use nom::{
    bytes::complete::tag,
    character::complete::{multispace0, multispace1},
    IResult,
};

use super::common::{parse_condition, parse_table_name};
use crate::syntax::RawQuerySyntax;

pub fn parse_delete(input: &str) -> IResult<&str, RawQuerySyntax> {
    let (input, _) = tag("DELETE")(input)?;
    let (input, _) = multispace1(input)?;
    let (input, _) = tag("FROM")(input)?;
    let (input, _) = multispace1(input)?;
    let (input, table_name) = parse_table_name(input)?;
    let (input, _) = multispace0(input)?;
    let (input, condition) = parse_condition(input)?;
    Ok((
        input,
        RawQuerySyntax::Delete(table_name.to_string(), condition),
    ))
}

#[cfg(test)]
mod tests {
    use crate::parsing::delete::parse_delete;
    use crate::parsing::literal::Literal;
    use crate::syntax::{Condition, RawQuerySyntax};

    #[test]
    fn test_parse_delete() {
        let (_, sntx) =
            parse_delete("DELETE FROM \"T1\" WHERE id = 1").expect("should parse");
        assert!(matches!(sntx, RawQuerySyntax::Delete(_, _)))
    }

    #[test]
    fn test_parse_delete_with_spaces() {
        let (_, sntx) =
            parse_delete("DELETE  FROM   T1   WHERE   id  =  1").expect("should parse");
        assert!(matches!(sntx, RawQuerySyntax::Delete(_, _)))
    }
    
    #[test]
    fn test_parse_delete_none() {
        let (_, sntx) =
            parse_delete("DELETE FROM games WHERE year = None").expect("should parse");
        if let RawQuerySyntax::Delete(tname, Some(Condition::Eq(column_name, lit))) = sntx {
            assert_eq!(tname, "games".to_string());
            assert_eq!(column_name, "year".to_string());
            assert_eq!(lit, Literal::None)
        } else {
            panic!()
        }
    }
}