"""
Copyright 2008, 2009 Free Software Foundation, Inc.
This file is part of GNU Radio

GNU Radio Companion is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

GNU Radio Companion is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
"""

from . import odict
from Element import Element
from Param import Param
from Port import Port

from Cheetah.Template import Template
from UserDict import UserDict

class TemplateArg(UserDict):
	"""
	A cheetah template argument created from a param.
	The str of this class evaluates to the param's to code method.
	The use of this class as a dictionary (enum only) will reveal the enum opts.
	The __call__ or () method can return the param evaluated to a raw python data type.
	"""

	def __init__(self, param):
		UserDict.__init__(self)
		self._param = param
		if param.is_enum():
			for key in param.get_opt_keys():
				self[key] = str(param.get_opt(key))

	def __str__(self):
		return str(self._param.to_code())

	def __call__(self):
		return self._param.get_evaluated()

def _get_keys(lst): return [elem.get_key() for elem in lst]
def _get_elem(lst, key):
	try: return lst[_get_keys(lst).index(key)]
	except ValueError: raise ValueError, 'Key "%s" not found in %s.'%(key, _get_keys(lst))

class Block(Element):

	def __init__(self, flow_graph, n):
		"""
		Make a new block from nested data.
		@param flow graph the parent element
		@param n the nested odict
		@return block a new block
		"""
		#build the block
		Element.__init__(self, flow_graph)
		#grab the data
		params = n.findall('param')
		sources = n.findall('source')
		sinks = n.findall('sink')
		self._name = n.find('name')
		self._key = n.find('key')
		self._category = n.find('category') or ''
		self._block_wrapper_path = n.find('block_wrapper_path')
		#create the param objects
		self._params = list()
		#add the id param
		self.get_params().append(self.get_parent().get_parent().Param(
			block=self,
			n=odict({
				'name': 'ID',
				'key': 'id',
				'type': 'id',
			})
		))
		self.get_params().append(self.get_parent().get_parent().Param(
			block=self,
			n=odict({
				'name': 'Enabled',
				'key': '_enabled',
				'type': 'raw',
				'value': 'True',
				'hide': 'all',
			})
		))
		for param in map(lambda n: self.get_parent().get_parent().Param(block=self, n=n), params):
			key = param.get_key()
			#test against repeated keys
			try: assert key not in self.get_param_keys()
			except AssertionError: raise Exception, 'Key "%s" already exists in params'%key
			#store the param
			self.get_params().append(param)
		#create the source objects
		self._sources = list()
		for source in map(lambda n: self.get_parent().get_parent().Port(block=self, n=n, dir='source'), sources):
			key = source.get_key()
			#test against repeated keys
			try: assert key not in self.get_source_keys()
			except AssertionError: raise Exception, 'Key "%s" already exists in sources'%key
			#store the port
			self.get_sources().append(source)
		#create the sink objects
		self._sinks = list()
		for sink in map(lambda n: self.get_parent().get_parent().Port(block=self, n=n, dir='sink'), sinks):
			key = sink.get_key()
			#test against repeated keys
			try: assert key not in self.get_sink_keys()
			except AssertionError: raise Exception, 'Key "%s" already exists in sinks'%key
			#store the port
			self.get_sinks().append(sink)

	def get_enabled(self):
		"""
		Get the enabled state of the block.
		@return true for enabled
		"""
		try: return eval(self.get_param('_enabled').get_value())
		except: return True

	def set_enabled(self, enabled):
		"""
		Set the enabled state of the block.
		@param enabled true for enabled
		"""
		self.get_param('_enabled').set_value(str(enabled))

	def __str__(self): return 'Block - %s - %s(%s)'%(self.get_id(), self.get_name(), self.get_key())

	def get_id(self): return self.get_param('id').get_value()
	def is_block(self): return True
	def get_name(self): return self._name
	def get_key(self): return self._key
	def get_category(self): return self._category
	def get_doc(self): return ''
	def get_ports(self): return self.get_sources() + self.get_sinks()
	def get_children(self): return self.get_ports() + self.get_params()
	def get_block_wrapper_path(self): return self._block_wrapper_path

	##############################################
	# Access Params
	##############################################
	def get_param_keys(self): return _get_keys(self._params)
	def get_param(self, key): return _get_elem(self._params, key)
	def get_params(self): return self._params

	##############################################
	# Access Sinks
	##############################################
	def get_sink_keys(self): return _get_keys(self._sinks)
	def get_sink(self, key): return _get_elem(self._sinks, key)
	def get_sinks(self): return self._sinks

	##############################################
	# Access Sources
	##############################################
	def get_source_keys(self): return _get_keys(self._sources)
	def get_source(self, key): return _get_elem(self._sources, key)
	def get_sources(self): return self._sources

	def get_connections(self):
		return sum([port.get_connections() for port in self.get_ports()], [])

	def resolve_dependencies(self, tmpl):
		"""
		Resolve a paramater dependency with cheetah templates.
		@param tmpl the string with dependencies
		@return the resolved value
		"""
		tmpl = str(tmpl)
		if '$' not in tmpl: return tmpl
		n = dict((p.get_key(), TemplateArg(p)) for p in self.get_params())
		try: return str(Template(tmpl, n))
		except Exception, e: return "-------->\n%s: %s\n<--------"%(e, tmpl)

	##############################################
	# Controller Modify
	##############################################
	def type_controller_modify(self, direction):
		"""
		Change the type controller.
		@param direction +1 or -1
		@return true for change
		"""
		changed = False
		type_param = None
		for param in filter(lambda p: p.is_enum(), self.get_params()):
			children = self.get_ports() + self.get_params()
			#priority to the type controller
			if param.get_key() in ' '.join(map(lambda p: p._type, children)): type_param = param
			#use param if type param is unset
			if not type_param: type_param = param
		if type_param:
			#try to increment the enum by direction
			try:
				keys = type_param.get_option_keys()
				old_index = keys.index(type_param.get_value())
				new_index = (old_index + direction + len(keys))%len(keys)
				type_param.set_value(keys[new_index])
				changed = True
			except: pass
		return changed

	def port_controller_modify(self, direction):
		"""
		Change the port controller.
		@param direction +1 or -1
		@return true for change
		"""
		return False

	##############################################
	## Import/Export Methods
	##############################################
	def export_data(self):
		"""
		Export this block's params to nested data.
		@return a nested data odict
		"""
		n = odict()
		n['key'] = self.get_key()
		n['param'] = map(lambda p: p.export_data(), self.get_params())
		return n

	def import_data(self, n):
		"""
		Import this block's params from nested data.
		Any param keys that do not exist will be ignored.
		@param n the nested data odict
		"""
		params_n = n.findall('param')
		for param_n in params_n:
			key = param_n.find('key')
			value = param_n.find('value')
			#the key must exist in this block's params
			if key in self.get_param_keys():
				self.get_param(key).set_value(value)