# Ultralytics 🚀 AGPL-3.0 License - https://ultralytics.com/license
"""
Export a YOLO PyTorch model to other formats. TensorFlow exports authored by https://github.com/zldrobit.

Format                  | `format=argument`         | Model
---                     | ---                       | ---
PyTorch                 | -                         | yolo26n.pt
TorchScript             | `torchscript`             | yolo26n.torchscript
ONNX                    | `onnx`                    | yolo26n.onnx
OpenVINO                | `openvino`                | yolo26n_openvino_model/
TensorRT                | `engine`                  | yolo26n.engine
CoreML                  | `coreml`                  | yolo26n.mlpackage
TensorFlow SavedModel   | `saved_model`             | yolo26n_saved_model/
TensorFlow GraphDef     | `pb`                      | yolo26n.pb
TensorFlow Lite         | `tflite`                  | yolo26n.tflite
TensorFlow Edge TPU     | `edgetpu`                 | yolo26n_edgetpu.tflite
TensorFlow.js           | `tfjs`                    | yolo26n_web_model/
PaddlePaddle            | `paddle`                  | yolo26n_paddle_model/
MNN                     | `mnn`                     | yolo26n.mnn
NCNN                    | `ncnn`                    | yolo26n_ncnn_model/
IMX                     | `imx`                     | yolo26n_imx_model/
RKNN                    | `rknn`                    | yolo26n_rknn_model/
ExecuTorch              | `executorch`              | yolo26n_executorch_model/
Axelera AI              | `axelera`                 | yolo26n_axelera_model/
DeepX                   | `deepx`                   | yolo26n_deepx_model/
Qualcomm QNN            | `qnn`                     | yolo26n_qnn_model/

Requirements:
    $ pip install "ultralytics[export]"

Python:
    from ultralytics import YOLO
    model = YOLO('yolo26n.pt')
    results = model.export(format='onnx')

CLI:
    $ yolo mode=export model=yolo26n.pt format=onnx

Inference:
    $ yolo predict model=yolo26n.pt                 # PyTorch
                         yolo26n.torchscript        # TorchScript
                         yolo26n.onnx               # ONNX Runtime or OpenCV DNN with dnn=True
                         yolo26n_openvino_model     # OpenVINO
                         yolo26n.engine             # TensorRT
                         yolo26n.mlpackage          # CoreML (macOS-only)
                         yolo26n_saved_model        # TensorFlow SavedModel
                         yolo26n.pb                 # TensorFlow GraphDef
                         yolo26n.tflite             # TensorFlow Lite
                         yolo26n_edgetpu.tflite     # TensorFlow Edge TPU
                         yolo26n_paddle_model       # PaddlePaddle
                         yolo26n.mnn                # MNN
                         yolo26n_ncnn_model         # NCNN
                         yolo26n_imx_model          # IMX
                         yolo26n_rknn_model         # RKNN
                         yolo26n_executorch_model   # ExecuTorch
                         yolo26n_axelera_model      # Axelera AI
                         yolo26n_deepx_model        # DeepX
                         yolo26n_qnn_model          # Qualcomm QNN

TensorFlow.js:
    $ cd .. && git clone https://github.com/zldrobit/tfjs-yolov5-example.git && cd tfjs-yolov5-example
    $ npm install
    $ ln -s ../../yolo26n_web_model public/yolo26n_web_model
    $ npm start
"""

from __future__ import annotations

import json
import os
import shutil
import time
from copy import deepcopy
from datetime import datetime
from functools import partial
from pathlib import Path

import numpy as np
import torch

from ultralytics import __version__
from ultralytics.cfg import TASK2CALIBRATIONDATA, TASK2DATA, get_cfg
from ultralytics.data import build_dataloader, build_yolo_dataset
from ultralytics.data.dataset import YOLODataset
from ultralytics.data.utils import check_cls_dataset, check_det_dataset
from ultralytics.nn.autobackend import check_class_names, default_class_names
from ultralytics.nn.modules import C2f, Classify, Detect, RTDETRDecoder, Segment26, SemanticSegment
from ultralytics.nn.tasks import ClassificationModel, DetectionModel, SegmentationModel, WorldModel
from ultralytics.utils import (
    ARM64,
    DEFAULT_CFG,
    IS_DOCKER,
    LINUX,
    LOGGER,
    MACOS,
    MACOS_VERSION,
    QNN_HTP_ARCHS,
    RKNN_CHIPS,
    SETTINGS,
    TORCH_VERSION,
    WINDOWS,
    YAML,
    callbacks,
    colorstr,
    get_default_args,
    is_jetson,
)
from ultralytics.utils.checks import IS_PYTHON_MINIMUM_3_9, check_imgsz, check_requirements, check_version, is_intel
from ultralytics.utils.files import file_size
from ultralytics.utils.metrics import batch_probiou
from ultralytics.utils.nms import TorchNMS
from ultralytics.utils.ops import Profile
from ultralytics.utils.patches import arange_patch
from ultralytics.utils.torch_utils import (
    TORCH_1_11,
    TORCH_1_13,
    TORCH_2_1,
    TORCH_2_3,
    TORCH_2_8,
    TORCH_2_9,
    select_device,
)


def export_formats():
    """Return a dictionary of Ultralytics YOLO export formats."""
    x = [
        ["PyTorch", "-", ".pt", True, True, []],
        ["TorchScript", "torchscript", ".torchscript", True, True, ["batch", "optimize", "half", "nms", "dynamic"]],
        ["ONNX", "onnx", ".onnx", True, True, ["batch", "dynamic", "half", "opset", "simplify", "nms"]],
        [
            "OpenVINO",
            "openvino",
            "_openvino_model",
            True,
            False,
            ["batch", "data", "dynamic", "half", "int8", "nms", "fraction"],
        ],
        [
            "TensorRT",
            "engine",
            ".engine",
            False,
            True,
            ["batch", "data", "dynamic", "half", "int8", "simplify", "nms", "fraction"],
        ],
        ["CoreML", "coreml", ".mlpackage", True, False, ["batch", "dynamic", "half", "int8", "nms"]],
        [
            "TensorFlow SavedModel",
            "saved_model",
            "_saved_model",
            True,
            True,
            ["batch", "data", "fraction", "int8", "keras", "nms"],
        ],
        ["TensorFlow GraphDef", "pb", ".pb", True, True, ["batch"]],
        ["TensorFlow Lite", "tflite", ".tflite", True, False, ["batch", "data", "half", "int8", "nms", "fraction"]],
        ["TensorFlow Edge TPU", "edgetpu", "_edgetpu.tflite", True, False, ["data", "fraction", "int8"]],
        ["TensorFlow.js", "tfjs", "_web_model", True, False, ["batch", "data", "fraction", "half", "int8", "nms"]],
        ["PaddlePaddle", "paddle", "_paddle_model", True, True, ["batch"]],
        ["MNN", "mnn", ".mnn", True, True, ["batch", "half", "int8"]],
        ["NCNN", "ncnn", "_ncnn_model", True, True, ["batch", "half"]],
        ["IMX", "imx", "_imx_model", True, True, ["data", "int8", "fraction", "nms"]],
        ["RKNN", "rknn", "_rknn_model", False, False, ["batch", "name"]],
        ["ExecuTorch", "executorch", "_executorch_model", True, False, ["batch"]],
        ["Axelera AI", "axelera", "_axelera_model", False, False, ["batch", "int8", "fraction", "data"]],
        ["DeepX", "deepx", "_deepx_model", False, False, ["data", "int8", "optimize"]],
        ["Qualcomm QNN", "qnn", "_qnn_model", False, False, ["batch", "name", "int8", "fraction", "data"]],
    ]
    return dict(zip(["Format", "Argument", "Suffix", "CPU", "GPU", "Arguments"], zip(*x)))


def validate_args(format, passed_args, valid_args):
    """Validate arguments based on the export format.

    Args:
        format (str): The export format.
        passed_args (SimpleNamespace): The arguments used during export.
        valid_args (list): List of valid arguments for the format.

    Raises:
        AssertionError: If an unsupported argument is used, or if the format lacks supported argument listings.
    """
    export_args = ["half", "int8", "dynamic", "keras", "nms", "batch", "fraction", "data"]

    assert valid_args is not None, f"ERROR ❌️ valid arguments for '{format}' not listed."
    custom = {"batch": 1, "data": None, "device": None}  # exporter defaults
    default_args = get_cfg(DEFAULT_CFG, custom)
    for arg in export_args:
        not_default = getattr(passed_args, arg, None) != getattr(default_args, arg, None)
        if not_default:
            assert arg in valid_args, f"ERROR ❌️ argument '{arg}' is not supported for format='{format}'"


def try_export(inner_func):
    """YOLO export decorator, i.e. @try_export."""
    inner_args = get_default_args(inner_func)

    def outer_func(*args, **kwargs):
        """Export a model."""
        prefix = inner_args["prefix"]
        dt = 0.0
        try:
            with Profile() as dt:
                f = inner_func(*args, **kwargs)  # exported file/dir or tuple of (file/dir, *)
            path = f if isinstance(f, (str, Path)) else f[0]
            mb = file_size(path)
            assert mb > 0.0, "0.0 MB output model size"
            LOGGER.info(f"{prefix} export success ✅ {dt.t:.1f}s, saved as '{path}' ({mb:.1f} MB)")
            return f
        except Exception as e:
            LOGGER.error(f"{prefix} export failure {dt.t:.1f}s: {e}")
            raise e

    return outer_func


class Exporter:
    """A class for exporting YOLO models to various formats.

    This class provides functionality to export YOLO models to different formats including ONNX, TensorRT, CoreML,
    TensorFlow, and others. It handles format validation, device selection, model preparation, and the actual export
    process for each supported format.

    Attributes:
        args (SimpleNamespace): Configuration arguments for the exporter.
        callbacks (dict): Dictionary of callback functions for different export events.
        im (torch.Tensor): Input tensor for model inference during export.
        model (torch.nn.Module): The YOLO model to be exported.
        file (Path): Path to the model file being exported.
        output_shape (tuple): Shape of the model output tensor(s).
        pretty_name (str): Formatted model name for display purposes.
        metadata (dict): Model metadata including description, author, version, etc.
        device (torch.device): Device on which the model is loaded.
        imgsz (list): Input image size for the model.

    Methods:
        __call__: Main export method that handles the export process.
        get_int8_calibration_dataloader: Build dataloader for INT8 calibration.
        export_torchscript: Export model to TorchScript format.
        export_onnx: Export model to ONNX format.
        export_openvino: Export model to OpenVINO format.
        export_paddle: Export model to PaddlePaddle format.
        export_mnn: Export model to MNN format.
        export_ncnn: Export model to NCNN format.
        export_coreml: Export model to CoreML format.
        export_engine: Export model to TensorRT format.
        export_saved_model: Export model to TensorFlow SavedModel format.
        export_pb: Export model to TensorFlow GraphDef format.
        export_tflite: Export model to TensorFlow Lite format.
        export_edgetpu: Export model to Edge TPU format.
        export_tfjs: Export model to TensorFlow.js format.
        export_rknn: Export model to RKNN format.
        export_imx: Export model to IMX format.
        export_executorch: Export model to ExecuTorch format.
        export_axelera: Export model to Axelera format.
        export_deepx: Export model to DeepX format.

    Examples:
        Export a YOLO26 model to ONNX format
        >>> from ultralytics.engine.exporter import Exporter
        >>> exporter = Exporter()
        >>> exporter(model="yolo26n.pt")  # exports to yolo26n.onnx

        Export with specific arguments
        >>> args = {"format": "onnx", "dynamic": True, "half": True}
        >>> exporter = Exporter(overrides=args)
        >>> exporter(model="yolo26n.pt")
    """

    def __init__(self, cfg=DEFAULT_CFG, overrides=None, _callbacks: dict | None = None):
        """Initialize the Exporter class.

        Args:
            cfg (str | Path | dict | SimpleNamespace, optional): Configuration file path or configuration object.
            overrides (dict, optional): Configuration overrides.
            _callbacks (dict, optional): Dictionary of callback functions.
        """
        self.args = get_cfg(cfg, overrides)
        self.callbacks = _callbacks or callbacks.get_default_callbacks()
        callbacks.add_integration_callbacks(self)

    def __call__(self, model=None) -> str:
        """Export a model and return the final exported path as a string.

        Returns:
            (str): Path to the exported file or directory (the last export artifact).
        """
        t = time.time()
        fmt = self.args.format.lower()  # to lowercase
        if fmt in {"tensorrt", "trt"}:  # 'engine' aliases
            fmt = "engine"
        if fmt in {"mlmodel", "mlpackage", "mlprogram", "apple", "ios", "coreml"}:  # 'coreml' aliases
            fmt = "coreml"
        fmts_dict = export_formats()
        fmts = tuple(fmts_dict["Argument"][1:])  # available export formats
        if fmt not in fmts:
            import difflib

            # Get the closest match if format is invalid
            matches = difflib.get_close_matches(fmt, fmts, n=1, cutoff=0.6)  # 60% similarity required to match
            if not matches:
                msg = "Model is already in PyTorch format." if fmt == "pt" else f"Invalid export format='{fmt}'."
                raise ValueError(f"{msg} Valid formats are {fmts}")
            LOGGER.warning(f"Invalid export format='{fmt}', updating to format='{matches[0]}'")
            fmt = matches[0]
        is_tf_format = fmt in {"saved_model", "pb", "tflite", "edgetpu", "tfjs"}

        # Device
        self.dla = None
        if fmt == "engine" and self.args.device is None:
            LOGGER.warning("TensorRT requires GPU export, automatically assigning device=0")
            self.args.device = "0"
        if fmt == "engine" and "dla" in str(self.args.device):  # convert int/list to str first
            device_str = str(self.args.device)
            self.dla = device_str.rsplit(":", 1)[-1]
            self.args.device = "0"  # update device to "0"
            assert self.dla in {"0", "1"}, f"Expected device 'dla:0' or 'dla:1', but got {device_str}."
        if fmt == "imx" and self.args.device is None and torch.cuda.is_available():
            LOGGER.warning("Exporting on CPU while CUDA is available, setting device=0 for faster export on GPU.")
            self.args.device = "0"  # update device to "0"
        self.device = select_device("cpu" if self.args.device is None else self.args.device)

        # Argument compatibility checks
        fmt_keys = dict(zip(fmts_dict["Argument"], fmts_dict["Arguments"]))[fmt]
        validate_args(fmt, self.args, fmt_keys)
        if fmt in {"deepx", "axelera", "imx", "edgetpu", "qnn"} and not self.args.int8:
            LOGGER.warning(f"{fmt} export requires int8=True, setting int8=True.")
            self.args.int8 = True
        if fmt == "axelera":
            if model.task == "segment" and any(isinstance(m, Segment26) for m in model.modules()):
                raise ValueError("Axelera export does not currently support YOLO26 segmentation models.")
            if not self.args.data:
                self.args.data = TASK2CALIBRATIONDATA.get(model.task)
        if fmt == "imx":
            if not self.args.nms and model.task in {"detect", "pose", "segment"}:
                LOGGER.warning("IMX export requires nms=True, setting nms=True.")
                self.args.nms = True
            if model.task not in {"detect", "pose", "classify", "segment"}:
                raise ValueError(
                    "IMX export only supported for detection, pose estimation, classification, and segmentation models."
                )
        if not hasattr(model, "names"):
            model.names = default_class_names()
        model.names = check_class_names(model.names)
        if hasattr(model, "end2end"):
            if self.args.end2end is not None:
                model.end2end = self.args.end2end
            if fmt in {"rknn", "ncnn", "executorch", "paddle", "imx", "edgetpu", "qnn"}:
                # Disable end2end branch for certain export formats as they does not support topk
                model.end2end = False
                LOGGER.warning(f"{fmt.upper()} export does not support end2end models, disabling end2end branch.")
            if fmt == "engine" and self.args.int8:
                # TensorRT 10.3.0 on JetPack 6 with int8 has known end2end build issues
                # https://github.com/ultralytics/ultralytics/issues/23841
                try:
                    import tensorrt as trt

                    if check_version(trt.__version__, "==10.3.0") and is_jetson(jetpack=6):
                        model.end2end = False
                        LOGGER.warning(
                            "TensorRT 10.3.0 on JetPack 6 with int8 has known end2end build issues, disabling end2end branch. "
                            "For a fix, see https://docs.ultralytics.com/guides/nvidia-jetson/#why-does-my-tensorrt-int8-export-disable-end2end-on-jetpack-6"
                            ""
                        )
                except ImportError:
                    pass
        if self.args.half and self.args.int8:
            LOGGER.warning("half=True and int8=True are mutually exclusive, setting half=False.")
            self.args.half = False
        if self.args.half and fmt == "torchscript" and self.device.type == "cpu":
            LOGGER.warning(
                "half=True only compatible with GPU export for TorchScript, i.e. use device=0, setting half=False."
            )
            self.args.half = False
        self.imgsz = check_imgsz(self.args.imgsz, stride=model.stride, min_dim=2)  # check image size
        if self.args.optimize:
            assert fmt != "ncnn", "optimize=True not compatible with format='ncnn', i.e. use optimize=False"
            assert self.device.type == "cpu", "optimize=True not compatible with cuda devices, i.e. use device='cpu'"
        if fmt == "rknn":
            if not self.args.name:
                LOGGER.warning(
                    "Rockchip RKNN export requires a missing 'name' arg for processor type. "
                    "Using default name='rk3588'."
                )
                self.args.name = "rk3588"
            self.args.name = self.args.name.lower()
            assert self.args.name in RKNN_CHIPS, (
                f"Invalid processor name '{self.args.name}' for Rockchip RKNN export. Valid names are {RKNN_CHIPS}."
            )
        if fmt == "qnn":
            if not self.args.name:
                LOGGER.warning(
                    "Qualcomm QNN export requires a missing 'name' arg for the target Hexagon HTP architecture. "
                    "Using default name='73' (Snapdragon 8 Gen 2)."
                )
                self.args.name = "73"
            self.args.name = str(self.args.name).lower().lstrip("v")  # accept '73' or 'v73'
            assert self.args.name in QNN_HTP_ARCHS, (
                f"Invalid HTP architecture '{self.args.name}' for Qualcomm QNN export. Valid archs are {QNN_HTP_ARCHS} "
                "(Snapdragon 865/888/8Gen2/8Gen3/8Elite respectively)."
            )
        if self.args.nms and model.task == "semantic":
            LOGGER.warning("'nms=True' is not valid for semantic segmentation models. Forcing 'nms=False'.")
            self.args.nms = False
        if self.args.nms:
            assert not isinstance(model, ClassificationModel), "'nms=True' is not valid for classification models."
            assert fmt != "tflite" or not ARM64 or not LINUX, "TFLite export with NMS unsupported on ARM64 Linux"
            assert not is_tf_format or TORCH_1_13, "TensorFlow exports with NMS require torch>=1.13"
            assert fmt != "onnx" or TORCH_1_13, "ONNX export with NMS requires torch>=1.13"
            if getattr(model, "end2end", False) or isinstance(model.model[-1], RTDETRDecoder):
                LOGGER.warning("'nms=True' is not available for end2end models. Forcing 'nms=False'.")
                self.args.nms = False
            self.args.conf = self.args.conf or 0.25  # set conf default value for nms export
        if (fmt in {"engine", "coreml"} or self.args.nms) and self.args.dynamic and self.args.batch == 1:
            LOGGER.warning(
                f"'dynamic=True' model with '{'nms=True' if self.args.nms else f'format={self.args.format}'}' requires max batch size, i.e. 'batch=16'"
            )
        if fmt == "edgetpu":
            if not LINUX or ARM64:
                raise SystemError(
                    "Edge TPU export only supported on non-aarch64 Linux. See https://coral.ai/docs/edgetpu/compiler"
                )
            elif self.args.batch != 1:  # see github.com/ultralytics/ultralytics/pull/13420
                LOGGER.warning("Edge TPU export requires batch size 1, setting batch=1.")
                self.args.batch = 1
        if isinstance(model, WorldModel):
            LOGGER.warning(
                "YOLOWorld (original version) export is not supported to any format. "
                "YOLOWorldv2 models (i.e. 'yolov8s-worldv2.pt') only support export to "
                "(torchscript, onnx, openvino, engine, coreml) formats. "
                "See https://docs.ultralytics.com/models/yolo-world for details."
            )
            model.clip_model = None  # openvino int8 export error: https://github.com/ultralytics/ultralytics/pull/18445
        if self.args.int8 and not self.args.data:
            self.args.data = DEFAULT_CFG.data or TASK2DATA[getattr(model, "task", "detect")]  # assign default data
            LOGGER.warning(
                f"INT8 export requires a missing 'data' arg for calibration. Using default 'data={self.args.data}'."
            )
        if fmt == "tfjs" and ARM64 and LINUX:
            raise SystemError("TF.js exports are not currently supported on ARM64 Linux")
        # Recommend OpenVINO if export and Intel CPU
        if SETTINGS.get("openvino_msg"):
            if is_intel():
                LOGGER.info(
                    "💡 ProTip: Export to OpenVINO format for best performance on Intel hardware."
                    " Learn more at https://docs.ultralytics.com/integrations/openvino/"
                )
            SETTINGS["openvino_msg"] = False

        # Input
        im = torch.zeros(self.args.batch, model.yaml.get("channels", 3), *self.imgsz).to(self.device)
        file = Path(
            getattr(model, "pt_path", None) or getattr(model, "yaml_file", None) or model.yaml.get("yaml_file", "")
        )
        if file.suffix in {".yaml", ".yml"}:
            file = Path(file.name)

        # Update model
        model = deepcopy(model).to(self.device)
        for p in model.parameters():
            p.requires_grad = False
        model.eval()
        model.float()
        model = model.fuse()

        if fmt == "imx":
            from ultralytics.utils.export.imx import FXModel

            model = FXModel(model, self.imgsz)
        if fmt in {"tflite", "edgetpu"}:
            from ultralytics.utils.export.tensorflow import tf_wrapper

            model = tf_wrapper(model)
        if fmt == "executorch":
            from ultralytics.utils.export.executorch import executorch_wrapper

            model = executorch_wrapper(model)
        for m in model.modules():
            if isinstance(m, (Classify, SemanticSegment)):
                m.export = True
                m.format = self.args.format
            if isinstance(m, (Detect, RTDETRDecoder)):  # includes all Detect subclasses like Segment, Pose, OBB
                m.dynamic = self.args.dynamic
                m.export = True
                m.format = self.args.format
                # Clamp max_det to anchor count for small image sizes (required for TensorRT compatibility)
                anchors = sum(int(self.imgsz[0] / s) * int(self.imgsz[1] / s) for s in model.stride.tolist())
                m.max_det = min(self.args.max_det, anchors)
                m.agnostic_nms = self.args.agnostic_nms
                m.xyxy = self.args.nms and fmt != "coreml"
                m.shape = None  # reset cached shape for new export input size
                if hasattr(model, "pe") and hasattr(m, "fuse") and not hasattr(m, "lrpc"):  # for YOLOE models
                    m.fuse(model.pe.to(self.device))
            elif isinstance(m, C2f) and not is_tf_format:
                # EdgeTPU does not support FlexSplitV while split provides cleaner ONNX graph
                m.forward = m.forward_split

        y = None
        for _ in range(2):  # dry runs
            y = NMSModel(model, self.args)(im) if self.args.nms and fmt not in {"coreml", "imx"} else model(im)
        if self.args.half and fmt in {"onnx", "torchscript"} and self.device.type != "cpu":
            im, model = im.half(), model.half()  # to FP16

        # Assign
        self.im = im
        self.model = model
        self.file = file
        self.output_shape = (
            tuple(y.shape)
            if isinstance(y, torch.Tensor)
            else tuple(tuple(x.shape if isinstance(x, torch.Tensor) else []) for x in y)
        )
        self.pretty_name = Path(self.model.yaml.get("yaml_file", self.file)).stem.replace("yolo", "YOLO")
        data = model.args["data"] if hasattr(model, "args") and isinstance(model.args, dict) else ""
        description = f"Ultralytics {self.pretty_name} model {f'trained on {data}' if data else ''}"
        self.metadata = {
            "description": description,
            "author": "Ultralytics",
            "date": datetime.now().isoformat(),
            "version": __version__,
            "license": "AGPL-3.0 License (https://ultralytics.com/license)",
            "docs": "https://docs.ultralytics.com",
            "stride": int(max(model.stride)),
            "task": model.task,
            "batch": self.args.batch,
            "imgsz": self.imgsz,
            "names": model.names,
            "args": {k: v for k, v in self.args if k in fmt_keys},
            "channels": model.yaml.get("channels", 3),
            "end2end": getattr(model, "end2end", False),
        }  # model metadata
        if self.dla is not None:
            self.metadata["dla"] = self.dla  # make sure `AutoBackend` uses correct dla device if it has one
        if model.task == "pose":
            self.metadata["kpt_shape"] = model.model[-1].kpt_shape
            if hasattr(model, "kpt_names"):
                self.metadata["kpt_names"] = model.kpt_names

        LOGGER.info(
            f"\n{colorstr('PyTorch:')} starting from '{file}' with input shape {tuple(im.shape)} BCHW and "
            f"output shape(s) {self.output_shape} ({file_size(file):.1f} MB)"
        )
        self.run_callbacks("on_export_start")

        # Export
        if is_tf_format:
            f, keras_model = self.export_saved_model()
            if fmt in {"pb", "tfjs"}:  # pb prerequisite to tfjs
                f = self.export_pb(keras_model=keras_model)
            if fmt == "tflite":
                f = self.export_tflite()
            if fmt == "edgetpu":
                f = self.export_edgetpu(tflite_model=Path(f) / f"{self.file.stem}_full_integer_quant.tflite")
            if fmt == "tfjs":
                f = self.export_tfjs()
        else:
            f = getattr(self, f"export_{fmt}")()

        # Finish
        if f:
            square = self.imgsz[0] == self.imgsz[1]
            s = (
                ""
                if square
                else f"WARNING ⚠️ non-PyTorch val requires square images, 'imgsz={self.imgsz}' will not "
                f"work. Use export 'imgsz={max(self.imgsz)}' if val is required."
            )
            imgsz = self.imgsz[0] if square else str(self.imgsz)[1:-1].replace(" ", "")
            q = "int8" if self.args.int8 else "half" if self.args.half else ""  # quantization
            # Export-only formats deploy in-browser and are not loadable by AutoBackend
            predict_validate = (
                ""
                if fmt == "tfjs"
                else f"\nPredict:         yolo predict task={model.task} model={f} imgsz={imgsz} {q}"
                f"\nValidate:        yolo val task={model.task} model={f} imgsz={imgsz} data={data} {q} {s}"
            )
            LOGGER.info(
                f"\nExport complete ({time.time() - t:.1f}s)"
                f"\nResults saved to {colorstr('bold', Path(f).resolve())}"
                f"{predict_validate}"
                f"\nVisualize:       https://netron.app"
            )

        self.run_callbacks("on_export_end")
        return f  # path to final export artifact

    def get_int8_calibration_dataloader(self, prefix=""):
        """Build and return a dataloader for calibration of INT8 models."""
        LOGGER.info(f"{prefix} collecting INT8 calibration images from 'data={self.args.data}'")
        data = (check_cls_dataset if self.model.task == "classify" else check_det_dataset)(self.args.data)
        if self.model.task == "classify":
            dataset = YOLODataset(
                data[self.args.split or "val"],
                data=data,
                fraction=self.args.fraction,
                task=self.model.task,
                imgsz=max(self.imgsz),
                augment=False,
                batch_size=self.args.batch,
            )
        else:
            cfg = deepcopy(self.args)
            cfg.imgsz = max(self.imgsz)
            dataset = build_yolo_dataset(
                cfg,
                data[self.args.split or "val"],
                self.args.batch,
                data,
                mode="val",
                fraction=self.args.fraction,
            )
        if hasattr(dataset.transforms.transforms[0], "new_shape"):
            dataset.transforms.transforms[0].new_shape = self.imgsz  # LetterBox with non-square imgsz
        n = len(dataset)
        if n < 1:
            raise ValueError(f"The calibration dataset must have at least 1 image, but found {n} images.")
        batch = min(self.args.batch, n)
        if n < self.args.batch:
            LOGGER.warning(
                f"{prefix} calibration dataset has only {n} images, reducing calibration batch size to {batch}."
            )
        if self.args.format == "axelera" and n < 100:
            LOGGER.warning(f"{prefix} >100 images required for Axelera calibration, found {n} images.")
        elif self.args.format != "axelera" and n < 300:
            LOGGER.warning(f"{prefix} >300 images recommended for INT8 calibration, found {n} images.")
        return build_dataloader(dataset, batch=batch, workers=0, drop_last=True)  # required for batch loading

    @try_export
    def export_torchscript(self, prefix=colorstr("TorchScript:")):
        """Export YOLO model to TorchScript format."""
        from ultralytics.utils.export.torchscript import torch2torchscript

        return torch2torchscript(
            model=NMSModel(self.model, self.args) if self.args.nms else self.model,
            im=self.im,
            output_file=self.file.with_suffix(".torchscript"),
            optimize=self.args.optimize,
            metadata=self.metadata,
            prefix=prefix,
        )

    @try_export
    def export_onnx(self, prefix=colorstr("ONNX:")):
        """Export YOLO model to ONNX format."""
        requirements = ["onnx>=1.12.0,<2.0.0"]
        if self.args.simplify:
            # Pass onnxruntime variants as interchangeable candidates so AutoUpdate keeps an installed build
            # (e.g. onnxruntime-qnn for QNN export) instead of reinstalling stable onnxruntime and breaking its ABI.
            ort = "onnxruntime-gpu" if "cuda" in self.device.type else "onnxruntime"
            requirements += ["onnxslim>=0.1.71", (ort, "onnxruntime", "onnxruntime-gpu", "onnxruntime-qnn")]
        check_requirements(requirements)
        import onnx

        from ultralytics.utils.export.engine import best_onnx_opset, torch2onnx

        opset = self.args.opset or best_onnx_opset(onnx, cuda="cuda" in self.device.type)
        LOGGER.info(f"\n{prefix} starting export with onnx {onnx.__version__} opset {opset}...")
        if self.args.nms:
            assert TORCH_1_13, f"'nms=True' ONNX export requires torch>=1.13 (found torch=={TORCH_VERSION})"

        f = str(self.file.with_suffix(".onnx"))
        output_names = ["output0", "output1"] if self.model.task == "segment" else ["output0"]
        dynamic = self.args.dynamic
        if dynamic:
            dynamic = {"images": {0: "batch", 2: "height", 3: "width"}}  # shape(1,3,640,640)
            if isinstance(self.model, SegmentationModel):
                dynamic["output0"] = {0: "batch", 2: "anchors"}  # shape(1, 116, 8400)
                dynamic["output1"] = {0: "batch", 2: "mask_height", 3: "mask_width"}  # shape(1,32,160,160)
            elif isinstance(self.model, DetectionModel):
                dynamic["output0"] = {0: "batch", 2: "anchors"}  # shape(1, 84, 8400)
            if self.args.nms:  # only batch size is dynamic with NMS
                dynamic["output0"].pop(2)
        if self.args.nms and self.model.task == "obb":
            self.args.opset = opset  # for NMSModel
            self.args.simplify = True  # fix OBB runtime error related to topk

        with arange_patch(dynamic=bool(dynamic), half=self.args.half, fmt=self.args.format):
            torch2onnx(
                NMSModel(self.model, self.args) if self.args.nms else self.model,
                self.im,
                f,
                opset=opset,
                input_names=["images"],
                output_names=output_names,
                dynamic=dynamic or None,
            )

        # Checks
        model_onnx = onnx.load(f)  # load onnx model

        # Simplify
        if self.args.simplify:
            try:
                import onnxslim

                LOGGER.info(f"{prefix} slimming with onnxslim {onnxslim.__version__}...")
                model_onnx = onnxslim.slim(model_onnx)

            except Exception as e:
                LOGGER.warning(f"{prefix} simplifier failure: {e}")

        # Metadata
        for k, v in self.metadata.items():
            meta = model_onnx.metadata_props.add()
            meta.key, meta.value = k, str(v)

        # IR version
        if getattr(model_onnx, "ir_version", 0) > 10:
            LOGGER.info(f"{prefix} limiting IR version {model_onnx.ir_version} to 10 for ONNXRuntime compatibility...")
            model_onnx.ir_version = 10

        # FP16 conversion for CPU export (GPU exports are already FP16 from model.half() during tracing)
        if self.args.half and self.args.format == "onnx" and self.device.type == "cpu":
            try:
                from onnxruntime.transformers import float16

                LOGGER.info(f"{prefix} converting to FP16...")
                model_onnx = float16.convert_float_to_float16(model_onnx, keep_io_types=True)
            except Exception as e:
                LOGGER.warning(f"{prefix} FP16 conversion failure: {e}")

        onnx.save(model_onnx, f)
        return f

    @try_export
    def export_openvino(self, prefix=colorstr("OpenVINO:")):
        """Export YOLO model to OpenVINO format."""
        from ultralytics.utils.export.openvino import torch2openvino

        # OpenVINO <= 2025.1.0 error on macOS 15.4+: https://github.com/openvinotoolkit/openvino/issues/30023
        check_requirements("openvino>=2025.2.0" if MACOS and MACOS_VERSION >= "15.4" else "openvino>=2024.0.0")
        import openvino as ov

        assert TORCH_2_1, f"OpenVINO export requires torch>=2.1 but torch=={TORCH_VERSION} is installed"

        def serialize(ov_model, file):
            """Set RT info, serialize, and save metadata YAML."""
            ov_model.set_rt_info("YOLO", ["model_info", "model_type"])
            ov_model.set_rt_info(True, ["model_info", "reverse_input_channels"])
            ov_model.set_rt_info(114, ["model_info", "pad_value"])
            ov_model.set_rt_info([255.0], ["model_info", "scale_values"])
            ov_model.set_rt_info(self.args.iou, ["model_info", "iou_threshold"])
            ov_model.set_rt_info([v.replace(" ", "_") for v in self.model.names.values()], ["model_info", "labels"])
            if self.model.task != "classify":
                ov_model.set_rt_info("fit_to_window_letterbox", ["model_info", "resize_type"])

            ov.save_model(ov_model, file, compress_to_fp16=self.args.half)
            YAML.save(Path(file).parent / "metadata.yaml", self.metadata)  # add metadata.yaml

        calibration_dataset, ignored_scope = None, None
        if self.args.int8:
            check_requirements("packaging>=23.2")  # must be installed first to build nncf wheel
            check_requirements("nncf>=2.14.0,<3.0.0" if not TORCH_2_3 else "nncf>=2.14.0")
            import nncf

            calibration_dataset = nncf.Dataset(self.get_int8_calibration_dataloader(prefix), self._transform_fn)
            if isinstance(self.model.model[-1], Detect):
                # Includes all Detect subclasses like Segment, Pose, OBB, WorldDetect, YOLOEDetect
                head_module_name = ".".join(list(self.model.named_modules())[-1][0].split(".")[:2])
                ignored_scope = nncf.IgnoredScope(  # ignore operations
                    patterns=[
                        f".*{head_module_name}/.*/Add",
                        f".*{head_module_name}/.*/Sub*",
                        f".*{head_module_name}/.*/Mul*",
                        f".*{head_module_name}/.*/Div*",
                    ],
                    types=["Sigmoid"],
                )

        ov_model = torch2openvino(
            model=NMSModel(self.model, self.args) if self.args.nms else self.model,
            im=self.im,
            dynamic=self.args.dynamic,
            half=self.args.half,
            int8=self.args.int8,
            calibration_dataset=calibration_dataset,
            ignored_scope=ignored_scope,
            prefix=prefix,
        )

        suffix = f"_{'int8_' if self.args.int8 else ''}openvino_model{os.sep}"
        f = str(self.file).replace(self.file.suffix, suffix)
        f_ov = str(Path(f) / self.file.with_suffix(".xml").name)

        serialize(ov_model, f_ov)
        return f

    @try_export
    def export_paddle(self, prefix=colorstr("PaddlePaddle:")):
        """Export YOLO model to PaddlePaddle format."""
        from ultralytics.utils.export.paddle import torch2paddle

        return torch2paddle(
            model=self.model,
            im=self.im,
            output_dir=str(self.file).replace(self.file.suffix, f"_paddle_model{os.sep}"),
            metadata=self.metadata,
            prefix=prefix,
        )

    @try_export
    def export_mnn(self, prefix=colorstr("MNN:")):
        """Export YOLO model to MNN format using MNN https://github.com/alibaba/MNN."""
        from ultralytics.utils.export.mnn import onnx2mnn

        return onnx2mnn(
            onnx_file=self.export_onnx(),
            output_file=self.file.with_suffix(".mnn"),
            half=self.args.half,
            int8=self.args.int8,
            metadata=self.metadata,
            prefix=prefix,
        )

    @try_export
    def export_ncnn(self, prefix=colorstr("NCNN:")):
        """Export YOLO model to NCNN format using PNNX https://github.com/pnnx/pnnx."""
        from ultralytics.utils.export.ncnn import torch2ncnn

        return torch2ncnn(
            model=self.model,
            im=self.im,
            output_dir=str(self.file).replace(self.file.suffix, "_ncnn_model/"),
            half=self.args.half,
            metadata=self.metadata,
            device=self.device,
            prefix=prefix,
        )

    @try_export
    def export_coreml(self, prefix=colorstr("CoreML:")):
        """Export YOLO model to CoreML format."""
        mlmodel = self.args.format.lower() == "mlmodel"  # legacy *.mlmodel export format requested
        from ultralytics.utils.export.coreml import IOSDetectModel, pipeline_coreml, torch2coreml

        # latest numpy 2.4.0rc1 breaks coremltools exports
        check_requirements(["coremltools>=9.0", "numpy>=1.14.5,<=2.3.5"])
        import coremltools as ct

        assert not WINDOWS, "CoreML export is not supported on Windows, please run on macOS or Linux."
        assert TORCH_1_11, "CoreML export requires torch>=1.11"
        if self.args.batch > 1:
            assert self.args.dynamic, (
                "batch sizes > 1 are not supported without 'dynamic=True' for CoreML export. Please retry at 'dynamic=True'."
            )
        if self.args.dynamic:
            assert not self.args.nms, (
                "'nms=True' cannot be used together with 'dynamic=True' for CoreML export. Please disable one of them."
            )
            assert self.model.task != "classify", "'dynamic=True' is not supported for CoreML classification models."
        f = self.file.with_suffix(".mlmodel" if mlmodel else ".mlpackage")
        if f.is_dir():
            shutil.rmtree(f)

        if self.model.task == "detect":
            model = IOSDetectModel(self.model, self.im, mlprogram=not mlmodel) if self.args.nms else self.model
        else:
            if self.args.nms:
                LOGGER.warning(f"{prefix} 'nms=True' is only available for Detect models like 'yolo26n.pt'.")
                # TODO CoreML Segment and Pose model pipelining
            model = self.model

        if self.args.dynamic:
            input_shape = ct.Shape(
                shape=(
                    ct.RangeDim(lower_bound=1, upper_bound=self.args.batch, default=1),
                    self.im.shape[1],
                    ct.RangeDim(lower_bound=32, upper_bound=self.imgsz[0] * 2, default=self.imgsz[0]),
                    ct.RangeDim(lower_bound=32, upper_bound=self.imgsz[1] * 2, default=self.imgsz[1]),
                )
            )
            inputs = [ct.TensorType("image", shape=input_shape)]
        else:
            inputs = [ct.ImageType("image", shape=self.im.shape, scale=1 / 255, bias=[0.0, 0.0, 0.0])]

        ct_model = torch2coreml(
            model=model,
            inputs=inputs,
            im=self.im,
            classifier_names=list(self.model.names.values()) if self.model.task == "classify" else None,
            mlmodel=mlmodel,
            half=self.args.half,
            int8=self.args.int8,
            metadata=self.metadata,
            prefix=prefix,
        )

        if self.args.nms and self.model.task == "detect":
            ct_model = pipeline_coreml(
                ct_model,
                self.output_shape,
                weights_dir=None if mlmodel else ct_model.weights_dir,
                metadata=self.metadata,
                mlmodel=mlmodel,
                iou=self.args.iou,
                conf=self.args.conf,
                agnostic_nms=self.args.agnostic_nms,
                prefix=prefix,
            )

        if self.model.task == "classify":
            ct_model.user_defined_metadata.update({"com.apple.coreml.model.preview.type": "imageClassifier"})

        try:
            ct_model.save(str(f))  # save *.mlpackage
        except Exception as e:
            LOGGER.warning(
                f"{prefix} CoreML export to *.mlpackage failed ({e}), reverting to *.mlmodel export. "
                f"Known coremltools Python 3.11 and Windows bugs https://github.com/apple/coremltools/issues/1928."
            )
            f = f.with_suffix(".mlmodel")
            ct_model.save(str(f))
        return f

    @try_export
    def export_engine(self, prefix=colorstr("TensorRT:")):
        """Export YOLO model to TensorRT format https://developer.nvidia.com/tensorrt."""
        assert self.im.device.type != "cpu", "export running on CPU but must be on GPU, i.e. use 'device=0'"
        f_onnx = self.export_onnx()  # run before TRT import https://github.com/ultralytics/ultralytics/issues/7016
        from ultralytics.utils.export.engine import onnx2engine

        assert Path(f_onnx).exists(), f"failed to export ONNX file: {f_onnx}"
        f = self.file.with_suffix(".engine")  # TensorRT engine file
        onnx2engine(
            f_onnx,
            f,
            self.args.workspace,
            self.args.half,
            self.args.int8,
            self.args.dynamic,
            self.im.shape,
            dla=self.dla,
            dataset=self.get_int8_calibration_dataloader(prefix) if self.args.int8 else None,
            metadata=self.metadata,
            verbose=self.args.verbose,
            prefix=prefix,
        )

        return f

    @try_export
    def export_saved_model(self, prefix=colorstr("TensorFlow SavedModel:")):
        """Export YOLO model to TensorFlow SavedModel format."""
        from ultralytics.utils.export.tensorflow import onnx2saved_model

        f = Path(str(self.file).replace(self.file.suffix, "_saved_model"))
        if f.is_dir():
            shutil.rmtree(f)  # delete output folder

        # Export to TF
        images = None
        if self.args.int8 and self.args.data:
            images = [batch["img"] for batch in self.get_int8_calibration_dataloader(prefix)]
            images = (
                torch.nn.functional.interpolate(torch.cat(images, 0).float(), size=self.imgsz)
                .permute(0, 2, 3, 1)
                .numpy()
                .astype(np.float32)
            )

        # Export to ONNX
        if isinstance(self.model.model[-1], RTDETRDecoder):
            self.args.opset = self.args.opset or 19
            assert 16 <= self.args.opset <= 19, "RTDETR export requires opset>=16;<=19"
        self.args.simplify = True
        f_onnx = self.export_onnx()  # ensure ONNX is available
        keras_model = onnx2saved_model(
            f_onnx,
            f,
            int8=self.args.int8,
            images=images,
            disable_group_convolution=self.args.format in {"tfjs", "edgetpu"},
            prefix=prefix,
        )
        YAML.save(f / "metadata.yaml", self.metadata)  # add metadata.yaml
        # Add TFLite metadata
        for file in f.rglob("*.tflite"):
            file.unlink() if "quant_with_int16_act.tflite" in str(file) else self._add_tflite_metadata(file)

        return str(f), keras_model  # or keras_model = tf.saved_model.load(f, tags=None, options=None)

    @try_export
    def export_pb(self, keras_model, prefix=colorstr("TensorFlow GraphDef:")):
        """Export YOLO model to TensorFlow GraphDef *.pb format https://github.com/leimao/Frozen-Graph-TensorFlow."""
        from ultralytics.utils.export.tensorflow import keras2pb

        return keras2pb(keras_model, output_file=self.file.with_suffix(".pb"), prefix=prefix)

    @try_export
    def export_tflite(self, prefix=colorstr("TensorFlow Lite:")):
        """Export YOLO model to TensorFlow Lite format."""
        # BUG https://github.com/ultralytics/ultralytics/issues/13436
        import tensorflow as tf

        LOGGER.info(f"\n{prefix} starting export with tensorflow {tf.__version__}...")
        saved_model = Path(str(self.file).replace(self.file.suffix, "_saved_model"))
        if self.args.int8:
            f = saved_model / f"{self.file.stem}_int8.tflite"  # fp32 in/out
        elif self.args.half:
            f = saved_model / f"{self.file.stem}_float16.tflite"  # fp32 in/out
        else:
            f = saved_model / f"{self.file.stem}_float32.tflite"
        return str(f)

    @try_export
    def export_axelera(self, prefix=colorstr("Axelera:")):
        """Export YOLO model to Axelera format."""
        assert LINUX and not (ARM64 and IS_DOCKER), (
            "export is only supported on Linux and is not supported on ARM64 Docker."
        )
        assert TORCH_2_8, "export requires torch>=2.8.0."

        from ultralytics.utils.export.axelera import torch2axelera

        output_dir = self.file.parent / f"{self.file.stem}_axelera_model"
        return torch2axelera(
            model=self.model,
            output_dir=output_dir,
            calibration_dataset=self.get_int8_calibration_dataloader(prefix),
            transform_fn=self._transform_fn,
            model_name=self.file.stem,
            metadata=self.metadata,
            prefix=prefix,
        )

    @try_export
    def export_executorch(self, prefix=colorstr("ExecuTorch:")):
        """Export YOLO model to ExecuTorch *.pte format."""
        assert TORCH_2_9, f"ExecuTorch requires torch>=2.9.0 but torch=={TORCH_VERSION} is installed"
        from ultralytics.utils.export.executorch import torch2executorch

        return torch2executorch(
            model=self.model,
            im=self.im,
            output_dir=str(self.file).replace(self.file.suffix, "_executorch_model/"),
            metadata=self.metadata,
            prefix=prefix,
        )

    @try_export
    def export_edgetpu(self, tflite_model="", prefix=colorstr("Edge TPU:")):
        """Export YOLO model to Edge TPU format https://coral.ai/docs/edgetpu/models-intro/."""
        from ultralytics.utils.export.tensorflow import tflite2edgetpu

        output_file = tflite2edgetpu(tflite_file=tflite_model, output_dir=tflite_model.parent, prefix=prefix)
        self._add_tflite_metadata(output_file)
        return output_file

    @try_export
    def export_tfjs(self, prefix=colorstr("TensorFlow.js:")):
        """Export YOLO model to TensorFlow.js format."""
        from ultralytics.utils.export.tensorflow import pb2tfjs

        output_dir = pb2tfjs(
            pb_file=str(self.file.with_suffix(".pb")),
            output_dir=str(self.file).replace(self.file.suffix, "_web_model/"),
            half=self.args.half,
            int8=self.args.int8,
            prefix=prefix,
        )
        YAML.save(Path(output_dir) / "metadata.yaml", self.metadata)
        return output_dir

    @try_export
    def export_rknn(self, prefix=colorstr("RKNN:")):
        """Export YOLO model to RKNN format."""
        from ultralytics.utils.export.rknn import onnx2rknn

        self.args.opset = min(self.args.opset or 19, 19)  # rknn-toolkit expects opset<=19
        f_onnx = self.export_onnx()
        return onnx2rknn(
            onnx_file=f_onnx,
            output_dir=str(self.file).replace(self.file.suffix, f"_rknn_model{os.sep}"),
            name=self.args.name,
            metadata=self.metadata,
            prefix=prefix,
        )

    @try_export
    def export_imx(self, prefix=colorstr("IMX:")):
        """Export YOLO model to IMX format."""
        assert LINUX, (
            "Export only supported on Linux."
            "See https://developer.aitrios.sony-semicon.com/en/docs/raspberry-pi-ai-camera/imx500-converter?version=3.17.3&progLang="
        )
        assert IS_PYTHON_MINIMUM_3_9, "IMX export is only supported on Python 3.9 or above."

        if getattr(self.model, "end2end", False):
            raise ValueError("IMX export is not supported for end2end models.")
        from ultralytics.utils.export.imx import torch2imx

        return torch2imx(
            model=self.model,
            output_dir=str(self.file).replace(self.file.suffix, "_imx_model/"),
            conf=self.args.conf,
            iou=self.args.iou,
            max_det=self.args.max_det,
            metadata=self.metadata,
            dataset=partial(self.get_int8_calibration_dataloader, prefix),
            prefix=prefix,
        )

    @try_export
    def export_deepx(self, prefix=colorstr("DeepX:")):
        """Export YOLO model to DeepX format."""
        assert LINUX and not ARM64, "DeepX export only supported on non-aarch64 Linux"
        from ultralytics.utils.export.deepx import onnx2deepx

        f = self.export_onnx()
        return onnx2deepx(
            onnx_file=f,
            imgsz=self.imgsz,
            dataset=self.get_int8_calibration_dataloader(prefix),
            metadata=self.metadata,
            optimize=self.args.optimize,
            prefix=prefix,
        )

    @try_export
    def export_qnn(self, prefix=colorstr("Qualcomm QNN:")):
        """Export YOLO model to a Qualcomm QNN context binary using ONNX Runtime QNN."""
        from ultralytics.utils.export.qnn import onnx2qnn

        f_onnx = self.export_onnx()
        return onnx2qnn(
            onnx_file=f_onnx,
            output_dir=str(self.file).replace(self.file.suffix, f"_qnn_model{os.sep}"),
            dataset=self.get_int8_calibration_dataloader(prefix),
            transform_fn=self._transform_fn,
            name=self.args.name,
            metadata=self.metadata,
            prefix=prefix,
        )

    def _add_tflite_metadata(self, file):
        """Add metadata to *.tflite models per https://ai.google.dev/edge/litert/models/metadata."""
        import zipfile

        with zipfile.ZipFile(file, "a", zipfile.ZIP_DEFLATED) as zf:
            zf.writestr("metadata.json", json.dumps(self.metadata, indent=2))

    @staticmethod
    def _transform_fn(data_item) -> np.ndarray:
        """The transformation function for Axelera/OpenVINO quantization preprocessing."""
        data_item: torch.Tensor = data_item["img"] if isinstance(data_item, dict) else data_item
        assert data_item.dtype == torch.uint8, "Input image must be uint8 for the quantization preprocessing"
        im = data_item.numpy().astype(np.float32) / 255.0  # uint8 to fp16/32 and 0 - 255 to 0.0 - 1.0
        return im[None] if im.ndim == 3 else im

    def add_callback(self, event: str, callback):
        """Append the given callback to the specified event."""
        self.callbacks[event].append(callback)

    def run_callbacks(self, event: str):
        """Execute all callbacks for a given event."""
        for callback in self.callbacks.get(event, []):
            callback(self)


class NMSModel(torch.nn.Module):
    """Model wrapper with embedded NMS for Detect, Segment, Pose and OBB."""

    def __init__(self, model, args):
        """Initialize the NMSModel.

        Args:
            model (torch.nn.Module): The model to wrap with NMS postprocessing.
            args (SimpleNamespace): The export arguments.
        """
        super().__init__()
        self.model = model
        self.args = args
        self.obb = model.task == "obb"
        self.is_tf = self.args.format in frozenset({"saved_model", "tflite", "tfjs"})

    def forward(self, x):
        """Perform inference with NMS post-processing. Supports Detect, Segment, OBB and Pose.

        Args:
            x (torch.Tensor): The preprocessed tensor with shape (B, C, H, W).

        Returns:
            (torch.Tensor | tuple): Tensor of shape (B, max_det, 4 + 2 + extra_shape) where B is the batch size, or a
                tuple of (detections, proto) for segmentation models.
        """
        from torchvision.ops import nms

        preds = self.model(x)
        pred = preds[0] if isinstance(preds, tuple) else preds
        kwargs = dict(device=pred.device, dtype=pred.dtype)
        bs = pred.shape[0]
        pred = pred.transpose(-1, -2)  # shape(1,84,6300) to shape(1,6300,84)
        extra_shape = pred.shape[-1] - (4 + len(self.model.names))  # extras from Segment, OBB, Pose
        if self.args.dynamic and self.args.batch > 1:  # batch size needs to always be same due to loop unroll
            pad = torch.zeros(torch.max(torch.tensor(self.args.batch - bs), torch.tensor(0)), *pred.shape[1:], **kwargs)
            pred = torch.cat((pred, pad))
        boxes, scores, extras = pred.split([4, len(self.model.names), extra_shape], dim=2)
        scores, classes = scores.max(dim=-1)
        self.args.max_det = min(pred.shape[1], self.args.max_det)  # in case num_anchors < max_det
        # (N, max_det, 4 coords + 1 class score + 1 class label + extra_shape).
        out = torch.zeros(pred.shape[0], self.args.max_det, boxes.shape[-1] + 2 + extra_shape, **kwargs)
        for i in range(bs):
            box, cls, score, extra = boxes[i], classes[i], scores[i], extras[i]
            mask = score > self.args.conf
            if self.is_tf or (self.args.format == "onnx" and self.obb):
                # TFLite GatherND error if mask is empty
                score *= mask
                # Explicit length otherwise reshape error, hardcoded to `self.args.max_det * 5`
                mask = score.topk(min(self.args.max_det * 5, score.shape[0])).indices
            box, score, cls, extra = box[mask], score[mask], cls[mask], extra[mask]
            nmsbox = box.clone()
            # `8` is the minimum value experimented to get correct NMS results for obb
            multiplier = 8 if self.obb else 1 / max(len(self.model.names), 1)
            # Normalize boxes for NMS since large values for class offset causes issue with int8 quantization
            if self.args.format == "tflite":  # TFLite is already normalized
                nmsbox *= multiplier
            else:
                nmsbox = multiplier * (nmsbox / torch.tensor(x.shape[2:], **kwargs).max())
            if not self.args.agnostic_nms:  # class-wise NMS
                end = 2 if self.obb else 4
                # fully explicit expansion otherwise reshape error
                cls_offset = cls.view(cls.shape[0], 1).expand(cls.shape[0], end)
                offbox = nmsbox[:, :end] + cls_offset * multiplier
                nmsbox = torch.cat((offbox, nmsbox[:, end:]), dim=-1)
            nms_fn = (
                partial(
                    TorchNMS.fast_nms,
                    use_triu=not (
                        self.is_tf
                        or (self.args.opset or 14) < 14
                        or (self.args.format == "openvino" and self.args.int8)  # OpenVINO int8 error with triu
                    ),
                    iou_func=batch_probiou,
                    exit_early=False,
                )
                if self.obb
                else nms
            )
            keep = nms_fn(
                torch.cat([nmsbox, extra], dim=-1) if self.obb else nmsbox,
                score,
                self.args.iou,
            )[: self.args.max_det]
            dets = torch.cat(
                [box[keep], score[keep].view(-1, 1), cls[keep].view(-1, 1).to(out.dtype), extra[keep]], dim=-1
            )
            # Zero-pad to max_det size to avoid reshape error
            pad = (0, 0, 0, self.args.max_det - dets.shape[0])
            out[i] = torch.nn.functional.pad(dets, pad)
        return (out[:bs], preds[1]) if self.model.task == "segment" else out[:bs]
