/*
Astrolog, a logging framework for Rust
Copyright (C) 2019 Alessandro Pellizzari

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

extern crate astrolog;

use std::env;
use std::fs::File;
use std::error::Error;
use std::fmt;

use astrolog::handler::console::ConsoleHandler;
use astrolog::prelude::*;

struct MyError {
	msg: String,
	cause: Option<Box<Error>>,
}

impl MyError {
	pub fn new(msg: &str) -> MyError {
		MyError {
			msg: msg.into(),
			cause: None,
		}
	}

	pub fn with_cause<E: Error + 'static>(mut self, cause: E) -> Self {
		self.cause = Some(Box::new(cause));
		self
	}
}

impl Error for MyError {
	fn description(&self) -> &str {
		&self.msg
	}

	fn cause(&self) -> Option<&Error> {
		match &self.cause {
			Some(c) => Some(c.as_ref()),
			None => None,
		}
	}
}

impl fmt::Display for MyError {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		write!(f, "{}", self.description())
	}
}

impl fmt::Debug for MyError {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		write!(f, "{}", self.description())
	}
}

fn main() {
	let logger = Logger::new()
		.with_global("OS", env::consts::OS)
		.with_handler(ConsoleHandler::new().with_levels_range(Level::Info, Level::Emergency));

	let _ = File::open("foo.txt")
		.map_err(|e| {
			logger.with_error(&e).error("Simple error opening foo.txt")
		});

	let _ = File::open("foo.txt")
		.map_err(|e| {
			let e_with_trace = MyError::new("Opening foo.txt").with_cause(e);
			logger.with_error(&e_with_trace).error("Tracing error opening file")
		});

	let _ = File::open("foo.txt")
		.map_err(|e| {
			let e_with_trace = MyError::new("Opening foo.txt").with_cause(MyError::new("second-level error").with_cause(e));
			logger.with_error(&e_with_trace).error("Deep tracing error opening file")
		});
}