surrealdb-sql 1.1.0

use super::super::{comment::shouldbespace, literal::ident_raw, IResult};
use crate::statements::UseStatement;
use nom::{
	branch::alt,
	bytes::complete::tag_no_case,
	combinator::{cut, map, opt},
	sequence::{preceded, tuple},
};

pub fn r#use(i: &str) -> IResult<&str, UseStatement> {
	let (i, _) = tag_no_case("USE")(i)?;
	let (i, _) = shouldbespace(i)?;
	let (i, (ns, db)) = alt((
		map(tuple((namespace, opt(preceded(shouldbespace, database)))), |x| (Some(x.0), x.1)),
		map(database, |x| (None, Some(x))),
	))(i)?;
	Ok((
		i,
		UseStatement {
			ns,
			db,
		},
	))
}

fn namespace(i: &str) -> IResult<&str, String> {
	let (i, _) = alt((tag_no_case("NAMESPACE"), tag_no_case("NS")))(i)?;
	let (i, _) = shouldbespace(i)?;
	cut(ident_raw)(i)
}

fn database(i: &str) -> IResult<&str, String> {
	let (i, _) = alt((tag_no_case("DATABASE"), tag_no_case("DB")))(i)?;
	let (i, _) = shouldbespace(i)?;
	cut(ident_raw)(i)
}

#[cfg(test)]
mod tests {

	use super::*;

	#[test]
	fn use_query_ns() {
		let sql = "USE NS test";
		let res = r#use(sql);
		let out = res.unwrap().1;
		assert_eq!(
			out,
			UseStatement {
				ns: Some(String::from("test")),
				db: None,
			}
		);
		assert_eq!("USE NS test", format!("{}", out));
	}

	#[test]
	fn use_query_db() {
		let sql = "USE DB test";
		let res = r#use(sql);
		let out = res.unwrap().1;
		assert_eq!(
			out,
			UseStatement {
				ns: None,
				db: Some(String::from("test")),
			}
		);
		assert_eq!("USE DB test", format!("{}", out));
	}

	#[test]
	fn use_query_both() {
		let sql = "USE NS test DB test";
		let res = r#use(sql);
		let out = res.unwrap().1;
		assert_eq!(
			out,
			UseStatement {
				ns: Some(String::from("test")),
				db: Some(String::from("test")),
			}
		);
		assert_eq!("USE NS test DB test", format!("{}", out));
	}
}