require 'openbabel'
module OpenTox
  class Application < Service

    FORMATS = {
      "chemical/x-daylight-smiles" => "smi",
      "chemical/x-inchi" => "inchi",
      #"chemical/x-inchikey" => "inchikey",
      # OpenBabel segfaults randomly durng inchikey calculation
      "chemical/x-mdl-sdfile" => "sdf",
      "chemical/x-mdl-molfile" => "sdf",
      "image/png" => 'png',
    }

    helpers do
      # Convert identifier from OpenBabel input_format to OpenBabel output_format
      def obconversion(identifier,input_format,output_format)
        obconversion = OpenBabel::OBConversion.new
        obmol = OpenBabel::OBMol.new
        obconversion.set_in_and_out_formats input_format, output_format
        obconversion.read_string obmol, identifier
        case output_format
        when /smi|can|inchi/
          obconversion.write_string(obmol).gsub(/\s/,'').chomp
        else
          obconversion.write_string(obmol)
        end
      end
    end

    before do
      @inchi = URI.unescape request.env['REQUEST_URI'].sub(/^\//,'').sub(/.*compound\//,'').sub(/\/smarts.*$/,'').sub(/\/image/,'').sub(/\?.*$/,'') # hack to avoid sinatra's URI/CGI unescaping, splitting, ..."
    end

    get "/compound/?" do
      not_implemented_error "Object listing not implemented, because compounds are not stored at the server.", to("/compound")
    end

    get %r{/compound/(.+)/image} do |inchi| # catches all remaining get requests
      obconversion @inchi, "inchi", "png"
    end

    # Get compound representation
    # @param [optinal, HEADER] Accept one of `chemical/x-daylight-smiles, chemical/x-inchi, chemical/x-mdl-sdfile, chemical/x-mdl-molfile, text/plain, image/gif, image/png`, defaults to chemical/x-daylight-smiles
    # @example Get smiles
    #   curl http://webservices.in-silico.ch/compound/InChI=1S/C6H6/c1-2-4-6-5-3-1/h1-6H
    # @example Get all known names 
    #   curl -H "Accept:text/plain" http://webservices.in-silico.ch/compound/InChI=1S/C6H6/c1-2-4-6-5-3-1/h1-6H
    # @return [chemical/x-daylight-smiles, chemical/x-inchi, chemical/x-mdl-sdfile, chemical/x-mdl-molfile, text/plain, image/gif, image/png] Compound representation
    get %r{/compound/(.+)} do |inchi| # catches all remaining get requests
      bad_request_error "Unsupported MIME type '#{@accept}.", uri unless FORMATS.keys.include? @accept
      return @inchi if @accept == "chemical/x-inchi"
      obconversion @inchi, "inchi", FORMATS[@accept]
    end

    # Create a new compound URI (compounds are not saved at the compound service)
    # @param [HEADER] Content-type one of `chemical/x-daylight-smiles, chemical/x-inchi, chemical/x-mdl-sdfile, chemical/x-mdl-molfile, text/plain`
    # @example Create compound from Smiles string
    #   curl -X POST -H "Content-type:chemical/x-daylight-smiles" --data "c1ccccc1" http://webservices.in-silico.ch/compound
    # @example Create compound from name, uses an external lookup service and should work also with trade names, CAS numbers, ...
    #   curl -X POST -H "Content-type:text/plain" --data "Benzene" http://webservices.in-silico.ch/compound
    # @param [BODY] - string with identifier/data in selected Content-type
    # @return [text/uri-list] compound URI
    post '/compound/?' do 
      response['Content-Type'] = 'text/uri-list'
      bad_request_error "Unsupported MIME type '#{@content_type}.", uri unless FORMATS.keys.include? @content_type
      return to(File.join("/compound",@body)) if @content_type == "chemical/x-inchi"
      to(File.join("compound",obconversion(@body, FORMATS[@content_type], "inchi")))
    end

  end
end