use serde::{Deserialize, Serialize};
use std::fmt;

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

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum Error {
    Disconnected,
    AlreadyConnected,
    ChannelIdentifierError(String, ChannelIdentifierError),
    InvalidServerAddr(String, u16),
    InvalidUsername(String),
    InvalidServerPassword,
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Error::Disconnected=> write!(f, "Not connected to a server"),
            Error::AlreadyConnected=> write!(f, "Already connected to a server"),
            Error::ChannelIdentifierError(id, kind) => write!(f, "{}: {}", kind, id),
            Error::InvalidServerAddr(addr, port) => {
                write!(f, "Invalid server address: {}: {}", addr, port)
            }
            Error::InvalidUsername(username) => write!(f, "Invalid username: {}", username),
            Error::InvalidServerPassword => write!(f, "Invalid server password")
        }
    }
}

#[derive(Clone, Copy, Debug, Serialize, Deserialize)]
pub enum ChannelIdentifierError {
    Invalid,
    Ambiguous,
}

impl fmt::Display for ChannelIdentifierError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            ChannelIdentifierError::Invalid => write!(f, "Invalid channel identifier"),
            ChannelIdentifierError::Ambiguous => write!(f, "Ambiguous channel identifier"),
        }
    }
}

pub enum ConfigError {
    InvalidConfig,
    TOMLErrorSer(toml::ser::Error),
    TOMLErrorDe(toml::de::Error),

    WontCreateFile,
    IOError(std::io::Error),
}

impl fmt::Display for ConfigError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            ConfigError::InvalidConfig => write!(f, "Invalid configuration"),
            ConfigError::TOMLErrorSer(e) => write!(f, "Invalid TOML when serializing: {}", e),
            ConfigError::TOMLErrorDe(e) => write!(f, "Invalid TOML when deserializing: {}", e),
            ConfigError::WontCreateFile => write!(f, "File does not exist but caller didn't allow creation"),
            ConfigError::IOError(e) => write!(f, "IO error: {}", e),
        }
    }
}

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

impl From<toml::ser::Error> for ConfigError {
    fn from(e: toml::ser::Error) -> Self {
        ConfigError::TOMLErrorSer(e)
    }
}

impl From<toml::de::Error> for ConfigError {
    fn from(e: toml::de::Error) -> Self {
        ConfigError::TOMLErrorDe(e)
    }
}