#![allow(clippy::module_name_repetitions)]
mod builder;
mod config;
mod infix_filter;
mod rotation_config;
mod state;
mod state_handle;
mod threads;

pub use self::builder::{ArcFileLogWriter, FileLogWriterBuilder, FileLogWriterHandle};
pub use self::config::FileLogWriterConfig;
pub(crate) use infix_filter::InfixFilter;

use self::{rotation_config::RotationConfig, state::State, state_handle::StateHandle};
use crate::{
    writers::LogWriter, DeferredNow, EffectiveWriteMode, FileSpec, FlexiLoggerError,
    FormatFunction, LogfileSelector,
};
use log::Record;
use std::path::PathBuf;

const WINDOWS_LINE_ENDING: &[u8] = b"\r\n";
const UNIX_LINE_ENDING: &[u8] = b"\n";

/// A configurable [`LogWriter`] implementation that writes to a file or a sequence of files.
///
/// See [writers](crate::writers) for usage guidance.
#[derive(Debug)]
pub struct FileLogWriter {
    // the state needs to be mutable; since `Log.log()` requires an unmutable self,
    // which translates into a non-mutating `LogWriter::write()`,
    // we need internal mutability and thread-safety.
    state_handle: StateHandle,
    max_log_level: log::LevelFilter,
}
impl FileLogWriter {
    fn new(
        state: State,
        max_log_level: log::LevelFilter,
        format_function: FormatFunction,
    ) -> FileLogWriter {
        let state_handle = match state.config().write_mode.effective_write_mode() {
            EffectiveWriteMode::Direct
            | EffectiveWriteMode::BufferAndFlushWith(_)
            | EffectiveWriteMode::BufferDontFlushWith(_) => {
                StateHandle::new_sync(state, format_function)
            }

            #[cfg(feature = "async")]
            EffectiveWriteMode::AsyncWith {
                pool_capa,
                message_capa,
                flush_interval: _,
                o_core_id,
            } => StateHandle::new_async(pool_capa, message_capa, state, format_function, o_core_id),
        };

        FileLogWriter {
            state_handle,
            max_log_level,
        }
    }

    /// Instantiates a builder for `FileLogWriter`.
    #[must_use]
    pub fn builder(file_spec: FileSpec) -> FileLogWriterBuilder {
        FileLogWriterBuilder::new(file_spec)
    }

    /// Returns a reference to its configured output format function.
    #[must_use]
    #[inline]
    pub fn format(&self) -> FormatFunction {
        self.state_handle.format_function()
    }

    pub(crate) fn plain_write(&self, buffer: &[u8]) -> std::result::Result<usize, std::io::Error> {
        self.state_handle.plain_write(buffer)
    }

    /// Replaces parts of the configuration of the file log writer.
    ///
    /// Note that the write mode and the format function cannot be reset and
    /// that the provided `FileLogWriterBuilder` must have the same values for these as the
    /// current `FileLogWriter`.
    ///
    /// # Errors
    ///
    /// `FlexiLoggerError::Reset` if a reset was tried with a different write mode.
    ///
    /// `FlexiLoggerError::Io` if the specified path doesn't work.
    ///
    /// `FlexiLoggerError::OutputBadDirectory` if the specified path is not a directory.
    ///
    /// `FlexiLoggerError::Poison` if some mutex is poisoned.
    pub fn reset(&self, flwb: &FileLogWriterBuilder) -> Result<(), FlexiLoggerError> {
        self.state_handle.reset(flwb)
    }

    /// Returns the current configuration of the file log writer
    ///
    /// # Errors
    ///
    /// `FlexiLoggerError::Poison` if some mutex is poisoned.
    pub fn config(&self) -> Result<FileLogWriterConfig, FlexiLoggerError> {
        self.state_handle.config()
    }

    /// Makes the `FileLogWriter` re-open the current log file.
    ///
    /// `FileLogWriter` expects that nobody else modifies the file to which it writes,
    /// and offers capabilities to rotate, compress, and clean up log files.
    ///
    /// However, if you use tools like linux' `logrotate`
    /// to rename or delete the current output file, you need to inform the `FileLogWriter` about
    /// such actions by calling this method. Otherwise the `FileLogWriter` will not stop
    /// writing to the renamed or even deleted file!
    ///
    /// # Example
    ///
    /// `logrotate` e.g. can be configured to send a `SIGHUP` signal to your program. You should
    /// handle `SIGHUP` in your program explicitly,
    /// e.g. using a crate like [`ctrlc`](https://docs.rs/ctrlc/latest/ctrlc/),
    /// and call this function from the registered signal handler.
    ///
    /// # Errors
    ///
    /// `FlexiLoggerError::Poison` if some mutex is poisoned.
    pub fn reopen_outputfile(&self) -> Result<(), FlexiLoggerError> {
        self.state_handle.reopen_outputfile()
    }

    /// Trigger an extra log file rotation.
    ///
    /// Does nothing if rotation is not configured.
    ///
    /// # Errors
    ///
    /// `FlexiLoggerError::Poison` if some mutex is poisoned.
    ///
    /// IO errors.
    pub fn rotate(&self) -> Result<(), FlexiLoggerError> {
        self.state_handle.rotate()
    }

    /// Returns the list of existing log files according to the current `FileSpec`.
    ///
    /// The list includes the current log file and the compressed files, if they exist.
    ///
    /// # Errors
    ///
    /// `FlexiLoggerError::Poison` if some mutex is poisoned.
    pub fn existing_log_files(
        &self,
        selector: &LogfileSelector,
    ) -> Result<Vec<PathBuf>, FlexiLoggerError> {
        self.state_handle.existing_log_files(selector)
    }
}

impl LogWriter for FileLogWriter {
    #[inline]
    fn write(&self, now: &mut DeferredNow, record: &Record) -> std::io::Result<()> {
        if record.level() <= self.max_log_level {
            self.state_handle.write(now, record)
        } else {
            Ok(())
        }
    }

    #[inline]
    fn flush(&self) -> std::io::Result<()> {
        self.state_handle.flush()
    }

    #[inline]
    fn max_log_level(&self) -> log::LevelFilter {
        self.max_log_level
    }

    fn reopen_output(&self) -> Result<(), FlexiLoggerError> {
        self.reopen_outputfile()
    }

    fn rotate(&self) -> Result<(), FlexiLoggerError> {
        self.state_handle.rotate()
    }

    fn validate_logs(&self, expected: &[(&'static str, &'static str, &'static str)]) {
        self.state_handle.validate_logs(expected);
    }

    fn shutdown(&self) {
        self.state_handle.shutdown();
    }
}

impl Drop for FileLogWriter {
    fn drop(&mut self) {
        self.shutdown();
    }
}

#[cfg(test)]
mod test {
    #[cfg(feature = "async")]
    use crate::ZERO_DURATION;
    use crate::{writers::LogWriter, Cleanup, Criterion, DeferredNow, FileSpec, Naming, WriteMode};
    use chrono::Local;
    use std::ops::Add;
    use std::path::{Path, PathBuf};
    use std::time::Duration;

    const DIRECTORY: &str = r"log_files/rotate";
    const ONE: &str = "ONE";
    const TWO: &str = "TWO";
    const THREE: &str = "THREE";
    const FOUR: &str = "FOUR";
    const FIVE: &str = "FIVE";
    const SIX: &str = "SIX";
    const SEVEN: &str = "SEVEN";
    const EIGHT: &str = "EIGHT";
    const NINE: &str = "NINE";

    const FMT_DASHES_U_DASHES: &str = "%Y-%m-%d_%H-%M-%S";

    #[test]
    fn test_rotate_no_append_numbers() {
        // we use timestamp as discriminant to allow repeated runs
        let ts =
            String::from("false-numbers-") + &Local::now().format(FMT_DASHES_U_DASHES).to_string();
        let naming = Naming::Numbers;

        // ensure we start with -/-/-
        assert!(not_exists("00000", &ts));
        assert!(not_exists("00001", &ts));
        assert!(not_exists("CURRENT", &ts));

        // ensure this produces -/-/ONE
        write_loglines(false, naming, &ts, &[ONE]);
        assert!(not_exists("00000", &ts));
        assert!(not_exists("00001", &ts));
        assert!(contains("CURRENT", &ts, ONE));

        // ensure this produces ONE/-/TWO
        write_loglines(false, naming, &ts, &[TWO]);
        assert!(contains("00000", &ts, ONE));
        assert!(not_exists("00001", &ts));
        assert!(contains("CURRENT", &ts, TWO));

        // ensure this also produces ONE/-/TWO
        remove("CURRENT", &ts);
        assert!(not_exists("CURRENT", &ts));
        write_loglines(false, naming, &ts, &[TWO]);
        assert!(contains("00000", &ts, ONE));
        assert!(not_exists("00001", &ts));
        assert!(contains("CURRENT", &ts, TWO));

        // ensure this produces ONE/TWO/THREE
        write_loglines(false, naming, &ts, &[THREE]);
        assert!(contains("00000", &ts, ONE));
        assert!(contains("00001", &ts, TWO));
        assert!(contains("CURRENT", &ts, THREE));
    }

    #[test]
    fn test_rotate_with_append_numbers() {
        // we use timestamp as discriminant to allow repeated runs
        let ts =
            String::from("true-numbers-") + &Local::now().format(FMT_DASHES_U_DASHES).to_string();
        let naming = Naming::Numbers;

        // ensure we start with -/-/-
        assert!(not_exists("00000", &ts));
        assert!(not_exists("00001", &ts));
        assert!(not_exists("CURRENT", &ts));

        // ensure this produces 12/-/3
        write_loglines(true, naming, &ts, &[ONE, TWO, THREE]);
        assert!(contains("00000", &ts, ONE));
        assert!(contains("00000", &ts, TWO));
        assert!(not_exists("00001", &ts));
        assert!(contains("CURRENT", &ts, THREE));

        // ensure this produces 12/34/56
        write_loglines(true, naming, &ts, &[FOUR, FIVE, SIX]);
        assert!(contains("00000", &ts, ONE));
        assert!(contains("00000", &ts, TWO));
        assert!(contains("00001", &ts, THREE));
        assert!(contains("00001", &ts, FOUR));
        assert!(contains("CURRENT", &ts, FIVE));
        assert!(contains("CURRENT", &ts, SIX));

        // ensure this also produces 12/34/56
        remove("CURRENT", &ts);
        remove("00001", &ts);
        assert!(not_exists("CURRENT", &ts));
        write_loglines(true, naming, &ts, &[THREE, FOUR, FIVE, SIX]);
        assert!(contains("00000", &ts, ONE));
        assert!(contains("00000", &ts, TWO));
        assert!(contains("00001", &ts, THREE));
        assert!(contains("00001", &ts, FOUR));
        assert!(contains("CURRENT", &ts, FIVE));
        assert!(contains("CURRENT", &ts, SIX));

        // ensure this produces 12/34/56/78/9
        write_loglines(true, naming, &ts, &[SEVEN, EIGHT, NINE]);
        assert!(contains("00002", &ts, FIVE));
        assert!(contains("00002", &ts, SIX));
        assert!(contains("00003", &ts, SEVEN));
        assert!(contains("00003", &ts, EIGHT));
        assert!(contains("CURRENT", &ts, NINE));
    }

    #[test]
    fn test_rotate_no_append_timestamps() {
        // we use timestamp as discriminant to allow repeated runs
        let ts_discr = String::from("false-timestamps-")
            + &Local::now().format(FMT_DASHES_U_DASHES).to_string();

        let basename = String::from(DIRECTORY).add("/").add(
            &Path::new(&std::env::args().next().unwrap())
                .file_stem().unwrap(/*cannot fail*/)
                .to_string_lossy(),
        );
        let naming = Naming::Timestamps;

        println!("{} ensure we start with -/-/-", chrono::Local::now());
        assert!(list_rotated_files(&basename, &ts_discr).is_empty());
        assert!(not_exists("CURRENT", &ts_discr));

        println!("{} ensure this produces -/-/ONE", chrono::Local::now());
        write_loglines(false, naming, &ts_discr, &[ONE]);
        assert!(list_rotated_files(&basename, &ts_discr).is_empty());
        assert!(contains("CURRENT", &ts_discr, ONE));

        std::thread::sleep(Duration::from_secs(2));
        println!("{} ensure this produces ONE/-/TWO", chrono::Local::now());
        write_loglines(false, naming, &ts_discr, &[TWO]);
        assert_eq!(list_rotated_files(&basename, &ts_discr).len(), 1);
        assert!(contains("CURRENT", &ts_discr, TWO));

        std::thread::sleep(Duration::from_secs(2));
        println!(
            "{} ensure this produces ONE/TWO/THREE",
            chrono::Local::now()
        );
        write_loglines(false, naming, &ts_discr, &[THREE]);
        assert_eq!(list_rotated_files(&basename, &ts_discr).len(), 2);
        assert!(contains("CURRENT", &ts_discr, THREE));
    }

    #[test]
    fn test_rotate_with_append_timestamps() {
        // we use timestamp as discriminant to allow repeated runs
        let ts = String::from("true-timestamps-")
            + &Local::now().format(FMT_DASHES_U_DASHES).to_string();

        let basename = String::from(DIRECTORY).add("/").add(
            &Path::new(&std::env::args().next().unwrap())
                .file_stem().unwrap(/*cannot fail*/)
                .to_string_lossy(),
        );
        let naming = Naming::Timestamps;

        // ensure we start with -/-/-
        assert!(list_rotated_files(&basename, &ts).is_empty());
        assert!(not_exists("CURRENT", &ts));

        // ensure this produces 12/-/3
        write_loglines(true, naming, &ts, &[ONE, TWO, THREE]);
        assert_eq!(list_rotated_files(&basename, &ts).len(), 1);
        assert!(contains("CURRENT", &ts, THREE));

        // ensure this produces 12/34/56
        write_loglines(true, naming, &ts, &[FOUR, FIVE, SIX]);
        assert!(contains("CURRENT", &ts, FIVE));
        assert!(contains("CURRENT", &ts, SIX));
        assert_eq!(list_rotated_files(&basename, &ts).len(), 2);

        // ensure this produces 12/34/56/78/9
        write_loglines(true, naming, &ts, &[SEVEN, EIGHT, NINE]);
        assert_eq!(list_rotated_files(&basename, &ts).len(), 4);
        assert!(contains("CURRENT", &ts, NINE));
    }

    #[test]
    fn issue_38() {
        const NUMBER_OF_FILES: usize = 5;
        const NUMBER_OF_PSEUDO_PROCESSES: usize = 11;
        const ISSUE_38: &str = "issue_38";
        const LOG_FOLDER: &str = "log_files/issue_38";

        for _ in 0..NUMBER_OF_PSEUDO_PROCESSES {
            let flwb = crate::writers::file_log_writer::FileLogWriter::builder(
                FileSpec::default()
                    .directory(LOG_FOLDER)
                    .discriminant(ISSUE_38),
            )
            .rotate(
                Criterion::Size(500),
                Naming::Timestamps,
                Cleanup::KeepLogFiles(NUMBER_OF_FILES),
            )
            .o_append(false);

            #[cfg(feature = "async")]
            let flwb = flwb.write_mode(WriteMode::AsyncWith {
                pool_capa: 5,
                message_capa: 400,
                flush_interval: ZERO_DURATION,
            });

            let flw = flwb.try_build().unwrap();

            // write some lines, but not enough to rotate
            for i in 0..4 {
                flw.write(
                    &mut DeferredNow::new(),
                    &log::Record::builder()
                        .args(format_args!("{i}"))
                        .level(log::Level::Error)
                        .target("myApp")
                        .file(Some("server.rs"))
                        .line(Some(144))
                        .module_path(Some("server"))
                        .build(),
                )
                .unwrap();
            }
            flw.flush().ok();
        }

        // give the cleanup thread a short moment of time
        std::thread::sleep(Duration::from_millis(50));

        let fn_pattern = String::with_capacity(180)
            .add(
                &String::from(LOG_FOLDER).add("/").add(
                    &Path::new(&std::env::args().next().unwrap())
            .file_stem().unwrap(/*cannot fail*/)
            .to_string_lossy(),
                ),
            )
            .add("_")
            .add(ISSUE_38)
            .add("_r[0-9]*")
            .add(".log");

        assert_eq!(
            glob::glob(&fn_pattern)
                .unwrap()
                .filter_map(Result::ok)
                .count(),
            NUMBER_OF_FILES
        );
    }

    #[test]
    fn test_reset() {
        #[cfg(not(feature = "async"))]
        let write_mode = WriteMode::BufferDontFlushWith(4);
        #[cfg(feature = "async")]
        let write_mode = WriteMode::AsyncWith {
            pool_capa: 7,
            message_capa: 8,
            flush_interval: ZERO_DURATION,
        };
        let flw = super::FileLogWriter::builder(
            FileSpec::default()
                .directory(DIRECTORY)
                .discriminant("test_reset-1"),
        )
        .rotate(
            Criterion::Size(28),
            Naming::Numbers,
            Cleanup::KeepLogFiles(20),
        )
        .append()
        .write_mode(write_mode)
        .try_build()
        .unwrap();

        flw.write(
            &mut DeferredNow::new(),
            &log::Record::builder()
                .args(format_args!("{}", "test_reset-1"))
                .level(log::Level::Error)
                .target("test_reset")
                .file(Some("server.rs"))
                .line(Some(144))
                .module_path(Some("server"))
                .build(),
        )
        .unwrap();

        println!("FileLogWriter {flw:?}");

        flw.reset(
            &super::FileLogWriter::builder(
                FileSpec::default()
                    .directory(DIRECTORY)
                    .discriminant("test_reset-2"),
            )
            .rotate(
                Criterion::Size(28),
                Naming::Numbers,
                Cleanup::KeepLogFiles(20),
            )
            .write_mode(write_mode),
        )
        .unwrap();
        flw.write(
            &mut DeferredNow::new(),
            &log::Record::builder()
                .args(format_args!("{}", "test_reset-2"))
                .level(log::Level::Error)
                .target("test_reset")
                .file(Some("server.rs"))
                .line(Some(144))
                .module_path(Some("server"))
                .build(),
        )
        .unwrap();
        println!("FileLogWriter {flw:?}");

        assert!(flw
            .reset(
                &super::FileLogWriter::builder(
                    FileSpec::default()
                        .directory(DIRECTORY)
                        .discriminant("test_reset-3"),
                )
                .rotate(
                    Criterion::Size(28),
                    Naming::Numbers,
                    Cleanup::KeepLogFiles(20),
                )
                .write_mode(WriteMode::Direct),
            )
            .is_err());
    }

    #[test]
    fn test_max_log_level() {
        let spec = FileSpec::default()
            .directory(DIRECTORY)
            .discriminant("test_max_log_level-1")
            .suppress_basename()
            .suppress_timestamp();
        let flw = super::FileLogWriter::builder(spec.clone())
            .max_level(log::LevelFilter::Warn)
            .write_mode(WriteMode::Direct)
            .try_build()
            .unwrap();

        let write_msg = |level, msg| {
            flw.write(
                &mut DeferredNow::new(),
                &log::Record::builder()
                    .args(format_args!("{msg}"))
                    .level(level)
                    .target("test_max_log_level")
                    .file(Some("server.rs"))
                    .line(Some(144))
                    .module_path(Some("server"))
                    .build(),
            )
            .unwrap();
        };

        write_msg(log::Level::Trace, "trace message");
        write_msg(log::Level::Debug, "debug message");
        write_msg(log::Level::Info, "info message");
        write_msg(log::Level::Warn, "warn message");
        write_msg(log::Level::Error, "error message");

        let log_contents = std::fs::read_to_string(spec.as_pathbuf(None)).unwrap();

        assert!(!log_contents.contains("trace message"));
        assert!(!log_contents.contains("debug message"));
        assert!(!log_contents.contains("info message"));
        assert!(log_contents.contains("warn message"));
        assert!(log_contents.contains("error message"));
    }

    fn remove(s: &str, discr: &str) {
        std::fs::remove_file(get_hackyfilepath(s, discr)).unwrap();
    }

    fn not_exists(s: &str, discr: &str) -> bool {
        !get_hackyfilepath(s, discr).exists()
    }

    fn contains(s: &str, discr: &str, text: &str) -> bool {
        match std::fs::read_to_string(get_hackyfilepath(s, discr)) {
            Err(_) => false,
            Ok(s) => s.contains(text),
        }
    }

    fn get_hackyfilepath(infix: &str, discr: &str) -> Box<Path> {
        let arg0 = std::env::args().next().unwrap();
        let mut s_filename = Path::new(&arg0)
            .file_stem()
            .unwrap()
            .to_string_lossy()
            .to_string();
        s_filename += "_";
        s_filename += discr;
        s_filename += "_r";
        s_filename += infix;
        s_filename += ".log";
        let mut path_buf = PathBuf::from(DIRECTORY);
        path_buf.push(s_filename);
        path_buf.into_boxed_path()
    }

    fn write_loglines(append: bool, naming: Naming, discr: &str, texts: &[&'static str]) {
        let flw = get_file_log_writer(append, naming, discr);
        for text in texts {
            flw.write(
                &mut DeferredNow::new(),
                &log::Record::builder()
                    .args(format_args!("{text}"))
                    .level(log::Level::Error)
                    .target("myApp")
                    .file(Some("server.rs"))
                    .line(Some(144))
                    .module_path(Some("server"))
                    .build(),
            )
            .unwrap();
        }
    }

    fn get_file_log_writer(
        append: bool,
        naming: Naming,
        discr: &str,
    ) -> crate::writers::FileLogWriter {
        super::FileLogWriter::builder(FileSpec::default().directory(DIRECTORY).discriminant(discr))
            .rotate(
                Criterion::Size(if append { 28 } else { 10 }),
                naming,
                Cleanup::Never,
            )
            .o_append(append)
            .try_build()
            .unwrap()
    }

    fn list_rotated_files(basename: &str, discr: &str) -> Vec<String> {
        let fn_pattern = String::with_capacity(180)
            .add(basename)
            .add("_")
            .add(discr)
            .add("_r2[0-9]*") // Year 3000 problem!!!
            .add(".log");

        glob::glob(&fn_pattern)
            .unwrap()
            .map(|r| r.unwrap().into_os_string().to_string_lossy().to_string())
            .collect()
    }
}
