# Copyright (c) 2003-2013 LOGILAB S.A. (Paris, FRANCE).
# This program 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.
#
# This program 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.,
# 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
"""utilities methods and classes for reporters"""

import sys
import locale
import os

from pylint.utils import MSG_TYPES

from pylint import utils

CMPS = ['=', '-', '+']

# py3k has no more cmp builtin
if sys.version_info >= (3, 0):
    def cmp(a, b):
        return (a > b) - (a < b)

def diff_string(old, new):
    """given a old and new int value, return a string representing the
    difference
    """
    diff = abs(old - new)
    diff_str = "%s%s" % (CMPS[cmp(old, new)], diff and ('%.2f' % diff) or '')
    return diff_str


class Message(object):
    """This class represent a message to be issued by the reporters"""

    def __init__(self, reporter, msg_id, location, msg):
        self.msg_id = msg_id
        self.abspath, self.module, self.obj, self.line, self.column = location
        self.path = self.abspath.replace(reporter.path_strip_prefix, '')
        self.msg = msg
        self.C = msg_id[0]
        self.category = MSG_TYPES[msg_id[0]]
        self.symbol = reporter.linter.check_message_id(msg_id).symbol

    def format(self, template):
        """Format the message according to the given template.

        The template format is the one of the format method :
        cf. http://docs.python.org/2/library/string.html#formatstrings
        """
        return template.format(**(self.__dict__))


class BaseReporter(object):
    """base class for reporters

    symbols: show short symbolic names for messages.
    """

    extension = ''

    def __init__(self, output=None):
        self.linter = None
        # self.include_ids = None # Deprecated
        # self.symbols = None # Deprecated
        self.section = 0
        self.out = None
        self.out_encoding = None
        self.encode = None
        self.set_output(output)
        # Build the path prefix to strip to get relative paths
        self.path_strip_prefix = os.getcwd() + os.sep

    def add_message(self, msg_id, location, msg):
        """Client API to send a message"""
        # Shall we store the message objects somewhere, do some validity checking ?
        raise NotImplementedError

    def set_output(self, output=None):
        """set output stream"""
        self.out = output or sys.stdout
        # py3k streams handle their encoding :
        if sys.version_info >= (3, 0):
            self.encode = lambda x: x
            return

        def encode(string):
            if not isinstance(string, unicode):
                return string
            encoding = (getattr(self.out, 'encoding', None) or
                        locale.getdefaultlocale()[1] or
                        sys.getdefaultencoding())
            # errors=replace, we don't want to crash when attempting to show
            # source code line that can't be encoded with the current locale
            # settings
            return string.encode(encoding, 'replace')
        self.encode = encode

    def writeln(self, string=''):
        """write a line in the output buffer"""
        print >> self.out, self.encode(string)

    def display_results(self, layout):
        """display results encapsulated in the layout tree"""
        self.section = 0
        if hasattr(layout, 'report_id'):
            layout.children[0].children[0].data += ' (%s)' % layout.report_id
        self._display(layout)

    def _display(self, layout):
        """display the layout"""
        raise NotImplementedError()

    # Event callbacks

    def on_set_current_module(self, module, filepath):
        """starting analyzis of a module"""
        pass

    def on_close(self, stats, previous_stats):
        """global end of analyzis"""
        pass


def initialize(linter):
    """initialize linter with reporters in this package """
    utils.register_plugins(linter, __path__[0])
