generate_solar_models.rb

# Add the folder you choose in your config/application.rb
# example:
# config.autoload_paths << Rails.root.join('app/solargraph')
gen_directory = Rails.root.join("app", "solargraph")

# run the script as a rails runner:
# bundle exec rails r ./bin/generate_solar_models.rb

type_translation = {
  decimal: "Decimal",
  integer: "Int",
  date: "Date",
  datetime: "DateTime",
  string: "String",
  boolean: "Bool"
}

def class_for(name)
  name = name.to_s
  found = ApplicationRecord.descendants.detect do |model| 
    model.model_name.plural == name || model.model_name.singular == name
  end
  found&.first&.model_name&.name
end

def reflection_type(reflection)
      case reflection
      when ActiveRecord::Reflection::HasManyReflection
        :many
      when ActiveRecord::Reflection::HasOneReflection
      when ActiveRecord::Reflection::BelongsToReflection
        :one
      when ActiveRecord::Reflection::ThroughReflection
        reflection_type(reflection.through_reflection)
      else
        puts("# cannot infer association for #{reflection.name} -> #{reflection.class}")
        nil
      end
end

def reflection_class_name(reflection)
      case reflection
      when ActiveRecord::Reflection::HasManyReflection
      when ActiveRecord::Reflection::ThroughReflection
        class_name = 
          if reflection.options[:class_name].present?
            reflection.options[:class_name] 
          else
            class_for(reflection.name)
          end
        class_name
      when ActiveRecord::Reflection::HasOneReflection
      when ActiveRecord::Reflection::BelongsToReflection
        reflection.name.to_s.capitalize
      else
        puts("# cannot infer association for #{reflection.name} -> #{reflection.class}")
        nil
      end
end

def reflection_comment(reflection)
  case reflection_type(reflection)
  when :one
    "[#{reflection_class_name(reflection)}]"
  when :many
    "[Array<#{reflection_class_name(reflection)}>]"
  end
end

# if you wanted to choose specific models to generate for
# models =  [User]
Rails.application.eager_load!
models = ApplicationRecord.descendants
puts("generating for #{models.count} models")

models.each do |model|
  puts "processing #{model.name}."
  attributes = 
  columns = model.columns.map do |col| 

    type = type_translation[col.type]
    <<-TXT
       # @!attribute #{col.name}
       #   @return [#{type}]
    TXT
  end

  reflections = model.reflections.map do |key, reflection|
    type = reflection_comment(reflection)
    next if type.nil?
    <<-TXT
       # @!attribute #{key}
       #    @return #{type}
    TXT
  end

  generated_attributes = <<-TXT
    class #{model.name}
#{reflections.join("\n")}
#{attributes.join("\n")}
    end
  TXT

  path = gen_directory.join("#{model.model_name.singular}_attrs.rb")
  File.write(path, generated_attributes)
  puts("written : #{path}")
end