From 8374b452719e93105c72f156104be20a7204b749 Mon Sep 17 00:00:00 2001
From: SqrtMinusOne <thexcloud@gmail.com>
Date: Wed, 16 Mar 2022 11:49:22 +0300
Subject: [PATCH] feat: query the list of feeds

---
 elfeed-summary.el | 84 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

diff --git a/elfeed-summary.el b/elfeed-summary.el
index fa75a1d..5e0d467 100644
--- a/elfeed-summary.el
+++ b/elfeed-summary.el
@@ -28,6 +28,90 @@
 
 ;;; Code:
 (require 'elfeed)
+(require 'elfeed-db)
+(require 'seq)
+
+(cl-defun elfeed-summary--match-tag (query &key tags title url author title-meta)
+  (cond
+   ;; symbol
+   ((symbolp query) (member query tags))
+   ;; (title . "Title")
+   ;; (title . (rx "Title"))
+   ((eq (car query) 'title)
+    (or (and title
+             (string-match-p
+              (if (stringp (cdr query))
+                  (cdr query)
+                (eval (cdr query)))
+              title))
+        (and title-meta
+             (string-match-p
+              (if (stringp (cdr query))
+                  (cdr query)
+                (eval (cdr query)))
+              title-meta))))
+   ;; (author . "Author")
+   ;; (author . (rx "Author"))
+   ((eq (car query) 'author)
+    (and author
+         (string-match-p
+          (if (stringp (cdr query))
+              (cdr query)
+            (eval (cdr query)))
+          author)))
+   ;; (url . "URL")
+   ;; (url . (rx "URL"))
+   ((eq (car query) 'url)
+    (and url
+         (string-match-p
+          (if (stringp (cdr query))
+              (cdr query)
+            (eval (cdr query)))
+          url)))
+   ;; (and <query-1> <query-2> ... <query-n>)
+   ((eq (car query) 'and)
+    (seq-every-p
+     (lambda (query-elem)
+       (elfeed-summary--match-tag
+        query-elem
+        :tags tags
+        :title title
+        :title-meta title-meta
+        :url url
+        :author author))
+     (cdr query)))
+   ;; (or <query-1> <query-2> ... <query-n>)
+   ;; (<query-1> <query-2> ... <query-n>)
+   (t (seq-some
+       (lambda (query-elem)
+         (elfeed-summary--match-tag
+          query-elem
+          :tags tags
+          :title title
+          :title-meta title-meta
+          :url url
+          :author author))
+       (if (eq (car query) 'or)
+           (cdr query)
+         query)))))
+
+(defun elfeed-summary--get-feeds (query)
+  (cl-loop for feed in elfeed-feeds
+           for url = (car feed)
+           for tags = (cdr feed)
+           for feed = (elfeed-db-get-feed url)
+           if (elfeed-summary--match-tag
+               query
+               :tags tags
+               :title (elfeed-feed-title feed)
+               :title-meta (plist-get (elfeed-feed-meta feed) :title)
+               :url url
+               :author (plist-get (car (elfeed-feed-author feed)) :name))
+           collect feed))
+
+(elfeed-summary--get-feeds '(or (title . "Andrea")
+                                (author . "Bozhidar")
+                                (url . (rx "sacha"))))
 
 (provide 'elfeed-summary)
 ;;; elfeed-summary.el ends here