"""CallTips.py - An IDLE Extension to Jog Your Memory

Call Tips are floating windows which display function, class, and method

parameter and docstring information when you type an opening parenthesis, and

which disappear when you type a closing parenthesis.

"""

import sys

import types

import CallTipWindow

from HyperParser import HyperParser

import __main__

class CallTips:

    menudefs = [

        ('edit', [

            ("Show call tip", "<<force-open-calltip>>"),

        ])

    ]

    def __init__(self, editwin=None):

        if editwin is None:  # subprocess and test

            self.editwin = None

            return

        self.editwin = editwin

        self.text = editwin.text

        self.calltip = None

        self._make_calltip_window = self._make_tk_calltip_window

    def close(self):

        self._make_calltip_window = None

    def _make_tk_calltip_window(self):

        # See __init__ for usage

        return CallTipWindow.CallTip(self.text)

    def _remove_calltip_window(self, event=None):

        if self.calltip:

            self.calltip.hidetip()

            self.calltip = None

    def force_open_calltip_event(self, event):

        """Happens when the user really wants to open a CallTip, even if a

        function call is needed.

        """

        self.open_calltip(True)

    def try_open_calltip_event(self, event):

        """Happens when it would be nice to open a CallTip, but not really

        neccesary, for example after an opening bracket, so function calls

        won't be made.

        """

        self.open_calltip(False)

    def refresh_calltip_event(self, event):

        """If there is already a calltip window, check if it is still needed,

        and if so, reload it.

        """

        if self.calltip and self.calltip.is_active():

            self.open_calltip(False)

    def open_calltip(self, evalfuncs):

        self._remove_calltip_window()

        hp = HyperParser(self.editwin, "insert")

        sur_paren = hp.get_surrounding_brackets('(')

        if not sur_paren:

            return

        hp.set_index(sur_paren[0])

        name = hp.get_expression()

        if not name or (not evalfuncs and name.find('(') != -1):

            return

        arg_text = self.fetch_tip(name)

        if not arg_text:

            return

        self.calltip = self._make_calltip_window()

        self.calltip.showtip(arg_text, sur_paren[0], sur_paren[1])

    def fetch_tip(self, name):

        """Return the argument list and docstring of a function or class

        If there is a Python subprocess, get the calltip there.  Otherwise,

        either fetch_tip() is running in the subprocess itself or it was called

        in an IDLE EditorWindow before any script had been run.

        The subprocess environment is that of the most recently run script.  If

        two unrelated modules are being edited some calltips in the current

        module may be inoperative if the module was not the last to run.

        """

        try:

            rpcclt = self.editwin.flist.pyshell.interp.rpcclt

        except:

            rpcclt = None

        if rpcclt:

            return rpcclt.remotecall("exec", "get_the_calltip",

                                     (name,), {})

        else:

            entity = self.get_entity(name)

            return get_arg_text(entity)

    def get_entity(self, name):

        "Lookup name in a namespace spanning sys.modules and __main.dict__"

        if name:

            namespace = sys.modules.copy()

            namespace.update(__main__.__dict__)

            try:

                return eval(name, namespace)

            except:

                return None

def _find_constructor(class_ob):

    # Given a class object, return a function object used for the

    # constructor (ie, __init__() ) or None if we can't find one.

    try:

        return class_ob.__init__.im_func

    except AttributeError:

        for base in class_ob.__bases__:

            rc = _find_constructor(base)

            if rc is not None: return rc

    return None

def get_arg_text(ob):

    """Get a string describing the arguments for the given object"""

    argText = ""

    if ob is not None:

        argOffset = 0

        if type(ob) in (types.ClassType, types.TypeType):

            # Look for the highest __init__ in the class chain.

            fob = _find_constructor(ob)

            if fob is None:

                fob = lambda: None

            else:

                argOffset = 1

        elif type(ob)==types.MethodType:

            # bit of a hack for methods - turn it into a function

            # but we drop the "self" param.

            fob = ob.im_func

            argOffset = 1

        else:

            fob = ob

        # Try and build one for Python defined functions

        if type(fob) in [types.FunctionType, types.LambdaType]:

            try:

                realArgs = fob.func_code.co_varnames[argOffset:fob.func_code.co_argcount]

                defaults = fob.func_defaults or []

                defaults = list(map(lambda name: "=%s" % repr(name), defaults))

                defaults = [""] * (len(realArgs)-len(defaults)) + defaults

                items = map(lambda arg, dflt: arg+dflt, realArgs, defaults)

                if fob.func_code.co_flags & 0x4:

                    items.append("...")

                if fob.func_code.co_flags & 0x8:

                    items.append("***")

                argText = ", ".join(items)

                argText = "(%s)" % argText

            except:

                pass

        # See if we can use the docstring

        doc = getattr(ob, "__doc__", "")

        if doc:

            doc = doc.lstrip()

            pos = doc.find("\n")

            if pos < 0 or pos > 70:

                pos = 70

            if argText:

                argText += "\n"

            argText += doc[:pos]

    return argText

#################################################

#

# Test code

#

if __name__=='__main__':

    def t1(): "()"

    def t2(a, b=None): "(a, b=None)"

    def t3(a, *args): "(a, ...)"

    def t4(*args): "(...)"

    def t5(a, *args): "(a, ...)"

    def t6(a, b=None, *args, **kw): "(a, b=None, ..., ***)"

    class TC:

        "(a=None, ...)"

        def __init__(self, a=None, *b): "(a=None, ...)"

        def t1(self): "()"

        def t2(self, a, b=None): "(a, b=None)"

        def t3(self, a, *args): "(a, ...)"

        def t4(self, *args): "(...)"

        def t5(self, a, *args): "(a, ...)"

        def t6(self, a, b=None, *args, **kw): "(a, b=None, ..., ***)"

    def test(tests):

        ct = CallTips()

        failed=[]

        for t in tests:

            expected = t.__doc__ + "\n" + t.__doc__

            name = t.__name__

            arg_text = ct.fetch_tip(name)

            if arg_text != expected:

                failed.append(t)

                print "%s - expected %s, but got %s" % (t, expected,

                                                        get_arg_text(entity))

        print "%d of %d tests failed" % (len(failed), len(tests))

    tc = TC()

    tests = (t1, t2, t3, t4, t5, t6,

             TC, tc.t1, tc.t2, tc.t3, tc.t4, tc.t5, tc.t6)

    test(tests)