require 'singleton'
require 'guid'
require 'bootstrap-rails-engine'
require 'slim-rails'
require 'will_paginate'
require 'draper'
require 'sidekiq'
require 'active_model_serializers'
require 'rails_workflow/db/mysql'
require 'rails_workflow/db/pg'

module RailsWorkflow
  class Config
    include Singleton

    attr_accessor :operation_types, :activejob_enabled
    attr_writer :sql_dialect, :assignment_by, :import_preprocessor, :process_class
    attr_reader :cache

    def initialize
      @default_operation_types = {
        default: {
          title: 'Default Operation',
          class: 'RailsWorkflow::Operation'
        },
        user_role: {
          title: 'Operation for User By Role',
          class: 'RailsWorkflow::UserByRoleOperation'
        },
        user_group: {
          title: 'Operation by User Group',
          class: 'RailsWorkflow::UserByGroupOperation'
        }
      }
      @default_import_preprocessor = 'RailsWorkflow::DefaultImporterPreprocessor'
      @default_operation_template_type = 'RailsWorkflow::OperationTemplate'
      @default_process_manager = 'RailsWorkflow::ProcessManager'
      @default_process_class = 'RailsWorkflow::Process'
      @default_process_template_type = 'RailsWorkflow::ProcessTemplate'
      @default_assignment_by = [:group, :role]
      @default_sql_dialect = 'pg'
    end

    def sql_dialect
      case @sql_dialect || @default_sql_dialect
      when 'pg'
        RailsWorkflow::Db::Pg
      when 'mysql'
        RailsWorkflow::Db::Mysql
      end
    end

    def assignment_by
      @assignment_by || @default_assignment_by
    end

    def operation_types
      @default_operation_types.merge(@operation_types || {})
    end

    def operation_template_klass=(value)
      @operation_template_type = value
    end

    def import_preprocessor
      processor = @import_preprocessor || @default_import_preprocessor
      processor.constantize.new
    end

    def default_operation_template_type
      @operation_template_type || @default_operation_template_type
    end

    def manager_class=(value)
      @process_manager = value
    end

    def manager_class
      @process_manager || @default_process_manager
    end

    def process_template_klass=(value)
      @process_template_type = value
    end

    def process_class
      @process_class || @default_process_class
    end

    def process_template_type
      @process_template_type || @default_process_template_type
    end

    # template_id - Process Template Id
    def template(template_id)
      @cache ||= {}
      @cache[template_id.to_i] ||= RailsWorkflow::ProcessTemplate.eager_load(:operations).find(template_id)
    end
  end
end