// This file is part of Deja-vu.
//
// Deja-vu is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Deja-vu 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Deja-vu. If not, see <https://www.gnu.org/licenses/>.
//
use color_eyre::Result;
use tracing_error::ErrorLayer;
use tracing_subscriber::{fmt, prelude::*, EnvFilter};

use crate::config;

lazy_static::lazy_static! {
    pub static ref LOG_ENV: String = format!("{}_LOG_LEVEL", config::PROJECT_NAME.clone());
    pub static ref LOG_FILE: String = format!("{}.log", env!("CARGO_PKG_NAME"));
}

pub fn init() -> Result<()> {
    let directory = config::get_data_dir();
    std::fs::create_dir_all(directory.clone())?;
    let log_path = directory.join(LOG_FILE.clone());
    let log_file = std::fs::File::create(log_path)?;
    let env_filter = EnvFilter::builder().with_default_directive(tracing::Level::INFO.into());
    // If the `RUST_LOG` environment variable is set, use that as the default, otherwise use the
    // value of the `LOG_ENV` environment variable. If the `LOG_ENV` environment variable contains
    // errors, then this will return an error.
    let env_filter = env_filter
        .try_from_env()
        .or_else(|_| env_filter.with_env_var(LOG_ENV.clone()).from_env())?;
    let file_subscriber = fmt::layer()
        .with_file(true)
        .with_line_number(true)
        .with_writer(log_file)
        .with_target(false)
        .with_ansi(false)
        .with_filter(env_filter);
    tracing_subscriber::registry()
        .with(file_subscriber)
        .with(ErrorLayer::default())
        .try_init()?;
    Ok(())
}