=begin
#MX API

#The MX Atrium API supports over 48,000 data connections to thousands of financial institutions. It provides secure access to your users' accounts and transactions with industry-leading cleansing, categorization, and classification.  Atrium is designed according to resource-oriented REST architecture and responds with JSON bodies and HTTP response codes.  Use Atrium's development environment, vestibule.mx.com, to quickly get up and running. The development environment limits are 100 users, 25 members per user, and access to the top 15 institutions. Contact MX to purchase production access. 


=end

require 'date'
require 'json'
require 'logger'
require 'tempfile'
require 'typhoeus'
require 'uri'

module Atrium
  class ApiClient
    # The Configuration object holding settings to be used in the API client.
    attr_accessor :config

    # Defines the headers to be used in HTTP requests of all API calls by default.
    #
    # @return [Hash]
    attr_accessor :default_headers

    # Initializes the ApiClient
    # @option config [Configuration] Configuration for initializing the object, default to Configuration.default
    def initialize(config = Configuration.default)
      @config = config
      @user_agent = "MX-Codegen/#{VERSION}/ruby"
      @default_headers = {
        'Content-Type' => 'application/json',
        'User-Agent' => @user_agent
      }
    end

    def self.default
      @@default ||= ApiClient.new
    end

    # Call an API with given options.
    #
    # @return [Array<(Object, Fixnum, Hash)>] an array of 3 elements:
    #   the data deserialized from response body (could be nil), response status code and response headers.
    def call_api(http_method, path, opts = {})
      request = build_request(http_method, path, opts)
      response = request.run

      if @config.debugging
        @config.logger.debug "HTTP response body ~BEGIN~\n#{response.body}\n~END~\n"
      end

      unless response.success?
        if response.timed_out?
          fail ApiError.new('Connection timed out')
        elsif response.code == 0
          # Errors from libcurl will be made visible here
          fail ApiError.new(:code => 0,
                            :message => response.return_message)
        else
          fail ApiError.new(:code => response.code,
                            :response_headers => response.headers,
                            :response_body => response.body),
               response.status_message
        end
      end

      if opts[:return_type]
        data = deserialize(response, opts[:return_type])
      else
        data = nil
      end
      return data, response.code, response.headers
    end

    # Builds the HTTP request
    #
    # @param [String] http_method HTTP method/verb (e.g. POST)
    # @param [String] path URL path (e.g. /account/new)
    # @option opts [Hash] :header_params Header parameters
    # @option opts [Hash] :query_params Query parameters
    # @option opts [Hash] :form_params Query parameters
    # @option opts [Object] :body HTTP body (JSON/XML)
    # @return [Typhoeus::Request] A Typhoeus Request
    def build_request(http_method, path, opts = {})
      url = build_request_url(path)
      http_method = http_method.to_sym.downcase

      header_params = @default_headers.merge(opts[:header_params] || {})
      query_params = opts[:query_params] || {}
      form_params = opts[:form_params] || {}

      update_params_for_auth! header_params, query_params, opts[:auth_names]

      # set ssl_verifyhosts option based on @config.verify_ssl_host (true/false)
      _verify_ssl_host = @config.verify_ssl_host ? 2 : 0

      req_opts = {
        :method => http_method,
        :headers => header_params,
        :params => query_params,
        :params_encoding => @config.params_encoding,
        :timeout => @config.timeout,
        :ssl_verifypeer => @config.verify_ssl,
        :ssl_verifyhost => _verify_ssl_host,
        :sslcert => @config.cert_file,
        :sslkey => @config.key_file,
        :verbose => @config.debugging,
        :proxy => @config.proxy_url
      }

      # set custom cert, if provided
      req_opts[:cainfo] = @config.ssl_ca_cert if @config.ssl_ca_cert

      if [:post, :patch, :put, :delete].include?(http_method)
        req_body = build_request_body(header_params, form_params, opts[:body])
        req_opts.update :body => req_body
        if @config.debugging
          @config.logger.debug "HTTP request body param ~BEGIN~\n#{req_body}\n~END~\n"
        end
      end

      request = Typhoeus::Request.new(url, req_opts)
      download_file(request) if opts[:return_type] == 'File'
      request
    end

    # Check if the given MIME is a JSON MIME.
    # JSON MIME examples:
    #   application/json
    #   application/json; charset=UTF8
    #   APPLICATION/JSON
    #   */*
    # @param [String] mime MIME
    # @return [Boolean] True if the MIME is application/json
    def json_mime?(mime)
      (mime == '*/*') || !(mime =~ /Application\/.*json(?!p)(;.*)?/i).nil?
    end

    # Deserialize the response to the given return type.
    #
    # @param [Response] response HTTP response
    # @param [String] return_type some examples: "User", "Array[User]", "Hash[String,Integer]"
    def deserialize(response, return_type)
      body = response.body

      # handle file downloading - return the File instance processed in request callbacks
      # note that response body is empty when the file is written in chunks in request on_body callback
      return @tempfile if return_type == 'File'

      return nil if body.nil? || body.empty?

      # return response body directly for String return type
      return body if return_type == 'String'

      # ensuring a default content type
      content_type = response.headers['Content-Type'] || 'application/json'

      fail "Content-Type is not supported: #{content_type}" unless json_mime?(content_type)

      begin
        data = JSON.parse("[#{body}]", :symbolize_names => true)[0]
      rescue JSON::ParserError => e
        if %w(String Date DateTime).include?(return_type)
          data = body
        else
          raise e
        end
      end

      convert_to_type data, return_type
    end

    # Convert data to the given return type.
    # @param [Object] data Data to be converted
    # @param [String] return_type Return type
    # @return [Mixed] Data in a particular type
    def convert_to_type(data, return_type)
      return nil if data.nil?
      case return_type
      when 'String'
        data.to_s
      when 'Integer'
        data.to_i
      when 'Float'
        data.to_f
      when 'BOOLEAN'
        data == true
      when 'DateTime'
        # parse date time (expecting ISO 8601 format)
        DateTime.parse data
      when 'Date'
        # parse date time (expecting ISO 8601 format)
        Date.parse data
      when 'Object'
        # generic object (usually a Hash), return directly
        data
      when /\AArray<(.+)>\z/
        # e.g. Array<Pet>
        sub_type = $1
        data.map { |item| convert_to_type(item, sub_type) }
      when /\AHash\<String, (.+)\>\z/
        # e.g. Hash<String, Integer>
        sub_type = $1
        {}.tap do |hash|
          data.each { |k, v| hash[k] = convert_to_type(v, sub_type) }
        end
      else
        # models, e.g. Pet
        Atrium.const_get(return_type).new.tap do |model|
          model.build_from_hash data
        end
      end
    end

    # Save response body into a file in (the defined) temporary folder, using the filename
    # from the "Content-Disposition" header if provided, otherwise a random filename.
    # The response body is written to the file in chunks in order to handle files which
    # size is larger than maximum Ruby String or even larger than the maximum memory a Ruby
    # process can use.
    #
    # @see Configuration#temp_folder_path
    def download_file(request)
      tempfile = nil
      encoding = nil
      request.on_headers do |response|
        content_disposition = response.headers['Content-Disposition']
        if content_disposition && content_disposition =~ /filename=/i
          filename = content_disposition[/filename=['"]?([^'"\s]+)['"]?/, 1]
          prefix = sanitize_filename(filename)
        else
          prefix = 'download-'
        end
        prefix = prefix + '-' unless prefix.end_with?('-')
        encoding = response.body.encoding
        tempfile = Tempfile.open(prefix, @config.temp_folder_path, encoding: encoding)
        @tempfile = tempfile
      end
      request.on_body do |chunk|
        chunk.force_encoding(encoding)
        tempfile.write(chunk)
      end
      request.on_complete do |response|
        tempfile.close
        @config.logger.info "Temp file written to #{tempfile.path}, please copy the file to a proper folder "\
                            "with e.g. `FileUtils.cp(tempfile.path, '/new/file/path')` otherwise the temp file "\
                            "will be deleted automatically with GC. It's also recommended to delete the temp file "\
                            "explicitly with `tempfile.delete`"
      end
    end

    # Sanitize filename by removing path.
    # e.g. ../../sun.gif becomes sun.gif
    #
    # @param [String] filename the filename to be sanitized
    # @return [String] the sanitized filename
    def sanitize_filename(filename)
      filename.gsub(/.*[\/\\]/, '')
    end

    def build_request_url(path)
      # Add leading and trailing slashes to path
      path = "/#{path}".gsub(/\/+/, '/')
      URI.encode(@config.base_url + path)
    end

    # Builds the HTTP request body
    #
    # @param [Hash] header_params Header parameters
    # @param [Hash] form_params Query parameters
    # @param [Object] body HTTP body (JSON/XML)
    # @return [String] HTTP body data in the form of string
    def build_request_body(header_params, form_params, body)
      # http form
      if header_params['Content-Type'] == 'application/x-www-form-urlencoded' ||
          header_params['Content-Type'] == 'multipart/form-data'
        data = {}
        form_params.each do |key, value|
          case value
          when ::File, ::Array, nil
            # let typhoeus handle File, Array and nil parameters
            data[key] = value
          else
            data[key] = value.to_s
          end
        end
      elsif body
        data = body.is_a?(String) ? body : body.to_json
      else
        data = nil
      end
      data
    end

    # Update hearder and query params based on authentication settings.
    #
    # @param [Hash] header_params Header parameters
    # @param [Hash] query_params Query parameters
    # @param [String] auth_names Authentication scheme name
    def update_params_for_auth!(header_params, query_params, auth_names)
      Array(auth_names).each do |auth_name|
        auth_setting = @config.auth_settings[auth_name]
        next unless auth_setting
        case auth_setting[:in]
        when 'header' then header_params[auth_setting[:key]] = auth_setting[:value]
        when 'query'  then query_params[auth_setting[:key]] = auth_setting[:value]
        else fail ArgumentError, 'Authentication token must be in `query` of `header`'
        end
      end
    end

    # Sets user agent in HTTP header
    #
    def user_agent=(user_agent)
      @user_agent = user_agent
      @default_headers['User-Agent'] = @user_agent
    end

    # Return Accept header based on an array of accepts provided.
    # @param [Array] accepts array for Accept
    # @return [String] the Accept header (e.g. application/json)
    def select_header_accept(accepts)
      return nil if accepts.nil? || accepts.empty?
      # use JSON when present, otherwise use all of the provided
      json_accept = accepts.find { |s| json_mime?(s) }
      json_accept || accepts.join(',')
    end

    # Return Content-Type header based on an array of content types provided.
    # @param [Array] content_types array for Content-Type
    # @return [String] the Content-Type header  (e.g. application/json)
    def select_header_content_type(content_types)
      # use application/json by default
      return 'application/json' if content_types.nil? || content_types.empty?
      # use JSON when present, otherwise use the first one
      json_content_type = content_types.find { |s| json_mime?(s) }
      json_content_type || content_types.first
    end

    # Convert object (array, hash, object, etc) to JSON string.
    # @param [Object] model object to be converted into JSON string
    # @return [String] JSON string representation of the object
    def object_to_http_body(model)
      return model if model.nil? || model.is_a?(String)
      local_body = nil
      if model.is_a?(Array)
        local_body = model.map { |m| object_to_hash(m) }
      else
        local_body = object_to_hash(model)
      end
      local_body.to_json
    end

    # Convert object(non-array) to hash.
    # @param [Object] obj object to be converted into JSON string
    # @return [String] JSON string representation of the object
    def object_to_hash(obj)
      if obj.respond_to?(:to_hash)
        obj.to_hash
      else
        obj
      end
    end

    # Build parameter value according to the given collection format.
    # @param [String] collection_format one of :csv, :ssv, :tsv, :pipes and :multi
    def build_collection_param(param, collection_format)
      case collection_format
      when :csv
        param.join(',')
      when :ssv
        param.join(' ')
      when :tsv
        param.join("\t")
      when :pipes
        param.join('|')
      when :multi
        # return the array directly as typhoeus will handle it as expected
        param
      else
        fail "unknown collection format: #{collection_format.inspect}"
      end
    end
  end
end
