# Copyright 2020 The HuggingFace Datasets Authors and the current dataset script contributor.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import evaluate
import datasets
import motmetrics as mm
import numpy as np

_CITATION = """\
@InProceedings{huggingface:module,
title = {A great new module},
authors={huggingface, Inc.},
year={2020}
}\
@article{milan2016mot16,
  title={MOT16: A benchmark for multi-object tracking},
  author={Milan, Anton and Leal-Taix{\'e}, Laura and Reid, Ian and Roth, Stefan and Schindler, Konrad},
  journal={arXiv preprint arXiv:1603.00831},
  year={2016}
}
"""

_DESCRIPTION = """\
The MOT Metrics module is designed to evaluate multi-object tracking (MOT) 
algorithms by computing various metrics based on predicted and ground truth bounding 
boxes. It serves as a crucial tool in assessing the performance of MOT systems, 
aiding in the iterative improvement of tracking algorithms."""


_KWARGS_DESCRIPTION = """

Calculates how good are predictions given some references, using certain scores
Args:
    predictions: list of predictions to score. Each predictions
        should be a string with tokens separated by spaces.
    references: list of reference for each prediction. Each
        reference should be a string with tokens separated by spaces.
    max_iou (`float`, *optional*):
        If specified, this is the minimum Intersection over Union (IoU) threshold to consider a detection as a true positive.
        Default is 0.5.
"""


@evaluate.utils.file_utils.add_start_docstrings(_DESCRIPTION, _KWARGS_DESCRIPTION)
class MotMetrics(evaluate.Metric):
    """TODO: Short description of my evaluation module."""

    def _info(self):
        # TODO: Specifies the evaluate.EvaluationModuleInfo object
        return evaluate.MetricInfo(
            # This is the description that will appear on the modules page.
            module_type="metric",
            description=_DESCRIPTION,
            citation=_CITATION,
            inputs_description=_KWARGS_DESCRIPTION,
            # This defines the format of each prediction and reference
            features=datasets.Features({
                "predictions": datasets.Sequence(
                                datasets.Sequence(datasets.Value("float"))
                            ),
                "references": datasets.Sequence(
                                datasets.Sequence(datasets.Value("float"))
                            )
            }),
            # Additional links to the codebase or references
            codebase_urls=["http://github.com/path/to/codebase/of/new_module"],
            reference_urls=["http://path.to.reference.url/new_module"]
        )

    def _download_and_prepare(self, dl_manager):
        """Optional: download external resources useful to compute the scores"""
        # TODO: Download external resources if needed
        pass

    def _compute(self, payload, max_iou: float = 0.5, debug: bool = False):
        """Returns the scores"""
        # TODO: Compute the different scores of the module
        return calculate_from_payload(payload, max_iou, debug)
        #return calculate(predictions, references, max_iou)

def calculate(predictions, references, max_iou: float = 0.5):
    """Returns the scores"""
    
    try: 
        np_predictions = np.array(predictions)
    except:
        raise ValueError("The predictions should be a list of np.arrays in the format [frame number, object id, bb_left, bb_top, bb_width, bb_height, confidence]")
    
    try:
        np_references = np.array(references)
    except:
        raise ValueError("The references should be a list of np.arrays in the format [frame number, object id, bb_left, bb_top, bb_width, bb_height]")
    
    if np_predictions.shape[1] != 7:
        raise ValueError("The predictions should be a list of np.arrays in the format [frame number, object id, bb_left, bb_top, bb_width, bb_height, confidence]")
    if np_references.shape[1] != 6:
        raise ValueError("The references should be a list of np.arrays in the format [frame number, object id, bb_left, bb_top, bb_width, bb_height]")

    if np_predictions[:, 0].min() <= 0:
        raise ValueError("The frame number in the predictions should be a positive integer")
    if np_references[:, 0].min() <= 0:
        raise ValueError("The frame number in the references should be a positive integer")


    num_frames = int(max(np_references[:, 0].max(), np_predictions[:, 0].max()))

    acc = mm.MOTAccumulator(auto_id=True)
    for i in range(1, num_frames+1):
        preds = np_predictions[np_predictions[:, 0] == i, 1:6]
        refs = np_references[np_references[:, 0] == i, 1:6]
        C = mm.distances.iou_matrix(refs[:,1:], preds[:,1:], max_iou = max_iou)
        acc.update(refs[:,0].astype('int').tolist(), preds[:,0].astype('int').tolist(), C)

    mh = mm.metrics.create()
    summary = mh.compute(acc).to_dict()
    for key in summary:
        summary[key] = summary[key][0]
    
    return summary

def calculate_from_payload(payload: dict, max_iou: float = 0.5, debug: bool = False):
    if not isinstance(payload, dict):
        try:
            payload = payload.to_dict()
        except Exception as e:
            raise ValueError(
                "The payload should be a dictionary or a compatible object"
            ) from e
    gt_field_name = payload['gt_field_name']
    models = payload['models']
    sequence_list = payload['sequence_list']

    if debug:
        print("gt_field_name: ", gt_field_name)
        print("models: ", models)
        print("sequence_list: ", sequence_list)

    output = {}

    for sequence in sequence_list:
        output[sequence] = {}
        frames = payload['sequences'][sequence][gt_field_name]
        formated_references = []
        for frame_id, frame in enumerate(frames):
            for detection in frame:
                id = detection['index']
                x, y, w, h = detection['bounding_box']
                formated_references.append([frame_id+1, id, x, y, w, h])  

        for model in models:
            frames = payload['sequences'][sequence][model]
            formated_predictions = []
            
            for frame_id, frame in enumerate(frames):
                for detection in frame:
                    id = detection['index']
                    x, y, w, h = detection['bounding_box']
                    confidence = detection['confidence']
                    confidence = 1  #TODO: remove this line
                    formated_predictions.append([frame_id+1, id, x, y, w, h, confidence])
            if debug:
                print("sequence/model: ", sequence, model)
                print("formated_predictions: ", formated_predictions)
                print("formated_references: ", formated_references)
            if len(formated_predictions) == 0:
                output[sequence][model] = "Model had no predictions."
            elif len(formated_references) == 0:
                output[sequence][model] = "No ground truth."
            else:
                output[sequence][model] = calculate(formated_predictions, formated_references, max_iou=max_iou)
    return output