require "rghost/font_map"
require "rghost/ps_object"
require "rghost/which"

# Rghost setup with Ghostscript.
# Ghostscript runs on a variety of platforms, this is why we recommend the non coupled install for non *nix environments.
# The gem already comes with a set of defaults but you can change the settings using the Hash RGhost::Config::GS before each use of the API. Listed below are the keys of the said hash.
#===RGhost::Config::GS[:mode]
# Operating mode
# * <tt>:gsparams</tt> In this mode RGhost just pass parameters to the Ghostscript framework.
# * <tt>:gsapi</tt> based on the exchange of data between Ruby and Ghostscript via rgengine.so using gslib.so.8 or gslib-esp.so.8.
#
#===RGhost::Config::GS[:path]
# Path to the ghostscript executable.
#====Example on windows
# RGhost::Config::GS[:path] = "C:\\gs\\bin\\gswin32c.exe"
#====Example on Linux
# RGhost::Config::GS[:path] = "/usr/bin/gs"
#
#===RGhost::Config::GS[:tmpdir]
# Temporary directory
#====Example
# RGhost::Config::GS[:tmpdir] = "/tmp"
#
#===RGhost::Config::GS[:default_params]
# Allows you to add/remove options. (use with caution!)
#====Example
# RGhost::Config::GS[:default_params] << "-dSAFER"
#
#===RGhost::Config::GS[:stack_elements]
# Defines the maximum number of elements for each matrix inside postscript's internal stack, avoiding a stack overflow error..
#====Example
# RGhost::Config::GS[:stack_elements]=5000
#
#===RGhost::Config::GS[:unit]
# Set the measure units. See Units::Unit for available units.
#====Example
# RGhost::Config::GS[:unit]=Units::Cm
#
#===RGhost::Config::GS[:charset_convert]
# Ruby to PS character conversion proxy.  Necessary when the source code isn't on the same encoding of the document.
# Params is a block that returns a String. The default setting is nil.
#====Example
# RGhost::Config::GS[:charset_convert]= lambda {|text| Iconv::iconv("latin1","utf8", text).to_s}
#
#===RGhost::Config::GS[:font_encoding]
# Sets the Postscript font encoding. Default: :IsoLatin
#====Example
# RGhost::Config::GS[:font_encoding]= :IsoLatin
#
#===RGhost::Config::GS[:external_encoding]
# Sets the file-in external encoding (Ruby 1.9). Affects how data will be written and
# could help when dealing with encoding conversion errors. Default: nil
#====Example
# RGhost::Config::GS[:external_encoding]= 'ascii-8bit'
module RGhost
  module Config
    DEFAULT_PORTRAIT_TEMPLATE = File.join(File.dirname(__FILE__), "ps", "rghost_default_template.eps")

    GS = {
      mode: :gsparams,
      raise_on_error: true,
      plugin: nil,
      path: nil,
      tmpdir: ENV["TMP"] || ENV["TMPDIR"] || ENV["TEMPDIR"] || ENV["TEMP"] || "/tmp",
      pslibdir: File.join(File.dirname(__FILE__), "ps"),
      extensions: [],
      preload: [],
      default_params: %w[gs -dNOPAUSE -dBATCH -dQUIET -dNOPAGEPROMPT],
      stack_elements: 5000,
      font_encoding: :IsoLatin,
      external_encoding: "ascii-8bit",
      charset_convert: nil,
      fontsize: 8,
      unit: RGhost::Units::Cm
    }

    def self.config_platform(which: Which, config_options: GS) # :nodoc:
      config_options[:path] = which.call("gs")

      raise GS_NOT_FOUND_MSG unless config_options[:path]
    end

    GS_NOT_FOUND_MSG = <<~MSG
      Ghostscript not found on your $PATH.
      Install it and set RGhost::Config::GS[:path] with the path to the executable.
      Example: RGhost::Config::GS[:path] = '/path/to/my/gs' # unix-style
               RGhost::Config::GS[:path] = 'C:\\gs\\bin\\gswin32c.exe' # windows-style
    MSG
    private_constant :GS_NOT_FOUND_MSG

    # Test if your environment is ready to works. If yes the page below will show.
    #
    # link:images/is_ok.png
    #
    # You can generate this page with the code.
    # RGhost::Config.is_ok?.render :pdf, :filename => "/tmp/mytest.pdf"
    #
    def self.is_ok?
      d = RGhost::Document.new margin_left: 2.3, margin_bottom: 2.3
      d.benchmark(:start)
      d.before_page_create do |b|
        b.image RGhost::Config::DEFAULT_PORTRAIT_TEMPLATE
      end
      d.define_tags do
        new :bigger, size: 150, color: "#AAFF33"
      end
      d.text_in x: 6, y: 15, write: "Yes!", with: :bigger
      d.text_in x: 10, y: 14, write: "Your environment is ready!"
      d.text_in x: 10, y: 13, write: "RGhost Version " + RGhost::VERSION::STRING
      d.text_in x: 10, y: 12, write: "Now " + Time.now.to_s

      d.benchmark(:stop)
      d.done
      d
    end

    # Generate the UTF-8 encoding mapping
    #
    # RGhost::Config.utf8_encodings.render :pdf, :filename => "/tmp/encoding_map.pdf"
    #
    def self.utf8_encodings
      doc = RGhost::Document.new paper: [20, 10], margin_left: 2.3, margin_bottom: 2.3

      doc.virtual_pages do
        7.times do
          new_page width: 2, margin_left: 1
        end
      end

      RGhost::RubyToPs::UTF8_ENCODINGS.each do |k, v|
        doc.show "#{k} = #{v}"
        doc.next_row
      end
      doc
    end

    # This method is a helper to gets the best encoding.
    #
    # link:images/encode_test.png
    #
    # You can generate this page with the code.
    # RGhost::Config.encode_teste("Fiancé").render :pdf, :filename => "/tmp/mytest.pdf"
    #
    # The encode will use on Document class.
    # doc=Document.new :font_encoding => 'IsoLatin'
    #
    def self.encode_test(value)
      d = RGhost::Document.new paper: :A4, margin_left: 2 # , :landscape => true
      d.before_page_create do |b|
        b.image RGhost::Config::DEFAULT_PORTRAIT_TEMPLATE
      end
      exp = File.join(File.dirname(__FILE__), "ps", "*.enc")
      d.show "String (Using Helvetica Font)", with: :b
      d.moveto x: 16
      d.show "Encode Name", with: :b
      d.horizontal_line :bottom
      d.next_row

      Dir.glob(exp).sort.each do |f|
        name = File.basename(f)
        name.gsub!(".enc", "")
        d.set RGhost::Load.library(name, :enc)
        d.set RGhost::Variable.new(:default_encoding, name)
        d.set RGhost::FontMap.new {
          new(:font_test, name: "Helvetica", size: 8, color: "#FF0000", encoding: true)
        }

        d.show "#{value}", with: :font_test
        d.moveto x: 16
        d.show "#{name}", with: :i
        d.next_row
      end
      d
    end

    # Generates font catalog to use into method define_tags on Document
    #  RGhost::Config.enviroment_fonts.render :pdf, :filename => "mycatalog.pdf"
    # link:images/environment_fonts.png
    #
    def self.environment_fonts(text = "The quick brown fox jumps over the lazy dog")
      d = RGhost::Document.new margin_left: 2.3, margin_bottom: 2.3
      d.before_page_create do |b|
        b.image RGhost::Config::DEFAULT_PORTRAIT_TEMPLATE
      end
      d.show "Search Path"
      d.horizontal_line :bottom
      d.next_row
      d.raw :default_font
      d.raw %(
    LIBPATH{
      limit_left  current_row  moveto   show
      nrdp
    } forall

    )
      d.next_row
      d.show "Example"
      d.moveto x: 13
      d.show "Font Name"
      d.horizontal_line :bottom
      d.next_row
      #=begin
      d.raw %{
      Fontmap{
        50 string cvs pop dup findfont 10 scalefont setfont
        limit_left  current_row  moveto  (#{text})  show
    13 cm  current_row moveto default_font  0 setgray
    50 string cvs show
    nrdp
      } forall
    }
      #=end
      d.done
      d
    end

    # .
    #
    #
    # Preseted tags
    #
    #
    #
    # FONTMAP=RGhost::FontMap.new :name => "Helvetica", :size => 8, :encoding => false do
    #    new :span
    #    new :b,     :name => "Helvetica-Bold"
    #    new :bold,     :name => "Helvetica-Bold"
    #    new :normal,   :name => "Helvetica"
    #    new :i,     :name => "Helvetica-Oblique", :size => 8
    #    new :bi,    :name => "Helvetica-BoldOblique"
    #    new :big,   :size => 10
    #    new :small, :size => 7
    #    new :h1,    :name => "Helvetica", :size => 14
    #    new :h2,    :name => "Helvetica", :size => 13
    #    new :h3,    :name => "Helvetica", :size => 12
    #    new :h4,    :name => "Helvetica", :size => 11
    #    new :h5,    :name => "Helvetica", :size => 10
    #    new :title, :name => "Helvetica", :size => 20
    #    new :pre,   :name => "Courier"
    #  end
    #
    FONTMAP = RGhost::FontMap.new name: "Helvetica", size: 8, encoding: true do
      new :span
      new :b, name: "Helvetica-Bold"
      new :bold, name: "Helvetica-Bold"
      new :normal, name: "Helvetica"
      new :i, name: "Helvetica-Oblique", size: 8
      new :bi, name: "Helvetica-BoldOblique"
      new :big, size: 10
      new :small, size: 7
      new :h1, name: "Helvetica", size: 14
      new :h2, name: "Helvetica", size: 13
      new :h3, name: "Helvetica", size: 12
      new :h4, name: "Helvetica", size: 11
      new :h5, name: "Helvetica", size: 10
      new :title, name: "Helvetica", size: 20
      new :pre, name: "Courier"
    end
  end
end