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#
#  This program is free software; you can redistribute it and/or
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#  as published by the Free Software Foundation; either version 2
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#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
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#  along with this program; if not, write to the Free Software Foundation,
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# ##### END GPL LICENSE BLOCK #####

# <pep8 compliant>

"""
This module has utility functions for renaming
rna values in fcurves and drivers.

The main function to use is: update_data_paths(...) 
"""

IS_TESTING = False

class DataPathBuilder(object):
    __slots__ = ("data_path", )
    """ Dummy class used to parse fcurve and driver data paths.
    """
    def __init__(self, attrs):
        self.data_path = attrs

    def __getattr__(self, attr):
        str_value = ".%s" % attr
        return DataPathBuilder(self.data_path + (str_value, ))
        
    def __getitem__(self, key):
        str_value = '["%s"]' % key
        return DataPathBuilder(self.data_path + (str_value, ))

    def resolve(self, real_base, rna_update_from_map=None):
        """ Return (attribute, value) pairs.
        """
        pairs = []
        base = real_base
        for item in self.data_path:
            if base is not Ellipsis:
                try:
                    # this only works when running with an old blender
                    # where the old path will resolve 
                    base = eval("base" + item)
                except:
                    base_new = Ellipsis
                    # guess the new name
                    if item.startswith("."):
                        for item_new in rna_update_from_map.get(item[1:], ()):
                            try:
                                print("base." + item_new)
                                base_new = eval("base." + item_new)
                                break # found, dont keep looking
                            except:
                                pass

                    if base_new is Ellipsis:
                        print("Failed to resolve data path:", self.data_path)
                    base = base_new

            pairs.append((item, base))
        return pairs

import bpy


def id_iter():
    type_iter = type(bpy.data.objects)
    
    for attr in dir(bpy.data):
        data_iter = getattr(bpy.data, attr, None)
        if type(data_iter) == type_iter:
            for id_data in data_iter:
                if id_data.library is None:
                    yield id_data


def anim_data_actions(anim_data):
    actions = []
    actions.append(anim_data.action)
    for track in anim_data.nla_tracks:
        for strip in track.strips:
            actions.append(strip.action)

    # filter out None
    return [act for act in actions if act]


def classes_recursive(base_type, clss=None):
    if clss is None:
        clss = [base_type]
    else:
        clss.append(base_type)

    for base_type_iter in base_type.__bases__:
        if base_type_iter is not object:
            classes_recursive(base_type_iter, clss)

    return clss


def find_path_new(id_data, data_path, rna_update_dict, rna_update_from_map):
    # ignore ID props for now
    if data_path.startswith("["):
        return data_path
    
    # recursive path fixing, likely will be one in most cases.
    data_path_builder = eval("DataPathBuilder(tuple())." + data_path)
    data_resolve = data_path_builder.resolve(id_data, rna_update_from_map)

    path_new = [pair[0] for pair in data_resolve]
    
    # print(data_resolve)
    data_base = id_data

    for i, (attr, data) in enumerate(data_resolve):
        if data is Ellipsis:
            break

        if attr.startswith("."):
            # try all classes
            for data_base_type in classes_recursive(type(data_base)):
                attr_new = rna_update_dict.get(data_base_type.__name__, {}).get(attr[1:])
                if attr_new:
                    path_new[i] = "." + attr_new

        # set this as the base for further properties
        data_base = data
    
    data_path_new = "".join(path_new)[1:] # skip the first "."
    return data_path_new


def update_data_paths(rna_update):
    ''' rna_update triple [(class_name, from, to), ...]
    '''
    
    # make a faster lookup dict
    rna_update_dict = {}
    for ren_class, ren_from, ren_to in rna_update:
        rna_update_dict.setdefault(ren_class, {})[ren_from] = ren_to
        
    rna_update_from_map = {}
    for ren_class, ren_from, ren_to in rna_update:
        rna_update_from_map.setdefault(ren_from, []).append(ren_to)

    for id_data in id_iter():
        anim_data = getattr(id_data, "animation_data", None)
        if anim_data is None:
            continue
        
        for fcurve in anim_data.drivers:
            for var in fcurve.driver.variables:
                if var.type == 'SINGLE_PROP':
                    for tar in var.targets:
                        id_data_other = tar.id
                        data_path = tar.data_path
                        
                        if id_data_other and data_path:
                            data_path_new = find_path_new(id_data_other, data_path, rna_update_dict, rna_update_from_map)
                            # print(data_path_new)
                            if data_path_new != data_path:
                                if not IS_TESTING:
                                    tar.data_path = data_path_new
                                print("driver (%s): %s -> %s" % (id_data_other.name, data_path, data_path_new))
                
            
        
        for action in anim_data_actions(anim_data):
            for fcu in action.fcurves:
                data_path = fcu.data_path
                data_path_new = find_path_new(id_data, data_path, rna_update_dict, rna_update_from_map)
                # print(data_path_new)
                if data_path_new != data_path:
                    if not IS_TESTING:
                        fcu.data_path = data_path_new
                    print("fcurve (%s): %s -> %s" % (id_data.name, data_path, data_path_new))


if __name__ == "__main__":

    # Example, should be called externally
    # (class, from, to)
    replace_ls = [
        ('AnimVizMotionPaths', 'frame_after', 'frame_after'),
        ('AnimVizMotionPaths', 'frame_before', 'frame_before'),
        ('AnimVizOnionSkinning', 'frame_after', 'frame_after'),
    ]

    update_data_paths(replace_ls)
