use std::{
    io::{BufRead, BufReader},
    process::{Child, Command, Stdio},
    sync::mpsc::{self, Receiver, Sender},
    thread,
    time::Duration,
};

use dotenv::dotenv;
use tracing::debug;

use crate::config::ProtocolComponentWithTestConfig;

pub struct TychoRunner {
    db_url: String,
    initialized_accounts: Vec<String>,
    with_binary_logs: bool,
}

// TODO: Currently Tycho-Indexer cannot be run as a lib. We need to expose the entrypoints to allow
// running it as a lib
impl TychoRunner {
    pub fn new(db_url: String, initialized_accounts: Vec<String>, with_binary_logs: bool) -> Self {
        Self { db_url, initialized_accounts, with_binary_logs }
    }

    pub fn run_tycho(
        &self,
        spkg_path: &str,
        start_block: u64,
        end_block: u64,
        protocol_type_names: &[String],
    ) -> Result<(), Box<dyn std::error::Error>> {
        // Expects a .env present in the same folder as package root (where Cargo.toml is)
        dotenv().ok();

        let mut cmd = Command::new("tycho-indexer");
        cmd.env("RUST_LOG", "tycho_indexer=info");

        let all_accounts = self.initialized_accounts.clone();

        cmd.args([
            "--database-url",
            self.db_url.as_str(),
            "run",
            "--spkg",
            spkg_path,
            "--module",
            "map_protocol_changes",
            "--protocol-type-names",
            &protocol_type_names.join(","),
            "--start-block",
            &start_block.to_string(),
            "--stop-block",
            &(end_block + 2).to_string(), // +2 is to make up for the cache in the index side
        ]);

        if !all_accounts.is_empty() {
            cmd.args([
                "--initialized-accounts",
                &all_accounts.join(","),
                "--initialization-block",
                &start_block.to_string(),
            ]);
        }

        cmd.stdout(Stdio::piped())
            .stderr(Stdio::piped());

        let mut process = match cmd.spawn() {
            Ok(p) => p,
            Err(e) => {
                println!("Error running Tycho indexer: {}", e);
                return Err(e.into());
            }
        };

        if self.with_binary_logs {
            Self::handle_process_output(&mut process);
        }

        match process.wait() {
            Ok(status) => {
                if !status.success() {
                    return Err(format!("Process exited with non-zero status: {}", status).into());
                }
            }
            Err(e) => {
                println!("Error waiting for Tycho indexer: {}", e);
                return Err(e.into());
            }
        }

        Ok(())
    }

    pub fn run_with_rpc_server<F, R>(
        &self,
        func: F,
        expected_components: &Vec<ProtocolComponentWithTestConfig>,
        start_block: u64,
        stop_block: u64,
        skip_balance_check: bool,
    ) -> R
    where
        F: FnOnce(&Vec<ProtocolComponentWithTestConfig>, u64, u64, bool) -> R,
    {
        let (tx, rx): (Sender<bool>, Receiver<bool>) = mpsc::channel();
        let db_url = self.db_url.clone();
        let with_binary_logs = self.with_binary_logs;

        // Start the RPC server in a separate thread
        let rpc_thread = thread::spawn(move || {
            let binary_path = "tycho-indexer";

            let mut cmd = Command::new(binary_path)
                .args(["--database-url", db_url.as_str(), "rpc"])
                .stdout(Stdio::piped())
                .stderr(Stdio::piped())
                .env("RUST_LOG", "info")
                .spawn()
                .expect("Failed to start RPC server");

            if with_binary_logs {
                Self::handle_process_output(&mut cmd);
            }

            match rx.recv() {
                Ok(_) => {
                    debug!("Received termination message, stopping RPC server...");
                    cmd.kill()
                        .expect("Failed to kill RPC server");
                }
                Err(_) => {
                    // Channel closed, terminate anyway
                    let _ = cmd.kill();
                }
            }
        });

        // Give the RPC server time to start
        thread::sleep(Duration::from_secs(3));

        // Run the provided function
        let result = func(expected_components, start_block, stop_block, skip_balance_check);

        tx.send(true)
            .expect("Failed to send termination message");

        // Wait for the RPC thread to finish
        if rpc_thread.join().is_err() {
            eprintln!("Failed to join RPC thread");
        }

        result
    }

    // Helper method to handle process output in separate threads
    fn handle_process_output(child: &mut Child) {
        if let Some(stdout) = child.stdout.take() {
            thread::spawn(move || {
                let reader = BufReader::new(stdout);
                for line in reader.lines().map_while(Result::ok) {
                    println!("{}", line);
                }
            });
        }

        if let Some(stderr) = child.stderr.take() {
            thread::spawn(move || {
                let reader = BufReader::new(stderr);
                for line in reader.lines().map_while(Result::ok) {
                    eprintln!("{}", line);
                }
            });
        }
    }
}