"""
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 distutils.spawn import find_executable
from Cheetah.Template import Template

from .. gui import Messages
from .. base import ParseXML
from .. base import odict

from . Constants import TOP_BLOCK_FILE_MODE, FLOW_GRAPH_TEMPLATE, \
    XTERM_EXECUTABLE, HIER_BLOCK_FILE_MODE, HIER_BLOCKS_LIB_DIR, BLOCK_DTD
from . import expr_utils


class Generator(object):
    """Adaptor for various generators (uses generate_options)"""

    def __init__(self, flow_graph, file_path):
        """
        Initialize the generator object.
        Determine the file to generate.

        Args:
            flow_graph: the flow graph object
            file_path: the path to the grc file
        """
        self._generate_options = flow_graph.get_option('generate_options')
        if self._generate_options == 'hb':
            self._generator = HierBlockGenerator(flow_graph, file_path)
        else:
            self._generator = TopBlockGenerator(flow_graph, file_path)

    def get_generate_options(self):
        return self._generate_options

    def __getattr__(self, item):
        """get all other attrib from actual generator object"""
        return getattr(self._generator, item)


class TopBlockGenerator(object):

    def __init__(self, flow_graph, file_path):
        """
        Initialize the top block generator object.

        Args:
            flow_graph: the flow graph object
            file_path: the path to write the file to
        """
        self._flow_graph = flow_graph
        self._generate_options = self._flow_graph.get_option('generate_options')
        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):
        """generate output and write it to files"""
        # do throttle warning
        throttling_blocks = filter(lambda b: b.throttle(), self._flow_graph.get_enabled_blocks())
        if not throttling_blocks and self._generate_options != 'hb':
            Messages.send_warning("This flow graph may not have flow control: "
                                  "no audio or RF hardware blocks found. "
                                  "Add a Misc->Throttle block to your flow "
                                  "graph to avoid CPU congestion.")
        if len(throttling_blocks) > 1:
            keys = set(map(lambda b: b.get_key(), throttling_blocks))
            if len(keys) > 1 and 'blocks_throttle' in keys:
                Messages.send_warning("This flow graph contains a throttle "
                                      "block and another rate limiting block, "
                                      "e.g. a hardware source or sink. "
                                      "This is usually undesired. Consider "
                                      "removing the throttle block.")
        # generate
        open(self.get_file_path(), 'w').write(
            self._build_python_code_from_template()
        )

    def get_popen(self):
        """
        Execute this python flow graph.

        Returns:
            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 a graphical terminal (looks nice)
        xterm_executable = find_executable(XTERM_EXECUTABLE)
        if self._generate_options == 'no_gui' and xterm_executable:
            cmds = [xterm_executable, '-e'] + cmds

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

    def _build_python_code_from_template(self):
        """
        Convert the flow graph to python code.

        Returns:
            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()
        monitors = self._flow_graph.get_monitors()

        # 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 (sorted by domains, block names)
        connections = filter(lambda c: not (c.is_bus() or c.is_msg()), self._flow_graph.get_enabled_connections())
        connections.sort(key=lambda c: (
            c.get_source().get_domain(), c.get_sink().get_domain(),
            c.get_source().get_parent().get_id(), c.get_sink().get_parent().get_id()
        ))
        connection_templates = self._flow_graph.get_parent().get_connection_templates()
        msgs = filter(lambda c: c.is_msg(), 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,
            'monitors': monitors,
            'blocks': blocks,
            'connections': connections,
            'connection_templates': connection_templates,
            'msgs': msgs,
            'generate_options': self._generate_options,
            'var_id2cbs': var_id2cbs,
        }
        # build the template
        t = Template(open(FLOW_GRAPH_TEMPLATE, 'r').read(), namespace)
        return str(t)


class HierBlockGenerator(TopBlockGenerator):
    """Extends the top block generator to also generate a block XML file"""

    def __init__(self, flow_graph, file_path):
        """
        Initialize the hier block generator object.

        Args:
            flow_graph: the flow graph object
            file_path: where to write the py file (the xml goes into HIER_BLOCK_LIB_DIR)
        """
        TopBlockGenerator.__init__(self, flow_graph, file_path)
        self._mode = HIER_BLOCK_FILE_MODE
        self._file_path = os.path.join(HIER_BLOCKS_LIB_DIR,
                                       self._flow_graph.get_option('id') + '.py')
        self._file_path_xml = self._file_path + '.xml'

    def get_file_path_xml(self):
        return self._file_path_xml

    def write(self):
        """generate output and write it to files"""
        TopBlockGenerator.write(self)
        ParseXML.to_file(self._build_block_n_from_flow_graph_io(), self.get_file_path_xml())
        ParseXML.validate_dtd(self.get_file_path_xml(), BLOCK_DTD)

    def _build_block_n_from_flow_graph_io(self):
        """
        Generate a block XML nested data from the flow graph IO

        Returns:
            a xml node tree
        """
        # extract info from the flow graph
        block_key = self._flow_graph.get_option('id')
        parameters = self._flow_graph.get_parameters()

        def var_or_value(name):
            if name in map(lambda p: p.get_id(), parameters):
                return "$"+name
            return name

        # build the nested data
        block_n = odict()
        block_n['name'] = self._flow_graph.get_option('title') or \
            self._flow_graph.get_option('id').replace('_', ' ').title()
        block_n['key'] = block_key
        block_n['category'] = self._flow_graph.get_option('category')
        block_n['import'] = "from {0} import {0}  # grc-generated hier_block".format(
            self._flow_graph.get_option('id'))
        # make data
        if parameters:
            block_n['make'] = '{cls}(\n    {kwargs},\n)'.format(
                cls=block_key,
                kwargs=',\n    '.join(
                    '{key}=${key}'.format(key=param.get_id()) for param in parameters
                ),
            )
        else:
            block_n['make'] = '{cls}()'.format(cls=block_key)
        # callback data
        block_n['callback'] = [
            'set_{key}(${key})'.format(key=param.get_id()) for param in parameters
        ]

        # Parameters
        block_n['param'] = list()
        for param in parameters:
            param_n = odict()
            param_n['name'] = param.get_param('label').get_value() or param.get_id()
            param_n['key'] = param.get_id()
            param_n['value'] = param.get_param('value').get_value()
            param_n['type'] = 'raw'
            block_n['param'].append(param_n)

        # bus stuff
        if self._flow_graph.get_bussink():
            block_n['bus_sink'] = '1'
        if self._flow_graph.get_bussrc():
            block_n['bus_source'] = '1'

        # sink/source ports
        for direction in ('sink', 'source'):
            block_n[direction] = list()
            for port in self._flow_graph.get_hier_block_io(direction):
                port_n = odict()
                port_n['name'] = port['label']
                port_n['type'] = port['type']
                if port['type'] != "message":
                    port_n['vlen'] = var_or_value(port['vlen'])
                if port['optional']:
                    port_n['optional'] = '1'
                block_n[direction].append(port_n)

        # more bus stuff
        bus_struct_sink = self._flow_graph.get_bus_structure_sink()
        if bus_struct_sink:
            block_n['bus_structure_sink'] = bus_struct_sink[0].get_param('struct').get_value()
        bus_struct_src = self._flow_graph.get_bus_structure_src()
        if bus_struct_src:
            block_n['bus_structure_source'] = bus_struct_src[0].get_param('struct').get_value()

        # documentation
        block_n['doc'] = "\n".join(field for field in (
            self._flow_graph.get_option('author'),
            self._flow_graph.get_option('description'),
            self.get_file_path()
        ) if field)
        block_n['grc_source'] = str(self._flow_graph.grc_file_path)

        n = {'block': block_n}
        return n