freeswitch-log-parser 0.17.1

//! Which log files a directory holds, and which of them a date window can
//! reach.

use std::fs;
use std::path::{Path, PathBuf};

use anyhow::Context;
use freeswitch_log_parser::{log_rotation_stamp, stamp_lower_bound, stamp_upper_bound};

pub struct LogFile {
    pub path: PathBuf,
    pub date: Option<String>,
    pub size: u64,
}

pub fn discover_log_files(dir: &Path) -> anyhow::Result<Vec<LogFile>> {
    let mut files = Vec::new();
    let listing =
        fs::read_dir(dir).with_context(|| format!("listing log directory {}", dir.display()))?;
    for entry in listing {
        let entry = entry.with_context(|| format!("reading an entry of {}", dir.display()))?;
        let path = entry.path();
        let name = match path.file_name().and_then(|n| n.to_str()) {
            Some(n) => n.to_string(),
            None => continue,
        };
        if !name.starts_with("freeswitch.log") {
            continue;
        }
        let meta = entry
            .metadata()
            .with_context(|| format!("stat {}", path.display()))?;
        if !meta.is_file() {
            continue;
        }
        let date = log_rotation_stamp(&name).map(str::to_string);
        files.push(LogFile {
            path,
            date,
            size: meta.len(),
        });
    }
    files.sort_by(|a, b| a.date.cmp(&b.date));
    Ok(files)
}

/// A rotation stamp is the *end* of the span a file holds, so each bound reaches
/// one file past itself, and the unstamped active log is never excluded.
pub fn filter_files_by_date<'a>(
    files: &'a [LogFile],
    from: Option<&str>,
    until: Option<&str>,
) -> Vec<&'a LogFile> {
    let from_norm = from.map(stamp_lower_bound);
    let until_norm = until.map(stamp_upper_bound);

    files
        .iter()
        .enumerate()
        .filter(|(i, f)| {
            let Some(ref file_date) = f.date else {
                return true;
            };

            if let Some(ref until) = until_norm {
                if file_date.as_str() > until.as_str() && *i > 0 {
                    if let Some(ref prev_date) = files[*i - 1].date {
                        if prev_date.as_str() > until.as_str() {
                            return false;
                        }
                    }
                }
            }

            if let Some(ref from) = from_norm {
                if file_date.as_str() < from.as_str() {
                    if *i + 1 < files.len() {
                        if let Some(ref next_date) = files[*i + 1].date {
                            if next_date.as_str() >= from.as_str() {
                                return true;
                            }
                        } else {
                            return true;
                        }
                    }
                    return false;
                }
            }

            true
        })
        .map(|(_, f)| f)
        .collect()
}

#[cfg(test)]
mod tests {
    use super::*;

    /// These fixtures rotate daily at midnight.
    fn day_files(days: &[Option<&str>]) -> Vec<LogFile> {
        days.iter()
            .map(|d| LogFile {
                path: PathBuf::from("freeswitch.log"),
                date: d.map(|d| format!("2026-03-{d}-00-00-00")),
                size: 0,
            })
            .collect()
    }

    fn selected(files: &[LogFile], from: Option<&str>, until: Option<&str>) -> Vec<String> {
        filter_files_by_date(files, from, until)
            .iter()
            .map(|f| match &f.date {
                Some(d) => d[8..10].to_string(),
                None => "live".to_string(),
            })
            .collect()
    }

    #[test]
    fn unbounded_selection_keeps_everything() {
        let files = day_files(&[Some("08"), Some("09"), None]);
        assert_eq!(selected(&files, None, None), ["08", "09", "live"]);
    }

    #[test]
    fn from_reaches_back_one_file() {
        // Entries from the 10th live in the file stamped the 11th, and the file
        // stamped the 10th holds the small hours the 9th's rotation left behind.
        let files = day_files(&[Some("08"), Some("09"), Some("10"), Some("11")]);
        assert_eq!(
            selected(&files, Some("2026-03-10"), None),
            ["09", "10", "11"]
        );
    }

    #[test]
    fn from_drops_files_that_end_before_the_next_one_starts() {
        let files = day_files(&[Some("08"), Some("09"), Some("10"), Some("11")]);
        assert_eq!(selected(&files, Some("2026-03-11"), None), ["10", "11"]);
    }

    #[test]
    fn until_keeps_the_file_the_bound_falls_inside() {
        // The 10th's file spans the 9th, so an `until` on the 9th still needs it;
        // the 11th's cannot hold anything that early.
        let files = day_files(&[Some("08"), Some("09"), Some("10"), Some("11")]);
        assert_eq!(
            selected(&files, None, Some("2026-03-09")),
            ["08", "09", "10"]
        );
    }

    #[test]
    fn the_active_log_is_never_excluded_by_date() {
        // It has no stamp, so nothing can prove it lacks entries in the window.
        let files = day_files(&[Some("08"), Some("09"), None]);
        assert_eq!(
            selected(&files, None, Some("2026-03-08")),
            ["08", "09", "live"]
        );
        assert_eq!(selected(&files, Some("2026-03-20"), None), ["09", "live"]);
    }

    #[test]
    fn a_month_bound_spans_the_whole_month() {
        let files = day_files(&[Some("08"), Some("09")]);
        assert_eq!(
            selected(&files, Some("2026-03"), Some("2026-03")),
            ["08", "09"]
        );
        assert!(selected(&files, Some("2026-04"), Some("2026-04")).is_empty());
    }
}