sp_log2 0.1.3

use log::{
    set_boxed_logger, set_max_level, Level, LevelFilter, Log, Metadata, Record, SetLoggerError,
};
use std::default::Default;
use std::io::{Error, Write};
use std::sync::Mutex;
use termcolor2::{BufferedStandardStream, ColorChoice};
use termcolor2::{ColorSpec, WriteColor};

use super::logging::*;

use crate::config::Format;
use crate::{Config, SharedLogger, ThreadLogMode};

struct OutputStreams {
    err: BufferedStandardStream,
    out: BufferedStandardStream,
}

#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash, Default)]
pub enum TerminalMode {
    /// Only use Stdout
    Stdout,
    /// Only use Stderr
    Stderr,
    /// Use Stderr for Errors and Stdout otherwise
    #[default]
    Mixed,
}

/// The TermLogger struct. Provides a stderr/out based Logger implementation
///
/// Supports colored output
pub struct TermLogger {
    level: LevelFilter,
    config: Config,
    streams: Mutex<OutputStreams>,
}

impl TermLogger {
    /// init function. Globally initializes the TermLogger as the one and only used log facility.
    ///
    /// Takes the desired `Level` and `Config` as arguments. They cannot be changed later on.
    /// Fails if another Logger was already initialized
    ///
    /// # Examples
    /// ```
    /// # extern crate sp_log2;
    /// # use sp_log2::*;
    /// # fn main() {
    ///     TermLogger::init(
    ///         LevelFilter::Info,
    ///         Config::default(),
    ///         TerminalMode::Mixed,
    ///         ColorChoice::Auto
    ///     );
    /// # }
    /// ```
    pub fn init(
        log_level: LevelFilter,
        config: Config,
        mode: TerminalMode,
        color_choice: ColorChoice,
    ) -> Result<(), SetLoggerError> {
        let logger = TermLogger::new(log_level, config, mode, color_choice);
        set_max_level(log_level);
        set_boxed_logger(logger)?;
        Ok(())
    }

    /// allows to create a new logger, that can be independently used, no matter whats globally set.
    ///
    /// no macros are provided for this case and you probably
    /// dont want to use this function, but `init()`, if you dont want to build a `CombinedLogger`.
    ///
    /// Takes the desired `Level` and `Config` as arguments. They cannot be changed later on.
    ///
    /// Returns a `Box`ed TermLogger
    ///
    /// # Examples
    /// ```
    /// # extern crate sp_log2;
    /// # use sp_log2::*;
    /// # fn main() {
    /// let term_logger = TermLogger::new(
    ///     LevelFilter::Info,
    ///     Config::default(),
    ///     TerminalMode::Mixed,
    ///     ColorChoice::Auto
    /// );
    /// # }
    /// ```
    #[must_use]
    pub fn new(
        log_level: LevelFilter,
        config: Config,
        mode: TerminalMode,
        color_choice: ColorChoice,
    ) -> Box<TermLogger> {
        let streams = match mode {
            TerminalMode::Stdout => OutputStreams {
                err: BufferedStandardStream::stdout(color_choice),
                out: BufferedStandardStream::stdout(color_choice),
            },
            TerminalMode::Stderr => OutputStreams {
                err: BufferedStandardStream::stderr(color_choice),
                out: BufferedStandardStream::stderr(color_choice),
            },
            TerminalMode::Mixed => OutputStreams {
                err: BufferedStandardStream::stderr(color_choice),
                out: BufferedStandardStream::stdout(color_choice),
            },
        };

        Box::new(TermLogger {
            level: log_level,
            config,
            streams: Mutex::new(streams),
        })
    }

    fn try_log_term(
        &self,
        record: &Record<'_>,
        term_lock: &mut BufferedStandardStream,
    ) -> Result<(), Error> {
        let color = self.config.level_color[record.level() as usize].clone();

        if record.level() > self.config.min_level || record.level() < self.config.max_level {
            return Ok(());
        }

        let mut level = String::new();
        let mut time = String::new();
        let mut thread = String::new();
        let mut target = String::new();
        let mut location = String::new();
        let mut module = String::new();

        if self.config.format & Format::Time != 0 {
            time = write_time(&self.config)?;
        }

        if self.config.format & Format::LevelFlag != 0 {
            level = write_level(record, &self.config)?;
        }

        if self.config.format & Format::Thread != 0 {
            thread = match self.config.thread_log_mode {
                ThreadLogMode::IDs => write_thread_id(&self.config)?,
                ThreadLogMode::Names | ThreadLogMode::Both => write_thread_name(&self.config)?,
            }
        }

        if self.config.format & Format::Target != 0 {
            target = write_target(record, &self.config)?;
        }

        if self.config.format & Format::FileLocation != 0 {
            location = write_location(record)?;
        }

        if self.config.format & Format::Module != 0 {
            module = write_module(record)?;
        }

        let mut args = write_args(record, &self.config.line_ending)?;
        args = args.trim_end().to_string();

        if self.config.formatter.is_some() {
            parse_and_format_log_term(
                term_lock,
                color,
                &self.config,
                &level,
                &time,
                &thread,
                &target,
                &location,
                &module,
                &args,
            )?;
        } else {
            if !time.is_empty() {
                write!(term_lock, "{}", time)?;
            }

            if !level.is_empty() {
                if self.config.enable_colors {
                    term_lock.set_color(ColorSpec::new().set_fg(color))?;
                }
                write!(term_lock, " [{}]", level)?;
                if !self.config.enable_colors {
                    term_lock.reset()?;
                }
            }

            if !thread.is_empty() {
                write!(term_lock, " ({})", thread)?;
            }

            if !target.is_empty() {
                write!(term_lock, " {}:", target)?;
            }

            write!(term_lock, " {}", args)?;

            if !location.is_empty() {
                write!(term_lock, " [{}]", location)?;
            }

            writeln!(term_lock)?;
        }

        // The log crate holds the logger as a `static mut`, which isn't dropped
        // at program exit: https://doc.rust-lang.org/reference/items/static-items.html
        // Sadly, this means we can't rely on the BufferedStandardStreams flushing
        // themselves on the way out, so to avoid the Case of the Missing 8k,
        // flush each entry.
        term_lock.flush()
    }

    fn try_log(&self, record: &Record<'_>) -> Result<(), Error> {
        if self.enabled(record.metadata()) {
            if should_skip(&self.config, record) {
                return Ok(());
            }

            let mut streams = self.streams.lock().unwrap();

            if record.level() == Level::Error {
                self.try_log_term(record, &mut streams.err)
            } else {
                self.try_log_term(record, &mut streams.out)
            }
        } else {
            Ok(())
        }
    }
}

impl Log for TermLogger {
    fn enabled(&self, metadata: &Metadata<'_>) -> bool {
        metadata.level() <= self.level
    }

    fn log(&self, record: &Record<'_>) {
        let _ = self.try_log(record);
    }

    fn flush(&self) {
        let mut streams = self.streams.lock().unwrap();
        let _ = streams.out.flush();
        let _ = streams.err.flush();
    }
}

impl SharedLogger for TermLogger {
    fn level(&self) -> LevelFilter {
        self.level
    }

    fn config(&self) -> Option<&Config> {
        Some(&self.config)
    }

    fn as_log(self: Box<Self>) -> Box<dyn Log> {
        Box::new(*self)
    }
}