import bpy
from random import random
from mathutils import Matrix, Quaternion

ob = bpy.data.objects['Sphere']
frame_number = 0

max_dist = 0.5
#start_location = ob.location.copy()
start_location = (1.6766993999481201, 0.3146645724773407, -1.3483989238739014)

finger_grab_bones = ["index_3", "middle_3", "ring_3", "pinky_3"]
thumb_rot_bone = "thumb_3"

def grab_movement(open):
    # Todo:
    #  select the 4 base finger bones
    #  Then:
    #  To rotate around local axis (will cause to grab)
    #  Then do the same with thumb, but only around local Z axis!
    bpy.ops.object.mode_set(mode='OBJECT')
    bpy.ops.object.select_all(action='DESELECT') # Deselect all objects
    arm = bpy.data.objects['Armature']
    bpy.context.view_layer.objects.active = arm # Make the Armature the active object 
    bpy.ops.object.mode_set(mode='POSE')
    
    # Rotate all fingers
    if open:
        angle = -0.8
    else:
        angle = 0.8
    
    # Deselect all fingers
    for bone in arm.pose.bones:    # Deselect all selected bones
        bone.bone.select = False
    
    # Rotate fingers
    for name in finger_grab_bones:
        bone = arm.pose.bones.get(name)
        # Bones need to be selected when adding keyframes, otherwise blender will throw an error:
        # https://blender.stackexchange.com/questions/1828/what-constitutes-a-context-in-pose-mode
        bone.bone.select = True
        # rotate
        axis = bone.x_axis
        bone.rotation_quaternion = bone.rotation_quaternion @ Quaternion(axis, angle)
        # bone.matrix = bone.matrix @ Matrix.Rotation(-angle, 4, axis)
    
    # Add keyframe
    bpy.ops.anim.keying_set_active_set(type='Rotation')
    bpy.ops.anim.keyframe_insert(type='Rotation')
    
    # Now rotate the thumb too
    for bone in arm.pose.bones:    # Deselect all selected bones
        bone.bone.select = False
        
    bone = arm.pose.bones.get(thumb_rot_bone).bone
    if bone: bone.select = True
    bpy.ops.transform.rotate(value=angle, orient_axis='Z', orient_type='LOCAL')
    bpy.ops.anim.keyframe_insert(type='Rotation')

# Script start
open = False
#if len(bpy.data.scenes['Scene'].keying_sets) == 0:
#    # Add new keying set
#    bpy.ops.anim.keying_set_add()
#    # Activate keying set
#    bpy.ops.anim.keying_set_active_set()

for i in range(50):
    x = random()*max_dist
    y = random()*max_dist
    z = random()*max_dist
    
    bpy.context.scene.frame_set(frame_number)
    ob.location = (
        start_location[0] + x,
        start_location[1] + y,
        start_location[2] + z
    )
    ob.keyframe_insert(data_path='location', index=-1)
    grab_movement(open)
    open = not open
    frame_number += 20