"""
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 time
from . import odict
from Element import Element
from .. gui import Messages
from . Constants import FLOW_GRAPH_FILE_FORMAT_VERSION


class FlowGraph(Element):

    def __init__(self, platform):
        """
        Make a flow graph from the arguments.

        Args:
            platform: a platforms with blocks and contrcutors

        Returns:
            the flow graph object
        """
        #initialize
        Element.__init__(self, platform)
        self._elements = []
        self._timestamp = time.ctime()
        #inital blank import
        self.import_data()

    def _get_unique_id(self, base_id=''):
        """
        Get a unique id starting with the base id.

        Args:
            base_id: the id starts with this and appends a count

        Returns:
            a unique id
        """
        index = 0
        while True:
            id = '%s_%d' % (base_id, index)
            index += 1
            #make sure that the id is not used by another block
            if not filter(lambda b: b.get_id() == id, self.get_blocks()): return id

    def __str__(self):
        return 'FlowGraph - %s(%s)' % (self.get_option('title'), self.get_option('id'))

    def rewrite(self):
        def refactor_bus_structure():

            for block in self.get_blocks():
                for direc in ['source', 'sink']:
                    if direc == 'source':
                        get_p = block.get_sources;
                        get_p_gui = block.get_sources_gui;
                        bus_structure = block.form_bus_structure('source');
                    else:
                        get_p = block.get_sinks;
                        get_p_gui = block.get_sinks_gui
                        bus_structure = block.form_bus_structure('sink');

                    if 'bus' in map(lambda a: a.get_type(), get_p_gui()):
                        if len(get_p_gui()) > len(bus_structure):
                            times = range(len(bus_structure), len(get_p_gui()));
                            for i in times:
                                for connect in get_p_gui()[-1].get_connections():
                                    block.get_parent().remove_element(connect);
                                get_p().remove(get_p_gui()[-1]);
                        elif len(get_p_gui()) < len(bus_structure):
                            n = {'name':'bus','type':'bus'};
                            if True in map(lambda a: isinstance(a.get_nports(), int), get_p()):
                                n['nports'] = str(1);

                            times = range(len(get_p_gui()), len(bus_structure));

                            for i in times:
                                n['key'] = str(len(get_p()));
                                n = odict(n);
                                port = block.get_parent().get_parent().Port(block=block, n=n, dir=direc);
                                get_p().append(port);

        for child in self.get_children(): child.rewrite()
        refactor_bus_structure();

    def get_option(self, key):
        """
        Get the option for a given key.
        The option comes from the special options block.

        Args:
            key: the param key for the options block

        Returns:
            the value held by that param
        """
        return self._options_block.get_param(key).get_evaluated()

    def is_flow_graph(self): return True

    ##############################################
    ## Access Elements
    ##############################################
    def get_block(self, id): return filter(lambda b: b.get_id() == id, self.get_blocks())[0]
    def get_blocks_unordered(self): return filter(lambda e: e.is_block(), self.get_elements())
    def get_blocks(self):
        # refactored the slow, ugly version
        # don't know why we need this here, using it for sorted export_data()
        return sorted(self.get_blocks_unordered(), key=lambda b: (
            b.get_key() != 'options',  # options to the front
            not b.get_key().startswith('variable'),  # then vars
            str(b)
        ))
    def get_connections(self): return filter(lambda e: e.is_connection(), self.get_elements())
    def get_children(self): return self.get_elements()
    def get_elements(self):
        """
        Get a list of all the elements.
        Always ensure that the options block is in the list (only once).

        Returns:
            the element list
        """
        options_block_count = self._elements.count(self._options_block)
        if not options_block_count:
            self._elements.append(self._options_block)
        for i in range(options_block_count-1):
            self._elements.remove(self._options_block)
        return self._elements

    def get_enabled_blocks(self):
        """
        Get a list of all blocks that are enabled and not bypassed.

        Returns:
            a list of blocks
        """
        return filter(lambda b: b.get_enabled(), self.get_blocks())

    def get_bypassed_blocks(self):
        """
        Get a list of all blocks that are bypassed.

        Returns:
            a list of blocks
        """
        return filter(lambda b: b.get_bypassed(), self.get_blocks())

    def get_enabled_connections(self):
        """
        Get a list of all connections that are enabled.

        Returns:
            a list of connections
        """
        return filter(lambda c: c.get_enabled(), self.get_connections())

    def get_new_block(self, key):
        """
        Get a new block of the specified key.
        Add the block to the list of elements.

        Args:
            key: the block key

        Returns:
            the new block or None if not found
        """
        if key not in self.get_parent().get_block_keys(): return None
        block = self.get_parent().get_new_block(self, key)
        self.get_elements().append(block);
        if block._bussify_sink:
            block.bussify({'name':'bus','type':'bus'}, 'sink')
        if block._bussify_source:
            block.bussify({'name':'bus','type':'bus'}, 'source')
        return block;

    def connect(self, porta, portb):
        """
        Create a connection between porta and portb.

        Args:
            porta: a port
            portb: another port
        @throw Exception bad connection

        Returns:
            the new connection
        """
        connection = self.get_parent().Connection(flow_graph=self, porta=porta, portb=portb)
        self.get_elements().append(connection)
        return connection

    def remove_element(self, element):
        """
        Remove the element from the list of elements.
        If the element is a port, remove the whole block.
        If the element is a block, remove its connections.
        If the element is a connection, just remove the connection.
        """
        if element not in self.get_elements(): return
        #found a port, set to parent signal block
        if element.is_port():
            element = element.get_parent()
        #remove block, remove all involved connections
        if element.is_block():
            for port in element.get_ports():
                map(self.remove_element, port.get_connections())
        if element.is_connection():
            if element.is_bus():
                cons_list = []
                for i in map(lambda a: a.get_connections(), element.get_source().get_associated_ports()):
                    cons_list.extend(i);
                map(self.remove_element, cons_list);
        self.get_elements().remove(element)

    def evaluate(self, expr):
        """
        Evaluate the expression.

        Args:
            expr: the string expression
        @throw NotImplementedError
        """
        raise NotImplementedError

    ##############################################
    ## Import/Export Methods
    ##############################################
    def export_data(self):
        """
        Export this flow graph to nested data.
        Export all block and connection data.

        Returns:
            a nested data odict
        """
        n = odict()
        n['timestamp'] = self._timestamp
        n['block'] = [b.export_data() for b in self.get_blocks()]  # already sorted
        n['connection'] = [c.export_data() for c in sorted(self.get_connections(), key=str)]
        instructions = odict({
            'created': self.get_parent().get_version_short(),
            'format': FLOW_GRAPH_FILE_FORMAT_VERSION,
        })
        return odict({'flow_graph': n, '_instructions': instructions})

    def import_data(self, n=None):
        """
        Import blocks and connections into this flow graph.
        Clear this flowgraph of all previous blocks and connections.
        Any blocks or connections in error will be ignored.

        Args:
            n: the nested data odict
        """
        errors = False
        #remove previous elements
        self._elements = list()
        # set file format
        try:
            instructions = n.find('_instructions') or {}
            file_format = int(instructions.get('format', '0')) or self._guess_file_format_1(n)
        except:
            file_format = 0
        #use blank data if none provided
        fg_n = n and n.find('flow_graph') or odict()
        self._timestamp = fg_n.find('timestamp') or time.ctime()
        blocks_n = fg_n.findall('block')
        connections_n = fg_n.findall('connection')
        #create option block
        self._options_block = self.get_parent().get_new_block(self, 'options')
        #build the blocks
        for block_n in blocks_n:
            key = block_n.find('key')
            block = self._options_block if key == 'options' else self.get_new_block(key)

            if not block:  # looks like this block key cannot be found
                # create a dummy block instead
                block = self.get_new_block('dummy_block')
                # Ugly ugly ugly
                _initialize_dummy_block(block, block_n)
                Messages.send_error_msg_load('Block key "%s" not found in %s' % (key, self.get_parent()))

            block.import_data(block_n)
        #build the connections
        block_ids = map(lambda b: b.get_id(), self.get_blocks())
        for connection_n in connections_n:
            try:  # to make the connection
                #get the block ids
                source_block_id = connection_n.find('source_block_id')
                sink_block_id = connection_n.find('sink_block_id')
                #get the port keys
                source_key = connection_n.find('source_key')
                sink_key = connection_n.find('sink_key')
                #verify the blocks
                if source_block_id not in block_ids:
                    raise LookupError('source block id "%s" not in block ids'%source_block_id)
                if sink_block_id not in block_ids:
                    raise LookupError('sink block id "%s" not in block ids'%sink_block_id)
                #get the blocks
                source_block = self.get_block(source_block_id)
                sink_block = self.get_block(sink_block_id)
                # fix old, numeric message ports keys
                if file_format < 1:
                    source_key, sink_key = self._update_old_message_port_keys(
                        source_key, sink_key, source_block, sink_block
                    )
                #verify the ports
                if source_key not in source_block.get_source_keys():
                    # dummy blocks learn their ports here
                    if source_block.is_dummy_block():
                        _dummy_block_add_port(source_block, source_key, dir='source')
                    else:
                        raise LookupError('source key "%s" not in source block keys' % source_key)
                if sink_key not in sink_block.get_sink_keys():
                    # dummy blocks learn their ports here
                    if sink_block.is_dummy_block():
                        _dummy_block_add_port(sink_block, sink_key, dir='sink')
                    else:
                        raise LookupError('sink key "%s" not in sink block keys' % sink_key)
                #get the ports
                source = source_block.get_source(source_key)
                sink = sink_block.get_sink(sink_key)
                #build the connection
                self.connect(source, sink)
            except LookupError, e:
                Messages.send_error_load(
                    'Connection between %s(%s) and %s(%s) could not be made.\n\t%s'%(
                    source_block_id, source_key, sink_block_id, sink_key, e))
                errors = True
        self.rewrite() #global rewrite
        return errors

    @staticmethod
    def _update_old_message_port_keys(source_key, sink_key, source_block, sink_block):
        """Backward compatibility for message port keys

        Message ports use their names as key (like in the 'connect' method).
        Flowgraph files from former versions still have numeric keys stored for
        message connections. These have to be replaced by the name of the
        respective port. The correct message port is deduced from the integer
        value of the key (assuming the order has not changed).

        The connection ends are updated only if both ends translate into a
        message port.
        """
        try:
            # get ports using the "old way" (assuming liner indexed keys)
            source_port = source_block.get_sources()[int(source_key)]
            sink_port = sink_block.get_sinks()[int(sink_key)]
            if source_port.get_type() == "message" and sink_port.get_type() == "message":
                source_key, sink_key = source_port.get_key(), sink_port.get_key()
        except (ValueError, IndexError):
            pass
        return source_key, sink_key  # do nothing

    @staticmethod
    def _guess_file_format_1(n):
        """Try to guess the file format for flow-graph files without version tag"""
        try:
            has_non_numeric_message_keys = any(not (
                connection_n.find('source_key').isdigit() and
                connection_n.find('sink_key').isdigit()
            ) for connection_n in n.find('flow_graph').findall('connection'))
            if has_non_numeric_message_keys:
                return 1
        except:
            pass
        return 0


def _initialize_dummy_block(block, block_n):
    """This is so ugly... dummy-fy a block

    Modify block object to get the behaviour for a missing block
    """
    block._key = block_n.find('key')
    block.is_dummy_block = lambda: True
    block.is_valid = lambda: False
    block.get_enabled = lambda: False
    for param_n in block_n.findall('param'):
        if param_n['key'] not in block.get_param_keys():
            new_param_n = odict({'key': param_n['key'], 'name': param_n['key'], 'type': 'string'})
            block.get_params().append(block.get_parent().get_parent().Param(block=block, n=new_param_n))


def _dummy_block_add_port(block, key, dir):
    """This is so ugly... Add a port to a dummy-field block"""
    port_n = odict({'name': '?', 'key': key, 'type': ''})
    port = block.get_parent().get_parent().Port(block=block, n=port_n, dir=dir)
    if port.is_source():
        block.get_sources().append(port)
    else:
        block.get_sinks().append(port)
