"""
Copyright 2008-2015 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
from gnuradio import gr

from . import ParseXML
from .Constants import (
    BLOCK_TREE_DTD, FLOW_GRAPH_DTD, DOMAIN_DTD,
    HIER_BLOCKS_LIB_DIR, BLOCK_DTD, DEFAULT_FLOW_GRAPH, BLOCKS_DIRS,
    PREFS_FILE, CORE_TYPES, PREFS_FILE_OLD,
)
from .Element import Element
from .utils import odict, extract_docs
from ..gui import Messages
from .generator import Generator


class Platform(Element):

    is_platform = True

    def __init__(self):
        """ Make a platform for gnuradio """
        Element.__init__(self)

        # Ensure hier and conf directories
        if not os.path.exists(HIER_BLOCKS_LIB_DIR):
            os.mkdir(HIER_BLOCKS_LIB_DIR)
        if not os.path.exists(os.path.dirname(PREFS_FILE)):
            os.mkdir(os.path.dirname(PREFS_FILE))

        self.block_docstrings = {}
        self.block_docstrings_loaded_callback = lambda: None  # dummy to be replaced by BlockTreeWindow

        self._docstring_extractor = extract_docs.SubprocessLoader(
            callback_query_result=self._save_docstring_extraction_result,
            callback_finished=lambda: self.block_docstrings_loaded_callback()
        )

        self._name = 'GNU Radio Companion'
        # Save the version string to the first
        version = (gr.version(), gr.major_version(), gr.api_version(), gr.minor_version())
        self._version = version[0]
        self._version_major = version[1]
        self._version_api = version[2]
        self._version_minor = version[3]
        self._version_short = version[1] + "." + version[2] + "." + version[3]

        self._key = 'grc'
        self._license = __doc__.strip()
        self._website = 'http://gnuradio.org'
        self._block_paths = list(set(BLOCKS_DIRS))
        self._block_dtd = BLOCK_DTD
        self._default_flow_graph = DEFAULT_FLOW_GRAPH
        self._generator = Generator
        self._colors = [(name, color) for name, key, sizeof, color in CORE_TYPES]
        # Create a dummy flow graph for the blocks
        self._flow_graph = Element(self)
        self._flow_graph.connections = []

        self._blocks = None
        self._blocks_n = None
        self._category_trees_n = None
        self._domains = dict()
        self._connection_templates = dict()
        self.load_blocks()

        _move_old_pref_file()
        self._auto_hier_block_generate_chain = set()

    @staticmethod
    def find_file_in_paths(filename, paths, cwd):
        """Checks the provided paths relative to cwd for a certain filename"""
        if not os.path.isdir(cwd):
            cwd = os.path.dirname(cwd)
        if isinstance(paths, str):
            paths = (p for p in paths.split(':') if p)

        for path in paths:
            path = os.path.expanduser(path)
            if not os.path.isabs(path):
                path = os.path.normpath(os.path.join(cwd, path))
            file_path = os.path.join(path, filename)
            if os.path.exists(os.path.normpath(file_path)):
                return file_path

    def load_and_generate_flow_graph(self, file_path):
        """Loads a flowgraph from file and generates it"""
        Messages.set_indent(len(self._auto_hier_block_generate_chain))
        Messages.send('>>> Loading: %r\n' % file_path)
        if file_path in self._auto_hier_block_generate_chain:
            Messages.send('    >>> Warning: cyclic hier_block dependency\n')
            return False
        self._auto_hier_block_generate_chain.add(file_path)
        try:
            flow_graph = self.get_new_flow_graph()
            flow_graph.grc_file_path = file_path
            # Other, nested higiter_blocks might be auto-loaded here
            flow_graph.import_data(self.parse_flow_graph(file_path))
            flow_graph.rewrite()
            flow_graph.validate()
            if not flow_graph.is_valid():
                raise Exception('Flowgraph invalid')
        except Exception as e:
            Messages.send('>>> Load Error: {}: {}\n'.format(file_path, str(e)))
            return False
        finally:
            self._auto_hier_block_generate_chain.discard(file_path)
            Messages.set_indent(len(self._auto_hier_block_generate_chain))

        try:
            Messages.send('>>> Generating: {}\n'.format(file_path))
            generator = self.get_generator()(flow_graph, file_path)
            generator.write()
        except Exception as e:
            Messages.send('>>> Generate Error: {}: {}\n'.format(file_path, str(e)))
            return False

        self.load_block_xml(generator.get_file_path_xml())
        return True

    def load_blocks(self):
        """load the blocks and block tree from the search paths"""
        self._docstring_extractor.start()
        # Reset
        self._blocks = odict()
        self._blocks_n = odict()
        self._category_trees_n = list()
        self._domains.clear()
        self._connection_templates.clear()
        ParseXML.xml_failures.clear()
        # Try to parse and load blocks
        for xml_file in self.iter_xml_files():
            try:
                if xml_file.endswith("block_tree.xml"):
                    self.load_category_tree_xml(xml_file)
                elif xml_file.endswith('domain.xml'):
                    self.load_domain_xml(xml_file)
                else:
                    self.load_block_xml(xml_file)
            except ParseXML.XMLSyntaxError as e:
                # print >> sys.stderr, 'Warning: Block validation failed:\n\t%s\n\tIgnoring: %s' % (e, xml_file)
                pass
            except Exception as e:
                raise
                print >> sys.stderr, 'Warning: XML parsing failed:\n\t%r\n\tIgnoring: %s' % (e, xml_file)

        self._docstring_extractor.finish()
        # self._docstring_extractor.wait()

    def iter_xml_files(self):
        """Iterator for block descriptions and category trees"""
        for block_path in map(lambda x: os.path.abspath(os.path.expanduser(x)), self._block_paths):
            if os.path.isfile(block_path):
                yield block_path
            elif os.path.isdir(block_path):
                for dirpath, dirnames, filenames in os.walk(block_path):
                    for filename in sorted(filter(lambda f: f.endswith('.xml'), filenames)):
                        yield os.path.join(dirpath, filename)

    def load_block_xml(self, xml_file):
        """Load block description from xml file"""
        # Validate and import
        ParseXML.validate_dtd(xml_file, self._block_dtd)
        n = ParseXML.from_file(xml_file).find('block')
        n['block_wrapper_path'] = xml_file  # inject block wrapper path
        # Get block instance and add it to the list of blocks
        block = self.Block(self._flow_graph, n)
        key = block.get_key()
        if key in self._blocks:
            print >> sys.stderr, 'Warning: Block with key "{}" already exists.\n\tIgnoring: {}'.format(key, xml_file)
        else:  # Store the block
            self._blocks[key] = block
            self._blocks_n[key] = n

        self._docstring_extractor.query(
            block.get_key(),
            block.get_imports(raw=True),
            block.get_make(raw=True)
        )

    def _save_docstring_extraction_result(self, key, docstrings):
        docs = {}
        for match, docstring in docstrings.iteritems():
            if not docstring or match.endswith('_sptr'):
                continue
            docstring = docstring.replace('\n\n', '\n').strip()
            docs[match] = docstring
        self.block_docstrings[key] = docs

    def load_category_tree_xml(self, xml_file):
        """Validate and parse category tree file and add it to list"""
        ParseXML.validate_dtd(xml_file, BLOCK_TREE_DTD)
        n = ParseXML.from_file(xml_file).find('cat')
        self._category_trees_n.append(n)

    def load_domain_xml(self, xml_file):
        """Load a domain properties and connection templates from XML"""
        ParseXML.validate_dtd(xml_file, DOMAIN_DTD)
        n = ParseXML.from_file(xml_file).find('domain')

        key = n.find('key')
        if not key:
            print >> sys.stderr, 'Warning: Domain with emtpy key.\n\tIgnoring: {}'.foramt(xml_file)
            return
        if key in self.get_domains():  # test against repeated keys
            print >> sys.stderr, 'Warning: Domain with key "{}" already exists.\n\tIgnoring: {}'.format(key, xml_file)
            return

        #to_bool = lambda s, d: d if s is None else s.lower() not in ('false', 'off', '0', '')
        def to_bool(s, d):
            if s is not None:
                return s.lower() not in ('false', 'off', '0', '')
            return d

        color = n.find('color') or ''
        try:
            import gtk  # ugly but handy
            gtk.gdk.color_parse(color)
        except (ValueError, ImportError):
            if color:  # no color is okay, default set in GUI
                print >> sys.stderr, 'Warning: Can\'t parse color code "{}" for domain "{}" '.format(color, key)
                color = None

        self._domains[key] = dict(
            name=n.find('name') or key,
            multiple_sinks=to_bool(n.find('multiple_sinks'), True),
            multiple_sources=to_bool(n.find('multiple_sources'), False),
            color=color
        )
        for connection_n in n.findall('connection'):
            key = (connection_n.find('source_domain'), connection_n.find('sink_domain'))
            if not all(key):
                print >> sys.stderr, 'Warning: Empty domain key(s) in connection template.\n\t{}'.format(xml_file)
            elif key in self._connection_templates:
                print >> sys.stderr, 'Warning: Connection template "{}" already exists.\n\t{}'.format(key, xml_file)
            else:
                self._connection_templates[key] = connection_n.find('make') or ''

    def parse_flow_graph(self, flow_graph_file):
        """
        Parse a saved flow graph file.
        Ensure that the file exists, and passes the dtd check.

        Args:
            flow_graph_file: the flow graph file

        Returns:
            nested data
        @throws exception if the validation fails
        """
        flow_graph_file = flow_graph_file or self._default_flow_graph
        open(flow_graph_file, 'r')  # Test open
        ParseXML.validate_dtd(flow_graph_file, FLOW_GRAPH_DTD)
        return ParseXML.from_file(flow_graph_file)

    def load_block_tree(self, block_tree):
        """
        Load a block tree with categories and blocks.
        Step 1: Load all blocks from the xml specification.
        Step 2: Load blocks with builtin category specifications.

        Args:
            block_tree: the block tree object
        """
        # Recursive function to load categories and blocks
        def load_category(cat_n, parent=None):
            # Add this category
            parent = (parent or []) + [cat_n.find('name')]
            block_tree.add_block(parent)
            # Recursive call to load sub categories
            map(lambda c: load_category(c, parent), cat_n.findall('cat'))
            # Add blocks in this category
            for block_key in cat_n.findall('block'):
                if block_key not in self.get_block_keys():
                    print >> sys.stderr, 'Warning: Block key "{}" not found when loading category tree.'.format(block_key)
                    continue
                block = self.get_block(block_key)
                # If it exists, the block's category shall not be overridden by the xml tree
                if not block.get_category():
                    block.set_category(parent)

        # Recursively load the category trees and update the categories for each block
        for category_tree_n in self._category_trees_n:
            load_category(category_tree_n)

        # Add blocks to block tree
        for block in self.get_blocks():
            # Blocks with empty categories are hidden
            if not block.get_category():
                continue
            block_tree.add_block(block.get_category(), block)

    def __str__(self):
        return 'Platform - {}({})'.format(self.get_key(), self.get_name())

    def get_new_flow_graph(self):
        return self.FlowGraph(platform=self)

    def get_generator(self):
        return self._generator

    ##############################################
    # Access Blocks
    ##############################################
    def get_block_keys(self):
        return self._blocks.keys()

    def get_block(self, key):
        return self._blocks[key]

    def get_blocks(self):
        return self._blocks.values()

    def get_new_block(self, flow_graph, key):
        return self.Block(flow_graph, n=self._blocks_n[key])

    def get_domains(self):
        return self._domains

    def get_domain(self, key):
        return self._domains.get(key)

    def get_connection_templates(self):
        return self._connection_templates

    def get_name(self):
        return self._name

    def get_version(self):
        return self._version

    def get_version_major(self):
        return self._version_major

    def get_version_api(self):
        return self._version_api

    def get_version_minor(self):
        return self._version_minor

    def get_version_short(self):
        return self._version_short

    def get_key(self):
        return self._key

    def get_license(self):
        return self._license

    def get_website(self):
        return self._website

    def get_colors(self):
        return self._colors

    def get_block_paths(self):
        return self._block_paths


def _move_old_pref_file():
    if PREFS_FILE == PREFS_FILE_OLD:
        return  # prefs file overridden with env var
    if os.path.exists(PREFS_FILE_OLD) and not os.path.exists(PREFS_FILE):
        try:
            import shutil
            shutil.move(PREFS_FILE_OLD, PREFS_FILE)
        except Exception as e:
            print >> sys.stderr, e