Move DB queries related to statistics in a separate module

src/invidious/database/statistics.cr

@@ -0,0 +1,49 @@
+require "./base.cr"
+
+module Invidious::Database::Statistics
+  extend self
+
+  # -------------------
+  #  User stats
+  # -------------------
+
+  def count_users_total : Int64
+    request = <<-SQL
+      SELECT count(*) FROM users
+    SQL
+
+    PG_DB.query_one(request, as: Int64)
+  end
+
+  def count_users_active_1m : Int64
+    request = <<-SQL
+      SELECT count(*) FROM users
+      WHERE CURRENT_TIMESTAMP - updated < '6 months'
+    SQL
+
+    PG_DB.query_one(request, as: Int64)
+  end
+
+  def count_users_active_6m : Int64
+    request = <<-SQL
+      SELECT count(*) FROM users
+      WHERE CURRENT_TIMESTAMP - updated < '1 month'
+    SQL
+
+    PG_DB.query_one(request, as: Int64)
+  end
+
+  # -------------------
+  #  Channel stats
+  # -------------------
+
+  def channel_last_update : Time?
+    request = <<-SQL
+      SELECT updated FROM channels
+      ORDER BY updated DESC
+      LIMIT 1
+    SQL
+
+    PG_DB.query_one?(request, as: Time)
+  end
+end