# -*- encoding: utf-8 -*-

module Writexlsx
  class Worksheet
    class Hyperlink   # :nodoc:
      include Writexlsx::Utility

      attr_reader :url, :link_type, :str, :url_str
      attr_accessor :tip, :display

      def self.factory(url, str = nil)
        if url =~ /^internal:/
          InternalHyperlink.new(url, str)
        elsif url =~ /^external:/
          ExternalHyperlink.new(url, str)
        else
          new(url, str)
        end
      end

      def initialize(url, str = nil)
        @link_type = 1

        # The displayed string defaults to the url string.
        str ||= url.dup

        # Strip the mailto header.
        str.sub!(/^mailto:/, '')

        # Escape URL unless it looks already escaped.
        unless url =~ /%[0-9a-fA-F]{2}/
          # Escape the URL escape symbol.
          url = url.gsub(/%/, "%25")

          # Escape whitespae in URL.
          url = url.gsub(/[\s\x00]/, '%20')

          # Escape other special characters in URL.
          re = /(["<>\[\]`^{}])/
          while re =~ url
            match = $~[1]
            url = url.sub(re, sprintf("%%%x", match.ord))
          end
        end

        # Excel limits escaped URL to 255 characters.
        if url.bytesize > 255
          raise "URL '#{url}' > 255 characters, it exceeds Excel's limit for URLS."
        end

        @url       = url
        @str       = str
        @url_str   = nil
      end

      def write_external_attributes(row, col, id)
        ref = xl_rowcol_to_cell(row, col)

        attributes = [ ['ref', ref] ]
        attributes << r_id_attributes(id)

        attributes << ['location', url_str] if url_str
        attributes << ['display',  display] if display
        attributes << ['tooltip',  tip]     if tip
        attributes
      end

      def write_internal_attributes(row, col)
        ref = xl_rowcol_to_cell(row, col)

        attributes = [
                      ['ref', ref],
                      ['location', url]
                     ]

        attributes << ['tooltip', tip] if tip
        attributes << ['display', str]
      end
    end

    class InternalHyperlink < Hyperlink
      def initialize(url, str)
        @link_type = 2
        @url = url.sub(/^internal:/, '')

        # The displayed string defaults to the url string.
        str ||= @url.dup

        # Strip the mailto header.
        @str = str.sub(/^mailto:/, '')

        # Copy string for use in hyperlink elements.
        @url_str = @str.dup

        # Excel limits escaped URL to 255 characters.
        if @url.bytesize > 255
          raise "URL '#{@url}' > 255 characters, it exceeds Excel's limit for URLS."
        end
      end
    end

    class ExternalHyperlink < Hyperlink
      def initialize(url, str = nil)
        @link_type = 1

        # Remove the URI scheme from internal links.
        url = url.sub(/^external:/, '')

        # The displayed string defaults to the url string.
        str ||= url.dup

        # For external links change the directory separator from Unix to Dos.
        url = url.gsub(%r|/|, '\\')
        str.gsub!(%r|/|, '\\')

        # Strip the mailto header.
        str.sub!(/^mailto:/, '')

        # External Workbook links need to be modified into the right format.
        # The URL will look something like 'c:\temp\file.xlsx#Sheet!A1'.
        # We need the part to the left of the # as the URL and the part to
        # the right as the "location" string (if it exists).
        url, url_str = url.split(/#/)

        # Add the file:/// URI to the url if non-local.
        if url =~ %r![:]! ||        # Windows style "C:/" link.
            url =~ %r!^\\\\!        # Network share.
          url = "file:///#{url}"
        end

        # Convert a ./dir/file.xlsx link to dir/file.xlsx.
        url = url.sub(%r!^.\\!, '')

        # Excel limits escaped URL to 255 characters.
        if url.bytesize > 255
          raise "URL '#{url}' > 255 characters, it exceeds Excel's limit for URLS."
        end
        @url       = url
        @str       = str
        @url_str   = url_str
      end
    end
  end
end