// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.

use std::io::Write;

use super::draw_thread::DrawThread;

struct CliLogger(env_logger::Logger);

impl CliLogger {
  pub fn new(logger: env_logger::Logger) -> Self {
    Self(logger)
  }

  pub fn filter(&self) -> log::LevelFilter {
    self.0.filter()
  }
}

impl log::Log for CliLogger {
  fn enabled(&self, metadata: &log::Metadata) -> bool {
    self.0.enabled(metadata)
  }

  fn log(&self, record: &log::Record) {
    if self.enabled(record.metadata()) {
      // it was considered to hold the draw thread's internal lock
      // across logging, but if outputting to stderr blocks then that
      // could potentially block other threads that access the draw
      // thread's state
      DrawThread::hide();
      self.0.log(record);
      DrawThread::show();
    }
  }

  fn flush(&self) {
    self.0.flush();
  }
}

pub fn init(maybe_level: Option<log::Level>) {
  let log_level = maybe_level.unwrap_or(log::Level::Info);
  let logger = env_logger::Builder::from_env(
    env_logger::Env::default()
      .default_filter_or(log_level.to_level_filter().to_string()),
  )
  // https://github.com/denoland/deno/issues/6641
  .filter_module("rustyline", log::LevelFilter::Off)
  // wgpu crates (gfx_backend), have a lot of useless INFO and WARN logs
  .filter_module("wgpu", log::LevelFilter::Error)
  .filter_module("gfx", log::LevelFilter::Error)
  .filter_module("globset", log::LevelFilter::Error)
  // used to make available the lsp_debug which is then filtered out at runtime
  // in the cli logger
  .filter_module("deno::lsp::performance", log::LevelFilter::Debug)
  .filter_module("rustls", log::LevelFilter::Off)
  // swc_ecma_codegen's `srcmap!` macro emits error-level spans only on debug
  // build:
  // https://github.com/swc-project/swc/blob/74d6478be1eb8cdf1df096c360c159db64b64d8a/crates/swc_ecma_codegen/src/macros.rs#L112
  // We suppress them here to avoid flooding our CI logs in integration tests.
  .filter_module("swc_ecma_codegen", log::LevelFilter::Off)
  .filter_module("swc_ecma_transforms_optimization", log::LevelFilter::Off)
  .filter_module("swc_ecma_parser", log::LevelFilter::Error)
  // Suppress span lifecycle logs since they are too verbose
  .filter_module("tracing::span", log::LevelFilter::Off)
  .format(|buf, record| {
    let mut target = record.target().to_string();
    if let Some(line_no) = record.line() {
      target.push(':');
      target.push_str(&line_no.to_string());
    }
    if record.level() <= log::Level::Info
      || (record.target() == "deno::lsp::performance"
        && record.level() == log::Level::Debug)
    {
      // Print ERROR, WARN, INFO and lsp_debug logs as they are
      writeln!(buf, "{}", record.args())
    } else {
      // Add prefix to DEBUG or TRACE logs
      writeln!(
        buf,
        "{} RS - {} - {}",
        record.level(),
        target,
        record.args()
      )
    }
  })
  .build();

  let cli_logger = CliLogger::new(logger);
  let max_level = cli_logger.filter();
  let r = log::set_boxed_logger(Box::new(cli_logger));
  if r.is_ok() {
    log::set_max_level(max_level);
  }
  r.expect("Could not install logger.");
}