"""This plug-in provides base class for custom output parser.

Parsers are organized in chain. Output of one parser is passed as input
to next one. Chain of parser could be attached to a build target.

An example:

import GPS, tool_output

class PopupParser(tool_output.OutputParser):
    def on_stdout(self,text,command):
        #  This call accepts all output during target build.
        #  text    - piece of output of target's build.
        #  command - GPS.Command caused build to execute.
        GPS.MDI.dialog (text)
        if self.child != None:
            self.child.on_stdout (text,command)

    def on_exit(self,status,command):
        #  This is called after build competed.
        #  Then each output parser is destroyed.
        #  status  - integer status of execution.
        #  command - GPS.Command caused build to execute.

        GPS.MDI.dialog ("Build complete!")
        if self.child != None:
            self.child.on_exit (status,command)

To add custom parser to a target insert next line to target description:

<output-parsers>[default] popupparser</output-parsers>
</target>
"""

#############################################################################
# No user customization below this line
#############################################################################


class OutputParserMetaClass(type):
    registered = dict()   # list of registered parsers

    def __new__(cls, name, bases, attrs):
        new_class = type.__new__(cls, name, bases, attrs)
        OutputParserMetaClass.registered[new_class.get_name()] = new_class
        return new_class

    def get_name(self):
        """Return the name of the parser, either from a "name" class
            attribute, or from the class name
        """
        return getattr(self, 'name', self.__name__).lower()


class OutputParser(object):
    __metaclass__ = OutputParserMetaClass

    def __init__(self, child):
        self.child = child

    def on_stdout(self, text, command):
        if self.child is not None:
            self.child.on_stdout(text, command)

    def on_stderr(self, text, command):
        if self.child is not None:
            self.child.on_stderr(text, command)

    def on_exit(self, status, command):
        if self.child is not None:
            self.child.on_exit(status, command)


def create_parser(name, child=None):
    if name in OutputParserMetaClass.registered:
        return OutputParserMetaClass.registered[name](child)
    else:
        return None
