# -*- coding: utf-8 -*-
module Axlsx
  # a Pic object represents an image in your worksheet
  # Worksheet#add_image is the recommended way to manage images in your sheets
  # @see Worksheet#add_image
  class Pic

    # allowed file extenstions
    ALLOWED_EXTENSIONS = ['gif', 'jpeg', 'png', 'jpg']

    # The name to use for this picture
    # @return [String]
    attr_reader :name


    # A description of the picture
    # @return [String]
    attr_reader :descr

    # The path to the image you want to include
    # Only local images are supported at this time and only jpg support
    # @return [String]
    attr_reader :image_src

    # The anchor for this image
    # @return [OneCellAnchor]
    attr_reader :anchor

   
    # Creates a new Pic(ture) object
    # @param [Anchor] anchor the anchor that holds this image
    # @option options [String] name
    # @option options [String] descr
    # @option options [String] image_src
    # @option options [Array] start_at
    # @option options [Intger] width
    # @option options [Intger] height
    def initialize(anchor, options={})
      @anchor = anchor
      @anchor.drawing.worksheet.workbook.images << self
      options.each do |o|
        self.send("#{o[0]}=", o[1]) if self.respond_to? "#{o[0]}="
      end
      start_at(*options[:start_at]) if options[:start_at]
      yield self if block_given?
    end
    
    def image_src=(v) 
      Axlsx::validate_string(v)
      RestrictionValidator.validate 'Pic.image_src', ALLOWED_EXTENSIONS, File.extname(v).delete('.')
      raise ArgumentError, "File does not exist" unless File.exist?(v)
      @image_src = v
    end

    # @see name
    def name=(v) Axlsx::validate_string(v); @name = v; end

    # @see descr
    def descr=(v) Axlsx::validate_string(v); @descr = v; end


    # The file name of image_src without any path information
    # @return [String]
    def file_name
      File.basename(image_src) unless image_src.nil?
    end    
    
    # returns the extension of image_src without the preceeding '.'
    # @return [String]
    def extname
      File.extname(image_src).delete('.') unless image_src.nil?
    end

    # The index of this image in the workbooks images collections
    # @return [Index]
    def index
      @anchor.drawing.worksheet.workbook.images.index(self)
    end

    # The part name for this image used in serialization and relationship building
    # @return [String]
    def pn
      "#{IMAGE_PN % [(index+1), extname]}"
    end

    # providing access to the anchor's width attribute
    # @param [Integer] v
    # @see OneCellAnchor.width
    def width
      @anchor.width
    end

    # @see width
    def width=(v)
      @anchor.width = v
    end

    # providing access to update the anchor's height attribute
    # @param [Integer] v
    # @see OneCellAnchor.width
    def height
      @anchor.height
    end

    # @see height
    def height=(v)
      @anchor.height = v
    end

    # This is a short cut method to set the start anchor position
    # If you need finer granularity in positioning use
    # graphic_frame.anchor.from.colOff / rowOff
    # @param [Integer] x The column
    # @param [Integer] y The row
    # @return [Marker]
    def start_at(x, y)
      @anchor.from.col = x
      @anchor.from.row = y
    end

    # Serializes the picture
    # @param [Nokogiri::XML::Builder] xml The document builder instance this objects xml will be added to.
    # @return [String]
    def to_xml(xml)
      xml.send('xdr:pic') {
        xml.send('xdr:nvPicPr') {
          xml.send('xdr:cNvPr', :id=>"2", :name=>name, :descr=>descr)
          xml.send('xdr:cNvPicPr') {
            xml.send('a:picLocks', :noChangeAspect=>1)
          }
        }
        xml.send('xdr:blipFill') {
          xml.send('a:blip', :'xmlns:r' => XML_NS_R, :'r:embed'=>"rId1")
          xml.send('a:stretch') {
            xml.send('a:fillRect')
          }
        }
        xml.send('xdr:spPr') {
          xml.send('a:xfrm') {
            xml.send('a:off', :x=>0, :y=>0)
            xml.send('a:ext', :cx=>2336800, :cy=>2161540)
          }
          xml.send('a:prstGeom', :prst=>:rect) {
            xml.send('a:avLst')
          }
        }
      }
    end
  end
end