//! CSS ratio values.

use super::number::CSSNumber;

use crate::error::{ParserError, PrinterError};

use crate::printer::Printer;

use crate::traits::{Parse, ToCss};

#[cfg(feature = "visitor")]

use crate::visitor::Visit;

use cssparser::*;

/// A CSS [`<ratio>`](https://www.w3.org/TR/css-values-4/#ratios) value,

/// representing the ratio of two numeric values.

#[derive(Debug, Clone, PartialEq)]

#[cfg_attr(feature = "visitor", derive(Visit))]

Unexecuted instantiation: <lightningcss::values::ratio::Ratio as lightningcss::visitor::Visit<lightningcss::parser::DefaultAtRule, fallow_extract::css_metrics::ValueCollector>>::visit_children

Unexecuted instantiation: <lightningcss::values::ratio::Ratio as lightningcss::visitor::Visit<lightningcss::parser::DefaultAtRule, fallow_extract::css_metrics::FirstRgbColorCollector>>::visit_children

Unexecuted instantiation: <lightningcss::values::ratio::Ratio as lightningcss::visitor::Visit<_, _>>::visit_children

#[cfg_attr(feature = "visitor", visit(visit_ratio, RATIOS))]

#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]

#[cfg_attr(feature = "jsonschema", derive(schemars::JsonSchema))]

#[cfg_attr(feature = "into_owned", derive(static_self::IntoOwned))]

pub struct Ratio(pub CSSNumber, pub CSSNumber);

impl<'i> Parse<'i> for Ratio {

  fn parse<'t>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i, ParserError<'i>>> {

    let first = CSSNumber::parse(input)?;

    let second = if input.try_parse(|input| input.expect_delim('/')).is_ok() {

      CSSNumber::parse(input)?

    } else {

      1.0

    };

    Ok(Ratio(first, second))

  }

}

impl Ratio {

  /// Parses a ratio where both operands are required.

  pub fn parse_required<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i, ParserError<'i>>> {

    let first = CSSNumber::parse(input)?;

    input.expect_delim('/')?;

    let second = CSSNumber::parse(input)?;

    Ok(Ratio(first, second))

  }

}

impl ToCss for Ratio {

  fn to_css<W>(&self, dest: &mut Printer<W>) -> Result<(), PrinterError>

  where

    W: std::fmt::Write,

  {

    self.0.to_css(dest)?;

    if self.1 != 1.0 {

      dest.delim('/', true)?;

      self.1.to_css(dest)?;

    }

    Ok(())

  }

}

impl std::ops::Add<CSSNumber> for Ratio {

  type Output = Self;

  fn add(self, other: CSSNumber) -> Ratio {

    Ratio(self.0 + other, self.1)

  }

}