use anyhow::Context;
use derive_more::From;
use std::time::Duration;

/// Use HTTP and WS providers.
// TODO: instead of an enum, I tried to use Box<dyn Provider>, but hit <https://github.com/gakonst/ethers-rs/issues/592>
#[derive(From)]
pub enum Web3Provider {
    Http(ethers::providers::Provider<ethers::providers::Http>),
    Ws(ethers::providers::Provider<ethers::providers::Ws>),
    // TODO: only include this for tests.
    Mock,
}

impl Web3Provider {
    pub fn ready(&self) -> bool {
        match self {
            Self::Mock => true,
            Self::Http(_) => true,
            Self::Ws(provider) => provider.as_ref().ready(),
        }
    }

    pub async fn from_str(
        url_str: &str,
        http_client: Option<reqwest::Client>,
    ) -> anyhow::Result<Self> {
        let provider = if url_str.starts_with("http") {
            let url: url::Url = url_str.parse()?;

            let http_client = http_client.context("no http_client")?;

            let provider = ethers::providers::Http::new_with_client(url, http_client);

            // TODO: dry this up (needs https://github.com/gakonst/ethers-rs/issues/592)
            // TODO: i don't think this interval matters for our uses, but we should probably set it to like `block time / 2`
            ethers::providers::Provider::new(provider)
                .interval(Duration::from_secs(13))
                .into()
        } else if url_str.starts_with("ws") {
            let provider = ethers::providers::Ws::connect(url_str).await?;

            // TODO: dry this up (needs https://github.com/gakonst/ethers-rs/issues/592)
            // TODO: i don't think this interval matters
            ethers::providers::Provider::new(provider).into()
        } else {
            return Err(anyhow::anyhow!("only http and ws servers are supported"));
        };

        Ok(provider)
    }
}