import bpy
import re

def get_addon_prefs():
    '''
    function to read current addon preferences properties
    access with : get_addon_prefs().super_special_option
    '''
    import os 
    addon_name = os.path.splitext(__name__)[0]
    preferences = bpy.context.preferences
    addon_prefs = preferences.addons[addon_name].preferences
    return (addon_prefs)

def helper(name: str = '') -> str:
    '''Return name and arguments from calling obj as str
    :name: - replace definition name by your own str
    '''
    if not get_addon_prefs().debug:
        return
    import inspect
    func = inspect.currentframe().f_back
    name = name or f'def {func.f_code.co_name}'
    args = inspect.getargvalues(func).locals
    arguments = ', '.join([f'{k}={v}' for k, v in args.items()])
    return(f'{name}({arguments})')


def get_gnd():
    for o in bpy.context.scene.objects:
        if o.type == 'MESH' and o.name.lower() in ('ground', 'gnd'):
            return o
    # nothing found
    print('ERROR', 'No "gnd" object found')


def get_follow_curve_from_armature(arm):
    """Return curve and constraint or a tuple of string ('error', 'message')
    """
    pref = get_addon_prefs()
    name = pref.tgt_bone
    
    parents = []
    root = b.id_data.pose.bones.get(name)
    for c in root.constraints:
        if c.type == 'FOLLOW_PATH':
            const = c
        if c.type == 'CHILD_OF':
            print(f'found child-of on {name}')
            if c.target:
                parents.append(c.target)

    if not const:
        for p in parents:
            for c in p.constraints:
                if c.type == 'FOLLOW_PATH':
                    print('INFO', f'follow_path found on "{p.name}" parent object')
                    const = c
                    break
    
    if not const:
        return ('ERROR', 'No constraints founds')
    
    curve = const.target
    if not curve:
        return ('ERROR', f'no target set for {curve.name}')

    return curve, const

def get_obj_action(obj):
    print(helper())
    act = obj.animation_data
    if not act:
        print('ERROR', f'no animation data on {obj.name}')
        return

    act = act.action
    if not act:
        print('ERROR', f'no action on {obj.name}')
        return
    return act

def set_generated_action(obj):
    '''Backup object action and return a new action suffixed '_autogen'
    associated with the object
    '''
    print(helper())
    act = get_obj_action(obj)
    if not act: return

    regen = re.compile(r'_autogen\.?\d{0,3}$')

    if regen.search(act.name):
        # is an autogenerated one
        org_action_name = regen.sub('', act.name)
        org_action = bpy.data.actions.get(org_action_name)
        if not org_action:
            print('ERROR', f'{org_action_name} not found')
            return

        obj.animation_data.action = org_action
        bpy.data.actions.remove(act)
        
        act = org_action
    
    # backup action before doing anything crazy
    act.use_fake_user = True
    new_act = act.copy()
    new_act.name = act.name + '_autogen'
    obj.animation_data.action = new_act
    return new_act


def get_curve_length(ob):
    dg = bpy.context.evaluated_depsgraph_get()
    obeval = ob.evaluated_get(dg)#.copy()
    baked_me = obeval.to_mesh(preserve_all_data_layers=False, depsgraph=dg)
    mat = obeval.matrix_world
    total_length = 0
    for i, _v in enumerate(baked_me.vertices):
        if i == 0:
            continue
        total_length += ((mat @ baked_me.vertices[i-1].co) - (mat @ baked_me.vertices[i].co)).length

    print("total_length", total_length)#Dbg
    return total_length