class RubyTutor

# File lib/rubytutor.rb, line 17
def self.available_methods(object, filter_str = nil)
  class_name = object.class == Class ? object : object.class
  methods = retrieve_methods(class_name, filter_str)

  puts methods
end

# File lib/rubytutor.rb, line 9
def self.describe(object)
  puts retrieve_description(object)
end

# File lib/rubytutor.rb, line 13
def self.explain(object)
  puts retrieve_explanation(object).join("\n")
end

# File lib/rubytutor.rb, line 5
def self.explain_full(object)
  puts full_explanation(object).join("\n")
end

# File lib/rubytutor.rb, line 48
def self.construct_explain(object, class_name, ancestors, value)
  text = []

  text << "Instance of Class: #{class_name}"
  text << "Value: #{value}"

  variable_text(object, text)

  text << "Mutable? #{object.frozen? ? 'No' : 'Yes'}"
  text << "Object ID: #{object.object_id}"
  text << "Inherits From: #{ancestors}"
  text << ''
end

# File lib/rubytutor.rb, line 103
def self.extract_contents(files, description, object, class_name)
  files.each do |file_path|
    File.open(file_path) do |file|
      file.each do |line|
        description << format(line, value: object, class: class_name)
      end
    end
  end
end

# File lib/rubytutor.rb, line 113
def self.find(files, class_name)
  class_file = File.expand_path("../descriptions/#{class_name}.txt", __FILE__)
  blank_file = File.expand_path('../descriptions/blank.txt', __FILE__)

  files << File.expand_path('../descriptions/intro.txt', __FILE__)
  files << (File.file?(class_file) ? class_file : blank_file)
  files << File.expand_path('../descriptions/last.txt', __FILE__)
end

# File lib/rubytutor.rb, line 77
def self.full_explanation(object)
  full_string = []

  full_string << retrieve_explanation(object)
  full_string << retrieve_description(object)
  full_string.flatten
end

# File lib/rubytutor.rb, line 73
def self.need?(object, method_symbol)
  object.respond_to?(method_symbol)
end

# File lib/rubytutor.rb, line 99
def self.retrieve_class(object)
  object.respond_to?(:members) ? Struct : object.class
end

# File lib/rubytutor.rb, line 85
def self.retrieve_description(object)
  class_name = retrieve_class(object)
  description = ["Description:\n"]
  files = []

  find(files, class_name)
  extract_contents(files, description, object, class_name)
  description.join
end

# File lib/rubytutor.rb, line 40
def self.retrieve_explanation(object)
  class_name = retrieve_class(object)
  ancestors = class_name.ancestors[1..-1].join(', ')
  value = object.nil? ? 'nil' : object

  construct_explain(object, class_name, ancestors, value)
end

# File lib/rubytutor.rb, line 26
def self.retrieve_methods(class_name, filter_str = nil)
  method_names = class_name.methods.sort

  if valid?(filter_str)
    last_index = filter_str.length

    method_names = method_names.map(&:to_s).select do |method|
      method[0...last_index] == filter_str
    end
  end

  "Available Methods: \n" + method_names.join("\n").to_s + "\n\n"
end

# File lib/rubytutor.rb, line 95
def self.valid?(letter)
  letter.respond_to?(:match) ? letter.downcase.match(/[a-z]/) : false
end

# File lib/rubytutor.rb, line 64
def self.variable_text(object, text)
  text << "Return Value: #{object.call}" if need?(object, :call)
  text << "Source Value: #{object.source}" if need?(object, :source)
  text << "Members: #{object.members.join(', ')}" if need?(object, :members)
  text << "Keys: #{object.keys.join(', ')}" if need?(object, :keys)
  text << "Values: #{object.values.join(', ')}" if need?(object, :values)
  text << "Length: #{object.length}" if need?(object, :length)
end