import bpy
import os
import sys
import argparse

class ArgumentParserForBlender(argparse.ArgumentParser):
    """
    This class is identical to its superclass, except for the parse_args
    method (see docstring). It resolves the ambiguity generated when calling
    Blender from the CLI with a python script, and both Blender and the script
    have arguments. E.g., the following call will make Blender crash because
    it will try to process the script's -a and -b flags:
    >>> blender --python my_script.py -a 1 -b 2

    To bypass this issue this class uses the fact that Blender will ignore all
    arguments given after a double-dash ('--'). The approach is that all
    arguments before '--' go to Blender, arguments after go to the script.
    The following calls work fine:
    >>> blender --python my_script.py -- -a 1 -b 2
    >>> blender --python my_script.py --
    """

    def _get_argv_after_doubledash(self):
        """
        Given the sys.argv as a list of strings, this method returns the
        sublist right after the '--' element (if present, otherwise returns
        an empty list).
        """
        try:
            idx = sys.argv.index("--")
            return sys.argv[idx+1:] # the list after '--'
        except ValueError as e: # '--' not in the list:
            return []

    # overrides superclass
    def parse_args(self):
        """
        This method is expected to behave identically as in the superclass,
        except that the sys.argv list will be pre-processed using
        _get_argv_after_doubledash before. See the docstring of the class for
        usage examples and details.
        """
        return super().parse_args(args=self._get_argv_after_doubledash())



def find_pid_objname(pid):
    for obj in bpy.data.objects:
        if obj.type == 'MESH':
            return obj.name



def obj2glb(input_path: str, output_path: str, human_num, face_num, is_reduce_face) -> None:
    """
    将OBJ文件转换为GLB格式并保存。

    参数:
    input_path (str): 输入OBJ文件的路径
    output_path (str): 输出GLB文件的路径
    human_num (int): 人物数量
    face_num (int): 目标面数
    is_reduce_face (str): 是否减面
    img_quality (int): 图片质量



    返回:
    None
    """
    if is_reduce_face == "True":
        is_reduce_face = True
    else:
        is_reduce_face = False
    if not os.path.exists(input_path):
        raise FileNotFoundError(f"输入文件 {input_path} 不存在")
    
    bpy.ops.object.delete(use_global=False, confirm=False)
    bpy.ops.object.select_all(action="DESELECT")
    bpy.ops.object.select_by_type(type="MESH")
    bpy.ops.object.delete(use_global=False, confirm=False)

    bpy.ops.wm.obj_import(filepath=input_path)


    pid = os.path.splitext(os.path.basename(input_path))[0]
    
    print(f'人物数量：{human_num}，目标面数：{face_num}')
    faces_dest = face_num * human_num

    total_faces: int = 0
    for obj in bpy.data.objects:
        if obj.type == 'MESH':
            # 获取对象的面数并累加
            total_faces += len(obj.data.polygons)
    print(f"所有对象的面数之和: {total_faces}")

    if not is_reduce_face:
        print("不减面")
        faces_dest = total_faces

    print(f"目标面数：{faces_dest} 当前面数：{total_faces}")

    for obj in bpy.data.objects:
        if obj.type == 'MESH':
            # 取消选中所有对象
            bpy.ops.object.select_all(action='DESELECT')
            # 选中当前对象
            obj.select_set(True)
            bpy.context.view_layer.objects.active = obj
            
            # 添加和应用修改器
            modifier = obj.modifiers.new(name="Decimate", type='DECIMATE')
            modifier.ratio = faces_dest / total_faces
            # 应用修改器
            bpy.ops.object.modifier_apply(modifier="Decimate")


    pid_objname = find_pid_objname(pid)
    obj = bpy.data.objects[pid_objname]

    # scale = 90 / bpy.data.objects[pid_objname].dimensions.y
    print(bpy.data.objects[pid_objname].dimensions)
    # bpy.data.objects[pid_objname].scale = (scale, scale, scale)
    # bpy.ops.object.transform_apply(scale=True)

    bpy.ops.outliner.orphans_purge(do_recursive=True)

    # 导出GLB文件
    bpy.ops.export_scene.fbx(filepath=output_path,
                            use_selection=False,                         # 导出所有对象，若只导出选中对象可设为 True
                            object_types={'MESH'},                       # 只导出网格对象
                            path_mode='RELATIVE',                        # 使用相对贴图路径
                            # embed_textures=False,                        # 不嵌入贴图（路径生效）
                            # apply_unit_scale=True,                       # 应用单位缩放
                            # apply_scale_options='FBX_SCALE_ALL',         # 应用缩放
                            bake_space_transform=False)                   # 保持原始空间变换
    
    # 清理所有资源的优化版本
    def clean_data_blocks():
        """清理所有数据块"""
        # 首先删除所有对象
        bpy.ops.object.select_all(action='SELECT')
        bpy.ops.object.delete()

        # 按特定顺序清理数据块以避免依赖问题
        data_blocks = [
            (bpy.data.actions, "动作"),
            (bpy.data.armatures, "骨骼"),
            (bpy.data.cameras, "相机"),
            (bpy.data.lights, "灯光"),
            (bpy.data.meshes, "网格"),
            (bpy.data.materials, "材质"),
            (bpy.data.textures, "纹理"),
            (bpy.data.images, "图片"),
            (bpy.data.curves, "曲线"),
            (bpy.data.lights, "灯光"),
            (bpy.data.worlds, "世界"),
            (bpy.data.collections, "集合")
        ]

        # 循环清理每种类型的数据
        for data_block, block_name in data_blocks:
            try:
                for item in data_block:
                    if item.users == 0:
                        data_block.remove(item)
                    else:
                        item.user_clear()
                        data_block.remove(item)
            except Exception as e:
                print(f"清理{block_name}时出错: {str(e)}")

        # 强制执行垃圾回收
        bpy.ops.outliner.orphans_purge(do_recursive=True)
        import gc
        gc.collect()

    # 执行清理
    clean_data_blocks()


if __name__ == "__main__":
    parser = ArgumentParserForBlender()
    parser.add_argument("--input_path", type=str, required=True)
    parser.add_argument("--output_path", type=str, required=True)
    parser.add_argument("--human_num", type=int, required=True)
    parser.add_argument("--face_num", type=int, required=True)
    parser.add_argument("--is_reduce_face", type=str, required=True)
    args = parser.parse_args()

    obj2glb(args.input_path, args.output_path, args.human_num, args.face_num, args.is_reduce_face)