use std::{collections::HashMap, sync::Arc};

use async_trait::async_trait;

use torn_api::{
    local::{ApiClient, ApiProvider, RequestExecutor},
    ApiRequest, ApiResponse, ApiSelection, ResponseError,
};

use crate::{ApiKey, KeyPoolError, KeyPoolExecutor, KeyPoolStorage, IntoSelector};

#[async_trait(?Send)]
impl<'client, C, S> RequestExecutor<C> for KeyPoolExecutor<'client, C, S>
where
    C: ApiClient,
    S: KeyPoolStorage + 'static,
{
    type Error = KeyPoolError<S::Error, C::Error>;

    async fn execute<A>(
        &self,
        client: &C,
        mut request: ApiRequest<A>,
        id: Option<String>,
    ) -> Result<ApiResponse, Self::Error>
    where
        A: ApiSelection,
    {
        request.comment = self.comment.map(ToOwned::to_owned);
        loop {
            let key = self
                .storage
                .acquire_key(self.selector.clone())
                .await
                .map_err(|e| KeyPoolError::Storage(Arc::new(e)))?;
            let url = request.url(key.value(), id.as_deref());
            let value = client.request(url).await?;

            match ApiResponse::from_value(value) {
                Err(ResponseError::Api { code, reason }) => {
                    if !self
                        .storage
                        .flag_key(key, code)
                        .await
                        .map_err(Arc::new)
                        .map_err(KeyPoolError::Storage)?
                    {
                        return Err(KeyPoolError::Response(ResponseError::Api { code, reason }));
                    }
                }
                Err(parsing_error) => return Err(KeyPoolError::Response(parsing_error)),
                Ok(res) => return Ok(res),
            };
        }
    }

    async fn execute_many<A, I>(
        &self,
        client: &C,
        mut request: ApiRequest<A>,
        ids: Vec<I>,
    ) -> HashMap<I, Result<ApiResponse, Self::Error>>
    where
        A: ApiSelection,
        I: ToString + std::hash::Hash + std::cmp::Eq,
    {
        let keys = match self
            .storage
            .acquire_many_keys(self.selector.clone(), ids.len() as i64)
            .await
        {
            Ok(keys) => keys,
            Err(why) => {
                let shared = Arc::new(why);
                return ids
                    .into_iter()
                    .map(|i| (i, Err(Self::Error::Storage(shared.clone()))))
                    .collect();
            }
        };

        request.comment = self.comment.map(ToOwned::to_owned);
        let request_ref = &request;

        let tuples =
            futures::future::join_all(std::iter::zip(ids, keys).map(|(id, mut key)| async move {
                let id_string = id.to_string();
                loop {
                    let url = request_ref.url(key.value(), Some(&id_string));
                    let value = match client.request(url).await {
                        Ok(v) => v,
                        Err(why) => return (id, Err(Self::Error::Client(why))),
                    };

                    match ApiResponse::from_value(value) {
                        Err(ResponseError::Api { code, reason }) => {
                            match self.storage.flag_key(key, code).await {
                                Ok(false) => {
                                    return (
                                        id,
                                        Err(KeyPoolError::Response(ResponseError::Api {
                                            code,
                                            reason,
                                        })),
                                    )
                                }
                                Ok(true) => (),
                                Err(why) => return (id, Err(KeyPoolError::Storage(Arc::new(why)))),
                            }
                        }
                        Err(parsing_error) => {
                            return (id, Err(KeyPoolError::Response(parsing_error)))
                        }
                        Ok(res) => return (id, Ok(res)),
                    };

                    key = match self.storage.acquire_key(self.selector.clone()).await {
                        Ok(k) => k,
                        Err(why) => return (id, Err(Self::Error::Storage(Arc::new(why)))),
                    };
                }
            }))
            .await;

        HashMap::from_iter(tuples)
    }
}

#[derive(Clone, Debug)]
pub struct KeyPool<C, S>
where
    C: ApiClient,
    S: KeyPoolStorage,
{
    client: C,
    pub storage: S,
    comment: Option<String>,
}

impl<C, S> KeyPool<C, S>
where
    C: ApiClient,
    S: KeyPoolStorage + 'static,
{
    pub fn new(client: C, storage: S, comment: Option<String>) -> Self {
        Self {
            client,
            storage,
            comment,
        }
    }

    pub fn torn_api<I>(&self, selector: I) -> ApiProvider<C, KeyPoolExecutor<C, S>> where I: IntoSelector<S::Key, S::Domain> {
        ApiProvider::new(
            &self.client,
            KeyPoolExecutor::new(&self.storage, selector.into_selector(), self.comment.as_deref()),
        )
    }
}

pub trait WithStorage {
    fn with_storage<'a, S, I>(
        &'a self,
        storage: &'a S,
        selector: I
    ) -> ApiProvider<Self, KeyPoolExecutor<Self, S>>
    where
        Self: ApiClient + Sized,
        S: KeyPoolStorage + 'static,
        I: IntoSelector<S::Key, S::Domain>
    {
        ApiProvider::new(self, KeyPoolExecutor::new(storage, selector.into_selector(), None))
    }
}

#[cfg(feature = "awc")]
impl WithStorage for awc::Client {}

#[cfg(all(test, feature = "postgres", feature = "awc"))]
mod test {
    use tokio::test;

    use super::*;
    use crate::postgres::test::{setup, Domain};

    #[test]
    async fn test_pool_request() {
        let storage = setup().await;
        let pool = KeyPool::new(awc::Client::default(), storage);

        let response = pool.torn_api(Domain::All).user(|b| b).await.unwrap();
        _ = response.profile().unwrap();
    }

    #[test]
    async fn test_with_storage_request() {
        let storage = setup().await;

        let response = awc::Client::new()
            .with_storage(&storage, Domain::All)
            .user(|b| b)
            .await
            .unwrap();
        _ = response.profile().unwrap();
    }
}