use std::{
	fs::read,
	io::Write,
	net::{SocketAddr, TcpListener, TcpStream},
	result,
	str::FromStr,
};

const IP: &str = "0.0.0.0";
const PORT: &str = "9696";

type Result<T> = result::Result<T, ()>;

fn main() -> Result<()> {
	let socket = SocketAddr::from_str(&format!("{}:{}", IP, PORT)).unwrap();
	let listener = TcpListener::bind(socket).unwrap();

	for stream in listener.incoming() {
		match stream {
			Ok(conn) => handle_connection(conn)?,
			Err(e) => eprintln!("Something went wrong while listening {e}"),
		}
	}

	Ok(())
}

fn handle_connection(mut conn: TcpStream) -> Result<()> {
	let files = ["examples/test.md", "examples/test2.md"];

	for file in files {
		let mut buffer: Vec<u8> = vec![];
		match read(format!("./{file}")) {
			Ok(data) => {
				let _ = buffer.write(&file.len().to_be_bytes());
				let _ = buffer.write(file.as_bytes());

				let _ = buffer.write(&data.len().to_be_bytes());
				let _ = buffer.write(&data);

				let _ = buffer.write(b"\n");

				let _ = conn.write_all(&buffer);
				let _ = conn.flush();
			}
			Err(_) => eprintln!("No file found"),
		};
	}

	Ok(())
}

#[cfg(test)]
mod tests {
	use std::io::Read;

	use super::*;

	#[test]
	fn test_connection() {
		let conn = TcpStream::connect(format!("{}:{}", IP, PORT));
		assert!(conn.is_ok());

		let mut conn = conn.unwrap();
		let mut buffer = Vec::new();

		let bytes_read = conn.read_to_end(&mut buffer);
		assert!(bytes_read.is_ok());

		let data = String::from_utf8(buffer);
		assert!(data.is_ok());

		let data = data.unwrap().into_bytes();

		let mut usize_buffer = [0; 8];
		usize_buffer.copy_from_slice(&data[0..8]);
		let path_len = usize::from_be_bytes(usize_buffer);

		let mut name_buffer: Vec<u8> = vec![];
		name_buffer.extend(&data[8..8 + path_len]);
		let file_name = String::from_utf8(name_buffer.to_vec()).unwrap();

		assert_eq!(file_name, "examples/test.md");
	}
}