require 'aws'

module Dynamoid
  module Adapter
    module AwsSdk
      extend self
      @@connection = nil
    
      def connect!
        @@connection = AWS::DynamoDB.new(:access_key_id => Dynamoid::Config.access_key, :secret_access_key => Dynamoid::Config.secret_key)
      end
    
      def connection
        @@connection
      end
    
      # BatchGetItem
      def batch_get_item(options)
        batch = AWS::DynamoDB::BatchGet.new(:config => @@connection.config)
        hash = Hash.new{|h, k| h[k] = []}
        return hash if options.all?{|k, v| v.empty?}
        options.each do |t, ids|
          batch.table(t, :all, Array(ids)) unless ids.nil? || ids.empty?
        end
        batch.each do |table_name, attributes|
          hash[table_name] << attributes.symbolize_keys!
        end
        hash
      end
    
      # CreateTable
      def create_table(table_name, key)
        table = @@connection.tables.create(table_name, 10, 5, :hash_key => {key.to_sym => :string})
        sleep 0.5 while table.status == :creating
        return table
      end
    
      # DeleteItem
      def delete_item(table_name, key)
        table = @@connection.tables[table_name]
        table.load_schema
        result = table.items[key]
        result.delete unless result.attributes.to_h.empty?
        true
      end
    
      # DeleteTable
      def delete_table(table_name)
        @@connection.tables[table_name].delete
      end
    
      # DescribeTable
    
      # GetItem
      def get_item(table_name, key)
        table = @@connection.tables[table_name]
        table.load_schema
        result = table.items[key].attributes.to_h
        if result.empty?
          nil
        else
          result.symbolize_keys!
        end
      end
    
      # ListTables
      def list_tables
        @@connection.tables.collect(&:name)
      end
    
      # PutItem
      def put_item(table_name, object)
        table = @@connection.tables[table_name]
        table.load_schema
        table.items.create(object.delete_if{|k, v| v.nil? || v.empty?})
      end
    
      # Query
      def query(table_name, id)
        get_item(table_name, id)
      end
    
      # Scan
      def scan(table_name, scan_hash)
        table = @@connection.tables[table_name]
        table.load_schema
        results = []
        table.items.where(scan_hash).select do |data|
          results << data.attributes.symbolize_keys!
        end
        results
      end
    
      # UpdateItem
    
      # UpdateTable
    end
  end
end