use anyhow::{anyhow, bail, Result};
use log::debug;
use std::{
    io::{copy, BufRead, BufReader, BufWriter, Read, Write},
    net::{TcpStream, ToSocketAddrs},
};

use crate::Serial;

pub struct Client {
    wsock: BufWriter<TcpStream>,
    rsock: BufReader<TcpStream>,
}
impl Client {
    pub fn new(address: impl ToSocketAddrs, secret: &str) -> Result<Self> {
        let mut sock = TcpStream::connect(address)?;
        writeln!(sock, "{secret}")?;
        Ok(Self {
            rsock: BufReader::new(sock.try_clone()?),
            wsock: BufWriter::new(sock),
        })
    }
    pub fn list(&mut self) -> Result<Vec<(i64, u64, Serial)>> {
        writeln!(self.wsock, "list")?;
        self.wsock.flush()?;
        let mut line = String::new();
        let mut out = Vec::new();
        loop {
            line.clear();
            self.rsock.read_line(&mut line)?;
            if line.trim().is_empty() {
                break Ok(out);
            }
            check_error(&line)?;
            let (mtime, rest) = line.trim().split_once(":").ok_or(anyhow!("size missing"))?;
            let (size, serial) = rest.split_once(":").ok_or(anyhow!("serial missing"))?;
            out.push((mtime.parse()?, size.parse()?, serial.parse()?));
        }
    }
    pub fn upload(&mut self, size: u64, mut reader: impl Read) -> Result<()> {
        debug!("announcing upload of {size} bytes");
        writeln!(self.wsock, "upload,{size}")?;
        self.wsock.flush()?;

        let mut line = String::new();
        self.rsock.read_line(&mut line)?;
        check_error(&line)?;
        if line.trim() != "ready" {
            bail!("invalid response, not ready");
        }
        debug!("server ready");

        copy(&mut reader, &mut self.wsock)?;

        line.clear();
        self.rsock.read_line(&mut line)?;
        check_error(&line)?;
        if line.trim() != "done" {
            bail!("invalid response, not done");
        }
        debug!("server done");
        Ok(())
    }
    pub fn download(&mut self, serial: Serial, mut writer: impl Write) -> Result<()> {
        debug!("requesting download for serial={serial}");
        writeln!(self.wsock, "download,{serial}")?;
        self.wsock.flush()?;

        let mut line = String::new();
        self.rsock.read_line(&mut line)?;
        check_error(&line)?;
        let Some(size) = line.trim().strip_prefix("ready,") else {
            bail!("server not ready")
        };
        eprintln!("{size:?}");
        let size = size.parse()?;
        debug!("server ready");

        copy(&mut self.rsock.by_ref().take(size), &mut writer)?;

        line.clear();
        self.rsock.read_line(&mut line)?;
        check_error(&line)?;
        if line.trim() != "done" {
            bail!("invalid response, not done");
        }
        debug!("server done");
        Ok(())
    }
    pub fn quit(mut self) -> Result<()> {
        writeln!(self.wsock, "quit")?;
        self.wsock.flush()?;
        Ok(())
    }
}

fn check_error(line: &str) -> Result<()> {
    if let Some(message) = line.trim().strip_prefix("error,") {
        bail!("server error: {message}")
    }
    Ok(())
}