# Copyright (C) 2001-2006 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']

import warnings

from cStringIO import StringIO

from email.feedparser import FeedParser

from email.message import Message

class Parser:

    def __init__(self, *args, **kws):

        """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.

        """

        if len(args) >= 1:

            if '_class' in kws:

                raise TypeError("Multiple values for keyword arg '_class'")

            kws['_class'] = args[0]

        if len(args) == 2:

            if 'strict' in kws:

                raise TypeError("Multiple values for keyword arg 'strict'")

            kws['strict'] = args[1]

        if len(args) > 2:

            raise TypeError('Too many arguments')

        if '_class' in kws:

            self._class = kws['_class']

            del kws['_class']

        else:

            self._class = Message

        if 'strict' in kws:

            warnings.warn("'strict' argument is deprecated (and ignored)",

                          DeprecationWarning, 2)

            del kws['strict']

        if kws:

            raise TypeError('Unexpected keyword arguments')

    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)

        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)