pub static CLIENT_NAME: &str = "cart-manager";

pub enum Topic {}

#[derive(Debug, Clone, thiserror::Error, serde::Serialize, serde::Deserialize)]
pub enum Error {
    #[error("Internal server error")]
    InternalServerError,
    #[error("Failed to load account shopping carts")]
    NoCarts,
    #[error("Account does not have active shopping cart")]
    NoActiveCart,
    #[error("Failed to delete item {0:?}")]
    DeleteItem(model::ShoppingCartItemId),
    #[error("Failed to modify item {0:?}")]
    ModifyItem(model::ShoppingCartItemId),
    #[error("Failed to create item")]
    CreateItem,
    #[error("Failed to modify cart {0:?}")]
    ModifyCart(model::ShoppingCartId),
    #[error("Failed to load cart {0:?} items")]
    LoadItems(model::ShoppingCartId),
}

pub mod remove_product {
    use super::Error;

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Input {
        pub shopping_cart_id: model::ShoppingCartId,
        pub shopping_cart_item_id: model::ShoppingCartItemId,
    }

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Details {
        pub item: model::ShoppingCartItem,
    }

    pub type Output = Result<Details, Error>;
}

pub mod modify_item {
    use super::Error;

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Input {
        pub buyer_id: model::AccountId,
        pub product_id: model::ProductId,
        pub quantity: model::Quantity,
        pub quantity_unit: model::QuantityUnit,
    }

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Details {
        pub item: model::ShoppingCartItem,
    }

    pub type Output = Result<Details, Error>;
}

pub mod modify_cart {
    use super::{modify_item, Error};

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Input {
        pub buyer_id: model::AccountId,
        pub items: Vec<modify_item::Input>,
        pub checkout_notes: String,
        pub payment_method: Option<model::PaymentMethod>,
    }

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct CartDetails {
        pub cart_id: model::ShoppingCartId,
        pub items: Vec<model::ShoppingCartItem>,
        pub checkout_notes: String,
        pub payment_method: model::PaymentMethod,
    }

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Details {
        pub cart: CartDetails,
    }

    pub type Output = Result<Details, Error>;
}

pub mod active_shopping_cart {
    use super::Error;

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Input {
        pub buyer_id: model::AccountId,
    }

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Details {
        pub cart: model::ShoppingCart,
    }

    pub type Output = Result<Details, Error>;
}

pub mod rpc {
    use config::SharedAppConfig;

    use super::{active_shopping_cart, modify_cart, modify_item, remove_product};

    #[tarpc::service]
    pub trait Carts {
        /// Change shopping cart item.
        async fn modify_item(input: modify_item::Input) -> modify_item::Output;

        /// Change entire shopping cart content.
        async fn modify_cart(input: modify_cart::Input) -> modify_cart::Output;

        /// Remove product from shopping cart.
        async fn remove_product(input: remove_product::Input) -> remove_product::Output;

        async fn active_shopping_cart(
            input: active_shopping_cart::Input,
        ) -> active_shopping_cart::Output;
    }

    pub async fn create_client(config: SharedAppConfig) -> CartsClient {
        use tarpc::client;
        use tarpc::tokio_serde::formats::Bincode;

        let addr = {
            let l = config.lock();
            (
                l.account_manager().rpc_bind.clone(),
                l.account_manager().rpc_port,
            )
        };

        let transport = tarpc::serde_transport::tcp::connect(addr, Bincode::default);

        let client = CartsClient::new(
            client::Config::default(),
            transport.await.expect("Failed to connect to server"),
        )
        .spawn();

        client
    }
}

pub mod mqtt {
    use config::SharedAppConfig;
    use rumqttc::EventLoop;

    use crate::carts::CLIENT_NAME;
    use crate::AsyncClient;

    pub fn create_client(config: SharedAppConfig) -> (AsyncClient, EventLoop) {
        crate::mqtt::create_client(CLIENT_NAME, config.lock().cart_manager().mqtt_addr())
    }
}