#![warn(missing_docs)]

//!
//! Electrsd
//!
//! Utility to run a regtest electrsd process, useful in integration testing environment
//!

use bitcoind::bitcoincore_rpc::RpcApi;
use bitcoind::tempfile::TempDir;
use bitcoind::{get_available_port, BitcoinD};
use electrum_client::raw_client::{ElectrumPlaintextStream, RawClient};
use std::ffi::OsStr;
use std::process::{Child, Command, Stdio};
use std::time::Duration;

// re-export bitcoind
pub use bitcoind;

/// Struct representing the bitcoind process with related information
pub struct ElectrsD {
    /// Process child handle, used to terminate the process when this struct is dropped
    process: Child,
    /// Electrum client connected to the electrs process
    pub client: RawClient<ElectrumPlaintextStream>,
    /// DB directory, where electrs store indexes. It is kept in the struct so that
    /// directory is deleted only when this struct is dropped
    _db_dir: TempDir,
    /// Url to connect to the electrum protocol (tcp)
    pub electrum_url: String,
    /// Url to connect to esplora protocol (http)
    pub esplora_url: Option<String>,
}

/// All the possible error in this crate
#[derive(Debug)]
pub enum Error {
    /// Wrapper of io Error
    Io(std::io::Error),

    /// Wrapper of bitcoind Error
    Bitcoind(bitcoind::Error),

    /// Wrapper of electrum_client Error
    ElectrumClient(electrum_client::Error),

    /// Wrapper of bitcoincore_rpc Error
    BitcoinCoreRpc(bitcoind::bitcoincore_rpc::Error),

    #[cfg(feature = "trigger")]
    /// Wrapper of nix Error
    Nix(nix::Error),
}

impl ElectrsD {
    /// Create a new electrs process connected with the given bitcoind
    pub fn new<S: AsRef<OsStr>>(
        exe: S,
        bitcoind: &BitcoinD,
        view_stderr: bool,
        http_enabled: bool,
    ) -> Result<ElectrsD, Error> {
        if bitcoind
            .client
            .get_blockchain_info()?
            .initial_block_download
        {
            // electrum will remain idle until bitcoind is in IBD
            // bitcoind will remain in IBD if doesn't see a block from a long time, thus adding a block
            let node_address = bitcoind.client.get_new_address(None, None).unwrap();
            bitcoind
                .client
                .generate_to_address(1, &node_address)
                .unwrap();
        }

        let mut args = vec!["-vvv"];

        let _db_dir = TempDir::new()?;
        let db_dir = format!("{}", _db_dir.path().display());
        args.push("--db-dir");
        args.push(&db_dir);

        args.push("--network");
        args.push("regtest");

        #[cfg(not(feature = "legacy"))]
        let cookie_file;
        #[cfg(not(feature = "legacy"))]
        {
            args.push("--cookie-file");
            cookie_file = format!("{}", bitcoind.params.cookie_file.display());
            args.push(&cookie_file);
        }

        #[cfg(feature = "legacy")]
        let mut cookie_value;
        #[cfg(feature = "legacy")]
        {
            use std::io::Read;
            args.push("--cookie");
            let mut cookie = std::fs::File::open(&bitcoind.params.cookie_file)?;
            cookie_value = String::new();
            cookie.read_to_string(&mut cookie_value)?;
            args.push(&cookie_value);
        }

        args.push("--daemon-rpc-addr");
        let rpc_socket = bitcoind.params.rpc_socket.to_string();
        args.push(&rpc_socket);

        args.push("--jsonrpc-import");

        let electrum_url = format!("0.0.0.0:{}", get_available_port()?);
        args.push("--electrum-rpc-addr");
        args.push(&electrum_url);

        // would be better to disable it, didn't found a flag
        let monitoring = format!("0.0.0.0:{}", get_available_port()?);
        args.push("--monitoring-addr");
        args.push(&monitoring);

        let esplora_url_string;
        let esplora_url = if http_enabled {
            esplora_url_string = format!("0.0.0.0:{}", get_available_port()?);
            args.push("--http-addr");
            args.push(&esplora_url_string);
            #[allow(clippy::redundant_clone)]
            Some(esplora_url_string.clone())
        } else {
            None
        };

        let view_stderr = if view_stderr {
            Stdio::inherit()
        } else {
            Stdio::null()
        };

        eprintln!("args: {:?}", args);
        let process = Command::new(exe).args(args).stderr(view_stderr).spawn()?;

        let client = loop {
            match RawClient::new(&electrum_url, None) {
                Ok(client) => break client,
                Err(_) => std::thread::sleep(Duration::from_millis(500)),
            }
        };

        Ok(ElectrsD {
            process,
            client,
            _db_dir,
            electrum_url,
            esplora_url,
        })
    }

    #[cfg(feature = "trigger")]
    /// triggers electrs sync by sending the `SIGUSR1` signal, useful to call after a block for example
    pub fn trigger(&self) -> Result<(), Error> {
        Ok(nix::sys::signal::kill(
            nix::unistd::Pid::from_raw(self.process.id() as i32),
            nix::sys::signal::SIGUSR1,
        )?)
    }
}

impl Drop for ElectrsD {
    fn drop(&mut self) {
        let _ = self.process.kill();
    }
}

impl From<std::io::Error> for Error {
    fn from(e: std::io::Error) -> Self {
        Error::Io(e)
    }
}

impl From<bitcoind::Error> for Error {
    fn from(e: bitcoind::Error) -> Self {
        Error::Bitcoind(e)
    }
}

impl From<electrum_client::Error> for Error {
    fn from(e: electrum_client::Error) -> Self {
        Error::ElectrumClient(e)
    }
}

impl From<bitcoind::bitcoincore_rpc::Error> for Error {
    fn from(e: bitcoind::bitcoincore_rpc::Error) -> Self {
        Error::BitcoinCoreRpc(e)
    }
}

#[cfg(feature = "trigger")]
impl From<nix::Error> for Error {
    fn from(e: nix::Error) -> Self {
        Error::Nix(e)
    }
}

#[cfg(test)]
mod test {
    use crate::ElectrsD;
    use bitcoind::bitcoincore_rpc::RpcApi;
    use bitcoind::{downloaded_exe_path, BitcoinD, Conf};
    use electrum_client::ElectrumApi;
    use std::env;

    #[test]
    fn test_electrsd() {
        let bitcoind_exe = downloaded_exe_path().unwrap();
        let electrs_exe = env::var("ELECTRS_EXE").expect("ELECTRS_EXE env var must be set");
        let conf = Conf {
            view_stdout: true,
            ..Default::default()
        };
        let bitcoind = BitcoinD::with_conf(&bitcoind_exe, &conf).unwrap();
        let electrsd = ElectrsD::new(&electrs_exe, &bitcoind, true, false).unwrap();
        let header = electrsd.client.block_headers_subscribe().unwrap();
        assert_eq!(header.height, 1);
        let address = bitcoind.client.get_new_address(None, None).unwrap();
        bitcoind.client.generate_to_address(100, &address).unwrap();

        #[cfg(feature = "trigger")]
        electrsd.trigger().unwrap();

        let header = loop {
            std::thread::sleep(std::time::Duration::from_secs(1));
            let header = electrsd.client.block_headers_subscribe().unwrap();
            if header.height > 100 {
                break header;
            }
        };
        assert_eq!(header.height, 101);

        // launch another instance to check there are no fixed port used
        let electrsd = ElectrsD::new(&electrs_exe, &bitcoind, true, false).unwrap();
        let header = electrsd.client.block_headers_subscribe().unwrap();
        assert_eq!(header.height, 101);
    }
}