From 8fa46074562f06e24ce86c2872f5814b758d225c Mon Sep 17 00:00:00 2001
From: Bauke <me@bauke.xyz>
Date: Wed, 21 Sep 2022 23:37:17 +0200
Subject: [PATCH] Add --url to figure out RSS feeds from store pages.

---
 Cargo.lock     | 27 +++++++++++++++++++++++++++
 Cargo.toml     |  1 +
 source/main.rs | 31 +++++++++++++++++++++++++++++--
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 8a13570..429e118 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -17,6 +17,15 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4f55bd91a0978cbfd91c457a164bab8b4001c833b7f323132c0a4e1922dd44e"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -446,6 +455,23 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "regex"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c4eb3267174b8c6c2f654116623910a0fef09c4753f8dd83db29c48a0df988b"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3f87b73ce11b1619a3c6332f45341e0047173771e8b8b73f87bfeefb7b56244"
+
 [[package]]
 name = "ring"
 version = "0.16.20"
@@ -532,6 +558,7 @@ dependencies = [
  "color-eyre",
  "indicatif",
  "opml",
+ "regex",
  "ureq",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index 4d547a5..c5f4db2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ path = "source/main.rs"
 color-eyre = "0.6.2"
 indicatif = "0.17.1"
 opml = "1.1.4"
+regex = "1.6.0"
 ureq = "2.5.0"
 
 [dependencies.clap]
diff --git a/source/main.rs b/source/main.rs
index b4b7703..e1feb10 100644
--- a/source/main.rs
+++ b/source/main.rs
@@ -13,6 +13,7 @@ use {
   clap::Parser,
   color_eyre::{install, Result},
   indicatif::{ProgressBar, ProgressStyle},
+  regex::Regex,
 };
 
 /// CLI arguments struct using [`clap`]'s Derive API.
@@ -34,6 +35,10 @@ pub struct Args {
   /// Verify potential feeds by downloading them and checking if they return XML.
   #[clap(short, long)]
   pub verify: bool,
+
+  /// A game's store URL, can be used multiple times.
+  #[clap(long)]
+  pub url: Vec<String>,
 }
 
 /// A simple feed struct.
@@ -54,6 +59,9 @@ pub struct Feed {
 pub enum FeedOption {
   /// `-a, --appid <APPID>` was used.
   AppID,
+
+  /// `--url <URL>` was used.
+  Url,
 }
 
 fn main() -> Result<()> {
@@ -68,20 +76,39 @@ fn main() -> Result<()> {
   let mut potential_feeds = vec![];
   let mut feeds_to_output = vec![];
 
+  let store_url_regex =
+    Regex::new(r"(?i)^https?://store.steampowered.com/app/(?P<appid>\d+)")?;
+
   for appid in args.appid {
     potential_feeds.push(Feed {
       option: FeedOption::AppID,
       text: Some(format!("Steam AppID {appid}")),
-      url: format!("https://steamcommunity.com/games/{appid}/rss/"),
+      url: appid_to_rss_url(appid),
     });
   }
 
+  for url in args.url {
+    let appid = store_url_regex
+      .captures(&url)
+      .and_then(|captures| captures.name("appid"))
+      .and_then(|appid_match| appid_match.as_str().parse::<usize>().ok());
+    if let Some(appid) = appid {
+      potential_feeds.push(Feed {
+        option: FeedOption::Url,
+        text: Some(format!("Steam AppID {appid}")),
+        url: appid_to_rss_url(appid),
+      });
+    }
+  }
+
   if args.verify {
     let progress = ProgressBar::new(potential_feeds.len().try_into()?)
       .with_style(ProgressStyle::with_template("Verifying {pos}/{len} {bar}")?);
 
     for potential_feed in potential_feeds {
-      let potential_feed = if potential_feed.option == FeedOption::AppID {
+      let potential_feed = if [FeedOption::AppID, FeedOption::Url]
+        .contains(&potential_feed.option)
+      {
         let response = ureq_agent.get(&potential_feed.url).call()?;
         if response.content_type() == "text/xml" {
           let body = response.into_string()?;