# frozen_string_literal: true

require 'active_support'
require 'active_support/all'

# Builder that add instance methods to a class
#
# @example
#
#   class MyModel
#   end
#
#   buider = Sinclair.new(MyModel)
#
#   value = 10
#   builder.add_method(:default_value) { value }
#   builder.add_method(:value, '@value || default_value')
#   builder.add_method(:value=) { |val| @value = val }
#   builder.build
#
#   instance = MyModel.new
#   instance.value # returns 10
#   instance.value = 20
#   instance.value # returns 20
class Sinclair
  require 'sinclair/options_parser'

  autoload :VERSION,          'sinclair/version'
  autoload :MethodDefinition, 'sinclair/method_definition'
  autoload :Matchers,         'sinclair/matchers'

  include OptionsParser

  # @param klass [Class] to receive the methods
  # @param options [Hash] open hash options to be used by builders inheriting from Sinclair
  #   through the Sinclair::OptionsParser concern
  #
  # @example
  #
  #   class Purchase
  #     def initialize(value, quantity)
  #       @value = value
  #       @quantity = quantity
  #     end
  #   end
  #
  #   builder = Sinclair.new(Purchase)
  #
  # @example
  #
  #   builder = Sinclair.new(Purchase, rescue_error: true)
  def initialize(klass, options = {})
    @klass = klass
    @options = options
  end

  # builds all the methods added into the klass
  #
  # @example
  #
  #   class MyModel
  #   end
  #
  #   buider = Sinclair.new(MyModel)
  #
  #   builder.add_method(:default_value) { value }
  #
  #   MyModel.new.respond_to(:default_value) # returns false
  #
  #   builder.build
  #
  #   MyModel.new.respond_to(:default_value) # returns true
  def build
    definitions.each do |definition|
      definition.build(klass)
    end
  end

  # add a method to the method list to be created on klass
  #
  # @overload add_method(name, code)
  #   @param name [String/Symbol] name of the method to be added
  #   @param code [String] code to be evaluated when the method is ran
  #
  #   @example
  #     class Person
  #       attr_reader :first_name, :last_name
  #
  #       def initialize(first_name, last_name)
  #         @first_name = first_name
  #         @last_name = last_name
  #       end
  #     end
  #
  #     builder = Sinclair.new(Person)
  #     builder.add_method(:full_name, '[first_name, last_name].join(" ")')
  #     builder.build
  #
  #     Person.new('john', 'wick').full_name # returns 'john wick'
  #
  # @overload add_method(name, &block)
  #   @param name [String/Symbol] name of the method to be added
  #   @param block [Proc]  block to be ran as method
  #
  #   @example
  #
  #     builder = Sinclair.new(Person)
  #     builder.add_method(:bond_name) { "#{last_name}, #{full_name}" }
  #     builder.build
  #
  #     Person.new('john', 'wick').bond_name # returns 'wick, john wick'
  def add_method(name, code = nil, &block)
    definitions << MethodDefinition.new(name, code, &block)
  end

  # evaluetes a block which will result in a [String] to be
  # then used as code for the method
  #
  # @example
  #
  #   module InitialValuer
  #     extend ActiveSupport::Concern
  #
  #     class_methods do
  #       def initial_value_for(attribute, value)
  #         builder = Sinclair.new(self, initial_value: value)
  #         builder.eval_and_add_method(attribute) do
  #           "@#{attribute} ||= #{options_object.initial_value}"
  #         end
  #         builder.build
  #       end
  #     end
  #   end
  #
  #   class MyClass
  #     include InitialValuer
  #     attr_writer :age
  #     initial_value_for :age, 20
  #   end
  #
  #   object = MyClass.new
  #   object.age # 20
  #   object.age = 30
  #   object.age # 30
  #
  # @example
  #
  #   class Purchase
  #     def initialize(value, quantity)
  #       @value = value
  #       @quantity = quantity
  #     end
  #   end
  #
  #   builder = Sinclair.new(Purchase)
  #
  #   builder.eval_and_add_method(:total_price) do
  #     code = 'self.value * self.quantity'
  #     code.concat ' rescue 0' if options_object.rescue_error
  #     code
  #   end
  #
  #   builder.build
  #
  #   Purchase.new(2.3, 5).total_price # raises error
  #
  # @example
  #
  #   builder = Sinclair.new(Purchase, rescue_error: true)
  #
  #   builder.eval_and_add_method(:total_price) do
  #     code = 'self.value * self.quantity'
  #     code.concat ' rescue 0' if options_object.rescue_error
  #     code
  #   end
  #
  #   builder.build
  #
  #   Purchase.new(2.3, 5).total_price # returns 0
  #
  #   class Purchase
  #     attr_reader :value, :quantity
  #   end
  #
  #   Purchase.new(2.3, 5).total_price # returns 11.5
  def eval_and_add_method(name, &block)
    add_method(name, instance_eval(&block))
  end

  private

  attr_reader :klass

  def definitions
    @definitions ||= []
  end
end