use crate::ast::executable::VariableDefinition;
use crate::ast::{FromTokens, IsMatch, ParseError, Tokens};
use crate::lexical_token::PunctuatorType;
use crate::Span;

#[derive(Debug)]
pub struct VariableDefinitions<'a> {
    variable_definitions: Vec<VariableDefinition<'a>>,
    _span: Span,
}

impl<'a> FromTokens<'a> for VariableDefinitions<'a> {
    fn from_tokens(tokens: &mut impl Tokens<'a>) -> Result<Self, ParseError> {
        let open_span = tokens.expect_punctuator(PunctuatorType::OpenRoundBracket)?;
        let mut variable_definitions: Vec<VariableDefinition> = Vec::new();
        let close_span = loop {
            variable_definitions.push(VariableDefinition::from_tokens(tokens)?);
            if let Some(close_span) = tokens.next_if_punctuator(PunctuatorType::CloseRoundBracket) {
                break close_span;
            }
        };
        let span = open_span.merge(&close_span);
        Ok(Self {
            variable_definitions,
            _span: span,
        })
    }
}

impl<'a> IsMatch<'a> for VariableDefinitions<'a> {
    fn is_match(tokens: &mut impl Tokens<'a>) -> bool {
        tokens.peek_punctuator_matches(0, PunctuatorType::OpenRoundBracket)
    }
}

impl<'a> bluejay_core::executable::VariableDefinitions for VariableDefinitions<'a> {
    type VariableDefinition = VariableDefinition<'a>;
}

impl<'a> AsRef<[VariableDefinition<'a>]> for VariableDefinitions<'a> {
    fn as_ref(&self) -> &[VariableDefinition<'a>] {
        &self.variable_definitions
    }
}