use super::{headermap::HeaderMap, status::Status};
use anyhow::{anyhow, bail, Context};
use std::{fmt::Display, str::FromStr};

#[derive(Debug, Clone)]
pub struct Response {
    pub status: Status,
    pub headers: HeaderMap,
}

impl FromStr for Response {
    type Err = anyhow::Error;
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let mut lines = s.lines();
        let statusline = lines.next().ok_or(anyhow!("status line missing"))?;
        let (sipver, rest) = statusline
            .split_once(" ")
            .ok_or(anyhow!("status line malformed"))?;
        let (code, _status_str) = rest
            .split_once(" ")
            .ok_or(anyhow!("status line malformed"))?;
        let code = u16::from_str(code).context("status code")?;

        let Some(ver) = sipver.strip_prefix("SIP/") else {
            bail!("sip version malformed");
        };
        if ver != "2.0" {
            bail!("sip version {ver:?} is not supported");
        }

        let headers = HeaderMap::parse(&mut lines)?;

        let status = Status::from_code(code);
        Ok(Self { status, headers })
    }
}
impl Display for Response {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let Self { status, headers } = self;
        write!(f, "SIP/2.0 {} {status:?}\r\n", status.to_code())?;
        write!(f, "{headers}\r\n")?;
        Ok(())
    }
}