import string

from Tkinter import *

from Delegator import Delegator

#$ event <<redo>>

#$ win <Control-y>

#$ unix <Alt-z>

#$ event <<undo>>

#$ win <Control-z>

#$ unix <Control-z>

#$ event <<dump-undo-state>>

#$ win <Control-backslash>

#$ unix <Control-backslash>

class UndoDelegator(Delegator):

    max_undo = 1000

    def __init__(self):

        Delegator.__init__(self)

        self.reset_undo()

    def setdelegate(self, delegate):

        if self.delegate is not None:

            self.unbind("<<undo>>")

            self.unbind("<<redo>>")

            self.unbind("<<dump-undo-state>>")

        Delegator.setdelegate(self, delegate)

        if delegate is not None:

            self.bind("<<undo>>", self.undo_event)

            self.bind("<<redo>>", self.redo_event)

            self.bind("<<dump-undo-state>>", self.dump_event)

    def dump_event(self, event):

        from pprint import pprint

        pprint(self.undolist[:self.pointer])

        print "pointer:", self.pointer,

        print "saved:", self.saved,

        print "can_merge:", self.can_merge,

        print "get_saved():", self.get_saved()

        pprint(self.undolist[self.pointer:])

        return "break"

    def reset_undo(self):

        self.was_saved = -1

        self.pointer = 0

        self.undolist = []

        self.undoblock = 0  # or a CommandSequence instance

        self.set_saved(1)

    def set_saved(self, flag):

        if flag:

            self.saved = self.pointer

        else:

            self.saved = -1

        self.can_merge = False

        self.check_saved()

    def get_saved(self):

        return self.saved == self.pointer

    saved_change_hook = None

    def set_saved_change_hook(self, hook):

        self.saved_change_hook = hook

    was_saved = -1

    def check_saved(self):

        is_saved = self.get_saved()

        if is_saved != self.was_saved:

            self.was_saved = is_saved

            if self.saved_change_hook:

                self.saved_change_hook()

    def insert(self, index, chars, tags=None):

        self.addcmd(InsertCommand(index, chars, tags))

    def delete(self, index1, index2=None):

        self.addcmd(DeleteCommand(index1, index2))

    # Clients should call undo_block_start() and undo_block_stop()

    # around a sequence of editing cmds to be treated as a unit by

    # undo & redo.  Nested matching calls are OK, and the inner calls

    # then act like nops.  OK too if no editing cmds, or only one

    # editing cmd, is issued in between:  if no cmds, the whole

    # sequence has no effect; and if only one cmd, that cmd is entered

    # directly into the undo list, as if undo_block_xxx hadn't been

    # called.  The intent of all that is to make this scheme easy

    # to use:  all the client has to worry about is making sure each

    # _start() call is matched by a _stop() call.

    def undo_block_start(self):

        if self.undoblock == 0:

            self.undoblock = CommandSequence()

        self.undoblock.bump_depth()

    def undo_block_stop(self):

        if self.undoblock.bump_depth(-1) == 0:

            cmd = self.undoblock

            self.undoblock = 0

            if len(cmd) > 0:

                if len(cmd) == 1:

                    # no need to wrap a single cmd

                    cmd = cmd.getcmd(0)

                # this blk of cmds, or single cmd, has already

                # been done, so don't execute it again

                self.addcmd(cmd, 0)

    def addcmd(self, cmd, execute=True):

        if execute:

            cmd.do(self.delegate)

        if self.undoblock != 0:

            self.undoblock.append(cmd)

            return

        if self.can_merge and self.pointer > 0:

            lastcmd = self.undolist[self.pointer-1]

            if lastcmd.merge(cmd):

                return

        self.undolist[self.pointer:] = [cmd]

        if self.saved > self.pointer:

            self.saved = -1

        self.pointer = self.pointer + 1

        if len(self.undolist) > self.max_undo:

            ##print "truncating undo list"

            del self.undolist[0]

            self.pointer = self.pointer - 1

            if self.saved >= 0:

                self.saved = self.saved - 1

        self.can_merge = True

        self.check_saved()

    def undo_event(self, event):

        if self.pointer == 0:

            self.bell()

            return "break"

        cmd = self.undolist[self.pointer - 1]

        cmd.undo(self.delegate)

        self.pointer = self.pointer - 1

        self.can_merge = False

        self.check_saved()

        return "break"

    def redo_event(self, event):

        if self.pointer >= len(self.undolist):

            self.bell()

            return "break"

        cmd = self.undolist[self.pointer]

        cmd.redo(self.delegate)

        self.pointer = self.pointer + 1

        self.can_merge = False

        self.check_saved()

        return "break"

class Command:

    # Base class for Undoable commands

    tags = None

    def __init__(self, index1, index2, chars, tags=None):

        self.marks_before = {}

        self.marks_after = {}

        self.index1 = index1

        self.index2 = index2

        self.chars = chars

        if tags:

            self.tags = tags

    def __repr__(self):

        s = self.__class__.__name__

        t = (self.index1, self.index2, self.chars, self.tags)

        if self.tags is None:

            t = t[:-1]

        return s + repr(t)

    def do(self, text):

        pass

    def redo(self, text):

        pass

    def undo(self, text):

        pass

    def merge(self, cmd):

        return 0

    def save_marks(self, text):

        marks = {}

        for name in text.mark_names():

            if name != "insert" and name != "current":

                marks[name] = text.index(name)

        return marks

    def set_marks(self, text, marks):

        for name, index in marks.items():

            text.mark_set(name, index)

class InsertCommand(Command):

    # Undoable insert command

    def __init__(self, index1, chars, tags=None):

        Command.__init__(self, index1, None, chars, tags)

    def do(self, text):

        self.marks_before = self.save_marks(text)

        self.index1 = text.index(self.index1)

        if text.compare(self.index1, ">", "end-1c"):

            # Insert before the final newline

            self.index1 = text.index("end-1c")

        text.insert(self.index1, self.chars, self.tags)

        self.index2 = text.index("%s+%dc" % (self.index1, len(self.chars)))

        self.marks_after = self.save_marks(text)

        ##sys.__stderr__.write("do: %s\n" % self)

    def redo(self, text):

        text.mark_set('insert', self.index1)

        text.insert(self.index1, self.chars, self.tags)

        self.set_marks(text, self.marks_after)

        text.see('insert')

        ##sys.__stderr__.write("redo: %s\n" % self)

    def undo(self, text):

        text.mark_set('insert', self.index1)

        text.delete(self.index1, self.index2)

        self.set_marks(text, self.marks_before)

        text.see('insert')

        ##sys.__stderr__.write("undo: %s\n" % self)

    def merge(self, cmd):

        if self.__class__ is not cmd.__class__:

            return False

        if self.index2 != cmd.index1:

            return False

        if self.tags != cmd.tags:

            return False

        if len(cmd.chars) != 1:

            return False

        if self.chars and \

           self.classify(self.chars[-1]) != self.classify(cmd.chars):

            return False

        self.index2 = cmd.index2

        self.chars = self.chars + cmd.chars

        return True

    alphanumeric = string.ascii_letters + string.digits + "_"

    def classify(self, c):

        if c in self.alphanumeric:

            return "alphanumeric"

        if c == "\n":

            return "newline"

        return "punctuation"

class DeleteCommand(Command):

    # Undoable delete command

    def __init__(self, index1, index2=None):

        Command.__init__(self, index1, index2, None, None)

    def do(self, text):

        self.marks_before = self.save_marks(text)

        self.index1 = text.index(self.index1)

        if self.index2:

            self.index2 = text.index(self.index2)

        else:

            self.index2 = text.index(self.index1 + " +1c")

        if text.compare(self.index2, ">", "end-1c"):

            # Don't delete the final newline

            self.index2 = text.index("end-1c")

        self.chars = text.get(self.index1, self.index2)

        text.delete(self.index1, self.index2)

        self.marks_after = self.save_marks(text)

        ##sys.__stderr__.write("do: %s\n" % self)

    def redo(self, text):

        text.mark_set('insert', self.index1)

        text.delete(self.index1, self.index2)

        self.set_marks(text, self.marks_after)

        text.see('insert')

        ##sys.__stderr__.write("redo: %s\n" % self)

    def undo(self, text):

        text.mark_set('insert', self.index1)

        text.insert(self.index1, self.chars)

        self.set_marks(text, self.marks_before)

        text.see('insert')

        ##sys.__stderr__.write("undo: %s\n" % self)

class CommandSequence(Command):

    # Wrapper for a sequence of undoable cmds to be undone/redone

    # as a unit

    def __init__(self):

        self.cmds = []

        self.depth = 0

    def __repr__(self):

        s = self.__class__.__name__

        strs = []

        for cmd in self.cmds:

            strs.append("    %r" % (cmd,))

        return s + "(\n" + ",\n".join(strs) + "\n)"

    def __len__(self):

        return len(self.cmds)

    def append(self, cmd):

        self.cmds.append(cmd)

    def getcmd(self, i):

        return self.cmds[i]

    def redo(self, text):

        for cmd in self.cmds:

            cmd.redo(text)

    def undo(self, text):

        cmds = self.cmds[:]

        cmds.reverse()

        for cmd in cmds:

            cmd.undo(text)

    def bump_depth(self, incr=1):

        self.depth = self.depth + incr

        return self.depth

def main():

    from Percolator import Percolator

    root = Tk()

    root.wm_protocol("WM_DELETE_WINDOW", root.quit)

    text = Text()

    text.pack()

    text.focus_set()

    p = Percolator(text)

    d = UndoDelegator()

    p.insertfilter(d)

    root.mainloop()

if __name__ == "__main__":

    main()