require "taiwan_city/engine"

module TaiwanCity
  TAIWAN = '00000' # 全国
  PATTERN = /(\d{2})(\d{3})(\d?)/

  class << self
    def list(parent_id = '00000')
      result = []
      return result if parent_id.blank?
      city_id = city(parent_id)
      children = data
      children = children[city_id][:children] if children.has_key?(city_id)
      children.each_key do |id|
        result.push [ children[id][:text], id]
      end

      #sort
      # result.sort! {|a, b| a[1] <=> b[1]}
      result
    end

    # @options[:prepend_parent] 是否显示上级区域
    def get(id, options = {})
      return '' if id.blank?
      prepend_parent = options[:prepend_parent] || false
      children = data
      return children[id][:text] if children.has_key?(id)
      city_id = city(id)
      city_text = children[city_id][:text]
      children = children[city_id][:children]
      return "#{prepend_parent ? (city_text) : ''}#{children[id][:text]}"
    end

    def city(code)
      match(code)[1].ljust(5, '0')
    end

    def get_info_from_address(address)
      return '' if address.blank?
      address.gsub!('臺', '台')
      addr = {
        city_code:'', city: '', 
        dist_code:'', dist: '', 
        post_code:'', address: '', 
        full_address: ''
      }
      data.each do |city_code, city|
        next if address.exclude?(city[:text])
        addr[:city] = city[:text] 
        addr[:city_code] = city_code
        city[:children].each do |dist_code, dist| 
          next if address.exclude?(dist[:text])
          addr[:dist] = dist[:text]
          addr[:dist_code] = dist_code
          addr[:post_code] = dist_code[2..4]
          break
        end
        break
      end

      dist_position = address.index(addr[:dist]) ? address.index(addr[:dist]) + addr[:dist].size : nil
      city_position = address.index(addr[:city]) ? address.index(addr[:city]) + addr[:city].size : nil
      del_position = dist_position || city_position || 0
      addr[:address] = address[del_position..-1]

      addr[:full_address] = address
      addr
    end

    private
    def data
      unless @list
        #{ '440000' =>
        #  {
        #    :text => '广东',
        #    :children =>
        #      {
        #        '440300' =>
        #          {
        #            :text => '深圳',
        #            :children =>
        #              {
        #                '440305' => { :text => '南山' }
        #              }
        #           }
        #       }
        #   }
        # }
        @list = {}
        #@see: http://github.com/RobinQu/LocationSelect-Plugin/raw/master/areas_1.0.json
        json = JSON.parse(File.read("#{Engine.root}/db/areas.json"))
        districts = json.values.flatten
        districts.each do |district|
          id = district['id']
          text = district['text']
          if id.end_with?('000')
            @list[id] =  {:text => text, :children => {}}
          else
            city_id = city(id)
            @list[city_id] = {:text => text, :children => {}} unless @list.has_key?(city_id)
            @list[city_id][:children][id] = {:text => text}
          end
        end
      end
      @list
    end

    def match(code)
      code.match(PATTERN)
    end
  end
end