use super::{MJFont, MJFontAttributes};
use crate::prelude::parse::{Error, Parsable, Parser};
use xmlparser::{StrSpan, Tokenizer};

#[derive(Debug, Default)]
struct MJFontParser(MJFontAttributes);

impl Parser for MJFontParser {
    type Output = MJFont;

    fn build(self) -> Result<Self::Output, Error> {
        Ok(MJFont { attributes: self.0 })
    }

    fn parse_attribute<'a>(&mut self, name: StrSpan<'a>, value: StrSpan<'a>) -> Result<(), Error> {
        match name.as_str() {
            "name" => {
                self.0.name = value.to_string();
                Ok(())
            }
            "href" => {
                self.0.href = value.to_string();
                Ok(())
            }
            _ => Err(Error::UnexpectedAttribute(name.start())),
        }
    }
}

impl Parsable for MJFont {
    fn parse(_tag: StrSpan, tokenizer: &mut Tokenizer) -> Result<Self, Error> {
        MJFontParser::default().parse(tokenizer)?.build()
    }
}

#[cfg(test)]
mod tests {
    use crate::mjml::MJML;

    #[test]
    fn success() {
        assert!(MJML::parse(
            r#"<mjml><mj-head><mj-font name="Comic" href="https://jolimail.io" /></mj-head></mjml>"#
        )
        .is_ok());
    }

    #[test]
    fn unexpected_attribute() {
        assert!(
            MJML::parse(r#"<mjml><mj-head><mj-font unknown="whatever" /></mj-head></mjml>"#)
                .is_err()
        );
    }
}