#[derive(Debug, thiserror::Error, serde::Serialize, serde::Deserialize)]
pub enum Error {
    #[error("Can't create index")]
    CantCreate,
    #[error("Failed to find records in bucket")]
    QueryFailed,
}

pub type Result<T> = std::result::Result<T, Error>;

#[allow(clippy::module_inception)]
pub mod search {
    use crate::search::create_index::Lang;
    use crate::search::Error;

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Input {
        pub query: String,
        pub bucket: String,
        pub collection: String,
        pub lang: Lang,
    }

    impl Input {
        pub fn new<Q: Into<String>, B: Into<String>, C: Into<String>>(
            query: Q,
            collection: C,
            bucket: B,
            lang: whatlang::Lang,
        ) -> Self {
            Self {
                query: query.into(),
                bucket: bucket.into(),
                collection: collection.into(),
                lang: Lang(lang),
            }
        }
    }

    #[derive(Debug, Default, serde::Serialize, serde::Deserialize)]
    pub struct Output {
        pub found: Option<Vec<String>>,
        pub error: Option<Error>,
    }

    impl Output {
        pub fn found(found: Vec<String>) -> Self {
            Self {
                found: Some(found),
                ..Default::default()
            }
        }

        pub fn error(error: Error) -> Self {
            Self {
                error: Some(error),
                ..Default::default()
            }
        }
    }
}

pub mod suggest {
    use crate::search::Error;

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Input {
        pub query: String,
        pub bucket: String,
        pub collection: String,
    }

    impl Input {
        pub fn new<Q: Into<String>, B: Into<String>, C: Into<String>>(
            query: Q,
            collection: C,
            bucket: B,
        ) -> Self {
            Self {
                query: query.into(),
                bucket: bucket.into(),
                collection: collection.into(),
            }
        }
    }

    #[derive(Debug, Default, serde::Serialize, serde::Deserialize)]
    pub struct Output {
        pub found: Option<Vec<String>>,
        pub error: Option<Error>,
    }

    impl Output {
        pub fn found(found: Vec<String>) -> Self {
            Self {
                found: Some(found),
                ..Default::default()
            }
        }

        pub fn error(error: Error) -> Self {
            Self {
                error: Some(error),
                ..Default::default()
            }
        }
    }
}

pub mod create_index {
    use std::fmt::Formatter;

    use serde::de::Visitor;
    use serde::{Deserialize, Deserializer, Serialize, Serializer};

    use crate::search::Error;

    #[derive(Debug)]
    pub struct Lang(pub whatlang::Lang);

    impl Serialize for Lang {
        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
        where
            S: Serializer,
        {
            serializer.serialize_str(self.0.code())
        }
    }

    impl<'de> Deserialize<'de> for Lang {
        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
        where
            D: Deserializer<'de>,
        {
            struct SV;

            impl Visitor<'_> for SV {
                type Value = whatlang::Lang;

                fn expecting(&self, formatter: &mut Formatter) -> std::fmt::Result {
                    formatter.write_str("must be valid whatlang::Lang")
                }

                fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
                where
                    E: serde::de::Error,
                {
                    match v.parse() {
                        Ok(l) => Ok(l),
                        Err(e) => Err(E::custom(format!("{}", e))),
                    }
                }
            }

            Ok(Self(deserializer.deserialize_string(SV)?))
        }
    }

    #[derive(Debug, serde::Serialize, serde::Deserialize)]
    pub struct Input {
        pub key: String,
        pub value: String,
        pub bucket: String,
        pub collection: String,
        pub lang: Lang,
    }

    impl Input {
        pub fn new<K: Into<String>, V: Into<String>, B: Into<String>, C: Into<String>>(
            key: K,
            value: V,
            collection: C,
            bucket: B,
            lang: whatlang::Lang,
        ) -> Self {
            Self {
                key: key.into(),
                value: value.into(),
                bucket: bucket.into(),
                collection: collection.into(),
                lang: Lang(lang),
            }
        }
    }

    #[derive(Debug, Default, serde::Serialize, serde::Deserialize)]
    pub struct Output {
        pub found: Option<()>,
        pub error: Option<Error>,
    }

    impl Output {
        pub fn ok() -> Self {
            Self {
                found: Some(()),
                ..Default::default()
            }
        }

        pub fn error(error: Error) -> Self {
            Self {
                error: Some(error),
                ..Default::default()
            }
        }
    }
}

pub mod rpc {
    use config::SharedAppConfig;

    use crate::search::{create_index, search, suggest};

    #[tarpc::service]
    pub trait Search {
        /// Search all matching indices.
        async fn search(input: search::Input) -> search::Output;

        /// Suggest all matching indices.
        async fn suggest(input: suggest::Input) -> suggest::Output;

        /// Create new search index.
        async fn create_index(input: create_index::Input) -> create_index::Output;
    }

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

        let l = config.lock();
        let transport =
            tarpc::serde_transport::tcp::connect(l.search().rpc_addr(), Bincode::default);

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

        client
    }
}