1 files changed, 64 insertions, 0 deletions
diff --git a/gems/click_house-client/lib/click_house/client.rb b/gems/click_house-client/lib/click_house/client.rb
new file mode 100644
index 00000000000..22c42d7be6e
--- /dev/null
+++ b/gems/click_house-client/lib/click_house/client.rb
@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+require 'addressable'
+require 'json'
+require 'active_support/time'
+require_relative "client/database"
+require_relative "client/configuration"
+require_relative "client/formatter"
+require_relative "client/response"
+
+module ClickHouse
+  module Client
+    class << self
+      def configuration
+        @configuration ||= Configuration.new
+      end
+
+      def configure
+        yield(configuration)
+        configuration.validate!
+      end
+    end
+
+    Error = Class.new(StandardError)
+    ConfigurationError = Class.new(Error)
+    DatabaseError = Class.new(Error)
+
+    # Executes a SELECT database query
+    def self.select(query, database, configuration = self.configuration)
+      db = lookup_database(configuration, database)
+
+      response = configuration.http_post_proc.call(
+        db.uri.to_s,
+        db.headers,
+        "#{query} FORMAT JSON" # always return JSON
+      )
+
+      raise DatabaseError, response.body unless response.success?
+
+      Formatter.format(configuration.json_parser.parse(response.body))
+    end
+
+    # Executes any kinds of database query without returning any data (INSERT, DELETE)
+    def self.execute(query, database, configuration = self.configuration)
+      db = lookup_database(configuration, database)
+
+      response = configuration.http_post_proc.call(
+        db.uri.to_s,
+        db.headers,
+        query
+      )
+
+      raise DatabaseError, response.body unless response.success?
+
+      true
+    end
+
+    private_class_method def self.lookup_database(configuration, database)
+      configuration.databases[database].tap do |db|
+        raise ConfigurationError, "The database '#{database}' is not configured" unless db
+      end
+    end
+  end
+end