# encoding: UTF-8

module Vines
  class Storage
    class CouchDB < Storage
      register :couchdb

      %w[host port database tls username password].each do |name|
        define_method(name) do |*args|
          if args.first
            @config[name.to_sym] = args.first
          else
            @config[name.to_sym]
          end
        end
      end

      def initialize(&block)
        @config = {}
        instance_eval(&block)
        [:host, :port, :database].each {|key| raise "Must provide #{key}" unless @config[key] }
        @url = url(@config)
      end

      def find_user(jid)
        jid = JID.new(jid || '').bare.to_s
        if jid.empty? then yield; return end
        get("user:#{jid}") do |doc|
          user = if doc && doc['type'] == 'User'
            User.new(:jid => jid).tap do |user|
              user.name, user.password = doc.values_at('name', 'password')
              (doc['roster'] || {}).each_pair do |jid, props|
                user.roster << Contact.new(
                  :jid => jid,
                  :name => props['name'],
                  :subscription => props['subscription'],
                  :ask => props['ask'],
                  :groups => props['groups'] || [])
              end
            end
          end
          yield user
        end
      end
      fiber :find_user

      def save_user(user, &callback)
        id = "user:#{user.jid.bare}"
        get(id) do |doc|
          doc ||= {'_id' => id}
          doc['type'] = 'User'
          doc['name'] = user.name
          doc['password'] = user.password
          doc['roster'] = {}
          user.roster.each do |contact|
            doc['roster'][contact.jid.bare.to_s] = contact.to_h
          end
          save_doc(doc, &callback)
        end
      end
      fiber :save_user

      def find_vcard(jid)
        jid = JID.new(jid || '').bare.to_s
        if jid.empty? then yield; return end
        get("vcard:#{jid}") do |doc|
          card = if doc && doc['type'] == 'Vcard'
            Nokogiri::XML(doc['card']).root rescue nil
          end
          yield card
        end
      end
      fiber :find_vcard

      def save_vcard(jid, card, &callback)
        jid = JID.new(jid).bare.to_s
        id = "vcard:#{jid}"
        get(id) do |doc|
          doc ||= {'_id' => id}
          doc['type'] = 'Vcard'
          doc['card'] = card.to_xml
          save_doc(doc, &callback)
        end
      end
      fiber :save_vcard

      private

      def url(config)
        scheme = config[:tls] ? 'https' : 'http'
        user, password = config.values_at(:username, :password)
        credentials = empty?(user, password) ? '' : "%s:%s@" % [user, password]
        "%s://%s%s:%s/%s" % [scheme, credentials, *config.values_at(:host, :port, :database)]
      end

      def get(jid)
        http = EM::HttpRequest.new("#{@url}/#{escape(jid)}").get
        http.errback { yield }
        http.callback do
          doc = if http.response_header.status == 200
            JSON.parse(http.response) rescue nil
          end
          yield doc
        end
      end

      def save_doc(doc, &callback)
        http = EM::HttpRequest.new(@url).post(
          :head => {'Content-Type' => 'application/json'}, :body => doc.to_json)
        http.callback(&callback) if callback
        http.errback(&callback) if callback
      end

      def escape(jid)
        URI.escape(jid, Regexp.new("[^#{URI::PATTERN::UNRESERVED}]"))
      end
    end
  end
end