minisql/parser/src/parsing/insert.rs

use super::{
    common::{parse_identifier, parse_table_name},
    literal::{parse_literal, Literal},
};
use crate::syntax::RawQuerySyntax;
use nom::{
    bytes::complete::tag,
    character::complete::{char, multispace0, multispace1},
    combinator::map,
    multi::separated_list0,
    sequence::terminated,
    IResult,
};

pub fn parse_insert(input: &str) -> IResult<&str, RawQuerySyntax> {
    let (input, _) = tag("INSERT")(input)?;
    let (input, _) = multispace1(input)?;
    let (input, _) = tag("INTO")(input)?;
    let (input, _) = multispace1(input)?;
    let (input, table_name) = parse_table_name(input)?;
    let (input, _) = multispace1(input)?;
    let (input, _) = char('(')(input)?;
    let (input, _) = multispace0(input)?;
    let (input, column_names) = parse_columns(input)?;
    let (input, _) = multispace0(input)?;
    let (input, _) = char(')')(input)?;
    let (input, _) = multispace1(input)?;
    let (input, _) = tag("VALUES")(input)?;
    let (input, _) = multispace0(input)?;
    let (input, _) = char('(')(input)?;
    let (input, _) = multispace0(input)?;
    let (input, values) = parse_values(input)?;
    let (input, _) = multispace0(input)?;
    let (input, _) = char(')')(input)?;
    Ok((
        input,
        RawQuerySyntax::Insert(
            table_name.to_string(),
            column_names.into_iter().zip(values).collect(),
        ),
    ))
}

pub fn parse_columns(input: &str) -> IResult<&str, Vec<String>> {
    separated_list0(
        terminated(char(','), multispace0),
        map(parse_identifier, |name| name.to_string()),
    )(input)
}

pub fn parse_values(input: &str) -> IResult<&str, Vec<Literal>> {
    separated_list0(terminated(char(','), multispace0), parse_literal)(input)
}

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

    #[test]
    fn test_parse_insert() {
        let sql = "INSERT INTO \"MyTable\" (id, data) VALUES(1, \"Text\")";
        let syntax = parse_insert(sql).expect("should parse");
        match syntax {
            ("", RawQuerySyntax::Insert(table_name, insertion_values)) => {
                assert_eq!(table_name, "MyTable");
                assert_eq!(
                    insertion_values,
                    vec![
                        ("id".to_string(), Literal::Int(1)),
                        (
                            "data".to_string(),
                            Literal::String("Text".to_string())
                        )
                    ]
                );
            }
            _ => {
                unreachable!()
            }
        }
    }

    #[test]
    fn test_parse_insert_with_spaces() {
        let sql =
            "INSERT   INTO    \"MyTable\"   (  id,   data   )   VALUES   (  1,   \"Text\"  )";
        let operation = parse_insert(sql).expect("should parse");
        match operation {
            ("", RawQuerySyntax::Insert(table_name, insertion_values)) => {
                assert_eq!(table_name, "MyTable");
                assert_eq!(
                    insertion_values,
                    vec![
                        ("id".to_string(), Literal::Int(1)),
                        (
                            "data".to_string(),
                            Literal::String("Text".to_string())
                        )
                    ]
                );
            }
            _ => {
                unreachable!()
            }
        }
    }

    #[test]
    fn test_parse_insert_option() {
        let sql = r#"INSERT INTO games (id, name, year, price) VALUES (u12345, "Doom", Some(1993), 6.5);"#;
        let syntax = parse_insert(sql).expect("should parse");
        match syntax {
            (";", RawQuerySyntax::Insert(table_name, insertion_values)) => {
                assert_eq!(table_name, "games");
                assert_eq!(
                    insertion_values,
                    vec![
                        ("id".to_string(), Literal::Uuid(12345)),
                        (
                            "name".to_string(),
                            Literal::String("Doom".to_string())
                        ),
                        (
                            "year".to_string(),
                            Literal::Some(Box::new(Literal::Int(1993)))
                        ),
                        (
                            "price".to_string(),
                            Literal::Number(6.5)
                        )
                    ]
                );
            }
            _ => {
                panic!()
            }
        }
    }
}