use std;
use std::fmt::{self, Display};

use serde::{de, ser};

use crate::{dec, enc};

pub type Result<T> = std::result::Result<T, Error>;

#[derive(Debug)]
pub enum Error {
    Message(String),
    Encode(enc::Error),
    Decode(String),
    Type(dec::TypeError),
    ParseInt(std::num::ParseIntError),
    ParseFloat(std::num::ParseFloatError),
    Utf8(std::string::FromUtf8Error),
}

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

impl<'a> From<dec::DecodeError<'a>> for Error {
    fn from(e: dec::DecodeError) -> Self {
        Error::Decode(e.to_string())
    }
}

impl From<dec::TypeError> for Error {
    fn from(e: dec::TypeError) -> Self {
        Error::Type(e)
    }
}

impl ser::Error for Error {
    fn custom<T: Display>(msg: T) -> Self {
        Error::Message(msg.to_string())
    }
}

impl From<std::num::ParseIntError> for Error {
    fn from(x: std::num::ParseIntError) -> Error {
        Error::ParseInt(x)
    }
}

impl From<std::num::ParseFloatError> for Error {
    fn from(x: std::num::ParseFloatError) -> Error {
        Error::ParseFloat(x)
    }
}

impl From<std::string::FromUtf8Error> for Error {
    fn from(x: std::string::FromUtf8Error) -> Error {
        Error::Utf8(x)
    }
}

impl de::Error for Error {
    fn custom<T: Display>(msg: T) -> Self {
        Error::Message(msg.to_string())
    }
}

impl Display for Error {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Error::Message(msg) => formatter.write_str(msg),
            Error::Encode(err) => write!(formatter, "Encode: {}", err),
            Error::Decode(err) => write!(formatter, "Decode: {}", err),
            Error::Type(err) => write!(formatter, "Type: {}", err),
            Error::ParseInt(err) => write!(formatter, "Parse (int): {}", err),
            Error::ParseFloat(err) => write!(formatter, "Parse (float): {}", err),
            Error::Utf8(err) => write!(formatter, "Invalid UTF-8 byte sequnence: {}", err),
        }
    }
}

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