use std::{fmt::Display, pin::Pin};

use diesel::result;
use diffy::ParsePatchError;
use r2d2;

type ParentError = Option<Pin<Box<dyn std::error::Error>>>;

#[derive(Debug)]
pub(crate) struct Error {
    source: ParentError,
    message: String,
}

unsafe impl Send for Error {}

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

impl std::error::Error for Error {
    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        self.source.as_deref()
    }
}

impl Display for Error {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Error { source: Some(source), message } =>
                write!(f, "{}: {}", message, source),
            Error { source: None, message } => write!(f, "{}", message),
        }
    }
}

impl From<&str> for Error {
    fn from(message: &str) -> Self {
        Self { source: None, message: String::from(message) }
    }
}

impl From<result::Error> for Error {
    fn from(source: result::Error) -> Self {
        Self { source: Some(Box::pin(source))
             , message: String::from("Diesel Result Error")
        }
    }
}

impl From<r2d2::Error> for Error {
    fn from(source: r2d2::Error) -> Self {
        Self { source: Some(Box::pin(source))
             , message: String::from("Diesel Result Error")
        }
    }
}

impl From<std::io::Error> for Error {
    fn from(source: std::io::Error) -> Self {
        Self { source: Some(Box::pin(source))
             , message: String::from("IO Error")
        }
    }
}

impl From<std::str::Utf8Error> for Error {
    fn from(source: std::str::Utf8Error) -> Self {
        Self { source: Some(Box::pin(source))
             , message: String::from("IO Error")
        }
    }
}

impl From<ParsePatchError> for Error {
    fn from(source: ParsePatchError) -> Self {
        Self { source: Some(Box::pin(source))
             , message: String::from("IO Error")
        }
    }
}