use serde::{Deserialize, Serialize};

use crate::{
    commands::{Command, CommandRequest, RequestParserError, empty_command_response},
    request_tokenizer::RequestTokenizer,
    types::SongPosition,
};

pub struct Swap;

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct SwapRequest {
    pub songpos1: SongPosition,
    pub songpos2: SongPosition,
}

impl CommandRequest for SwapRequest {
    const COMMAND: &'static str = "swap";

    fn into_request_enum(self) -> crate::Request {
        crate::Request::Swap(self.songpos1, self.songpos2)
    }

    fn from_request_enum(request: crate::Request) -> Option<Self> {
        match request {
            crate::Request::Swap(songpos1, songpos2) => Some(SwapRequest { songpos1, songpos2 }),
            _ => None,
        }
    }

    fn serialize(&self) -> String {
        format!("{} {} {}\n", Self::COMMAND, self.songpos1, self.songpos2)
    }

    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
        let songpos1 = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
        let songpos1 = songpos1
            .parse()
            .map_err(|_| RequestParserError::SyntaxError(0, songpos1.to_string()))?;

        let songpos2 = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
        let songpos2 = songpos2
            .parse()
            .map_err(|_| RequestParserError::SyntaxError(0, songpos2.to_string()))?;

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

        Ok(SwapRequest { songpos1, songpos2 })
    }
}

empty_command_response!(Swap);

impl Command for Swap {
    type Request = SwapRequest;
    type Response = SwapResponse;
}