module Screenbeacon

# File lib/screenbeacon.rb, line 49
def self.api_url(url='', api_base_url=nil)
  (api_base_url || @api_base) + url
end

# File lib/screenbeacon.rb, line 53
def self.request(method, url, api_id, api_token, params={}, headers={}, api_base_url=nil)
  api_base_url = api_base_url || @api_base

  unless api_id ||= @api_id
    raise AuthenticationError.new('No API ID provided. ' \
      'Set your API ID using "Screenbeacon.api_id = <API-ID>". ' \
      'You can generate API ID from the Screenbeacon web interface. ' \
      'See https://screenbeacon.com/dashboard/settings for details, or email support@screenbeacon.com ' \
      'if you have any questions.')
  end

  unless api_token ||= @api_token
    raise AuthenticationError.new('No API token provided. ' \
      'Set your API token using "Screenbeacon.api_token = <API-TOKEN>". ' \
      'You can generate API token from the Screenbeacon web interface. ' \
      'See https://screenbeacon.com/dashboard/settings for details, or email support@screenbeacon.com ' \
      'if you have any questions.')
  end

  if api_id =~ /\s/
    raise AuthenticationError.new('Your API key is invalid, as it contains ' \
      'whitespace. (HINT: You can double-check your API key from the ' \
      'Screenbeacon web interface. See https://screenbeacon.com/dashboard/settings for details, or ' \
      'email support@screenbeacon.com if you have any questions.)')
  end

  if api_token =~ /\s/
    raise AuthenticationError.new('Your API token is invalid, as it contains ' \
      'whitespace. (HINT: You can double-check your API token from the ' \
      'Screenbeacon web interface. See https://screenbeacon.com/dashboard/settings for details, or ' \
      'email support@screenbeacon.com if you have any questions.)')
  end

  if verify_ssl_certs
    request_opts = {:verify_ssl => OpenSSL::SSL::VERIFY_PEER,
                    :ssl_ca_file => @ssl_bundle_path}
  else
    request_opts = {:verify_ssl => false}
    unless @verify_ssl_warned
      @verify_ssl_warned = true
      $stderr.puts("WARNING: Running without SSL cert verification. " \
        "You should never do this in production. " \
        "Execute 'Screenbeacon.verify_ssl_certs = true' to enable verification.")
    end
  end

  params = Util.objects_to_ids(params)
  url = api_url(url, api_base_url)

  case method.to_s.downcase.to_sym
  when :get, :head, :delete
    # Make params into GET parameters
    url += "#{URI.parse(url).query ? '&' : '?'}#{uri_encode(params)}" if params && params.any?
    payload = nil
  else
    if headers[:content_type] && headers[:content_type] == "multipart/form-data"
      payload = params
    else
      payload = uri_encode(params)
    end
  end

  request_opts.update(:headers => request_headers(api_id, api_token).update(headers),
                      :method => method, :open_timeout => 30,
                      :payload => payload, :url => url, :timeout => 80)

  begin
    response = execute_request(request_opts)
  rescue SocketError => e
    handle_restclient_error(e, api_base_url)
  rescue NoMethodError => e
    # Work around RestClient bug
    if e.message =~ /\WRequestFailed\W/
      e = APIConnectionError.new('Unexpected HTTP response code')
      handle_restclient_error(e, api_base_url)
    else
      raise
    end
  rescue RestClient::ExceptionWithResponse => e
    if rcode = e.http_code and rbody = e.http_body
      handle_api_error(rcode, rbody)
    else
      handle_restclient_error(e, api_base_url)
    end
  rescue RestClient::Exception, Errno::ECONNREFUSED => e
    handle_restclient_error(e, api_base_url)
  end

  [parse(response), api_id, api_token]
end

# File lib/screenbeacon.rb, line 178
def self._uname_uname
  (`uname -a 2>/dev/null` || '').strip
rescue Errno::ENOMEM # couldn't create subprocess
  "uname lookup failed"
end

# File lib/screenbeacon.rb, line 184
def self._uname_ver
  (`ver` || '').strip
rescue Errno::ENOMEM # couldn't create subprocess
  "uname lookup failed"
end

# File lib/screenbeacon.rb, line 268
def self.api_error(error, rcode, rbody, error_obj)
  APIError.new(error, rcode, rbody, error_obj)
end

# File lib/screenbeacon.rb, line 264
def self.authentication_error(error, rcode, rbody, error_obj)
  AuthenticationError.new(error, rcode, rbody, error_obj)
end

# File lib/screenbeacon.rb, line 215
def self.execute_request(opts)
  RestClient::Request.execute(opts)
end

# File lib/screenbeacon.rb, line 231
def self.general_api_error(rcode, rbody)
  APIError.new("Invalid response object from API: #{rbody.inspect} " +
               "(HTTP response code was #{rcode})", rcode, rbody)
end

# File lib/screenbeacon.rb, line 163
def self.get_uname
  if File.exist?('/proc/version')
    File.read('/proc/version').strip
  else
    case RbConfig::CONFIG['host_os']
    when /linux|darwin|bsd|sunos|solaris|cygwin/i
      _uname_uname
    when /mswin|mingw/i
      _uname_ver
    else
      "unknown platform"
    end
  end
end

# File lib/screenbeacon.rb, line 236
def self.handle_api_error(rcode, rbody)
  begin
    error_obj = JSON.parse(rbody)
    error_obj = Util.symbolize_names(error_obj)
    error = error_obj[:error] or raise ScreenbeaconError.new # escape from parsing

  rescue JSON::ParserError, ScreenbeaconError
    raise general_api_error(rcode, rbody)
  end

  case rcode
  when 400, 404
    raise invalid_request_error error, rcode, rbody, error_obj
  when 401
    raise authentication_error error, rcode, rbody, error_obj
  when 402
    raise card_error error, rcode, rbody, error_obj
  else
    raise api_error error, rcode, rbody, error_obj
  end

end

# File lib/screenbeacon.rb, line 272
def self.handle_restclient_error(e, api_base_url=nil)
  api_base_url = @api_base unless api_base_url
  connection_message = "Please check your internet connection and try again. " \
      "If this problem persists, you should check Screenbeacon's service status at " \
      "https://twitter.com/screenbeacon, or let us know at support@screenbeacon.com."

  case e
  when RestClient::RequestTimeout
    message = "Could not connect to Screenbeacon (#{api_base_url}). #{connection_message}"

  when RestClient::ServerBrokeConnection
    message = "The connection to the server (#{api_base_url}) broke before the " \
      "request completed. #{connection_message}"

  when RestClient::SSLCertificateNotVerified
    message = "Could not verify Screenbeacon's SSL certificate. " \
      "Please make sure that your network is not intercepting certificates. " \
      "(Try going to https://api.screenbeacon.com in your browser.) " \
      "If this problem persists, let us know at support@screenbeacon.com."

  when SocketError
    message = "Unexpected error communicating when trying to connect to Screenbeacon. " \
      "You may be seeing this message because your DNS is not working. " \
      "To check, try running 'host screenbeacon.com' from the command line."

  else
    message = "Unexpected error communicating with Screenbeacon. " \
      "If this problem persists, let us know at support@screenbeacon.com."

  end

  raise APIConnectionError.new(message + "\n\n(Network error: #{e.message})")
end

# File lib/screenbeacon.rb, line 259
def self.invalid_request_error(error, rcode, rbody, error_obj)
  # We're not returning a params as part of the error for now, so set it to nil.
  InvalidRequestError.new(error, nil, rcode, rbody, error_obj)
end

# File lib/screenbeacon.rb, line 219
def self.parse(response)
  begin
    # Would use :symbolize_names => true, but apparently there is
    # some library out there that makes symbolize_names not work.
    response = JSON.parse(response.body)
  rescue JSON::ParserError
    raise general_api_error(response.code, response.body)
  end

  Util.symbolize_names(response)
end

# File lib/screenbeacon.rb, line 196
def self.request_headers(api_id, api_token)
  headers = {
    :user_agent => "Screenbeacon/v1 RubyBindings/#{Screenbeacon::VERSION}",
    # :authorization => "Bearer #{api_id}",
    :content_type => 'application/x-www-form-urlencoded'
  }

  headers['Screenbeacon-Version'] = api_version if api_version
  headers['X-API-ID'] = api_id
  headers['X-API-TOKEN'] = api_token

  begin
    headers.update(:x_screenbeacon_client_user_agent => JSON.generate(user_agent))
  rescue => e
    headers.update(:x_screenbeacon_client_raw_user_agent => user_agent.inspect,
                   :error => "#{e} (#{e.class})")
  end
end

# File lib/screenbeacon.rb, line 191
def self.uri_encode(params)
  Util.flatten_params(params).
    map { |k,v| "#{k}=#{Util.url_encode(v)}" }.join('&')
end

# File lib/screenbeacon.rb, line 146
def self.user_agent
  @uname ||= get_uname
  lang_version = "#{RUBY_VERSION} p#{RUBY_PATCHLEVEL} (#{RUBY_RELEASE_DATE})"

  {
    :bindings_version => Screenbeacon::VERSION,
    :lang => 'ruby',
    :lang_version => lang_version,
    :platform => RUBY_PLATFORM,
    :engine => defined?(RUBY_ENGINE) ? RUBY_ENGINE : '',
    :publisher => 'screenbeacon',
    :uname => @uname,
    :hostname => Socket.gethostname,
  }

end