"""
  Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.

  Permission is hereby granted, free of charge, to any person obtaining a copy of this
  software and associated documentation files (the "Software"), to deal in the Software
  without restriction, including without limitation the rights to use, copy, modify,
  merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
  permit persons to whom the Software is furnished to do so.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
  PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
"""
import sys
import logging
import six
try:
    from json.decoder import JSONDecodeError
except ImportError:
    JSONDecodeError = ValueError
from yaml.parser import ParserError, ScannerError
from yaml import YAMLError
from cfnlint.decode import cfn_yaml, cfn_json
from cfnlint.rules import Match, ParseError


LOGGER = logging.getLogger(__name__)


def decode(filename, ignore_bad_template):
    """
        Decode filename into an object
    """
    template = None
    matches = []
    try:
        template = cfn_yaml.load(filename)
    except IOError as e:
        if e.errno == 2:
            LOGGER.error('Template file not found: %s', filename)
            matches.append(create_match_file_error(
                filename, 'Template file not found: %s' % filename))
        elif e.errno == 21:
            LOGGER.error('Template references a directory, not a file: %s',
                         filename)
            matches.append(create_match_file_error(
                filename,
                'Template references a directory, not a file: %s' % filename))
        elif e.errno == 13:
            LOGGER.error('Permission denied when accessing template file: %s',
                         filename)
            matches.append(create_match_file_error(
                filename,
                'Permission denied when accessing template file: %s' % filename))

        if matches:
            return(None, matches)
    except UnicodeDecodeError as err:
        LOGGER.error('Cannot read file contents: %s', filename)
        matches.append(create_match_file_error(
            filename, 'Cannot read file contents: %s' % filename))
    except cfn_yaml.CfnParseError as err:
        err.match.Filename = filename
        matches = [err.match]
    except ParserError as err:
        matches = [create_match_yaml_parser_error(err, filename)]
    except ScannerError as err:
        if err.problem in [
                'found character \'\\t\' that cannot start any token',
                'found unknown escape character']:
            try:
                template = cfn_json.load(filename)
            except cfn_json.JSONDecodeError as json_err:
                json_err.match.filename = filename
                matches = [json_err.match]
            except JSONDecodeError as json_err:
                matches = [create_match_json_parser_error(json_err, filename)]
            except Exception as json_err:  # pylint: disable=W0703
                if ignore_bad_template:
                    LOGGER.info('Template %s is malformed: %s',
                                filename, err.problem)
                    LOGGER.info('Tried to parse %s as JSON but got error: %s',
                                filename, str(json_err))
                else:
                    LOGGER.error(
                        'Template %s is malformed: %s', filename, err.problem)
                    LOGGER.error('Tried to parse %s as JSON but got error: %s',
                                 filename, str(json_err))
                    return (None, [create_match_file_error(
                        filename,
                        'Tried to parse %s as JSON but got error: %s' % (
                            filename, str(json_err)))])
        else:
            matches = [create_match_yaml_parser_error(err, filename)]
    except YAMLError as err:
        matches = [create_match_file_error(filename, err)]

    if not isinstance(template, dict) and not matches:
        # Template isn't a dict which means nearly nothing will work
        matches = [Match(1, 1, 1, 1, filename, ParseError(),
                         message='Template needs to be an object.')]
    return (template, matches)


def create_match_yaml_parser_error(parser_error, filename):
    """Create a Match for a parser error"""
    lineno = parser_error.problem_mark.line + 1
    colno = parser_error.problem_mark.column + 1
    msg = parser_error.problem
    return Match(
        lineno, colno, lineno, colno + 1, filename,
        ParseError(), message=msg)


def create_match_file_error(filename, msg):
    """Create a Match for a parser error"""
    return Match(
        linenumber=1, columnnumber=1, linenumberend=1, columnnumberend=2,
        filename=filename, rule=ParseError(), message=msg)


def create_match_json_parser_error(parser_error, filename):
    """Create a Match for a parser error"""
    if sys.version_info[0] == 3:
        lineno = parser_error.lineno
        colno = parser_error.colno
        msg = parser_error.msg
    elif sys.version_info[0] == 2:
        lineno = 1
        colno = 1
        msg = parser_error.message
    return Match(
        lineno, colno, lineno, colno + 1, filename, ParseError(), message=msg)
