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// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.

use slog::Drain;

/// A slog Drain that uses println!.
pub struct PrintlnDrain {
    /// Minimum logging level that we're emitting.
    pub min_level: slog::Level,
}

/// slog Drain that uses println!.
impl slog::Drain for PrintlnDrain {
    type Ok = ();
    type Err = std::io::Error;

    fn log(
        &self,
        record: &slog::Record,
        _values: &slog::OwnedKVList,
    ) -> Result<Self::Ok, Self::Err> {
        if record.level().is_at_least(self.min_level) {
            println!("{}", record.msg());
        }

        Ok(())
    }
}

/// Context holding state for a logger.
pub struct LoggerContext {
    pub logger: slog::Logger,
}

/// Construct a slog::Logger from settings in environment.
pub fn logger_from_env(min_level: slog::Level) -> LoggerContext {
    LoggerContext {
        logger: slog::Logger::root(PrintlnDrain { min_level }.fuse(), slog::o!()),
    }
}

impl Default for LoggerContext {
    fn default() -> Self {
        LoggerContext {
            logger: slog::Logger::root(
                PrintlnDrain {
                    min_level: slog::Level::Warning,
                }
                .fuse(),
                slog::o!(),
            ),
        }
    }
}