lib/decode_this.rb in decode_this-0.1.6 vs lib/decode_this.rb in decode_this-0.1.7

@@ -1,3 +1,70 @@
 # frozen_string_literal: true
 require 'decode_this/version'
-require 'decode_this/decoder'
+require 'decode_this/safe_decoding'
+require 'yaml'
+require 'jwt'
+
+module DecodeThis
+  def self.decode(header_value)
+    token = token_from_header(header_value)
+
+    safe_decode { JWT.decode(token, public_key, true, algorithm: config['algorithm']).first }
+  end
+
+  def self.config
+    raise ConfigFileNotFoundError.new("Cannot found configuration file in #{@config_path}") unless @config_path
+
+    @config ||= YAML.load(File.open(@config_path))[@env]
+  end
+
+  def self.config_path=(config_path)
+    @config_path = File.expand_path(config_path)
+  end
+
+  def self.config_path
+    @config_path
+  end
+
+  def self.logger
+    @logger
+  end
+
+  def self.logger=(logger)
+    @logger = logger
+  end
+
+  def self.env=(env)
+    @env = env.to_s
+  end
+
+  def self.env
+    @env
+  end
+
+  private
+
+  def self.safe_decode(&block)
+    SafeDecoding.call(logger, &block)
+  end
+
+  def self.token_from_header(header_value)
+    return unless header_value
+
+    token = header_value.match(/^#{config['authorization_scheme']} (.+)/)
+    token[1] if token
+  end
+
+  def self.public_key
+    OpenSSL::PKey::RSA.new(pem).public_key
+  end
+
+  def self.pem
+    keys_absolute_path = File.expand_path(config['key_path'])
+
+    if !File.readable?(keys_absolute_path)
+      raise DecodeThis::KeyFileNotFoundError.new("Cannot found file in #{config['key_path']}")
+    end
+
+    File.read(config['key_path'])
+  end
+end