From f36f5be5d0727a940f9dda021947790c3a6f4231 Mon Sep 17 00:00:00 2001
From: Felisp <rspointer@post.cz>
Date: Sun, 24 Dec 2023 00:20:52 +0100
Subject: [PATCH] Make HTTP handler return feed and catch basic errors

---
 src/rss_thread_watch/feed_generator.clj | 50 ++++++++++++++++++++++---
 1 file changed, 44 insertions(+), 6 deletions(-)

diff --git a/src/rss_thread_watch/feed_generator.clj b/src/rss_thread_watch/feed_generator.clj
index 534629f..761e432 100644
--- a/src/rss_thread_watch/feed_generator.clj
+++ b/src/rss_thread_watch/feed_generator.clj
@@ -99,9 +99,47 @@
      rss-thread-watch.watcher.chod-threads-cache
      rss-thread-watch.core.CONFIG"
   [rqst]
-  {:status 200
-   ;; There shouldn't be any problems with this mime type but if there are
-   ;; replace with "text/xml", or even better, get RSS reader that is not utter shit
-   :header {"Content-Type" "application/rss+xml"}
-   :body "All pony here ^:)"})
-
+  (try (let [{{chod :chod :or {chod 60}
+               :as prms} :params
+              uri :uri} rqst
+             queries (if (vector? (prms "q")) (prms "q") [(prms "q")]) ; to always return vector
+             repeat? (prms "repeat")
+             real-chod (if (or (vector? chod)
+                               (< chod 60))
+                         94 chod) ;Never accept chod lower that 60 TODO: don't hardcode this
+             cache @watcher/chod-threads-cache
+             ]
+         ;; ====== Errors =====
+         ;; Something other than feed.xml requested
+         (when-not (s/ends-with? uri "feed.xml")
+           (throw (ex-info "404" {:status 404
+                                  :header {"Content-Type" "text/plain"}
+                                  :body "404 This server has nothing but /feed.xml"})))
+         ;; No querry specified - don't know what to search for
+         (when-not (prms "q")
+           (throw (ex-info "400" {:status 400
+                                  :header {"Content-Type" "text/plain"}
+                                  :body (str "400 You MUST specify query with one OR more'q=searchTerm' url parameter(s)\n\n\n"
+                                             "Exmple: '/feed.xml?q=pony&q=IWTCIRD' will show in your feed all threads with 'pony' or 'IWTCIRD'"
+                                             " in their title that are about to die.")})))
+         (when (empty? cache)
+           (throw (ex-info "503" {:status 503
+                                  :header {"Content-Type" "text/plain"}
+                                  :body (str "503 Service Unavailable\n"
+                                             "Cache is empty, cannot generate feed. Try again later, it may work.")})))
+         ;; ==== Everything good ====
+       ;; (println "RCVD: " rqst)
+       {:status 200
+        ;; There shouldn't be any problems with this mime type but if there are
+        ;; replace with "text/xml", or even better, get RSS reader that is not utter shit
+        :header {"Content-Type" "application/rss+xml"}
+        :body (generate-feed queries real-chod repeat? cache)})
+       (catch Exception e
+         ;; Ex-info has been crafted to match HTTP response body so we can send it
+         (if-let [caught (ex-data e)]   ;Tam bude ale vždycky ex-data myslím, to chce čekovat jestli t obsahuje nějaký klíč (body? at nemusí být nějaký extra)
+           caught                       ;We have custom crafted error
+           {:status 500                 ;Something else fucked up, we print what happened
+            :header {"Content-Type" "text/plain"}
+            :body (str "500 - Something fucked up while generating feed, If you decide to report it, please include url adress you used:\n"
+                       (ex-cause e) "\n"
+                       e)}))))