# Copyright (c) 2000 Gregory Trubetskoy.  All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 #
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer. 
 #
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in
 #    the documentation and/or other materials provided with the
 #    distribution.
 #
 # 3. The end-user documentation included with the redistribution, if
 #    any, must include the following acknowledgment: "This product 
 #    includes software developed by Gregory Trubetskoy."
 #    Alternately, this acknowledgment may appear in the software itself, 
 #    if and wherever such third-party acknowledgments normally appear.
 #
 # 4. The names "mod_python", "modpython" or "Gregory Trubetskoy" must not 
 #    be used to endorse or promote products derived from this software 
 #    without prior written permission. For written permission, please 
 #    contact grisha@modpython.org.
 #
 # 5. Products derived from this software may not be called "mod_python"
 #    or "modpython", nor may "mod_python" or "modpython" appear in their 
 #    names without prior written permission of Gregory Trubetskoy.
 #
 # THIS SOFTWARE IS PROVIDED BY GREGORY TRUBETSKOY ``AS IS'' AND ANY
 # EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 # PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL GREGORY TRUBETSKOY OR
 # HIS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 # NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 # STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 # OF THE POSSIBILITY OF SUCH DAMAGE.
 # ====================================================================
 #
 # $Id: util.py,v 1.6 2000/12/13 23:45:48 gtrubetskoy Exp $

import apache
import string
import StringIO

parse_qs = apache.parse_qs
parse_qsl = apache.parse_qsl

""" The classes below are a (almost) a drop-in replacement for the
    standard cgi.py FieldStorage class. They should have pretty much the
    same functionality.

    These classes differ in that unlike cgi.FieldStorage, they are not
    recursive. The class FieldStorage contains a list of instances of
    Field class. Field class is incapable of storing anything in it.

    These objects should be considerably faster than the ones in cgi.py
    because they do not expect CGI environment, and are
    optimized specifically for Apache and mod_python.
"""

class Field:

    filename = None
    headers = {}

    def __init__(self, name, file, ctype, type_options,
                 disp, disp_options):
        self.name = name
        self.file = file
        self.type = ctype
        self.type_options = type_options
        self.disposition = disp
        self.disposition_options = disp_options

    def __repr__(self):
        """Return printable representation."""
        return "Field(%s, %s)" % (`self.name`, `self.value`)

    def __getattr__(self, name):
        if name != 'value':
            raise AttributeError, name
        if self.file:
            self.file.seek(0)
            value = self.file.read()
            self.file.seek(0)
        else:
            value = None
        return value

    def __del__(self):
        self.file.close()


class FieldStorage:

    def __init__(self, req, keep_blank_values=0, strict_parsing=0):

        self._req =_req = req._req

        self.list = []

        # always process GET-style parameters
        if _req.args:
            pairs = parse_qsl(req.args, keep_blank_values)
            for pair in pairs:
                file = StringIO.StringIO(pair[1])
                self.list.append(Field(pair[0], file, "text/plain", {},
                                       None, {}))

        if _req.method == "POST":

            try:
                clen = int(_req.headers_in["content-length"])
            except (KeyError, ValueError):
                # absent content-length is not acceptable
                raise apache.SERVER_RETURN, apache.HTTP_LENGTH_REQUIRED

            if not _req.headers_in.has_key("content-type"):
                ctype = "application/x-www-form-urlencoded"
            else:
                ctype = _req.headers_in["content-type"]

            if ctype == "application/x-www-form-urlencoded":
                
                pairs = parse_qsl(req.read(clen), keep_blank_values)
                for pair in pairs:
                    file = StringIO.StringIO(pair[1])
                    self.list.append(Field(pair[0], file, "text/plain",
                                     {}, None, {}))

            elif ctype[:10] == "multipart/":

                # figure out boundary
                # XXX what about req.boundary?
                try:
                    i = string.rindex(string.lower(ctype), "boundary=")
                    boundary = ctype[i+9:]
                    if len(boundary) >= 2 and boundary[0] == boundary[-1] == '"':
                        boundary = boundary[1:-1]
                    boundary = "--" + boundary
                except ValueError:
                    raise apache.SERVER_RETURN, apache.HTTP_BAD_REQUEST

                #read until boundary
                line = _req.readline()
                sline = string.strip(line)
                while line and sline != boundary:
                    line = _req.readline()

                while 1:

                    ## parse headers
                    
                    ctype, type_options = "text/plain", {}
                    disp, disp_options = None, {}
                    headers = apache.make_table()
                    line = _req.readline()
                    while line and line not in ["\n", "\r\n"]:
                        h, v = string.split(line, ":", 1)
                        headers.add(h, v)
                        h = string.lower(h)
                        if h == "content-disposition":
                            disp, disp_options = parse_header(v)
                        elif h == "content-type":
                            ctype, type_options = parse_header(v)
                        line = _req.readline()

                    if disp_options.has_key("name"):
                        name = disp_options["name"]
                    else:
                        name = None

                    # is this a file?
                    if disp_options.has_key("filename"):
                        file = self.make_file()
                    else:
                        file = StringIO.StringIO()

                    # read it in
                    self.read_to_boundary(_req, boundary, file)
                    file.seek(0)

                    # make a Field
                    field = Field(name, file, ctype, type_options,
                                  disp, disp_options)
                    field.headers = headers
                    if disp_options.has_key("filename"):
                        field.filename = disp_options["filename"]

                    self.list.append(field)

                    if not line or sline == (boundary + "--"):
                        break

            else:
                # we don't understand this content-type
                raise apache.SERVER_RETURN, apache.HTTP_NOT_IMPLEMENTED


    def make_file(self):
        import tempfile
        return tempfile.TemporaryFile("w+b")


    def skip_to_boundary(self, _req, boundary):
        line = _req.readline()
        sline = string.strip(line)
        last_bound = boundary + "--"
        while line and sline != boundary and sline != last_bound:
            line = _req.readline()
            sline = string.strip(line)

    def read_to_boundary(self, _req, boundary, file):
        delim = ""
        line = _req.readline()
        sline = string.strip(line)
        last_bound = boundary + "--"
        while line and sline != boundary and sline != last_bound:
            odelim = delim
            if line[-2:] == "\r\n":
                delim = "\r\n"
                line = line[:-2]
            elif line[-1:] == "\n":
                delim = "\n"
                line = line[:-1]
            file.write(odelim + line)
            line = _req.readline()
            sline = string.strip(line)

    def __getitem__(self, key):
        """Dictionary style indexing."""
        if self.list is None:
            raise TypeError, "not indexable"
        found = []
        for item in self.list:
            if item.name == key:
                if isinstance(item.file, StringIO.StringIO):
                    found.append(item.value)
                else:
                    found.append(item)
        if not found:
            raise KeyError, key
        if len(found) == 1:
            return found[0]
        else:
            return found

    def keys(self):
        """Dictionary style keys() method."""
        if self.list is None:
            raise TypeError, "not indexable"
        keys = []
        for item in self.list:
            if item.name not in keys: keys.append(item.name)
        return keys

    def has_key(self, key):
        """Dictionary style has_key() method."""
        if self.list is None:
            raise TypeError, "not indexable"
        for item in self.list:
            if item.name == key: return 1
        return 0

    def __len__(self):
        """Dictionary style len(x) support."""
        return len(self.keys())

            
def parse_header(line):
    """Parse a Content-type like header.

    Return the main content-type and a dictionary of options.

    """
    plist = map(string.strip, string.splitfields(line, ';'))
    key = string.lower(plist[0])
    del plist[0]
    pdict = {}
    for p in plist:
        i = string.find(p, '=')
        if i >= 0:
            name = string.lower(string.strip(p[:i]))
            value = string.strip(p[i+1:])
            if len(value) >= 2 and value[0] == value[-1] == '"':
                value = value[1:-1]
            pdict[name] = value
    return key, pdict