use log::LevelFilter;
use rust_util::{simple_error, XResult};
use std::{env, fs};

const DEFAULT_LOG4RS_CONFIG: &str = r##"refresh_rate: 10 seconds
appenders:
  file:
    kind: rolling_file
    path: "log/local_mini_kms_log.log"
    append: true
    encoder:
      pattern: "{d} - {m}{n}"
    policy:
      kind: compound
      trigger:
        kind: size
        limit: 100 mb
      roller:
        kind: fixed_window
        pattern: log/local_mini_kms_log.{}.log
        count: 10
root:
  level: info
  appenders:
    - file"##;

pub fn init_logger(log_level: Option<&str>, log4rs_file: Option<&str>) -> XResult<()> {
    match log4rs_file {
        None => {
            let level = match env::var("LOGGER").ok().as_deref().map(get_log_level_filter) {
                Some(Ok(level)) => level,
                _ => log_level.map(get_log_level_filter).unwrap_or(Ok(LevelFilter::Debug))?,
            };
            let _ = env_logger::builder().filter_level(level).try_init();
        }
        Some(log4rs_file) => {
            let log4rs_config_file = if log4rs_file == "#DEFAULT" {
                let default_log4rs_file = "default_log4rs.yaml";
                let _ = fs::metadata(default_log4rs_file).map_err(|_| {
                    fs::write(default_log4rs_file, DEFAULT_LOG4RS_CONFIG).map_err(|e| {
                        println!("Write file: {} failed: {}", default_log4rs_file, e);
                    })
                });
                default_log4rs_file
            } else {
                log4rs_file
            };
            log4rs::init_file(log4rs_config_file, Default::default())?;
        }
    }
    Ok(())
}


fn get_log_level_filter(log_level: &str) -> XResult<LevelFilter> {
    Ok(match log_level {
        "trace" => LevelFilter::Trace,
        "debug" => LevelFilter::Debug,
        "info" => LevelFilter::Info,
        "warn" => LevelFilter::Warn,
        "error" => LevelFilter::Error,
        _ => {
            return simple_error!("invalid log_level");
        }
    })
}