use crate::CpuError;
use core::fmt;

#[derive(Debug)]
#[non_exhaustive]
pub enum RuntimeError {
    RomParse(String),
    MapperInit(String),
    Cpu(CpuError),
    BufferTooSmall { expected: usize, got: usize },
    InvalidState(String),
}

impl fmt::Display for RuntimeError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::RomParse(e) => write!(f, "ROM parse error: {e}"),
            Self::MapperInit(e) => write!(f, "mapper init error: {e}"),
            Self::Cpu(e) => write!(f, "CPU error: {e:?}"),
            Self::BufferTooSmall { expected, got } => {
                write!(f, "buffer too small: expected {expected} bytes, got {got}")
            }
            Self::InvalidState(e) => write!(f, "invalid runtime state: {e}"),
        }
    }
}

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