use serde_derive::{Deserialize, Serialize};

#[derive(Debug)]
pub enum TdlibSysError {
    LogLevelOutOfBounds(u16),
    Nul(usize),
    UtfDecode,
    CannotSetLogFile,
}

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

impl std::convert::From<std::ffi::NulError> for TdlibSysError {
    fn from(nul_err: std::ffi::NulError) -> Self {
        Self::Nul(nul_err.nul_position())
    }
}

impl std::fmt::Display for TdlibSysError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        use TdlibSysError::*;
        match self {
            LogLevelOutOfBounds(lvl) => {
                write!(f, "Log level should be less than 1024. Found {}", lvl)
            }
            Nul(pos) => write!(f, "String contains nul byte at pos: {}", pos),
            UtfDecode => write!(f, "String is not utf8 encoded"),
            CannotSetLogFile => write!(f, "Could not set log file"),
        }
    }
}

#[derive(Debug, thiserror::Error)]
pub enum TgError {
    /// Something went wrong, when (de)serializing shit
    #[error("Something went wrong, when (de)serializing shit: {}", .0)]
    Serde(#[from] serde_json::Error),

    /// tdlib-sys error
    #[error("tdlib-sys error: {}", .0)]
    TdSys(#[from] TdlibSysError),

    #[error("@type must not be in your structure used as Request")]
    HasTypeInJson,

    #[error("@type must be string in JsonValue used as Request")]
    HasNoTypeInJson,

    #[error("json is invalid: {}", .0)]
    InvalidJson(String),

    #[error("core channel has been closed unexpectedly")]
    ChannelClosed,

    #[error("telegram replied with error code: {} and message: {}", .0.code, .0.msg)]
    TelegramError(TelegramError),
}

#[derive(Debug, Serialize, Deserialize)]
pub struct TelegramError {
    code: i32,
    msg: String,
}

impl<T> std::convert::From<crossbeam::channel::SendError<T>> for TgError {
    fn from(_: crossbeam::channel::SendError<T>) -> Self {
        Self::ChannelClosed
    }
}

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