use nom::
{
	IResult,
	branch::alt,
	bytes::complete::tag,
	character::complete::digit1,
	combinator::{map, map_res, opt, recognize},
	sequence::{pair, terminated},
};

use super::word_boundary;

fn true_(i: &str) -> IResult<&str, bool>
{
	map
	(
		terminated
		(
			tag("true"),
			word_boundary,
		),
		|_| true,
	)(i)
}

fn false_(i: &str) -> IResult<&str, bool>
{
	map
	(
		terminated
		(
			tag("false"),
			word_boundary,
		),
		|_| false,
	)(i)
}

pub fn boolean(i: &str) -> IResult<&str, bool>
{
	alt
	((
		true_,
		false_,
	))(i)
}

pub fn integer(i: &str) -> IResult<&str, i32>
{
	map_res
	(
		recognize
		(
			terminated
			(
				pair
				(
					opt
					(
						alt
						((
							tag("-"),
							tag("+"),
						))
					),
					digit1,
				),
				word_boundary,
			)
		),
		std::str::FromStr::from_str,
	)(i)
}

#[cfg(test)]
mod tests
{
	use crate::parse::*;

	#[test]
	fn parse_boolean()
	{
		assert_eq!(boolean("true"), Ok(("", true)));
		assert_eq!(boolean("false"), Ok(("", false)));
		assert_eq!(boolean("true false"), Ok((" false", true)));
		assert_eq!(boolean("false true"), Ok((" true", false)));
		assert_eq!(boolean("true,"), Ok((",", true)));
		assert_eq!(boolean("false,"), Ok((",", false)));
		assert!(boolean("truefalse").is_err());
		assert!(boolean("falsetrue").is_err());
		assert!(boolean("truea").is_err());
		assert!(boolean("falsea").is_err());
		assert!(boolean("a").is_err());
		assert!(boolean("-").is_err());
		assert!(boolean(" ").is_err());
	}

	#[test]
	fn parse_integer()
	{
		assert_eq!(integer("0"), Ok(("", 0)));
		assert_eq!(integer("10000"), Ok(("", 10000)));
		assert_eq!(integer("+10000"), Ok(("", 10000)));
		assert_eq!(integer("-10000"), Ok(("", -10000)));
		assert_eq!(integer("0 42"), Ok((" 42", 0)));
		assert_eq!(integer("10000 42"), Ok((" 42", 10000)));
		assert_eq!(integer("+10000 42"), Ok((" 42", 10000)));
		assert_eq!(integer("-10000 42"), Ok((" 42", -10000)));
		assert_eq!(integer("10000,"), Ok((",", 10000)));
		assert_eq!(integer("+10000,"), Ok((",", 10000)));
		assert_eq!(integer("-10000,"), Ok((",", -10000)));
		assert!(integer("10000a").is_err());
		assert!(integer("+10000a").is_err());
		assert!(integer("-10000a").is_err());
		assert!(integer("1.5").is_err());
		assert!(integer("a").is_err());
		assert!(integer("-").is_err());
		assert!(integer(" ").is_err());
	}
}