use crate::*;


pub struct Token {
    pub source: SourceSpan,
    pub variant: TokenVariant,
}

pub enum TokenVariant {
    LabelDefinition(String),
    MacroDefinition(String),
    MacroDefinitionTerminator,

    DecimalLiteral(usize),
    HexadecimalLiteral(usize),
    PackedBinaryLiteral(PackedBinaryLiteral),

    Comment(String),
    ConstantExpression(ConstantExpression),

    BlockOpen,
    BlockClose,
    Separator,

    Symbol(String),

    Error(ParseError),
}

#[derive(Debug)]
pub enum ParseError {
    InvalidHexadecimalLiteral(String),
    InvalidSymbolIdentifier(String),
    UnterminatedComment,
    UnterminatedConstantExpression,
}


impl std::fmt::Debug for Token {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
        use TokenVariant::*;
        let start = &self.source.in_merged;
        let name = match &self.variant {
            LabelDefinition(name) => format!("LabelDefinition({name})"),
            MacroDefinition(name) => format!("MacroDefinition({name})"),
            MacroDefinitionTerminator => format!("MacroDefinitionTerminator"),

            DecimalLiteral(value) => format!("DecimalLiteral({value})"),
            HexadecimalLiteral(value) => format!("HexadecimalLiteral(0x{value:x})"),
            PackedBinaryLiteral(pbl) => format!("PackedBinaryLiteral({pbl})"),

            Comment(_) => format!("Comment"),
            ConstantExpression(expr) => format!("ConstantExpression({expr:?})"),

            BlockOpen => format!("BlockOpen"),
            BlockClose => format!("BlockClose"),
            Separator => format!("Separator"),

            Symbol(name) => format!("Symbol({name})"),

            Error(error) => format!("Error({error:?})"),
        };

        write!(f, "{start} {name}")
    }
}