# Copyright (C) 2001-2007 Python Software Foundation
# Author: Barry Warsaw, Thomas Wouters, Anthony Baxter
# Contact: email-sig@python.org

"""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 preceded 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 preceded 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')
 try:
 return self.parser.parse(fp, headersonly)
 finally:
 fp.detach()


 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)