From 71817230d1273907b7e895fb22b69e9ba877f48e Mon Sep 17 00:00:00 2001
From: "Yann Esposito (Yogsototh)" <yann.esposito@gmail.com>
Date: Tue, 9 Apr 2024 22:38:00 +0200
Subject: [PATCH] wip to detect cycles

---
 src/ydn/core.clj | 74 +++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 70 insertions(+), 4 deletions(-)

diff --git a/src/ydn/core.clj b/src/ydn/core.clj
index 1768cb0..8a73251 100644
--- a/src/ydn/core.clj
+++ b/src/ydn/core.clj
@@ -5,8 +5,11 @@
             [clojure.walk :refer [prewalk]])
   (:refer-clojure :exclude [read read-string]))
 
+(def keyword-re-str
+  ":ref([.][^/\\s}]*/|/)[^/.\\s}]*")
+
 (def keyword-re
-  #":ref([.][^/\s]*/|/)[^/.\s]*$")
+  (re-pattern (str "^" keyword-re-str "$")))
 
 (defn ref-kw
   "returns nil if the string does not matches a valid ref keyword format."
@@ -35,11 +38,16 @@
     (name-or-str
      (get-in! edn (key-to-path s)))))
 
+(def interpolation-re
+  (re-pattern
+   (str "\\$\\{(" keyword-re-str ")\\}")))
+
 (defn apply-interpolation
   [s edn]
-  (string/replace s #"\$\{([^}]*)\}" (fn [m]
-                                       (or (to-ref edn (second m))
-                                           (first m)))))
+  (string/replace s
+                  interpolation-re
+                  (fn [m] (or (to-ref edn (second m))
+                              (first m)))))
 
 (defn root-namespace [kw]
   (some-> kw namespace (string/split #"[.]") first))
@@ -72,6 +80,64 @@
            (take ydn-fix-point-limit (iterate apply-self-refs edn))
            [::error])))
 
+(defn extract-refs
+  [s]
+  (let [matcher (re-matcher interpolation-re s)]
+    (->> (repeatedly #(re-find matcher))
+         (take-while some?)
+         (mapv (comp key-to-path second)))))
+
+(comment
+  (extract-refs "${:ref.pg/scheme}://${:ref.pg/domain}:${:ref.pg/port}")
+  (extract-refs "${:ref.pg/scheme}")
+  )
+
+(defn path-to-kw
+  [p]
+  (if (> (count p) 1)
+    (keyword (string/join "." (mapv name (pop p)))
+             (name (last p)))
+    (keyword (name (last p)))
+    ))
+
+(defn rec-deps-list
+  [prefix-path edn]
+  (assert (vector? prefix-path))
+  (apply concat
+   (for [[k v] edn]
+     (cond
+       (keyword? v) (when-let [kw (ref-kw (str v))]
+                      [{(path-to-kw (conj prefix-path k))
+                        (keyword (string/replace  kw #"^:ref[./]" ""))
+                        }])
+       (string? v) (let [targets (extract-refs v)]
+                     (for [target targets]
+                       {(path-to-kw (conj prefix-path k))
+                        (path-to-kw target)}))
+       (map? v) (apply concat (rec-deps-list (conj prefix-path k) v))
+       :else nil))))
+
+(defn deps-list
+  [edn]
+  (assert (map? edn) "the edn config should be an hash-map")
+  (into {}
+        (rec-deps-list [] edn)))
+
+(comment
+  (deps-list {:x :ref/y
+              :y :ref/x
+              :foo {:bar :ref/x}
+              :z "${:ref/x} & ${:ref/y}"})
+
+  )
+
+(defn detect-cycles
+  [g]
+  :TODO
+  )
+
+
+
 (defn read-string-with-conf
   [{:keys [ydn-fix-point-limit] :as _conf} & args]
   (fix-apply-self-refs