"""More comprehensive traceback formatting for Python scripts.



To enable this module, do:



    import cgitb; cgitb.enable()



at the top of your script.  The optional arguments to enable() are:



    display     - if true, tracebacks are displayed in the web browser

    logdir      - if set, tracebacks are written to files in this directory

    context     - number of lines of source code to show for each stack frame

    format      - 'text' or 'html' controls the output format



By default, tracebacks are displayed but not saved, the context is 5 lines

and the output format is 'html' (for backwards compatibility with the

original use of this module)



Alternatively, if you have caught an exception and want cgitb to display it

for you, call cgitb.handler().  The optional argument to handler() is a

3-item tuple (etype, evalue, etb) just like the value of sys.exc_info().

The default handler displays output as HTML.

"""



__author__ = 'Ka-Ping Yee'



__version__ = '$Revision: 55348 $'



import sys



def reset():

    """Return a string that resets the CGI and browser to a known state."""

    return '''<!--: spam

Content-Type: text/html



<body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> -->

<body bgcolor="#f0f0f8"><font color="#f0f0f8" size="-5"> --> -->

</font> </font> </font> </script> </object> </blockquote> </pre>

</table> </table> </table> </table> </table> </font> </font> </font>'''



__UNDEF__ = []                          # a special sentinel object

def small(text):

    if text:

        return '<small>' + text + '</small>'

    else:

        return ''



def strong(text):

    if text:

        return '<strong>' + text + '</strong>'

    else:

        return ''



def grey(text):

    if text:

        return '<font color="#909090">' + text + '</font>'

    else:

        return ''



def lookup(name, frame, locals):

    """Find the value for a given name in the given environment."""

    if name in locals:

        return 'local', locals[name]

    if name in frame.f_globals:

        return 'global', frame.f_globals[name]

    if '__builtins__' in frame.f_globals:

        builtins = frame.f_globals['__builtins__']

        if type(builtins) is type({}):

            if name in builtins:

                return 'builtin', builtins[name]

        else:

            if hasattr(builtins, name):

                return 'builtin', getattr(builtins, name)

    return None, __UNDEF__



def scanvars(reader, frame, locals):

    """Scan one logical line of Python and look up values of variables used."""

    import tokenize, keyword

    vars, lasttoken, parent, prefix, value = [], None, None, '', __UNDEF__

    for ttype, token, start, end, line in tokenize.generate_tokens(reader):

        if ttype == tokenize.NEWLINE: break

        if ttype == tokenize.NAME and token not in keyword.kwlist:

            if lasttoken == '.':

                if parent is not __UNDEF__:

                    value = getattr(parent, token, __UNDEF__)

                    vars.append((prefix + token, prefix, value))

            else:

                where, value = lookup(token, frame, locals)

                vars.append((token, where, value))

        elif token == '.':

            prefix += lasttoken + '.'

            parent = value

        else:

            parent, prefix = None, ''

        lasttoken = token

    return vars



def html((etype, evalue, etb), context=5):

    """Return a nice HTML document describing a given traceback."""

    import os, types, time, traceback, linecache, inspect, pydoc



    if type(etype) is types.ClassType:

        etype = etype.__name__

    pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable

    date = time.ctime(time.time())

    head = '<body bgcolor="#f0f0f8">' + pydoc.html.heading(

        '<big><big>%s</big></big>' %

        strong(pydoc.html.escape(str(etype))),

        '#ffffff', '#6622aa', pyver + '<br>' + date) + '''

<p>A problem occurred in a Python script.  Here is the sequence of

function calls leading up to the error, in the order they occurred.</p>'''



    indent = '<tt>' + small('&nbsp;' * 5) + '&nbsp;</tt>'

    frames = []

    records = inspect.getinnerframes(etb, context)

    for frame, file, lnum, func, lines, index in records:

        if file:

            file = os.path.abspath(file)

            link = '<a href="file://%s">%s</a>' % (file, pydoc.html.escape(file))

        else:

            file = link = '?'

        args, varargs, varkw, locals = inspect.getargvalues(frame)

        call = ''

        if func != '?':

            call = 'in ' + strong(func) + \

                inspect.formatargvalues(args, varargs, varkw, locals,

                    formatvalue=lambda value: '=' + pydoc.html.repr(value))



        highlight = {}

        def reader(lnum=[lnum]):

            highlight[lnum[0]] = 1

            try: return linecache.getline(file, lnum[0])

            finally: lnum[0] += 1

        vars = scanvars(reader, frame, locals)



        rows = ['<tr><td bgcolor="#d8bbff">%s%s %s</td></tr>' %

                ('<big>&nbsp;</big>', link, call)]

        if index is not None:

            i = lnum - index

            for line in lines:

                num = small('&nbsp;' * (5-len(str(i))) + str(i)) + '&nbsp;'

                line = '<tt>%s%s</tt>' % (num, pydoc.html.preformat(line))

                if i in highlight:

                    rows.append('<tr><td bgcolor="#ffccee">%s</td></tr>' % line)

                else:

                    rows.append('<tr><td>%s</td></tr>' % grey(line))

                i += 1



        done, dump = {}, []

        for name, where, value in vars:

            if name in done: continue

            done[name] = 1

            if value is not __UNDEF__:

                if where in ('global', 'builtin'):

                    name = ('<em>%s</em> ' % where) + strong(name)

                elif where == 'local':

                    name = strong(name)

                else:

                    name = where + strong(name.split('.')[-1])

                dump.append('%s&nbsp;= %s' % (name, pydoc.html.repr(value)))

            else:

                dump.append(name + ' <em>undefined</em>')



        rows.append('<tr><td>%s</td></tr>' % small(grey(', '.join(dump))))

        frames.append('''

<table width="100%%" cellspacing=0 cellpadding=0 border=0>

%s</table>''' % '\n'.join(rows))



    exception = ['<p>%s: %s' % (strong(pydoc.html.escape(str(etype))),

                                pydoc.html.escape(str(evalue)))]

    if isinstance(evalue, BaseException):

        for name in dir(evalue):

            if name[:1] == '_': continue

            value = pydoc.html.repr(getattr(evalue, name))

            exception.append('\n<br>%s%s&nbsp;=\n%s' % (indent, name, value))



    import traceback

    return head + ''.join(frames) + ''.join(exception) + '''





<!-- The above is a description of an error in a Python program, formatted

     for a Web browser because the 'cgitb' module was enabled.  In case you

     are not reading this in a Web browser, here is the original traceback:



%s

-->

''' % pydoc.html.escape(

          ''.join(traceback.format_exception(etype, evalue, etb)))



def text((etype, evalue, etb), context=5):

    """Return a plain text document describing a given traceback."""

    import os, types, time, traceback, linecache, inspect, pydoc



    if type(etype) is types.ClassType:

        etype = etype.__name__

    pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable

    date = time.ctime(time.time())

    head = "%s\n%s\n%s\n" % (str(etype), pyver, date) + '''

A problem occurred in a Python script.  Here is the sequence of

function calls leading up to the error, in the order they occurred.

'''



    frames = []

    records = inspect.getinnerframes(etb, context)

    for frame, file, lnum, func, lines, index in records:

        file = file and os.path.abspath(file) or '?'

        args, varargs, varkw, locals = inspect.getargvalues(frame)

        call = ''

        if func != '?':

            call = 'in ' + func + \

                inspect.formatargvalues(args, varargs, varkw, locals,

                    formatvalue=lambda value: '=' + pydoc.text.repr(value))



        highlight = {}

        def reader(lnum=[lnum]):

            highlight[lnum[0]] = 1

            try: return linecache.getline(file, lnum[0])

            finally: lnum[0] += 1

        vars = scanvars(reader, frame, locals)



        rows = [' %s %s' % (file, call)]

        if index is not None:

            i = lnum - index

            for line in lines:

                num = '%5d ' % i

                rows.append(num+line.rstrip())

                i += 1



        done, dump = {}, []

        for name, where, value in vars:

            if name in done: continue

            done[name] = 1

            if value is not __UNDEF__:

                if where == 'global': name = 'global ' + name

                elif where != 'local': name = where + name.split('.')[-1]

                dump.append('%s = %s' % (name, pydoc.text.repr(value)))

            else:

                dump.append(name + ' undefined')



        rows.append('\n'.join(dump))

        frames.append('\n%s\n' % '\n'.join(rows))



    exception = ['%s: %s' % (str(etype), str(evalue))]

    if isinstance(evalue, BaseException):

        for name in dir(evalue):

            value = pydoc.text.repr(getattr(evalue, name))

            exception.append('\n%s%s = %s' % (" "*4, name, value))



    import traceback

    return head + ''.join(frames) + ''.join(exception) + '''



The above is a description of an error in a Python program.  Here is

the original traceback:



%s

''' % ''.join(traceback.format_exception(etype, evalue, etb))



class Hook:

    """A hook to replace sys.excepthook that shows tracebacks in HTML."""



    def __init__(self, display=1, logdir=None, context=5, file=None,

                 format="html"):

        self.display = display          # send tracebacks to browser if true

        self.logdir = logdir            # log tracebacks to files if not None

        self.context = context          # number of source code lines per frame

        self.file = file or sys.stdout  # place to send the output

        self.format = format



    def __call__(self, etype, evalue, etb):

        self.handle((etype, evalue, etb))



    def handle(self, info=None):

        info = info or sys.exc_info()

        if self.format == "html":

            self.file.write(reset())



        formatter = (self.format=="html") and html or text

        plain = False

        try:

            doc = formatter(info, self.context)

        except:                         # just in case something goes wrong

            import traceback

            doc = ''.join(traceback.format_exception(*info))

            plain = True



        if self.display:

            if plain:

                doc = doc.replace('&', '&amp;').replace('<', '&lt;')

                self.file.write('<pre>' + doc + '</pre>\n')

            else:

                self.file.write(doc + '\n')

        else:

            self.file.write('<p>A problem occurred in a Python script.\n')



        if self.logdir is not None:

            import os, tempfile

            suffix = ['.txt', '.html'][self.format=="html"]

            (fd, path) = tempfile.mkstemp(suffix=suffix, dir=self.logdir)

            try:

                file = os.fdopen(fd, 'w')

                file.write(doc)

                file.close()

                msg = '<p> %s contains the description of this error.' % path

            except:

                msg = '<p> Tried to save traceback to %s, but failed.' % path

            self.file.write(msg + '\n')

        try:

            self.file.flush()

        except: pass



handler = Hook().handle

def enable(display=1, logdir=None, context=5, format="html"):

    """Install an exception handler that formats tracebacks as HTML.



    The optional argument 'display' can be set to 0 to suppress sending the

    traceback to the browser, and 'logdir' can be set to a directory to cause

    tracebacks to be written to files there."""

    sys.excepthook = Hook(display=display, logdir=logdir,

                          context=context, format=format)

