# -*- ruby -*-
# vim: set nosta noet ts=4 sw=4 ft=ruby:
# encoding: utf-8

require 'mdbx' unless defined?( MDBX )


# TODO: rdoc
#
class MDBX::Database

	### Open an existing (or create a new) mdbx database at filesystem
	### +path+.  In block form, the database is automatically closed.
	###
	###    MDBX::Database.open( path ) -> db
	###    MDBX::Database.open( path, options ) -> db
	###    MDBX::Database.open( path, options ) do |db|
	###        db[ 'key' ] #=> value
	###    end
	###
	### FIXME: document all options!
	###
	def self::open( *args, &block )
		db = new( *args )

		db.serializer   = ->( v ) { Marshal.dump( v ) }
		db.deserializer = ->( v ) { Marshal.load( v ) }

		if block_given?
			begin
				yield db
			ensure
				db.close
			end
		end

		return db
	end


	# Only instantiate Database objects via #open.
	private_class_method :new


	# The options used to instantiate this database.
	attr_reader :options

	# The path on disk of the database.
	attr_reader :path

	# A Proc for automatically serializing values.
	attr_accessor :serializer

	# A Proc for automatically deserializing values.
	attr_accessor :deserializer


	### Switch to the top-level collection.
	###
	def main
		return self.collection( nil )
	end

	# Allow for some common nomenclature.
	alias_method :namespace, :collection


	### Return a hash of various metadata for the current database.
	###
	def statistics
		raw = self.raw_stats

		# Place build options in their own hash.
		#
		build_opts = raw.delete( :build_options ).split.each_with_object( {} ) do |opt, acc|
			key, val = opt.split( '=' )
			acc[ key.to_sym ] = Integer( val ) rescue val
		end

		stats = {
			build: {
				compiler: raw.delete( :build_compiler ),
				flags:    raw.delete( :build_flags ),
				options:  build_opts,
				target:   raw.delete( :build_target )
			}
		}
		stats.merge!( raw )

		return stats
	end

end # class MDBX::Database