use lalrpop_util::lalrpop_mod;

lalrpop_mod!(pub select); // synthesized by LALRPOP

#[derive(Debug)]
pub enum ParseError {
    Error(String),
}

pub fn parse_select(input: String) -> Result<Vec<String>, ParseError> {
    let mut result: Vec<String> = vec![];
    let parser = select::SelectParser::new();
    let maybe_error = parser.parse(&mut result, input.as_str());
    match maybe_error {
        Ok(_) => {
            return Ok(result);
        }
        Err(error) => {
            let error = format!("{:?}", error);
            return Err(ParseError::Error(format!(
                "Failed to parse, error: {}",
                error
            )));
        }
    };
}

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

    #[test]
    fn test_select_parser_single_column() {
        let mut result: Vec<String> = vec![];
        let parser = select::SelectParser::new();
        assert!(parser.parse(&mut result, "select churros;").is_ok());
        let v = vec!["churros".to_string()];
        assert_eq!(v, result);
    }

    #[test]
    fn test_select_parser_multiple_columns() {
        let mut result: Vec<String> = vec![];
        let parser = select::SelectParser::new();
        parser
            .parse(&mut result, "select brigadeiro, churros;")
            .unwrap();
        let v = vec!["brigadeiro".to_string(), "churros".to_string()];
        assert_eq!(v, result);
    }

    #[test]
    fn test_select_support_star() {
        let mut result: Vec<String> = vec![];
        let parser = select::SelectParser::new();
        assert!(parser.parse(&mut result, "select *;").is_ok());
        assert_eq!(result, vec!["*".to_string()]);
    }

    #[test]
    fn test_parse_select() {
        let result = parse_select("select brigadeiro, churros;".to_string()).unwrap();
        let v = vec!["brigadeiro".to_string(), "churros".to_string()];
        assert_eq!(v, result);
    }
}