# Copyright (C) 2001-2007 Python Software Foundation
# Author: Barry Warsaw, Thomas Wouters, Anthony Baxter
# Contact: [email protected]

"""A parser of RFC 2822 and MIME email messages."""

__all__ = ['Parser', 'HeaderParser', 'BytesParser', 'BytesHeaderParser',
'FeedParser', 'BytesFeedParser']

from io import StringIO, TextIOWrapper

from email.feedparser import FeedParser, BytesFeedParser
from email._policybase import compat32



class Parser:
def __init__(self, _class=None, *, policy=compat32):
"""Parser of RFC 2822 and MIME email messages.

Creates an in-memory object tree representing the email message, which
can then be manipulated and turned over to a Generator to return the
textual representation of the message.

The string must be formatted as a block of RFC 2822 headers and header
continuation lines, optionally preceeded by a `Unix-from' header. The
header block is terminated either by the end of the string or by a
blank line.

_class is the class to instantiate for new message objects when they
must be created. This class must have a constructor that can take
zero arguments. Default is Message.Message.

The policy keyword specifies a policy object that controls a number of
aspects of the parser's operation. The default policy maintains
backward compatibility.

"""
self._class = _class
self.policy = policy

def parse(self, fp, headersonly=False):
"""Create a message structure from the data in a file.

Reads all the data from the file and returns the root of the message
structure. Optional headersonly is a flag specifying whether to stop
parsing after reading the headers or not. The default is False,
meaning it parses the entire contents of the file.
"""
feedparser = FeedParser(self._class, policy=self.policy)
if headersonly:
feedparser._set_headersonly()
while True:
data = fp.read(8192)
if not data:
break
feedparser.feed(data)
return feedparser.close()

def parsestr(self, text, headersonly=False):
"""Create a message structure from a string.

Returns the root of the message structure. Optional headersonly is a
flag specifying whether to stop parsing after reading the headers or
not. The default is False, meaning it parses the entire contents of
the file.
"""
return self.parse(StringIO(text), headersonly=headersonly)



class HeaderParser(Parser):
def parse(self, fp, headersonly=True):
return Parser.parse(self, fp, True)

def parsestr(self, text, headersonly=True):
return Parser.parsestr(self, text, True)


class BytesParser:

def __init__(self, *args, **kw):
"""Parser of binary RFC 2822 and MIME email messages.

Creates an in-memory object tree representing the email message, which
can then be manipulated and turned over to a Generator to return the
textual representation of the message.

The input must be formatted as a block of RFC 2822 headers and header
continuation lines, optionally preceeded by a `Unix-from' header. The
header block is terminated either by the end of the input or by a
blank line.

_class is the class to instantiate for new message objects when they
must be created. This class must have a constructor that can take
zero arguments. Default is Message.Message.
"""
self.parser = Parser(*args, **kw)

def parse(self, fp, headersonly=False):
"""Create a message structure from the data in a binary file.

Reads all the data from the file and returns the root of the message
structure. Optional headersonly is a flag specifying whether to stop
parsing after reading the headers or not. The default is False,
meaning it parses the entire contents of the file.
"""
fp = TextIOWrapper(fp, encoding='ascii', errors='surrogateescape')
with fp:
return self.parser.parse(fp, headersonly)


def parsebytes(self, text, headersonly=False):
"""Create a message structure from a byte string.

Returns the root of the message structure. Optional headersonly is a
flag specifying whether to stop parsing after reading the headers or
not. The default is False, meaning it parses the entire contents of
the file.
"""
text = text.decode('ASCII', errors='surrogateescape')
return self.parser.parsestr(text, headersonly)


class BytesHeaderParser(BytesParser):
def parse(self, fp, headersonly=True):
return BytesParser.parse(self, fp, headersonly=True)

def parsebytes(self, text, headersonly=True):
return BytesParser.parsebytes(self, text, headersonly=True)