#coding: utf-8
module Ns
  module ControllerServicable
    def index
      @result = paginate(params) do |start, page_size|
        get_page_data(start, page_size, params)
      end
      render :json=>ResultPacker.data(@result.as_json)
    end

    #return [total_count, page_data]
    #可在子类中覆盖定制
    def get_page_data(start = 0, size = 10, params = {})
      where_conds = if @conds.present?
        @conds
      else
        query_conditionize(params, @conds)
      end
      logger.debug "====>conds: #{where_conds.inspect}"
      conds = {:conditions=>where_conds}
      total_count = model_class.count(conds)
      page_params = conds.merge!(:offset=>start, :limit=>size, :order=>params[:order])
      page_data = model_class.all(page_params)
      [total_count, page_data]
    end

    def query_conditionize(params = {}, conds = {})
      #清除空条件
      params.delete_if{|k, v| v.blank? }
      #TODO 有@conds时如何融入？？？
      #hash结构
      conds = model_class.db_hashize(params)
    end

    #分页方法 # 加入文档说明
    def paginate(params = {})
      current_page = params[:current_page].to_i
      current_page = current_page < 1 ? 1 : current_page
      page_size = params[:page_size].to_i
      page_size = page_size <= 0 ? 10 : page_size
      page_size = page_size > 250 ? 250 : page_size
      offset = (current_page-1)*page_size
      #返回总数和当前页数据           起始位置， 数量
      total_count, page_data =  yield(offset, page_size)
      {
       :total_size=>total_count,
       :page_size=>page_size,
       :current_page=>current_page,
       :page_from=>offset + 1,
       :page_to=>offset + page_data.size,
       :page_items=>page_data
      }
    end
    
    #查找单条记录
    def show
      @_obj = model_class.find(params[:id])
      render :json=>ResultPacker.data(@_obj.as_json)
    end
    
    #创建记录
    def create
      @_obj = model_class.new_from_buz(params[:data]) 
      if @_obj.save
        render :json=>ResultPacker.data(@_obj)
      else
        render :json=>ResultPacker.help(valid_errors(model_class.buz_hashize(@_obj.errors.to_hash)))
      end
    end
    
    #更新记录
    def update
      @_obj = model_class.find(params[:id])
      if @_obj.update_from_buz(params[:data])
        render :json=>ResultPacker.data(@_obj)
      else
        render :json=>ResultPacker.help(valid_errors(model_class.buz_hashize(@_obj.errors.to_hash)))
      end
    end
   
    #get a new buz obj with db default value
    def new_buz_obj
      @_data = model_class.buz_hashize
      render :json=>ResultPacker.data(model_class.name.underscore.to_sym=>@_data)
    end
   
    #get the mapping info
    def field_mapping
      @_data = model_class.mapping.data
      render :json=>ResultPacker.data(:field_mapping=>@_data)
    end

    #动态查看该模块发布接口列表
    def interfaces
      @routes = Rails.application.routes.routes
      #TODO 写一个像rails info一样的那种内置controller
      respond_to do |format|
        format.html #interfaces.html.erb
        format.json {render json: @routes.map{|r| r.path}}
      end
    end
    
    protected 
      #验证错误回传
      def valid_errors(error_hash={})
        (error_hash||{}).each{|k, v| error_hash[k] = v.join(', ') if v.is_a? Array }
      end
  end
end