use serde::{Deserialize, Serialize};

use crate::{
    Request,
    commands::{
        Command, RequestParserError, RequestParserResult, ResponseAttributes, ResponseParserError,
    },
    common::{Version, WindowRange},
};

pub struct PlChanges;

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct PlChangesRequest {
    pub version: Version,
    pub window: Option<WindowRange>,
}

impl Command for PlChanges {
    type Request = PlChangesRequest;
    type Response = ();
    const COMMAND: &'static str = "plchanges";

    fn serialize_request(&self, request: Self::Request) -> String {
        match request.window {
            Some(window) => format!("{} {} {}", Self::COMMAND, request.version, window),
            None => format!("{} {}", Self::COMMAND, request.version),
        }
    }

    fn parse_request(mut parts: std::str::SplitWhitespace<'_>) -> RequestParserResult<'_> {
        let version = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
        let version = version
            .parse()
            .map_err(|_| RequestParserError::SyntaxError(0, version.to_string()))?;

        let window = parts
            .next()
            .map(|w| {
                w.parse()
                    .map_err(|_| RequestParserError::SyntaxError(0, w.to_string()))
            })
            .transpose()?;

        debug_assert!(parts.next().is_none());

        Ok((Request::PlChanges(version, window), ""))
    }

    fn parse_response(
        parts: ResponseAttributes<'_>,
    ) -> Result<Self::Response, ResponseParserError<'_>> {
        unimplemented!()
    }
}