a `next_batch` result from a previous call to this endpoint.
        pub next_batch: Option<String>,
    }

    /// This API endpoint's response.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct Response {
        /// A grouping of search results by category.
        pub search_categories: ResultCategories,
    }

    /// Categories of events that can be searched for.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct ResultCategories {
        /// Room event results.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub room_events: Option<RoomEventResults>,
    }

    /// Categories of events that can be searched for.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct RoomEventResults {
        /// An approximate count of the total number of results found.
        pub count: u64,
        /// Any groups that were requested.
        // TODO: Not sure this is right. https://github.com/matrix-org/matrix-doc/issues/773
        pub groups: HashMap<GroupingKey, HashMap<RoomId, ResultGroup>>,
        /// Token that can be used to get the next batch of results, by passing as the `next_batch`
        /// parameter to the next call. If this field is absent, there are no more results.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub next_batch: Option<String>,
        /// List of results in the requested order.
        pub results: Vec<SearchResult>,
        /// The current state for every room in the results. This is included if the request had the
        /// `include_state` key set with a value of `true`.
        #[serde(skip_serializing_if = "Option::is_none")]
        // TODO: Major WTF here. https://github.com/matrix-org/matrix-doc/issues/773
        pub state: Option<()>,
    }

    /// A grouping of results, if requested.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct ResultGroup {
        /// Token that can be used to get the next batch of results in the group, by passing as the
        /// `next_batch` parameter to the next call. If this field is absent, there are no more
        /// results in this group.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub next_batch: Option<String>,
        /// Key that can be used to order different groups.
        pub order: u64,
        /// Which results are in this group.
        pub results: Vec<EventId>,
    }

    /// A search result.
    #[derive(Clone, Debug, Deserialize, Serialize)]
    pub struct SearchResult {
        /// Context for result, if requested.
        #[serde(skip_serializing_if = "Option::is_none")]
        pub context: Option<EventContextResult>,
        /// A number that describes how closely this result matches the search. Higher is closer.
        pub rank: f64,
        /// The event that matched.
        pub result: Event,
    }

    impl ::Endpoint for Endpoint {
        type BodyParams = BodyParams;
        type PathParams = ();
        type QueryParams = QueryParams;
        type Response = Response;

        fn method() -> ::Method {
            ::Method::Post
        }

        fn request_path(_params: Self::PathParams) -> String {
            Self::router_path()
        }

        fn router_path() -> String {
            "/_matrix/client/r0/search".to_string()
        }
    }
}