use std::{
    io::{ prelude::*, BufReader, BufWriter, WriterPanicked },
    net::{ TcpListener, TcpStream },
};

const PROTOCOL_ERROR_STRING: &str = "Client/Server protocol mismatch";

pub fn main() {
    let listener = TcpListener::bind("0.0.0.0:8000").unwrap();

    for stream in listener.incoming() {
        let (reader, writer) = create_buffers(stream.unwrap().try_clone().unwrap());
        let result = check_protocol(reader, writer).unwrap();
        if result == "Uno-Enthusiast99" {
            println!("It works!");
        }
    }
}

fn create_buffers(stream: TcpStream) -> (BufReader<TcpStream>, BufWriter<TcpStream>) {
    (
        BufReader::new(stream.try_clone().expect("Could not clone TcpStreams")),
        BufWriter::new(stream),
    )
}
fn check_protocol(
    reader: BufReader<TcpStream>,
    mut writer: BufWriter<TcpStream>
) -> Result<String, String> {
    let protocol_error_string = PROTOCOL_ERROR_STRING.to_string();
    let init_message: Vec<_> = reader
        .lines()
        .map(|result| result.unwrap())
        .take_while(|line| !line.is_empty())
        .collect();
    let mut init_message = init_message.iter();
    let is_valid1 = init_message.next().unwrap_or_else(|| &protocol_error_string) == "app:uno";
    let is_valid2= init_message.next().unwrap_or_else(|| &protocol_error_string) == "version:0.1";
    let player_name: &str = init_message.next().unwrap_or_else(|| &protocol_error_string);
    let is_valid3 = if player_name != "invalid" && player_name.contains("player_name:") {
        true
    } else {
        false
    };
    if init_message.next() != None || !(is_valid1 && is_valid2 && is_valid3){
        writer.write(protocol_error_string.as_bytes()).unwrap();
        writer.flush().unwrap();
        return Err(protocol_error_string);
    }
    writer.write("Ok".as_bytes()).unwrap();
    writer.flush().unwrap();
    return Ok(player_name.split(':').collect::<Vec<_>>()[1].to_owned());
}

//    fn register_player(player_name : &str, reader : BufReader, writer : BufWriter){
//
//   }