From b6f5b9d08cbd85a1cf00f09e6b810d235d17c67f Mon Sep 17 00:00:00 2001
From: Alex Clarke <alex.j.tusa@gmail.com>
Date: Sat, 9 Nov 2024 16:18:43 -0700
Subject: [PATCH] feat: Added a new command to the main managarr CLI:
 tail-logs, to enable users to tail the Managarr logs without needing to know
 where the log file itself is located

---
 src/cli/mod.rs |  6 +++++
 src/main.rs    |  2 ++
 src/utils.rs   | 68 ++++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/src/cli/mod.rs b/src/cli/mod.rs
index 05854f0..66c6bb2 100644
--- a/src/cli/mod.rs
+++ b/src/cli/mod.rs
@@ -27,6 +27,12 @@ pub enum Command {
     #[arg(value_enum)]
     shell: Shell,
   },
+
+  #[command(about = "Tail Managarr logs")]
+  TailLogs {
+    #[arg(long, help = "Disable colored log output")]
+    no_color: bool,
+  },
 }
 
 pub trait CliCommandHandler<'a, 'b, T: Into<Command>> {
diff --git a/src/main.rs b/src/main.rs
index 18728cb..388286b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -30,6 +30,7 @@ use tokio::select;
 use tokio::sync::mpsc::Receiver;
 use tokio::sync::{mpsc, Mutex};
 use tokio_util::sync::CancellationToken;
+use utils::tail_logs;
 
 use crate::app::App;
 use crate::cli::Command;
@@ -124,6 +125,7 @@ async fn main() -> Result<()> {
         let mut cli = Cli::command();
         generate(shell, &mut cli, "managarr", &mut io::stdout())
       }
+      Command::TailLogs { no_color } => tail_logs(no_color).await,
     },
     None => {
       let app_nw = Arc::clone(&app);
diff --git a/src/utils.rs b/src/utils.rs
index ac37626..816f0fb 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -1,10 +1,14 @@
-use std::fs;
+use std::fs::{self, File};
+use std::io::{BufRead, BufReader, Seek, SeekFrom};
 use std::path::PathBuf;
+use std::process;
 
+use colored::Colorize;
 use log::LevelFilter;
 use log4rs::append::file::FileAppender;
 use log4rs::config::{Appender, Root};
 use log4rs::encode::pattern::PatternEncoder;
+use regex::Regex;
 
 #[cfg(test)]
 #[path = "utils_tests.rs"]
@@ -21,7 +25,6 @@ pub fn get_log_path() -> PathBuf {
 
   log_path.push("managarr");
 
-  // Create the directory if it doesn't exist
   if let Err(e) = fs::create_dir_all(&log_path) {
     eprintln!("Failed to create log directory: {:?}", e);
   }
@@ -58,3 +61,64 @@ pub fn convert_runtime(runtime: i64) -> (i64, i64) {
 
   (hours, minutes)
 }
+
+pub async fn tail_logs(no_color: bool) {
+  let re = Regex::new(r"^(?P<timestamp>\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3})\s+<(?P<opid>[^\s>]+)>\s+\[(?P<level>[A-Z]+)\]\s+(?P<logger>[^:]+):(?P<line>\d+)\s+-\s+(?P<message>.*)$").unwrap();
+  let file_path = get_log_path();
+  let file = File::open(&file_path).expect("Cannot open file");
+  let mut reader = BufReader::new(file);
+
+  if let Err(e) = reader.seek(SeekFrom::End(0)) {
+    eprintln!("Unable to tail log file: {e:?}");
+    process::exit(1);
+  };
+
+  let mut lines = reader.lines();
+
+  tokio::spawn(async move {
+    loop {
+      if let Some(Ok(line)) = lines.next() {
+        if no_color {
+          println!("{}", line);
+        } else {
+          let colored_line = colorize_log_line(&line, &re);
+          println!("{}", colored_line);
+        }
+      }
+    }
+  })
+  .await
+  .unwrap();
+}
+
+fn colorize_log_line(line: &str, re: &Regex) -> String {
+  if let Some(caps) = re.captures(line) {
+    let level = &caps["level"];
+    let message = &caps["message"];
+
+    let colored_message = match level {
+      "ERROR" => message.red(),
+      "WARN" => message.yellow(),
+      "INFO" => message.green(),
+      "DEBUG" => message.blue(),
+      _ => message.normal(),
+    };
+
+    let timestamp = &caps["timestamp"];
+    let opid = &caps["opid"];
+    let logger = &caps["logger"];
+    let line_number = &caps["line"];
+
+    format!(
+      "{} <{}> [{}] {}:{} - {}",
+      timestamp.white(),
+      opid.cyan(),
+      level.bold(),
+      logger.magenta(),
+      line_number.bold(),
+      colored_message
+    )
+  } else {
+    line.to_string()
+  }
+}