    """This module co-ordinates the reading of the source file.

        It maintains the current position of the parser in the source file.

        (c) Copyright by Jay Love, 2000 (mailto:jsliv@jslove.net)

        Permission to use, copy, modify, and distribute this software and its
        documentation for any purpose and without fee or royalty is hereby granted,
        provided that the above copyright notice appear in all copies and that
        both that copyright notice and this permission notice appear in
        supporting documentation or portions thereof, including modifications,
        that you make.

        THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO
        THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
        FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
        INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
        FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
        NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
        WITH THE USE OR PERFORMANCE OF THIS SOFTWARE !

        This software is based in part on work done by the Jakarta group.

    """

    from Context import *

    import types
    import copy
    import string
    import os

    class Mark:
        """The Mark class marks a point in an input stream."""

        def __init__(self, reader, fileid=None, stream=None, inBaseDir=None, encoding=None):

            if isinstance(reader,StreamReader):
                self.reader = reader
                self.fileid = fileid
                self.includeStack = []
                self.cursor = 0
                self.stream = stream
                self.baseDir=inBaseDir
                self.encoding=encoding
            else:
                self = copy.copy(reader)
            # I think the includeStack will be copied correctly,
            # but check here for problems: raise 'clone include stack'
            # JSP has an equals function, but I don't think I need that,
            # because of using copy, but maybe I do.

        def getFile(self):
            return self.reader.getFile(self.fileid)

        def __str__(self):
            return self.getFile() + '(' + str(self.line) + str(self.col) + ')'

        def __repr__(self):
            return self.getFile() + '(' + str(self.col) + ')'

        def pushStream(self, infileid, inStream, inBaseDir, inEncoding):
            self.includeStack.append((self.cursor, self.fileid, self.baseDir, self.encoding, self.stream))
            self.cursor=0
            self.fileid=infileid
            self.baseDir=inBaseDir
            self.encoding=inEncoding
            self.stream=inStream

        def popStream(self):
            if len(self.includeStack) == 0:
                return 0 #false
            list=self.includeStack[len(self.includeStack)-1]
            del self.includeStack[len(self.includeStack)-1]
            self.cursor=list[0]
            self.fileid=list[1]
            self.baseDir=list[2]
            self.encoding=list[3]
            self.stream=list[4]
            return 1 # true

    class StreamReader:
        """This class handles the PSP source file.

        It provides the characters to the other parts of the system.
        It can move forward and backwards in a file and remember locactions.

        """

        def __init__(self,filename,ctxt):
            self._pspfile = filename
            self._ctxt = ctxt
            self._filehandle = None
            self.sourcefiles=[]
            self.current = None
            self.size = 0
            self.master=None

        def init(self):
            self.pushFile(self._ctxt.getFullPspFileName())

        def registerSourceFile(self, file):
            self.sourcefiles.append(file)
            self.size = self.size+1 #what is size for?
            return len(self.sourcefiles)-1

        def pushFile(self, file, encoding=None):
            assert type(file)==type('')
            # if type(file) != type(''):
            # we've got an open file handle - don't think this case exists
            # Don't know what this master stuff is, but until I do, implement it.
            # Oh, it's the original file.
            if self.master == None:
                parent = None
                self.master=file
            else:
                parent = os.path.split(self.master)[0]
            isAbsolute = os.path.isabs(file)
            if parent != None and not isAbsolute:
                file = os.path.join(parent,file)
            fileid = self.registerSourceFile(file)
            handle = open(file,'r')
            stream = handle.read()
            handle.seek(0,0)
            lines = handle.readlines()
            z = 0
            for i in lines:
                lines[z]=string.replace(i,'\r\n','\n')
                z = z + 1
            stream=string.join(lines,'')

            if self.current == None:
                self.current = mark = Mark(self, fileid, stream,
                    self._ctxt.getBaseUri(),encoding)
            else:
                self.current.pushStream(fileid, stream,
                    self._ctxt.getBaseUri(), encoding) # don't use yet

        def popFile(self):
            if self.current == None:
                return 0
            self.size = self.size - 1 # @@ what the hell is this?
            r = self.current.popStream()
            return r

        def getFile(self,i):
            return self.sourcefiles[i]

        def newSourceFile(self,filename):
            if filename in self.sourcefiles:
                return None
            sourcefiles.append(filename)
            return len(self.sourcefiles)

        def Mark(self):
            return copy.copy(self.current)

        def skipUntil(self, st):
            """Greedy search.

            Return the point before the string, but move reader past it.

            """
            pt = string.find(self.current.stream[self.current.cursor:],st)
            if pt == -1:
                self.current.cursor = len(self.current.stream)
                if self.hasMoreInput():
                    self.popFile() # @@ Should I do this here? 6/1/00
                    self.skipUntil(st)
                else:
                    raise "EndofInputError"
            else:
                self.current.cursor = self.current.cursor+pt
                ret =  self.Mark()
                self.current.cursor = self.current.cursor+len(st)
                return ret

        def reset(self, mark):
            self.current = mark

        def Matches(self,st):
            if st == self.current.stream[
                    self.current.cursor:self.current.cursor+len(st)]:
                return 1
            return 0

        def Advance(self,length):
            """Advance length characters"""
            if length + self.current.cursor <= len(self.current.stream):
                self.current.cursor = self.current.cursor+length
            else:
                prog = len(self.current.stream) - self.current.cursor
                self.current.cursor = len(self.current.stream) # @@ -1?
                if self.hasMoreInput():
                    self.Advance(length-prog)
                else:
                    raise EOFError()

        def nextChar(self):
            if self.hasMoreInput() == 0:
                return -1
            ch = self.current.stream[self.current.cursor]
            self.Advance(1)
            return ch

        def isSpace(self):
            """No advancing."""
            return self.current.stream[self.current.cursor] == ' ' \
                or self.current.stream[self.current.cursor] == '\n'

        def isDelimiter(self):
            if not self.isSpace():
                ch = self.peekChar()
                # Look for single character work delimiter:
                if ch == '=' or ch == '\"' or ch == "'" or ch == '/':
                    return 1
                # Look for end of comment or basic end tag:
                if ch == '-':
                    mark = self.Mark()
                    ch = self.nextChar()
                    ch2 = self.nextChar()
                    if ch == '>' or (ch == '-' and ch2 == '>'):
                        self.reset(mark)
                        return 1
                    else:
                        self.reset(mark)
                        return 0
            else:
                return 1

        def peekChar(self,cnt=1):
            if self.hasMoreInput():
                return self.current.stream[self.current.cursor:self.current.cursor+cnt]
            raise "EndofStream"

        def skipSpaces(self):
            i = 0
            while self.isSpace():
                self.nextChar()
                i = i+1
            return i

        def getChars(self,start,stop):
            oldcurr = self.Mark()
            self.reset(start)
            chars = self.current.stream[start.cursor:stop.cursor]
            self.reset(oldcurr)
            return chars

        def hasMoreInput(self):
            if self.current.cursor >= len(self.current.stream):
                while self.popFile():
                    if self.current.cursor < len(self.current.stream) :
                        return 1
                return 0
            return 1

        def nextContent(self):
            """Find next < char."""
            cur_cursor = self.current.cursor
            self.current.cursor = self.current.cursor+1
            pt = string.find(self.current.stream[self.current.cursor:],'<')
            if pt == -1:
                    self.current.cursor = len(self.current.stream) # @@ -1?
            else:
                self.current.cursor=self.current.cursor+pt
            return self.current.stream[cur_cursor:self.current.cursor]

        def parseTagAttributes(self):
            """Parse the attributes at the beginning of a tag."""
            values = {}
            while 1:
                self.skipSpaces()
                ch = self.peekChar()
                if ch == '>':
                    return values
                if ch == '-':
                    mark = self.Mark()
                    self.nextChar()
                    try:
                        if self.nextChar() == '-' and self.nextChar() == '>':
                            return values
                    finally:
                        self.reset(mark)
                elif ch == '%':
                    mark = self.Mark()
                    self.nextChar()
                    try:
                        ts = self.peekChar()
                        if ts == '>':
                            self.reset(mark)
                            return values
                    finally:
                        self.reset(mark)
                if ch == None:
                    break
                self.parseAttributeValue(values)
            # EOF
            raise 'Unterminated Attribute'

        def parseAttributeValue(self, valuedict):
            self.skipSpaces()
            name = self.parseToken(0)
            self.skipSpaces()
            if self.peekChar() != '=':
                raise 'PSP Error - no attribute value'
            ch = self.nextChar()
            self.skipSpaces()
            value = self.parseToken(1)
            self.skipSpaces()
            valuedict[name]=value

        def parseToken(self, quoted):
            # This may not be quite right:
            buffer=[]
            self.skipSpaces()
            ch = self.peekChar()
            if quoted:
                if (ch=='\"' or ch == "\'"):
                    endquote = ch
                    ch = self.nextChar()
                    ch=self.peekChar()
                    while ch != None and ch != endquote:
                        ch = self.nextChar()
                        if ch == '\\':
                            ch = nextChar()
                        buffer.append(ch)
                        ch = self.peekChar()
                    if ch == None:
                        raise 'Unterminated Attribute Value'
                    self.nextChar()
            else:
                if not self.isDelimiter():
                    while not self.isDelimiter():
                        ch = self.nextChar()
                        if ch == '\\':
                            ch = self.peekChar()
                            if ch == '\"' or ch == "'" or ch == '>' or ch == '%':
                                ch = self.nextChar()
                        buffer.append(ch)
            return string.join(buffer,'')