use nom::{
    bytes::complete::tag,
    character::complete::{char, multispace0, multispace1},
    combinator::opt,
    multi::separated_list0,
    sequence::terminated,
    IResult,
};

use super::common::{parse_db_type, parse_identifier, parse_table_name};
use crate::syntax::{ColumnSchema, RawQuerySyntax, RawTableSchema};

pub fn parse_create(input: &str) -> IResult<&str, RawQuerySyntax> {
    let (input, _) = tag("CREATE")(input)?;
    let (input, _) = multispace1(input)?;
    let (input, _) = tag("TABLE")(input)?;
    let (input, _) = multispace1(input)?;
    let (input, table_name) = parse_table_name(input)?;
    let (input, _) = multispace0(input)?;
    let (input, _) = char('(')(input)?;
    let (input, _) = multispace0(input)?;
    let (input, column_definitions) = parse_column_definitions(input)?;

    let (input, _) = char(')')(input)?;
    let schema = RawTableSchema {
        table_name: table_name.to_string(),
        columns: column_definitions,
    };
    Ok((input, RawQuerySyntax::CreateTable(schema)))
}

fn parse_column_definitions(input: &str) -> IResult<&str, Vec<ColumnSchema>> {
    separated_list0(terminated(char(','), multispace0), parse_column_definition)(input)
}

fn parse_primary_key(input: &str) -> IResult<&str, &str> {
    let (input, _) = multispace1(input)?;
    let (input, _) = tag("PRIMARY")(input)?;
    let (input, _) = multispace1(input)?;
    let (input, _) = tag("KEY")(input)?;
    Ok((input, "PRIMARY KEY"))
}

fn parse_column_definition(input: &str) -> IResult<&str, ColumnSchema> {
    let (input, identifier) = parse_identifier(input)?;
    let (input, _) = multispace1(input)?;
    let (input, db_type) = parse_db_type(input)?;
    let (input, pk) = opt(parse_primary_key)(input).map(|(input, pk)| (input, pk.is_some()))?;
    let (input, _) = multispace0(input)?;
    Ok((
        input,
        ColumnSchema {
            column_name: identifier.to_string(),
            type_: db_type,
            is_primary: pk,
        },
    ))
}

#[cfg(test)]
mod tests {
    use minisql::type_system::DbType;

    use crate::parsing::create::parse_create;
    use crate::syntax::RawQuerySyntax;

    #[test]
    fn test_parse_create_no_spaces() {
        parse_create("CREATE TABLE \"Table1\"(id UUID ,column1 INT)").expect("should parse");
    }

    #[test]
    fn test_parse_create_primary_key() {
        parse_create("CREATE TABLE \"Table1\"(id UUID PRIMARY KEY,column1 INT)")
            .expect("should parse");
    }

    #[test]
    fn test_parse_create_no_quotes_table_name() {
        parse_create("CREATE TABLE Table1(id UUID PRIMARY KEY,column1 INT)").expect("should parse");
    }

    #[test]
    fn test_parse_create_primary_key_with_spaces() {
        parse_create(
            "CREATE   TABLE   \"Table1\"  ( id   UUID   PRIMARY   KEY  ,  column1   INT  )",
        )
        .expect("should parse");
    }

    #[test]
    fn test_parse_create() {
        let (_, create) =
            parse_create("CREATE TABLE \"Table1\"( id UUID , column1 INT )").expect("should parse");
        assert!(matches!(create, RawQuerySyntax::CreateTable(_)));
        match create {
            RawQuerySyntax::CreateTable(schema) => {
                assert_eq!(schema.table_name, "Table1");
                assert_eq!(schema.number_of_columns(), 2);

                let result_id = schema.get_column(&"id".to_string());
                assert!(matches!(result_id, Some(_)));
                let Some(id_column) = result_id else { panic!() };
                assert_eq!(id_column.column_name, "id".to_string());

                let result_column1 = schema.get_column(&"column1".to_string());
                assert!(matches!(result_column1, Some(_)));
                let Some(column1_column) = result_column1 else {
                    panic!()
                };
                assert_eq!(column1_column.column_name, "column1".to_string());
            }
            _ => {}
        }
    }

    #[test]
    fn test_parse_create_option() {
        let (_, create) = parse_create(
            "CREATE TABLE games (id UUID PRIMARY KEY, name STRING, year Option(INT), price NUMBER)",
        )
        .expect("should parse");
        assert!(matches!(create, RawQuerySyntax::CreateTable(_)));
        match create {
            RawQuerySyntax::CreateTable(schema) => {
                assert_eq!(schema.table_name, "games");
                assert_eq!(schema.number_of_columns(), 4);

                let result_id = schema.get_column(&"id".to_string());
                assert!(matches!(result_id, Some(_)));
                let Some(id_column) = result_id else { panic!() };
                assert_eq!(id_column.column_name, "id".to_string());

                let result_column1 = schema.get_column(&"name".to_string());
                assert!(matches!(result_column1, Some(_)));
                let Some(column1_column) = result_column1 else {
                    panic!()
                };
                assert_eq!(column1_column.column_name, "name".to_string());
                assert_eq!(column1_column.type_, DbType::String);

                let column = schema.get_column(&"year".to_string());
                let Some(column) = column else { panic!() };
                assert_eq!(column.column_name, "year".to_string());
                assert_eq!(column.type_, DbType::Option(Box::new(DbType::Int)));

                let column = schema.get_column(&"price".to_string());
                let Some(column) = column else { panic!() };
                assert_eq!(column.column_name, "price".to_string());
                assert_eq!(column.type_, DbType::Number);
            }
            _ => {}
        }
    }
}