Add command line interface and refactor config handling

Introduced command line interface using Clap to handle update and last subcommands. Refactored configuration loading to use Confy and separated configurations into a new module. Enhanced error handling and debugging capabilities.

Author: geonaumov

src/main.rs

@@ -1,37 +1,21 @@
-// RSS to sqlite database collector
-
 mod modules {
     pub mod sql;
+    pub mod config;
 }
 
 use modules::sql::create_db;
 use modules::sql::insert_feed_items;
 use modules::sql::last;
+use modules::config::Config;
 
+use std::error::Error;
+use clap::{Arg, Command};
 use anyhow::{Context, Result};
+use env_logger;
 use env_logger::Builder;
-use log::{debug, info, warn, LevelFilter};
+use log::{debug, error, info, warn, LevelFilter};
 use reqwest::blocking;
 use rss::Channel;
-use serde::Deserialize;
-// use std::error::Error;
-use std::fs;
-
-#[derive(Deserialize)]
-struct FeedConfig {
-    dbfile: String,
-    feeds: Vec<String>,
-}
-
-fn load_config() -> Result<FeedConfig> {
-    debug!("Loading configuration");
-    let config_data =
-        fs::read_to_string("config.json").context("Failed to read configuration file")?;
-    debug!("Parsing configuration");
-    let config: FeedConfig =
-        serde_json::from_str(&config_data).context("Failed to parse configuration file")?;
-    Ok(config)
-}
 
 fn fetch_rss_feed(url: &str) -> Result<Channel> {
     debug!("Fetching RSS feed {}", url);
@@ -40,22 +24,64 @@ fn fetch_rss_feed(url: &str) -> Result<Channel> {
     Ok(channel)
 }
 
-fn main() -> Result<()> {
+fn main() -> Result<(), Box<dyn Error>> {
+    // Setup logger
     let mut builder = Builder::from_default_env();
     builder.filter_level(LevelFilter::Info);
     builder.init();
-    // let's go
-    info!("RSS feed collector");
-    warn!("Work in progress");
-    let config = load_config()?;
-    let conn = create_db(&config.dbfile)?;
-    info!("Processing {} feeds", config.feeds.len());
-    for feed in config.feeds.iter() {
-        let parsed_feed = fetch_rss_feed(feed).context("Failed to parse feed")?;
-        info!("{} items from {}", parsed_feed.items().len(), feed);
-        insert_feed_items(&conn, &parsed_feed).context("Failed to insert record")?;
+
+    // Setup command arguments
+    let matches = Command::new("RSS to SQLite")
+        .version("0.2.0")
+        .author("Geo Naumov <[email protected]>")
+        .about("A collector for RSS feeds written in Rust. Uses the SQLite database.")
+        .subcommand(Command::new("update").about("Update the feeds"))
+        .subcommand(Command::new("last").about("Print last news items"))
+        .arg(
+            Arg::new("debug")
+                .help("Turn on debugging information")
+                .short('d')
+                .long("debug")
+                .action(clap::ArgAction::SetTrue),
+        )
+        .get_matches();
+
+    // Debug flag
+    if matches.get_flag("debug") {
+        println!("Debugging mode is on");
+    }
+
+    // Match subcommands
+    match matches.subcommand() {
+        Some(("update", _)) => {
+            info!("Updating feeds...");
+            // Load configuration
+            debug!("Loading configuration");
+            let config: Config = confy::load("RSS2SQLite", None)?;
+            let conn = create_db(&config.dbfile);
+            info!("Processing {} feeds", config.feeds.len());
+            for feed in config.feeds.iter() {
+                let parsed_feed = fetch_rss_feed(feed).context("Failed to parse feed");
+                info!("Feed: {}", feed);
+                match &conn {
+                    Ok(ref conn) => {
+                        insert_feed_items(&conn, &parsed_feed.unwrap()).context("Failed to insert record")?;
+                    },
+                    Err(..) => {
+                        // return Err(anyhow::anyhow!("Failed to open database: {}", e));
+                        error!("Database error!");
+                    }
+                }
+            }
+        }
+        Some(("last", _)) => {
+            info!("Last news feeds...");
+            let config: Config = confy::load("RSS2SQLite", None)?;
+            let conn = create_db(&config.dbfile);
+            let _ = last(&conn.unwrap()).context("Failed to query the database")?;
+        }
+        _ => warn!("Subcommand is required"),
     }
-    let _ = last(&conn).context("Failed to query the database")?;
-    info!("Finished");
+    info!("Finished!");
     Ok(())
 }