use num::bigint::BigInt;
use std::convert::From;
use std::io;

#[derive(Debug)]
pub enum Error {
    Io(io::Error),
    Message(String),
    InvalidUnicodeScalar(u32),
    NumberOutOfRange(BigInt),
    MissingCloseDelimiter,
    MissingItem,
    Expected(ExpectedKind),
}

#[derive(Debug, PartialEq)]
pub enum ExpectedKind {
    Boolean,
    Float,
    Double,

    SignedIntegerI128,
    SignedIntegerU128,
    SignedInteger,
    String,
    ByteString,
    Symbol,

    Record,
    SimpleRecord(String),
    Sequence,
    Set,
    Dictionary,

    Embedded,

    Option,
    UnicodeScalar,
    Annotation,
}

impl From<io::Error> for Error {
    fn from(e: io::Error) -> Self {
        Error::Io(e)
    }
}

impl From<Error> for io::Error {
    fn from(e: Error) -> Self {
        match e {
            Error::Io(ioe) => ioe,
            Error::Message(str) => io::Error::new(io::ErrorKind::Other, str),
            _ => io::Error::new(io::ErrorKind::Other, e),
        }
    }
}

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

impl std::fmt::Display for Error {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{:?}", self)
    }
}

pub fn io_eof() -> io::Error {
    io::Error::new(io::ErrorKind::UnexpectedEof, "EOF")
}