module Msf

###
#
# The data store is just a bitbucket that holds keyed values.  It is used
# by various classes to hold option values and other state information.
#
###
class DataStore < Hash

	#
	# Initializes the data store's internal state.
	#
	def initialize()
		@imported    = Hash.new
		@imported_by = Hash.new
	end

	#
	# Clears the imported flag for the supplied key since it's being set
	# directly.
	#
	def []=(k, v)
		k = find_key_case(k)
		@imported[k] = false
		@imported_by[k] = nil

		super(k,v)
	end

	#
	# Case-insensitive wrapper around hash lookup
	#
	def [](k)
		super(find_key_case(k))
	end

	#
	# Case-insensitive wrapper around store
	#
	def store(k,v)
		super(find_key_case(k), v)
	end


	#
	# Updates a value in the datastore with the specified name, k, to the
	# specified value, v.  This update does not alter the imported status of
	# the value.
	#
	def update_value(k, v)
		self.store(k, v)
	end

	#
	# This method is a helper method that imports the default value for
	# all of the supplied options
	#
	def import_options(options, imported_by = nil, overwrite = false)
		options.each_option { |name, opt|
			# If there's already a value defined for this option, then skip it
			# and don't import it.
			next if self.has_key?(name) and overwrite == false

			# If the option has a default value, import it, but only if the
			# datastore doesn't already have a value set for it.
			if ((opt.default != nil) and (overwrite or self[name] == nil))
				import_option(name, opt.default.to_s, true, imported_by)
			end
		}
	end

	#
	# Imports option values from a whitespace separated string in
	# VAR=VAL format.
	#
	def import_options_from_s(option_str, delim = nil)
		hash = {}

		# Figure out the deliminter, default to space.
		if (delim.nil?)
			delim = /\s/

			if (option_str.split('=').length <= 2 or option_str.index(',') != nil)
				delim = ','
			end
		end

		# Split on the deliminter
		option_str.split(delim).each { |opt|
			var, val = opt.split('=')

			next if (var =~ /^\s+$/)


			# Invalid parse?  Raise an exception and let those bastards know.
			if (var == nil or val == nil)
				var = "unknown" if (!var)

				raise Rex::ArgumentParseError, "Invalid option specified: #{var}",
					caller
			end

			# Remove trailing whitespaces from the value
			val.gsub!(/\s+$/, '')

			# Store the value
			hash[var] = val
		}

		import_options_from_hash(hash)
	end

	#
	# Imports options from a hash and stores them in the datastore.
	#
	def import_options_from_hash(option_hash, imported = true, imported_by = nil)
		option_hash.each_pair { |key, val|
			import_option(key, val.to_s, imported, imported_by)
		}
	end

	def import_option(key, val, imported=true, imported_by=nil)
		self.store(key, val)

		@imported[key]    = imported
		@imported_by[key] = imported_by
	end

	#
	# Serializes the options in the datastore to a string.
	#
	def to_s(delim = ' ')
		str = ''

		keys.sort.each { |key|
			str << "#{key}=#{self[key]}" + ((str.length) ? delim : '')
		}

		return str
	end

	def to_h
		datastore_hash = {}
		self.keys.each do |k|
			datastore_hash[k.to_s] = self[k].to_s
		end
		datastore_hash
	end

	#
	# Persists the contents of the data store to a file
	#
	def to_file(path, name = 'global')
		ini = Rex::Parser::Ini.new(path)

		ini.add_group(name)

		# Save all user-defined options to the file.
		user_defined.each_pair { |k, v|
			ini[name][k] = v
		}

		ini.to_file(path)
	end

	#
	# Imports datastore values from the specified file path using the supplied
	# name
	#
	def from_file(path, name = 'global')
		begin
			ini = Rex::Parser::Ini.from_file(path)
		rescue
			return
		end

		if (ini.group?(name))
			import_options_from_hash(ini[name], false)
		end
	end

	#
	# Returns a hash of user-defined datastore values.  The returned hash does
	# not include default option values.
	#
	def user_defined
		reject { |k, v|
			@imported[k] == true
		}
	end

	#
	# Remove all imported options from the data store.
	#
	def clear_non_user_defined
		@imported.delete_if { |k, v|
			if (v and @imported_by[k] != 'self')
				self.delete(k)
				@imported_by.delete(k)
			end

			v
		}
	end

	#
	# Completely clear all values in the hash
	#
	def clear
		self.keys.each {|k| self.delete(k) }
		self
	end

protected

	#
	# Case-insensitive key lookup
	#
	def find_key_case(k)

		# Scan each key looking for a match
		self.each_key do |rk|
			if (rk.downcase == k.downcase)
				return rk
			end
		end

		# Fall through to the non-existent value
		return k
	end

end

###
#
# DataStore wrapper for modules that will attempt to back values against the
# framework's datastore if they aren't found in the module's datastore.  This
# is done to simulate global data store values.
#
###
class ModuleDataStore < DataStore

	def initialize(m)
		super()

		@_module = m
	end

	#
	# Fetch the key from the local hash first, or from the framework datastore
	# if we can't directly find it
	#
	def fetch(key)
		val = nil
		val = super if(@imported_by[key] != 'self')
		if (val.nil? and @_module and @_module.framework)
			val = @_module.framework.datastore[key]
		end
		val = super if val.nil?
		val
	end

	#
	# Same as fetch
	#
	def [](key)
		val = nil
		val = super if(@imported_by[key] != 'self')
		if (val.nil? and @_module and @_module.framework)
			val = @_module.framework.datastore[key]
		end
		val = super if val.nil?
		val
	end

	#
	# Was this entry actually set or just using its default
	#
	def default?(key)
		(@imported_by[key] == 'self')
	end

	#
	# Return a deep copy of this datastore.
	#
	def copy
		clone = self.class.new(@_module)
		self.keys.each do |k|
			clone.import_option(k, self[k].kind_of?(String) ? self[k].dup : self[k], @imported[k], @imported_by[k])
		end
		clone
	end
end

end

