use super::{ParserError, lexer::Token, pos::Span};
use std::fmt;

impl std::error::Error for ParserError {}

impl fmt::Display for ParserError {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		if let Some(file) = &self.file {
			write!(f, "{file} | ")?;
		}
		write!(f, "{} | {}", self.span, self.msg)
	}
}

pub trait SpanParserError {
	type Output;
	fn span_err(self, span: Span) -> Self::Output;
}

impl<T, E: std::error::Error> SpanParserError for Result<T, E> {
	type Output = Result<T, ParserError>;
	fn span_err(self, span: Span) -> Self::Output {
		self.map_err(|e| ParserError {
			span,
			msg: e.to_string(),
			file: None,
		})
	}
}

pub trait TokenError {
	fn token_err<T>(self, msg: impl Into<String>) -> Result<T, ParserError>;
}
impl TokenError for Token<'_> {
	fn token_err<T>(self, msg: impl Into<String>) -> Result<T, ParserError> {
		Err(ParserError {
			span: self.span,
			msg: msg.into(),
			file: None,
		})
	}
}