Improve logging (#117)

* add log formats and ansi handling

* update readme

* fix help indentation

* add `no-color` option

* rename default formatter

* add verbose option

* make fields depend on debug mode

* update help message

* improve control of color output

* improve log messages

Cargo.toml

@@ -43,7 +43,16 @@ rss = { version = "2", default-features = false }
 atom_syndication = { version = "0.12", default-features = false }
 chrono = { version = "0.4", features = ["serde"], default-features = false }
 tracing = "0.1"
-tracing-subscriber = "0.3"
+tracing-subscriber = { version = "0.3", features = [
+    "std",
+    "fmt",
+    "tracing-log",
+    "smallvec",
+    "parking_lot",
+    "env-filter",
+    "ansi",
+    "json",
+], default-features = false }
 thiserror = "1"
 humantime-serde = "1"
 toml = "0.7"

README.md

@@ -46,9 +46,12 @@ See [GitHub container package](https://github.com/morphy2k/rss-forwarder/pkgs/co
 USAGE: rss-forwarder [OPTIONS] <CONFIG_FILE>
 
 OPTIONS:
---debug             Enables debug mode
--h, --help          Show help information
--v, --version       Show version info
+  -f, --format <FORMAT>  Log format: full, pretty, compact, json (default: full)
+  --color <WHEN>         Colorize output: auto, always, never (default: auto)
+  --debug                Enables debug mode
+  --verbose              Enables verbose mode
+  -h, --help             Show this help message
+  -v, --version          Show version information
 ```
 
 [Examples](example)

src/feed/mod.rs

@@ -6,6 +6,8 @@ use self::item::{FeedItem, Item, Source};
 
 use std::{cmp::Reverse, io::BufRead};
 
+use tracing::debug;
+
 #[derive(Debug)]
 pub enum Feed {
     Rss(rss::Channel),
@@ -24,10 +26,16 @@ impl<'a> Feed {
                     let feed = atom_syndication::Feed::read_from(reader)?;
                     Self::Atom(feed)
                 }
-                _ => return Err(e.into()),
+                _ => return Err(e)?,
             },
         };
 
+        debug!(
+            format = %if feed.is_rss() { "RSS" } else { "Atom" },
+            items = feed.items().len(),
+            "parsed feed"
+        );
+
         Ok(feed)
     }
 
@@ -72,4 +80,20 @@ impl<'a> Feed {
 
         items
     }
+
+    /// Returns `true` if the feed is [`Rss`].
+    ///
+    /// [`Rss`]: Feed::Rss
+    #[must_use]
+    pub fn is_rss(&self) -> bool {
+        matches!(self, Self::Rss(..))
+    }
+
+    /// Returns `true` if the feed is [`Atom`].
+    ///
+    /// [`Atom`]: Feed::Atom
+    #[must_use]
+    pub fn is_atom(&self) -> bool {
+        matches!(self, Self::Atom(..))
+    }
 }