extern crate log;

use log::{LogMetadata, LogRecord, LogLevelFilter, SetLoggerError};
use std::io::Write;
use std::fs::OpenOptions;

struct Logger{
    file_name: String,
}

impl Logger {
    pub fn new(file_name: String) -> Logger{
        return Logger {
            file_name: file_name,
        };
    }
}

impl log::Log for Logger{
    fn enabled(&self, _: &LogMetadata) -> bool {
        return true;
    }

    fn log(&self, record: &LogRecord) {
        let mut f = match OpenOptions::new().append(true).open(&self.file_name) {
            // The `description` method of `io::Error` returns a string that
            // describes the error
            Err(_) => panic!("couldn't open {}", self.file_name),
            Ok(f) => f,
        };
        let _ = write!(f, "{} - {}", record.level(), record.args());
        let _ = f.flush();
    }
}

pub fn log_init(file_name: String) -> Result<(), SetLoggerError>{
    return log::set_logger(|max_log_level| {
        max_log_level.set(LogLevelFilter::Debug);
        Box::new(Logger::new(file_name))
    });
}

pub fn log_deinit(){
    let _ = log::shutdown_logger();
}