bms-rs 1.0.0

//! This module handles the tokens:
//!
//! - `#PLAYER [1-4]` - Play mode option, but supporting is unreliable.
//!   - 1: Single play.
//!   - 2: Couple play. Almost unsupported.
//!   - 3: Double play.
//!   - 4: Battle play. Deprecated.
//! - `#DIFFICULTY [1-5]` - Difficulty stage to sort scores of the same music.
//! - `#PLAYLEVEL n` - Difficulty number to show to the user.
//! - `#EMAIL email` / `%EMAIL email` - Email address of the author of the score.
//! - `#URL url` / `%URL url` - Distribution URL of the score.
//! - `#PATH_WAV path` - Base path of `#WAV`'s filenames for debug.
//! - `#DIVIDEPROP n` - Dividing resolution of playing. Obsolete.
//! - `#OCT/FP` - Octave mode option.

use std::{path::Path, str::FromStr};

use super::{ProcessContext, TokenProcessor};
use crate::bms::ParseErrorWithRange;
use crate::bms::{
    model::metadata::Metadata,
    parse::{ParseWarning, Result},
    prelude::*,
};

/// It processes metadata headers such as `#PLAYER`, `#DIFFICULTY` and so on.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct MetadataProcessor;

impl TokenProcessor for MetadataProcessor {
    type Output = Metadata;

    fn process<P: Prompter>(
        &self,
        ctx: &mut ProcessContext<'_, '_, P>,
    ) -> core::result::Result<Self::Output, ParseErrorWithRange> {
        let mut metadata = Metadata::default();
        ctx.all_tokens(|token, _prompter| match token.content() {
            Token::Header { name, args } => Ok(self
                .on_header(name.as_ref(), args.as_ref(), &mut metadata)
                .err()
                .map(|warn| warn.into_wrapper(token))),
            Token::Message { .. } => Ok(None),
            Token::NotACommand(line) => {
                self.on_comment(line, &mut metadata);
                Ok(None)
            }
        })?;
        Ok(metadata)
    }
}

impl MetadataProcessor {
    fn on_header(self, name: &str, args: &str, metadata: &mut Metadata) -> Result<()> {
        if name.eq_ignore_ascii_case("PLAYER") {
            metadata.player = Some(PlayerMode::from_str(args)?);
        }
        if name.eq_ignore_ascii_case("DIFFICULTY") {
            metadata.difficulty = Some(
                args.parse()
                    .map_err(|_| ParseWarning::SyntaxError("expected integer".into()))?,
            );
        }
        if name.eq_ignore_ascii_case("PLAYLEVEL") {
            metadata.play_level = Some(
                args.parse()
                    .map_err(|_| ParseWarning::SyntaxError("expected integer".into()))?,
            );
        }
        if name.eq_ignore_ascii_case("EMAIL") {
            metadata.email = Some(args.to_string());
        }
        if name.eq_ignore_ascii_case("URL") {
            metadata.url = Some(args.to_string());
        }
        if name.eq_ignore_ascii_case("PATH_WAV") {
            if args.is_empty() {
                return Err(ParseWarning::SyntaxError("expected wav root path".into()));
            }
            metadata.wav_path_root = Some(Path::new(args).into());
        }
        if name.eq_ignore_ascii_case("DIVIDEPROP") {
            metadata.divide_prop = Some(args.to_string());
        }
        if name.eq_ignore_ascii_case("OCT/FP") {
            metadata.is_octave = true;
        }
        Ok(())
    }

    fn on_comment(self, line: &str, metadata: &mut Metadata) {
        let line = line.trim();
        if line.starts_with("%EMAIL") {
            metadata.email = Some(line.trim_start_matches("%EMAIL").trim().to_string());
        }
        if line.starts_with("%URL") {
            metadata.url = Some(line.trim_start_matches("%URL").trim().to_string());
        }
    }
}