sp_api::decl_runtime_apis! {

    pub trait RegistrarApi<ParaId> where

        ParaId: parity_scale_codec::Codec,

    {

        /// Return the registered para ids

        fn registered_paras() -> Vec<ParaId>;

        /// Fetch genesis data for this para id

        fn genesis_data(para_id: ParaId) -> Option<ContainerChainGenesisData>;

        /// Fetch boot_nodes for this para id

        fn boot_nodes(para_id: ParaId) -> Vec<Vec<u8>>;

    }

}

sp_api::decl_runtime_apis! {

    pub trait OnDemandBlockProductionApi<ParaId, Slot> where

        ParaId: parity_scale_codec::Codec,

        Slot: parity_scale_codec::Codec,

    {

        /// Returns slot frequency for particular para thread. Slot frequency specifies amount of slot

        /// need to be passed between two parathread blocks. It is expressed as `(min, max)` pair where `min`

        /// indicates amount of slot must pass before we produce another block and `max` indicates amount of

        /// blocks before this parathread must produce the block.

        ///

        /// Simply put, parathread must produce a block after `min`  but before `(min+max)` slots.

        ///

        /// # Returns

        ///

        /// * `Some(slot_frequency)`.

        /// * `None` if the `para_id` is not a parathread.

        fn parathread_slot_frequency(para_id: ParaId) -> Option<SlotFrequency>;

    }

}