"""
Copyright 2008-2011 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
"""

import os
import sys
import subprocess
import tempfile
from Cheetah.Template import Template
import expr_utils
from Constants import \
	TOP_BLOCK_FILE_MODE, HIER_BLOCK_FILE_MODE, \
	HIER_BLOCKS_LIB_DIR, FLOW_GRAPH_TEMPLATE
import convert_hier
from .. gui import Messages

class Generator(object):

	def __init__(self, flow_graph, file_path):
		"""
		Initialize the generator object.
		Determine the file to generate.
		@param flow_graph the flow graph object
		@param file_path the path to write the file to
		"""
		self._flow_graph = flow_graph
		self._generate_options = self._flow_graph.get_option('generate_options')
		if self._generate_options == 'hb':
			self._mode = HIER_BLOCK_FILE_MODE
			dirname = HIER_BLOCKS_LIB_DIR
		else:
			self._mode = TOP_BLOCK_FILE_MODE
			dirname = os.path.dirname(file_path)
			#handle the case where the directory is read-only
			#in this case, use the system's temp directory
			if not os.access(dirname, os.W_OK):
				dirname = tempfile.gettempdir()
		filename = self._flow_graph.get_option('id') + '.py'
		self._file_path = os.path.join(dirname, filename)

	def get_file_path(self): return self._file_path

	def write(self):
		#do throttle warning
		throttled = any(map(lambda b: b.throttle(), self._flow_graph.get_enabled_blocks()))
		if not throttled and self._generate_options != 'hb':
			Messages.send_warning('''\
This flow graph may not have flow control: no audio or usrp blocks found. \
Add a Misc->Throttle block to your flow graph to avoid CPU congestion.''')
		#generate
		open(self.get_file_path(), 'w').write(str(self))
		if self._generate_options == 'hb':
			#convert hier block to xml wrapper
			convert_hier.convert_hier(self._flow_graph, self.get_file_path())
		os.chmod(self.get_file_path(), self._mode)

	def get_popen(self):
		"""
		Execute this python flow graph.
		@return a popen object
		"""
		#extract the path to the python executable
		python_exe = sys.executable

		#when using wx gui on mac os, execute with pythonw
		#using pythonw is not necessary anymore, disabled below
		#if self._generate_options == 'wx_gui' and 'darwin' in sys.platform.lower():
		#	python_exe = 'pythonw'

		#setup the command args to run
		cmds = [python_exe, '-u', self.get_file_path()] #-u is unbuffered stdio

		#when in no gui mode on linux, use an xterm (looks nice)
		if self._generate_options == 'no_gui' and 'linux' in sys.platform.lower():
			cmds = ['xterm', '-e'] + cmds

		p = subprocess.Popen(args=cmds, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, shell=False, universal_newlines=True)
		return p

	def __str__(self):
		"""
		Convert the flow graph to python code.
		@return a string of python code
		"""
		title = self._flow_graph.get_option('title') or self._flow_graph.get_option('id').replace('_', ' ').title()
		imports = self._flow_graph.get_imports()
		variables = self._flow_graph.get_variables()
		parameters = self._flow_graph.get_parameters()
		#list of blocks not including variables and imports and parameters and disabled
		def _get_block_sort_text(block):
			code = block.get_make().replace(block.get_id(), ' ')
			try: code += block.get_param('notebook').get_value() #older gui markup w/ wxgui
			except: pass
			try: code += block.get_param('gui_hint').get_value() #newer gui markup w/ qtgui
			except: pass
			return code
		blocks = expr_utils.sort_objects(
			self._flow_graph.get_enabled_blocks(),
			lambda b: b.get_id(), _get_block_sort_text
		)
		#list of regular blocks (all blocks minus the special ones)
		blocks = filter(lambda b: b not in (imports + parameters), blocks)
		#list of connections where each endpoint is enabled
		connections = filter(lambda c: not (c.is_msg() or c.is_message()), self._flow_graph.get_enabled_connections())
		messages = filter(lambda c: c.is_msg(), self._flow_graph.get_enabled_connections())
		messages2 = filter(lambda c: c.is_message(), self._flow_graph.get_enabled_connections())
		#list of variable names
		var_ids = [var.get_id() for var in parameters + variables]
		#prepend self.
		replace_dict = dict([(var_id, 'self.%s'%var_id) for var_id in var_ids])
		#list of callbacks
		callbacks = [
			expr_utils.expr_replace(cb, replace_dict)
			for cb in sum([block.get_callbacks() for block in self._flow_graph.get_enabled_blocks()], [])
		]
		#map var id to callbacks
		var_id2cbs = dict(
			[(var_id, filter(lambda c: expr_utils.get_variable_dependencies(c, [var_id]), callbacks))
			for var_id in var_ids]
		)
		#load the namespace
		namespace = {
			'title': title,
			'imports': imports,
			'flow_graph': self._flow_graph,
			'variables': variables,
			'parameters': parameters,
			'blocks': blocks,
			'connections': connections,
			'messages': messages,
			'messages2': messages2,
			'generate_options': self._generate_options,
			'var_id2cbs': var_id2cbs,
		}
		#build the template
		t = Template(open(FLOW_GRAPH_TEMPLATE, 'r').read(), namespace)
		return str(t)