# encoding: utf-8
require "generators/generators"
require "erb"
require 'active_support/inflector'
require "dslable_dsl"

module Dslable::Generators::ProductCodes
  class DslModel
    DSL_MODEL_TEMPLATE =<<-EOF
# encoding: utf-8
require 'active_model'

module <%=gem_name_camel%>
  class DslModel
    include ActiveModel::Model

<%=fields%>
  end
end
    EOF

    attr_accessor :dsl

    #== initialize dsl model
    #=== Params
    #- _dsl: input from dsl
    def initialize(_dsl)
      raise InvalidDslError.new("dsl not allow nil") if _dsl.nil?
      @dsl = _dsl
    end

    def generate
      dsl_model_src = adapt_template(@dsl.camelized_gem_name, get_fields)
      generate_dsl_model_src dsl_model_src
    end

    private
    def get_fields
      fields = []
      @dsl.fields.each do |field|
        field_codes = []
        field_codes << "    # #{field._desc}"
        field_codes << "    attr_accessor :#{field._field_name}"
        field_codes << "    validates :#{field._field_name}, :presence => true" if field._args._required
        field_codes << ""
        fields << field_codes.join("\n")
      end
      fields.join("\n")
    end

    def adapt_template(gem_name_camel, fields)
      gem_name = @dsl._gem_name
      erb = ERB.new(DSL_MODEL_TEMPLATE)
      erb.result(binding)
    end

    def generate_dsl_model_src(dsl_model_src)
      File.open("./lib/#{@dsl._gem_name}_dsl_model.rb", "w") {|f|f.puts dsl_model_src}
    end
  end

  class InvalidDslError < StandardError;end
end