//! Contains the error types used by the [`notify`](super) module.
#![allow(clippy::module_name_repetitions)]

use core::fmt::Display;
use std::error::Error;

use rustix::io::Errno;

#[derive(Debug)]
pub enum NewNotifierError {
    InvalidAbstractSocket(Errno),
    InvalidSocketPath(Errno),
    CouldntOpenSocket(std::io::Error),
}

impl Display for NewNotifierError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            NewNotifierError::InvalidAbstractSocket(error) => {
                write!(f, "couldn't open notify abstract socket: {error}")
            }
            NewNotifierError::InvalidSocketPath(error) => {
                write!(f, "couldn't open notify socket from path: {error}")
            }
            NewNotifierError::CouldntOpenSocket(error) => {
                write!(f, "couldn't open unix socket: {error}")
            }
        }
    }
}

impl Error for NewNotifierError {
    fn source(&self) -> Option<&(dyn Error + 'static)> {
        match self {
            NewNotifierError::InvalidAbstractSocket(error)
            | NewNotifierError::InvalidSocketPath(error) => Some(error),
            NewNotifierError::CouldntOpenSocket(error) => Some(error),
        }
    }
}

#[derive(Debug)]
pub enum NotifyError {
    SendMsg(Errno),
    PushAncillaryMessage,
    PartialSend,
}

impl Display for NotifyError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            NotifyError::SendMsg(error) => write!(f, "couldn't send the message: {error}"),
            NotifyError::PushAncillaryMessage => {
                f.write_str("couldn't push necessary ancillary message for fd passing")
            }
            NotifyError::PartialSend => f.write_str("only some of the message could be sent"),
        }
    }
}

impl Error for NotifyError {
    fn source(&self) -> Option<&(dyn Error + 'static)> {
        match self {
            NotifyError::SendMsg(error) => Some(error),
            NotifyError::PushAncillaryMessage | NotifyError::PartialSend => None,
        }
    }
}

#[derive(Debug)]
pub enum FdNameError {
    TooLong { length: usize, name: String },
    NotAsciiNonControl { disallowed_char: char, name: String },
    ContainColon(String),
}

impl Display for FdNameError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::TooLong { length, name } => write!(f, "the file descriptor name {name:?} is too long (is {length} characters and should be less than 255)"),
            Self::NotAsciiNonControl { disallowed_char, name } => write!(f, "the file descriptor name {name:?} contains invalid character '{disallowed_char}' (only ASCII allowed)"),
            Self::ContainColon(name) => write!(f, "the file descriptor name {name:?} contains a colon (':') which isn't allowed"),
        }
    }
}

impl Error for FdNameError {}

#[derive(Debug)]
pub enum StatusLineError {
    TooManyLines,
}

impl Display for StatusLineError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::TooManyLines => {
                f.write_str("The provided status line contains more than one line.")
            }
        }
    }
}

impl Error for StatusLineError {}

#[derive(Debug)]
pub enum OtherStateError {
    TooManyLines,
    NoAssignement,
    DisallowedState(String),
}

impl Display for OtherStateError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::DisallowedState(state) => write!(f, "The state assignement {state:?} isn't allowed."),
            Self::NoAssignement => write!(f, "No assignement was found in provided custom state."),
            Self::TooManyLines => write!(f, "States cannot contains newlines (they are newline separated in the underlying protocol).")
        }
    }
}

impl Error for OtherStateError {}

#[derive(Debug)]
pub enum BarrierError {
    Notify(NotifyError),
    FailedPipeCreation(Errno),
    FailedPolling(Errno),
    TimedOut,
}

impl From<NotifyError> for BarrierError {
    fn from(value: NotifyError) -> Self {
        Self::Notify(value)
    }
}

impl Display for BarrierError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Notify(_) => write!(f, "Couldn't notify of barrier."),
            Self::FailedPipeCreation(errno) => write!(
                f,
                "Couldn't create pipe to serve as a notify syncronisation barrier : error {errno}."
            ),
            Self::FailedPolling(errno) => write!(f, "poll failed with error : {errno}."),
            Self::TimedOut => write!(f, "Notification synchronisation timed out."),
        }
    }
}

impl Error for BarrierError {
    fn source(&self) -> Option<&(dyn Error + 'static)> {
        match self {
            Self::Notify(source) => Some(source),
            Self::FailedPipeCreation(source) | Self::FailedPolling(source) => Some(source),
            Self::TimedOut => None,
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum PollTimeoutFromIntError {
    Negative,
}

impl Display for PollTimeoutFromIntError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Negative => write!(f, "This variant of BarrierTimeout cannot be negative but a negative number was passed.")
        }
    }
}

impl Error for PollTimeoutFromIntError {}

#[derive(Debug)]
pub enum MicrosecondsFromDurationError {
    NoMicroseconds,
}

impl Display for MicrosecondsFromDurationError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::NoMicroseconds => write!(f, "Minimal precision is microseconds but no microseconds are within the Duration provided."),
        }
    }
}

impl Error for MicrosecondsFromDurationError {}