start using db2 in view use-case

src/snippets/infra/api.clj

@@ -38,12 +38,7 @@
       {:status 200
        :body  (snippets.use-cases.view/view-snippets {:limit limit-num :skip skip-num})})
     {:status 200
-     :body  (snippets.use-cases.view/view-snippets)}))
-
-(defn handle-view-snippet [{params :query-params}]
-  (let [id  (get params "id")]
-    {:status 200
-     :body (snippets.use-cases.view/view-snippet id)}))
+     :body  (snippets.use-cases.view/view-snippets nil)}))
 
 (defn handle-delete-snippet [{params :query-params}]
   (let [id (get params "id")]
@@ -82,7 +77,6 @@
      ["/snippet-by-slug" {:get handle-view-snippet-by-slug}]
      ["/snippets" {:get handle-view-snippets}]
      ["/snippet" {:post handle-create-snippet
-                  :get handle-view-snippet
                   :patch handle-edit-snippet
                   :delete handle-delete-snippet}]])
    (rr/create-default-handler)))

src/snippets/infra/db2.clj

@@ -7,20 +7,21 @@
 ;; Initialize the Datomic Local client
 ;; :system "dev" groups your databases in the "dev" system
 ;; In production, you'd set :storage-dir to a persistent path
+;; TODO: add save file location for prod
 (def client (d/client {:server-type :datomic-local
                        :system "dev"}))
 
 (def db-name "snippets")
 
 ;; Create the database if it doesn't exist
-(defn ensure-db
+(defn- ensure-db
   "Check if db exists, create it if not."
   []
   (d/create-database client {:db-name db-name})
   (t/log! {:level :info} "Snippets database created if needed"))
 
 ;; Get a connection to the database
-(defn get-conn []
+(defn- get-conn []
   (d/connect client {:db-name db-name}))
 
 ;; Define the schema for snippets
@@ -43,18 +44,20 @@
     :db/valueType :db.type/instant
     :db/cardinality :db.cardinality/one}])
 
-(defn ensure-schema
+(defn- ensure-schema
   "Transact the schema if it doesn't exist. Call this once on startup."
   []
   (let [conn (get-conn)]
     (d/transact conn {:tx-data snippet-schema})
     (t/log! {:level :info} "Snippet schema created if needed")))
 
-(defn start-up-check []
+(defn start-up-check
+  "Should be run at startup to ensure the database and schema are created."
+  []
   (ensure-db)
   (ensure-schema))
 
-(defn snippet-to-entity
+(defn- snippet-to-entity
   "Convert a snippet map to a Datomic DB entity."
   [snippet]
   {:snippet/title (:title snippet)
@@ -63,6 +66,26 @@
    :snippet/tags (:tags snippet)
    :snippet/pub-date (:pub-date snippet)})
 
+(defn- entity-to-snippet
+  "Convert a Datomic DB entity to a snippet map."
+  [entity]
+  {:title (:snippet/title entity)
+   :slug (:snippet/slug entity)
+   :markdown (:snippet/markdown entity)
+   :tags (:snippet/tags entity)
+   :pub-date (:snippet/pub-date entity)})
+
+(defn- wrap-snippet-return
+  "Wraps an fn that returns snippet, snippet[], or nil; converting the entity to a snippet map."
+  [snippet-fn]
+  (fn [& args]
+    (let [res (apply snippet-fn args)]
+      (cond
+        (nil? res) nil
+        :else (if (sequential? res)
+                (map entity-to-snippet res)
+                (entity-to-snippet res))))))
+
 ;; create
 (def create-schema
   "Malli schema for a valid snippet entity creation."
@@ -73,12 +96,12 @@
    [:snippet/tags [:vector :string]]
    [:snippet/pub-date [:fn #(instance? java.util.Date %)]]])
 
-(defn valid-create?
+(defn- valid-create?
   "Check if a snippet map is a valid Datomic entity."
   [entity]
   (m/validate create-schema entity))
 
-(defn put-snippets
+(defn- put-snippets
   "Create new snippets in the database."
   [snippets]
   (t/log! {:level :info, :data {:slugs (map :slug snippets)}} "Saving new snippets to db")
@@ -88,8 +111,11 @@
       (d/transact conn {:tx-data entities})
       (throw (ex-info "Invalid snippet entity" {:entities entities})))))
 
+(def create-snippets
+  (wrap-snippet-return put-snippets))
+
 ;; read
-(defn get-snippet-by-slug
+(defn- get-snippet-by-slug-from-db
   "Get a single snippet by its slug."
   [slug]
   (let [conn (get-conn)
@@ -99,6 +125,9 @@
                 :where [?e :snippet/slug ?slug]]]
     (ffirst (d/q query db slug))))
 
+(def get-snippet-by-slug
+  (wrap-snippet-return get-snippet-by-slug-from-db))
+
 ;; update
 (def update-schema
   "Malli schema for a valid update to a snippet entity."
@@ -108,14 +137,14 @@
    [:snippet/markdown {:optional true} :string]
    [:snippet/tags {:optional true} [:vector :string]]])
 
-(defn to-update [patch]
+(defn- to-update [patch]
   (cond-> {}
     (some? (:title patch)) (assoc :snippet/title (:title patch))
     (some? (:slug patch)) (assoc :snippet/slug (:slug patch))
     (some? (:markdown patch)) (assoc :snippet/markdown (:markdown patch))
     (some? (:tags patch)) (assoc :snippet/tags (:tags patch))))
 
-(defn patch-snippet
+(defn- patch-snippet-in-db
   "Update specific fields of a snippet."
   [slug raw-patch]
   (let [conn (get-conn)
@@ -129,7 +158,9 @@
     (let [tx-data [(merge {:db/id eid} patch)]]
       (d/transact conn {:tx-data tx-data}))))
 
-(defn list-snippets
+(def update-snippet (wrap-snippet-return patch-snippet-in-db))
+
+(defn list-snippets-in-db
   "List all the snippets"
   []
   (let [conn (get-conn)
@@ -140,12 +171,13 @@
     (->> (d/q query db)
          (map first))))
 
+(def list-snippets (wrap-snippet-return list-snippets-in-db))
+
 (defn delete-snippet-by-slug
   "Soft delete a snippet (retract its entity)."
   [slug]
   (t/log! {:level :info, :data {:slug slug}} "Retracting snippet")
   (let [conn (get-conn)
-        db (d/db conn)
         eid (:db/id (get-snippet-by-slug slug))]
     (when (nil? eid)
       (throw (ex-info "Snippet not found" {:slug slug})))
@@ -161,7 +193,7 @@
                 [?e :snippet/tags ?tag]]]
     (d/q query db)))
 
-(defn get-snippets-by-tag
+(defn get-snippets-by-tag-in-db
   "Get all snippets that have a specific tag."
   [tag]
   (let [conn (get-conn)
@@ -172,3 +204,5 @@
                 [?e :snippet/tags ?tag]]
         results (d/q query db tag)]
     (mapv first results)))
+
+(def get-snippets-by-tag (wrap-snippet-return get-snippets-by-tag-in-db))

src/snippets/use_cases/view.clj

@@ -1,7 +1,7 @@
 (ns snippets.use-cases.view
   (:require
    [taoensso.telemere :as t]
-   [snippets.infra.db :as db]))
+   [snippets.infra.db2 :as db]))
 
 (defn serialize-snippet
   "Converts snippet pub-date to ISO-8601 string for EDN serialization"
@@ -9,12 +9,15 @@
   (when snippet
     (assoc snippet :pub-date (.toString (:pub-date snippet)))))
 
-(defn view-snippet [key]
-  (t/log! {:level :info, :data {:key key}} "Viewing snippet by id")
-  (serialize-snippet (db/get-snippet-by-id key)))
-
-(defn view-snippets [& args]
-  (map serialize-snippet (db/list-snippets args)))
+(defn view-snippets [options]
+  (if (nil? options)
+    (map serialize-snippet (db/list-snippets))
+    (let [limit (:limit options)
+          skip (:skip options)]
+      (->> (db/list-snippets)
+           (drop skip)
+           (take limit)
+           (map serialize-snippet)))))
 
 (defn view-tags []
   (t/log! {:level :info} "Viewing tags")