import datetime
import sys

import bpy
import bmesh
from mathutils import Vector
from mathutils import Euler
from bpy_extras.object_utils import world_to_camera_view
import random
import math
import json

import time
import os
import gc

def RemoveImageFromMemory (passedName):
    # Extra test because this can crash Blender.
    img = bpy.data.images[passedName]
    try:
        img.user_clear()
        can_continue = True
    except:
        can_continue = False
    
    if can_continue == True:
        try:
            bpy.data.images.remove(img, True)
            result = True
        except:
            result = False
    else:
        result = False
    return result

def CollectBackgroundImagePaths(sourceDirectoryPath, imageExtension):
    file_paths = []

    for root, dirs, files in os.walk(sourceDirectoryPath):
        for file_name in files:
            if file_name.endswith(imageExtension):
                file_paths.append(root + "/" + file_name)
    return file_paths

def SetBackgroundImage(backgroundImagePath):
    #Store reference to old image so it can be removed
    old_image_name = bpy.data.materials[0].node_tree.nodes.get("Image Texture").image.name

    #Load new image to be used
    new_image = bpy.data.images.load(filepath = backgroundImagePath)

    #Set the new image to be used
    bpy.data.materials[0].node_tree.nodes.get("Image Texture").image = new_image

    #Delete the old one from the file
    remove_succeeded = RemoveImageFromMemory(old_image_name)
    gc.collect()

    if not remove_succeeded:
        print("Error removing " + old_image_name)
    else:
        print("Removing " + old_image_name + " worked")

def LoadAndRemoveTextures(texturesFolderPath, numberToLoad):
    background_image_paths = CollectBackgroundImagePaths(texturesFolderPath, ".png")

    for example_index in range(0, numberToLoad):
        SetBackgroundImage(random.choice(background_image_paths))

        #If you alternate adding/removing images and rendering, it will eat all the ram on your system and crash
        bpy.ops.render.render( write_still=True )