# -*- coding: utf-8 -*-
"""
 flask.debughelpers
 ~~~~~~~~~~~~~~~~~~

 Various helpers to make the development experience better.

 :copyright: © 2010 by the Pallets team.
 :license: BSD, see LICENSE for more details.
"""

import os
from warnings import warn

from ._compat import implements_to_string, text_type
from .app import Flask
from .blueprints import Blueprint
from .globals import _request_ctx_stack


class UnexpectedUnicodeError(AssertionError, UnicodeError):
 """Raised in places where we want some better error reporting for
 unexpected unicode or binary data.
 """


@implements_to_string
class DebugFilesKeyError(KeyError, AssertionError):
 """Raised from request.files during debugging. The idea is that it can
 provide a better error message than just a generic KeyError/BadRequest.
 """

 def __init__(self, request, key):
 form_matches = request.form.getlist(key)
 buf = ['You tried to access the file "%s" in the request.files '
 'dictionary but it does not exist. The mimetype for the request '
 'is "%s" instead of "multipart/form-data" which means that no '
 'file contents were transmitted. To fix this error you should '
 'provide enctype="multipart/form-data" in your form.' %
 (key, request.mimetype)]
 if form_matches:
 buf.append('\n\nThe browser instead transmitted some file names. '
 'This was submitted: %s' % ', '.join('"%s"' % x
 for x in form_matches))
 self.msg = ''.join(buf)

 def __str__(self):
 return self.msg


class FormDataRoutingRedirect(AssertionError):
 """This exception is raised by Flask in debug mode if it detects a
 redirect caused by the routing system when the request method is not
 GET, HEAD or OPTIONS. Reasoning: form data will be dropped.
 """

 def __init__(self, request):
 exc = request.routing_exception
 buf = ['A request was sent to this URL (%s) but a redirect was '
 'issued automatically by the routing system to "%s".'
 % (request.url, exc.new_url)]

 # In case just a slash was appended we can be extra helpful
 if request.base_url + '/' == exc.new_url.split('?')[0]:
 buf.append(' The URL was defined with a trailing slash so '
 'Flask will automatically redirect to the URL '
 'with the trailing slash if it was accessed '
 'without one.')

 buf.append(' Make sure to directly send your %s-request to this URL '
 'since we can\'t make browsers or HTTP clients redirect '
 'with form data reliably or without user interaction.' %
 request.method)
 buf.append('\n\nNote: this exception is only raised in debug mode')
 AssertionError.__init__(self, ''.join(buf).encode('utf-8'))


def attach_enctype_error_multidict(request):
 """Since Flask 0.8 we're monkeypatching the files object in case a
 request is detected that does not use multipart form data but the files
 object is accessed.
 """
 oldcls = request.files.__class__
 class newcls(oldcls):
 def __getitem__(self, key):
 try:
 return oldcls.__getitem__(self, key)
 except KeyError:
 if key not in request.form:
 raise
 raise DebugFilesKeyError(request, key)
 newcls.__name__ = oldcls.__name__
 newcls.__module__ = oldcls.__module__
 request.files.__class__ = newcls


def _dump_loader_info(loader):
 yield 'class: %s.%s' % (type(loader).__module__, type(loader).__name__)
 for key, value in sorted(loader.__dict__.items()):
 if key.startswith('_'):
 continue
 if isinstance(value, (tuple, list)):
 if not all(isinstance(x, (str, text_type)) for x in value):
 continue
 yield '%s:' % key
 for item in value:
 yield ' - %s' % item
 continue
 elif not isinstance(value, (str, text_type, int, float, bool)):
 continue
 yield '%s: %r' % (key, value)


def explain_template_loading_attempts(app, template, attempts):
 """This should help developers understand what failed"""
 info = ['Locating template "%s":' % template]
 total_found = 0
 blueprint = None
 reqctx = _request_ctx_stack.top
 if reqctx is not None and reqctx.request.blueprint is not None:
 blueprint = reqctx.request.blueprint

 for idx, (loader, srcobj, triple) in enumerate(attempts):
 if isinstance(srcobj, Flask):
 src_info = 'application "%s"' % srcobj.import_name
 elif isinstance(srcobj, Blueprint):
 src_info = 'blueprint "%s" (%s)' % (srcobj.name,
 srcobj.import_name)
 else:
 src_info = repr(srcobj)

 info.append('% 5d: trying loader of %s' % (
 idx + 1, src_info))

 for line in _dump_loader_info(loader):
 info.append(' %s' % line)

 if triple is None:
 detail = 'no match'
 else:
 detail = 'found (%r)' % (triple[1] or '<string>')
 total_found += 1
 info.append(' -> %s' % detail)

 seems_fishy = False
 if total_found == 0:
 info.append('Error: the template could not be found.')
 seems_fishy = True
 elif total_found > 1:
 info.append('Warning: multiple loaders returned a match for the template.')
 seems_fishy = True

 if blueprint is not None and seems_fishy:
 info.append(' The template was looked up from an endpoint that '
 'belongs to the blueprint "%s".' % blueprint)
 info.append(' Maybe you did not place a template in the right folder?')
 info.append(' See http://flask.pocoo.org/docs/blueprints/#templates')

 app.logger.info('\n'.join(info))


def explain_ignored_app_run():
 if os.environ.get('WERKZEUG_RUN_MAIN') != 'true':
 warn(Warning('Silently ignoring app.run() because the '
 'application is run from the flask command line '
 'executable. Consider putting app.run() behind an '
 'if __name__ == "__main__" guard to silence this '
 'warning.'), stacklevel=3)