# Copyright (c) 2012 Red Hat
#
# MIT License
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

require 'rest_client'
require 'oauth'
require 'json'
require 'thread'

module Runcible
  class Base
    def initialize(config = {})
      @mutex = Mutex.new
      @config = config
    end

    def lazy_config=(a_block)
      @mutex.synchronize { @lazy_config = a_block }
    end

    def config
      @mutex.synchronize do
        @config = @lazy_config.call if defined?(@lazy_config)
        fail Runcible::ConfigurationUndefinedError, Runcible::ConfigurationUndefinedError.message unless @config
        @config
      end
    end

    def path(*args)
      self.class.path(*args)
    end

    def call(method, path, options = {})
      clone_config = self.config.clone
      #on occation path will already have prefix (sync cancel)
      path = clone_config[:api_path] + path unless path.start_with?(clone_config[:api_path])

      RestClient.log    = []
      headers = clone_config[:headers].clone

      get_params = options[:params] if options[:params]
      path = combine_get_params(path, get_params) if get_params

      client_options = {}
      client_options[:timeout] =  clone_config[:timeout] if clone_config[:timeout]
      client_options[:open_timeout] =  clone_config[:open_timeout] if clone_config[:open_timeout]
      client_options[:verify_ssl] =  clone_config[:verify_ssl] unless clone_config[:verify_ssl].nil?

      if clone_config[:oauth]
        headers = add_oauth_header(method, path, headers) if clone_config[:oauth]
        headers['pulp-user'] = clone_config[:user]
        client = RestClient::Resource.new(clone_config[:url], client_options)
      else
        client_options[:user] =  clone_config[:user]
        client_options[:password] = config[:http_auth][:password]
        client = RestClient::Resource.new(clone_config[:url], client_options)
      end

      args = [method]
      args << generate_payload(options) if [:post, :put].include?(method)
      args << headers

      response = get_response(client, path, *args)
      process_response(response)

    rescue => e
      log_exception
      raise e
    end

    def get_response(client, path, *args)
      client[path].send(*args) do |response, request, result, &_block|
        resp = response.return!(request, result)
        log_debug
        return resp
      end
    end

    def combine_get_params(path, params)
      query_string  = params.map do |k, v|
        if v.is_a? Array
          v.map { |y| "#{k}=#{y}" }.join('&')
        else
          "#{k}=#{v}"
        end
      end
      query_string = query_string.flatten.join('&')
      path + "?#{query_string}"
    end

    def generate_payload(options)
      if options[:payload].is_a?(String)
        return options[:payload]
      elsif options[:payload].is_a?(Hash)
        format_payload_json(options[:payload])
      end
    end

    def format_payload_json(payload_hash)
      if payload_hash
        if payload_hash[:optional]
          if payload_hash[:required]
            payload = payload_hash[:required].merge(payload_hash[:optional])
          else
            payload = payload_hash[:optional]
          end
        elsif payload_hash[:delta]
          payload = payload_hash
        else
          payload = payload_hash[:required]
        end
      else
        payload = {}
      end

      return payload.to_json
    end

    def process_response(response)
      begin
        body = response.body == "null" ? nil : JSON.parse(response.body)
        if body.respond_to? :with_indifferent_access
          body = body.with_indifferent_access
        elsif body.is_a? Array
          body = body.map  do |i|
            i.respond_to?(:with_indifferent_access) ? i.with_indifferent_access : i
          end
        end
        response = RestClient::Response.create(body, response.net_http_res, response.args)
      rescue JSON::ParserError
        log_exception
      end

      return response
    end

    def required_params(local_names, binding, keys_to_remove = [])
      local_names = local_names.each_with_object({}) do |v, acc|
        value = binding.eval(v.to_s) unless v == :_
        acc[v] = value unless value.nil?
        acc
      end

      #The double delete is to support 1.8.7 and 1.9.3
      local_names.delete(:payload)
      local_names.delete(:optional)
      local_names.delete('payload')
      local_names.delete('optional')
      keys_to_remove.each do |key|
        local_names.delete(key)
        local_names.delete(key.to_sym)
      end

      return local_names
    end

    def add_http_auth_header
      return {:user => config[:user], :password => config[:http_auth][:password]}
    end

    def add_oauth_header(method, path, headers)
      default_options = { :site               => config[:url],
                          :http_method        => method,
                          :request_token_path => '',
                          :authorize_path     => '',
                          :access_token_path  => '' }

      default_options[:ca_file] = config[:ca_cert_file] unless config[:ca_cert_file].nil?
      consumer = OAuth::Consumer.new(config[:oauth][:oauth_key], config[:oauth][:oauth_secret], default_options)

      method_to_http_request = { :get    => Net::HTTP::Get,
                                 :post   => Net::HTTP::Post,
                                 :put    => Net::HTTP::Put,
                                 :delete => Net::HTTP::Delete }

      http_request = method_to_http_request[method].new(path)
      consumer.sign!(http_request)

      headers['Authorization'] = http_request['Authorization']
      return headers
    end

    def log_debug
      if self.config[:logging][:debug]
        log_message = generate_log_message
        self.config[:logging][:logger].debug(log_message)
      end
    end

    def log_exception
      if self.config[:logging][:exception]
        log_message = generate_log_message
        self.config[:logging][:logger].error(log_message)
      end
    end

    def generate_log_message
      RestClient.log.join('\n')
    end

    def logger
      self.config[:logging][:logger]
    end
  end

  class ConfigurationUndefinedError < StandardError
    def self.message
      # override me to change the error message
      'Configuration not set. Runcible::Base.config= must be called before Runcible::Base.config.'
    end
  end
end