Initial commit

lib/peatio/coin_market_cap.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+class CoinMarketCap
+  Error = Class.new(StandardError)
+
+  class << self
+    def default_client
+      new(default_options)
+    end
+
+    def default_options
+      {
+        host:   ENV.fetch('CMC_HOST','pro-api.coinmarketcap.com'),
+        path:   '/v1/cryptocurrency/map',
+        query:  {
+          CMC_PRO_API_KEY: 'UNIFIED-CRYPTOASSET-INDEX',
+          listing_status:  'active'
+        }.to_query
+      }
+    end
+  end
+
+  def initialize(options)
+    url = ::URI::HTTPS.build(options.slice(:host, :path, :query))
+
+    @connection = Faraday.new(url) do |conn|
+      conn.response :raise_error
+      conn.adapter Faraday.default_adapter
+    end
+  end
+
+  def get(params={})
+    response = @connection.get do |req|
+      req.params = @connection.params.merge(params.as_json)
+    end
+
+    JSON(response.body).deep_symbolize_keys.yield_self do |body|
+      # Error code will be equal to zero if there is no error
+      raise Error, body[:status][:error_message] if body[:status][:error_code].nonzero? || body[:data].blank?
+      body[:data]
+    end
+  end
+end