require 'bigdecimal'
require 'thread'

class HBase
# @!attribute [r] name
#   @return [String] The name of the table
# @!attribute [r] config
#   @return [org.apache.hadoop.conf.Configuration]
class Table
  attr_reader :name
  attr_reader :config

  include Enumerable
  include Admin
  include Scoped::Aggregation::Admin
  include HBase::Util

  # (INTERNAL) Returns the underlying org.apache.hadoop.hbase.client.HTable object (local to current thread)
  # @return [org.apache.hadoop.hbase.client.HTable]
  def htable
    check_closed

    local_htables = Thread.current[:htable] ||= {}
    local_htables[@name] ||= @pool.get_table(@name)
  end

  # @deprecated
  # @return [nil]
  def close
    nil
  end

  [:get, :count, :aggregate,
   :range, :project, :filter, :while,
   :limit, :versions, :caching, :batch,
   :time_range, :at
  ].each do |method|
    define_method(method) do |*args|
      self.each.send(method, *args)
    end
  end

  # Performs PUT operations
  # @overload put(rowkey, data)
  #   Put operation on a rowkey
  #   @param [Object] rowkey Rowkey
  #   @param [Hash] data Data to put
  #   @return [Fixnum] Number of puts succeeded
  # @overload put(data)
  #   Put operation on multiple rowkeys
  #   @param [Hash<Hash>] data Data to put indexed by rowkeys
  #   @return [Fixnum] Number of puts succeeded
  def put *args
    return put(args.first => args.last) if args.length == 2

    puts = args.first.map { |rowkey, props| putify rowkey, props }
    htable.put puts
    puts.length
  end

  # Deletes data
  # @overload delete(rowkey)
  #   Deletes a row with the given rowkey
  #   @param [Object] rowkey
  #   @return [nil]
  #   @example
  #     table.delete('a000')
  # @overload delete(rowkey, column_family)
  #   Deletes columns with the given column family from the row
  #   @param [Object] rowkey
  #   @param [String] column_family
  #   @return [nil]
  #   @example
  #     table.delete('a000', 'cf1')
  # @overload delete(rowkey, column)
  #   Deletes a column
  #   @param [Object] rowkey
  #   @param [String, Array] column Column expression in String "FAMILY:QUALIFIER", or in Array [FAMILY, QUALIFIER]
  #   @return [nil]
  #   @example
  #     table.delete('a000', 'cf1:col1')
  # @overload delete(rowkey, column, *timestamps)
  #   Deletes specified versions of a column
  #   @param [Object] rowkey
  #   @param [String, Array] column Column expression in String "FAMILY:QUALIFIER", or in Array [FAMILY, QUALIFIER]
  #   @param [*Fixnum] timestamps Timestamps.
  #   @return [nil]
  #   @example
  #     table.delete('a000', 'cf1:col1', 1352978648642)
  # @overload delete(*delete_specs)
  #   Batch deletion
  #   @param [Array<Array>] delete_specs
  #   @return [nil]
  #   @example
  #     table.delete(
  #       ['a000', 'cf1:col1', 1352978648642],
  #       ['a001', 'cf1:col1'],
  #       ['a002', 'cf1'],
  #       ['a003'])
  def delete *args
    specs = args.first.is_a?(Array) ? args : [args]

    htable.delete specs.map { |spec|
      rowkey, cfcq, *ts = spec
      cf, cq = Util.parse_column_name(cfcq) if cfcq

      Delete.new(Util.to_bytes rowkey).tap { |del|
        if !ts.empty?
          ts.each do |t|
            del.deleteColumn cf, cq, time_to_long(t)
          end
        elsif cq
          # Delete all versions
          del.deleteColumns cf, cq
        elsif cf
          del.deleteFamily cf
        end
      }
    }
  end

  # Atomically increase numeric values
  # @overload increment(rowkey, column, by)
  #   Atomically increase column value by the specified amount
  #   @param [Object] rowkey Rowkey
  #   @param [String, Array] column Column expression in String "FAMILY:QUALIFIER", or in Array [FAMILY, QUALIFIER]
  #   @param [Fixnum] by Increment amount
  #   @return [Fixnum] Column value after increment
  #   @example
  #     table.increment('a000', 'cf1:col1', 1)
  # @overload increment(rowkey, column_by_hash)
  #   Atomically increase values of multiple columns
  #   @param [Object] rowkey Rowkey
  #   @param [Hash] column_by_hash Column expression to increment amount pairs
  #   @example
  #     table.increment('a000', 'cf1:col1' => 1, 'cf1:col2' => 2)
  def increment rowkey, *args
    if args.first.is_a?(Hash)
      cols = args.first
      htable.increment Increment.new(Util.to_bytes rowkey).tap { |inc|
        cols.each do |col, by|
          cf, cq = Util.parse_column_name(col)
          inc.addColumn cf, cq, by
        end
      }
    else
      col, by = args
      cf, cq = Util.parse_column_name(col)
      htable.incrementColumnValue Util.to_bytes(rowkey), cf, cq, by || 1
    end
  end

  # Scan through the table
  # @yield [row] Yields each row in the scope
  # @yieldparam [HBase::Result] row
  # @return [HBase::Scoped]
  def each
    check_closed

    if block_given?
      Scoped.send(:new, self).each { |r| yield r }
    else
      Scoped.send(:new, self)
    end
  end

private
  def initialize hbase, config, htable_pool, name
    @hbase  = hbase
    @config = config
    @pool   = htable_pool
    @name   = name.to_s
  end

  def check_closed
    raise RuntimeError, "HBase connection is already closed" if @hbase.closed?
  end

  def putify rowkey, props
    Put.new(Util.to_bytes rowkey).tap { |put|
      props.each do |col, val|
        cf, cq = Util.parse_column_name(col)
        case val
        when Hash
          val.each do |t, v|
            case t
            # Timestamp / Ruby Time
            when Time, Fixnum
              put.add cf, cq, time_to_long(t), Util.to_bytes(v)
            # Types: :byte, :short, :int, ...
            else
              put.add cf, cq, Util.to_bytes(t => v)
            end
          end
        else
          put.add cf, cq, Util.to_bytes(val)
        end
      end
    }
  end
end#Table
end#HBase