use std::env;
use std::fs::File;
use std::io::{self, BufRead, Write};
use std::process::{Command, Stdio};

fn read_game_log(log_file: &str) -> Option<Vec<String>> {
    if let Ok(file) = File::open(log_file) {
        let lines: Result<Vec<String>, _> = io::BufReader::new(file).lines().collect();
        return lines.ok();
    }

    None
}

fn main() {
    let args: Vec<String> = env::args().collect();

    if args.len() != 2 {
        eprintln!("Usage: ./anomaly-searcher game.log");
        std::process::exit(1);
    }

    let game_log_file = &args[1];
    if let Some(lines) = read_game_log(game_log_file) {
        let mut engine_process = Command::new("./target/release/chessnost")
            .stdin(Stdio::piped())
            .stdout(Stdio::piped())
            .spawn()
            .expect("Failed to start the engine process");

        let mut engine_stdin = engine_process
            .stdin
            .take()
            .expect("Failed to open engine STDIN");
        let mut engine_stdout = io::BufReader::new(
            engine_process
                .stdout
                .take()
                .expect("Failed to open engine STDOUT"),
        );

        for line in lines.iter().filter(|l| !l.contains("info string")) {
            if line.starts_with("<<") {
                // Send the line to the engine without printing it
                writeln!(engine_stdin, "{}", &line[3..]).expect("Failed to write to engine STDIN");
                println!("{}", line);
            } else if line.starts_with(">>") {
                // Wait for the engine's output
                let mut response = String::new();
                while response.is_empty() || response.contains("info string") {
                    response = String::new();
                    engine_stdout
                        .read_line(&mut response)
                        .expect("Failed to read from engine STDOUT");
                }

                // Print the engine's response
                print!(">> {}", response);

                // Compare the engine's response to the original log
                let original_response = line[3..].trim(); // Remove the ">> " prefix
                if response.trim() != original_response {
                    println!("** {}\n", original_response);
                }
            }
        }

        // Close the engine's STDIN to signal that we're done sending commands
        drop(engine_stdin);

        // Wait for the engine process to finish
        let _ = engine_process.wait();
    } else {
        eprintln!("Error reading the game log.");
        std::process::exit(1);
    }
}