"""Utilities and tools for tracking runs with Weights & Biases."""
import logging
import sys
from contextlib import contextmanager
from pathlib import Path

import yaml
from tqdm import tqdm

sys.path.append(str(Path(__file__).parent.parent.parent))  # add utils/ to path
from utils.datasets import LoadImagesAndLabels
from utils.datasets import img2label_paths
from utils.general import colorstr, check_dataset, check_file

try:
    import wandb
    from wandb import init, finish
except ImportError:
    wandb = None

WANDB_ARTIFACT_PREFIX = 'wandb-artifact://'


def remove_prefix(from_string, prefix=WANDB_ARTIFACT_PREFIX):
    return from_string[len(prefix):]


def check_wandb_config_file(data_config_file):
    wandb_config = '_wandb.'.join(data_config_file.rsplit('.', 1))  # updated data.yaml path
    if Path(wandb_config).is_file():
        return wandb_config
    return data_config_file


def get_run_info(run_path):
    run_path = Path(remove_prefix(run_path, WANDB_ARTIFACT_PREFIX))
    run_id = run_path.stem
    project = run_path.parent.stem
    entity = run_path.parent.parent.stem
    model_artifact_name = 'run_' + run_id + '_model'
    return entity, project, run_id, model_artifact_name


def check_wandb_resume(opt):
    process_wandb_config_ddp_mode(opt) if opt.global_rank not in [-1, 0] else None
    if isinstance(opt.resume, str):
        if opt.resume.startswith(WANDB_ARTIFACT_PREFIX):
            if opt.global_rank not in [-1, 0]:  # For resuming DDP runs
                entity, project, run_id, model_artifact_name = get_run_info(opt.resume)
                api = wandb.Api()
                artifact = api.artifact(entity + '/' + project + '/' + model_artifact_name + ':latest')
                modeldir = artifact.download()
                opt.weights = str(Path(modeldir) / "last.pt")
            return True
    return None


def process_wandb_config_ddp_mode(opt):
    with open(check_file(opt.data)) as f:
        data_dict = yaml.safe_load(f)  # data dict
    train_dir, val_dir = None, None
    if isinstance(data_dict['train'], str) and data_dict['train'].startswith(WANDB_ARTIFACT_PREFIX):
        api = wandb.Api()
        train_artifact = api.artifact(remove_prefix(data_dict['train']) + ':' + opt.artifact_alias)
        train_dir = train_artifact.download()
        train_path = Path(train_dir) / 'data/images/'
        data_dict['train'] = str(train_path)

    if isinstance(data_dict['val'], str) and data_dict['val'].startswith(WANDB_ARTIFACT_PREFIX):
        api = wandb.Api()
        val_artifact = api.artifact(remove_prefix(data_dict['val']) + ':' + opt.artifact_alias)
        val_dir = val_artifact.download()
        val_path = Path(val_dir) / 'data/images/'
        data_dict['val'] = str(val_path)
    if train_dir or val_dir:
        ddp_data_path = str(Path(val_dir) / 'wandb_local_data.yaml')
        with open(ddp_data_path, 'w') as f:
            yaml.safe_dump(data_dict, f)
        opt.data = ddp_data_path


class WandbLogger():
    """Log training runs, datasets, models, and predictions to Weights & Biases.

    This logger sends information to W&B at wandb.ai. By default, this information
    includes hyperparameters, system configuration and metrics, model metrics,
    and basic data metrics and analyses.

    By providing additional command line arguments to train.py, datasets,
    models and predictions can also be logged.

    For more on how this logger is used, see the Weights & Biases documentation:
    https://docs.wandb.com/guides/integrations/yolov5
    """

    def __init__(self, opt, name, run_id, data_dict, job_type='Training'):
        # Pre-training routine --
        self.job_type = job_type
        self.wandb, self.wandb_run, self.data_dict = wandb, None if not wandb else wandb.run, data_dict
        # It's more elegant to stick to 1 wandb.init call, but useful config data is overwritten in the WandbLogger's wandb.init call
        if isinstance(opt.resume, str):  # checks resume from artifact
            if opt.resume.startswith(WANDB_ARTIFACT_PREFIX):
                entity, project, run_id, model_artifact_name = get_run_info(opt.resume)
                model_artifact_name = WANDB_ARTIFACT_PREFIX + model_artifact_name
                assert wandb, 'install wandb to resume wandb runs'
                # Resume wandb-artifact:// runs here| workaround for not overwriting wandb.config
                self.wandb_run = wandb.init(id=run_id,
                                            project=project,
                                            entity=entity,
                                            resume='allow',
                                            allow_val_change=True)
                opt.resume = model_artifact_name
        elif self.wandb:
            self.wandb_run = wandb.init(config=opt,
                                        resume="allow",
                                        project='YOLOv5' if opt.project == 'runs/train' else Path(opt.project).stem,
                                        entity=opt.entity,
                                        name=name,
                                        job_type=job_type,
                                        id=run_id,
                                        allow_val_change=True) if not wandb.run else wandb.run
        if self.wandb_run:
            if self.job_type == 'Training':
                if not opt.resume:
                    wandb_data_dict = self.check_and_upload_dataset(opt) if opt.upload_dataset else data_dict
                    # Info useful for resuming from artifacts
                    self.wandb_run.config.opt = vars(opt)
                    self.wandb_run.config.data_dict = wandb_data_dict
                self.data_dict = self.setup_training(opt, data_dict)
            if self.job_type == 'Dataset Creation':
                self.data_dict = self.check_and_upload_dataset(opt)
        else:
            prefix = colorstr('wandb: ')
            print(f"{prefix}Install Weights & Biases for YOLOv5 logging with 'pip install wandb' (recommended)")

    def check_and_upload_dataset(self, opt):
        assert wandb, 'Install wandb to upload dataset'
        check_dataset(self.data_dict)
        config_path = self.log_dataset_artifact(check_file(opt.data),
                                                opt.single_cls,
                                                'YOLOv5' if opt.project == 'runs/train' else Path(opt.project).stem)
        print("Created dataset config file ", config_path)
        with open(config_path) as f:
            wandb_data_dict = yaml.safe_load(f)
        return wandb_data_dict

    def setup_training(self, opt, data_dict):
        self.log_dict, self.current_epoch, self.log_imgs = {}, 0, 16  # Logging Constants
        self.bbox_interval = opt.bbox_interval
        if isinstance(opt.resume, str):
            modeldir, _ = self.download_model_artifact(opt)
            if modeldir:
                self.weights = Path(modeldir) / "last.pt"
                config = self.wandb_run.config
                opt.weights, opt.save_period, opt.batch_size, opt.bbox_interval, opt.epochs, opt.hyp = str(
                    self.weights), config.save_period, config.total_batch_size, config.bbox_interval, config.epochs, \
                                                                                                       config.opt['hyp']
            data_dict = dict(self.wandb_run.config.data_dict)  # eliminates the need for config file to resume
        if 'val_artifact' not in self.__dict__:  # If --upload_dataset is set, use the existing artifact, don't download
            self.train_artifact_path, self.train_artifact = self.download_dataset_artifact(data_dict.get('train'),
                                                                                           opt.artifact_alias)
            self.val_artifact_path, self.val_artifact = self.download_dataset_artifact(data_dict.get('val'),
                                                                                       opt.artifact_alias)
            self.result_artifact, self.result_table, self.val_table, self.weights = None, None, None, None
            if self.train_artifact_path is not None:
                train_path = Path(self.train_artifact_path) / 'data/images/'
                data_dict['train'] = str(train_path)
            if self.val_artifact_path is not None:
                val_path = Path(self.val_artifact_path) / 'data/images/'
                data_dict['val'] = str(val_path)
                self.val_table = self.val_artifact.get("val")
                self.map_val_table_path()
        if self.val_artifact is not None:
            self.result_artifact = wandb.Artifact("run_" + wandb.run.id + "_progress", "evaluation")
            self.result_table = wandb.Table(["epoch", "id", "prediction", "avg_confidence"])
        if opt.bbox_interval == -1:
            self.bbox_interval = opt.bbox_interval = (opt.epochs // 10) if opt.epochs > 10 else 1
        return data_dict

    def download_dataset_artifact(self, path, alias):
        if isinstance(path, str) and path.startswith(WANDB_ARTIFACT_PREFIX):
            artifact_path = Path(remove_prefix(path, WANDB_ARTIFACT_PREFIX) + ":" + alias)
            dataset_artifact = wandb.use_artifact(artifact_path.as_posix())
            assert dataset_artifact is not None, "'Error: W&B dataset artifact doesn\'t exist'"
            datadir = dataset_artifact.download()
            return datadir, dataset_artifact
        return None, None

    def download_model_artifact(self, opt):
        if opt.resume.startswith(WANDB_ARTIFACT_PREFIX):
            model_artifact = wandb.use_artifact(remove_prefix(opt.resume, WANDB_ARTIFACT_PREFIX) + ":latest")
            assert model_artifact is not None, 'Error: W&B model artifact doesn\'t exist'
            modeldir = model_artifact.download()
            epochs_trained = model_artifact.metadata.get('epochs_trained')
            total_epochs = model_artifact.metadata.get('total_epochs')
            is_finished = total_epochs is None
            assert not is_finished, 'training is finished, can only resume incomplete runs.'
            return modeldir, model_artifact
        return None, None

    def log_model(self, path, opt, epoch, fitness_score, best_model=False):
        model_artifact = wandb.Artifact('run_' + wandb.run.id + '_model', type='model', metadata={
            'original_url': str(path),
            'epochs_trained': epoch + 1,
            'save period': opt.save_period,
            'project': opt.project,
            'total_epochs': opt.epochs,
            'fitness_score': fitness_score
        })
        model_artifact.add_file(str(path / 'last.pt'), name='last.pt')
        wandb.log_artifact(model_artifact,
                           aliases=['latest', 'last', 'epoch ' + str(self.current_epoch), 'best' if best_model else ''])
        print("Saving model artifact on epoch ", epoch + 1)

    def log_dataset_artifact(self, data_file, single_cls, project, overwrite_config=False):
        with open(data_file) as f:
            data = yaml.safe_load(f)  # data dict
        nc, names = (1, ['item']) if single_cls else (int(data['nc']), data['names'])
        names = {k: v for k, v in enumerate(names)}  # to index dictionary
        self.train_artifact = self.create_dataset_table(LoadImagesAndLabels(
            data['train'], rect=True, batch_size=1), names, name='train') if data.get('train') else None
        self.val_artifact = self.create_dataset_table(LoadImagesAndLabels(
            data['val'], rect=True, batch_size=1), names, name='val') if data.get('val') else None
        if data.get('train'):
            data['train'] = WANDB_ARTIFACT_PREFIX + str(Path(project) / 'train')
        if data.get('val'):
            data['val'] = WANDB_ARTIFACT_PREFIX + str(Path(project) / 'val')
        path = data_file if overwrite_config else '_wandb.'.join(data_file.rsplit('.', 1))  # updated data.yaml path
        data.pop('download', None)
        with open(path, 'w') as f:
            yaml.safe_dump(data, f)

        if self.job_type == 'Training':  # builds correct artifact pipeline graph
            self.wandb_run.use_artifact(self.val_artifact)
            self.wandb_run.use_artifact(self.train_artifact)
            self.val_artifact.wait()
            self.val_table = self.val_artifact.get('val')
            self.map_val_table_path()
        else:
            self.wandb_run.log_artifact(self.train_artifact)
            self.wandb_run.log_artifact(self.val_artifact)
        return path

    def map_val_table_path(self):
        self.val_table_map = {}
        print("Mapping dataset")
        for i, data in enumerate(tqdm(self.val_table.data)):
            self.val_table_map[data[3]] = data[0]

    def create_dataset_table(self, dataset, class_to_id, name='dataset'):
        # TODO: Explore multiprocessing to slpit this loop parallely| This is essential for speeding up the the logging
        artifact = wandb.Artifact(name=name, type="dataset")
        img_files = tqdm([dataset.path]) if isinstance(dataset.path, str) and Path(dataset.path).is_dir() else None
        img_files = tqdm(dataset.img_files) if not img_files else img_files
        for img_file in img_files:
            if Path(img_file).is_dir():
                artifact.add_dir(img_file, name='data/images')
                labels_path = 'labels'.join(dataset.path.rsplit('images', 1))
                artifact.add_dir(labels_path, name='data/labels')
            else:
                artifact.add_file(img_file, name='data/images/' + Path(img_file).name)
                label_file = Path(img2label_paths([img_file])[0])
                artifact.add_file(str(label_file),
                                  name='data/labels/' + label_file.name) if label_file.exists() else None
        table = wandb.Table(columns=["id", "train_image", "Classes", "name"])
        class_set = wandb.Classes([{'id': id, 'name': name} for id, name in class_to_id.items()])
        for si, (img, labels, paths, shapes) in enumerate(tqdm(dataset)):
            box_data, img_classes = [], {}
            for cls, *xywh in labels[:, 1:].tolist():
                cls = int(cls)
                box_data.append({"position": {"middle": [xywh[0], xywh[1]], "width": xywh[2], "height": xywh[3]},
                                 "class_id": cls,
                                 "box_caption": "%s" % (class_to_id[cls])})
                img_classes[cls] = class_to_id[cls]
            boxes = {"ground_truth": {"box_data": box_data, "class_labels": class_to_id}}  # inference-space
            table.add_data(si, wandb.Image(paths, classes=class_set, boxes=boxes), list(img_classes.values()),
                           Path(paths).name)
        artifact.add(table, name)
        return artifact

    def log_training_progress(self, predn, path, names):
        if self.val_table and self.result_table:
            class_set = wandb.Classes([{'id': id, 'name': name} for id, name in names.items()])
            box_data = []
            total_conf = 0
            for *xyxy, conf, cls in predn.tolist():
                if conf >= 0.25:
                    box_data.append(
                        {"position": {"minX": xyxy[0], "minY": xyxy[1], "maxX": xyxy[2], "maxY": xyxy[3]},
                         "class_id": int(cls),
                         "box_caption": "%s %.3f" % (names[cls], conf),
                         "scores": {"class_score": conf},
                         "domain": "pixel"})
                    total_conf = total_conf + conf
            boxes = {"predictions": {"box_data": box_data, "class_labels": names}}  # inference-space
            id = self.val_table_map[Path(path).name]
            self.result_table.add_data(self.current_epoch,
                                       id,
                                       wandb.Image(self.val_table.data[id][1], boxes=boxes, classes=class_set),
                                       total_conf / max(1, len(box_data))
                                       )

    def log(self, log_dict):
        if self.wandb_run:
            for key, value in log_dict.items():
                self.log_dict[key] = value

    def end_epoch(self, best_result=False):
        if self.wandb_run:
            with all_logging_disabled():
                wandb.log(self.log_dict)
                self.log_dict = {}
            if self.result_artifact:
                train_results = wandb.JoinedTable(self.val_table, self.result_table, "id")
                self.result_artifact.add(train_results, 'result')
                wandb.log_artifact(self.result_artifact, aliases=['latest', 'last', 'epoch ' + str(self.current_epoch),
                                                                  ('best' if best_result else '')])
                self.result_table = wandb.Table(["epoch", "id", "prediction", "avg_confidence"])
                self.result_artifact = wandb.Artifact("run_" + wandb.run.id + "_progress", "evaluation")

    def finish_run(self):
        if self.wandb_run:
            if self.log_dict:
                with all_logging_disabled():
                    wandb.log(self.log_dict)
            wandb.run.finish()


@contextmanager
def all_logging_disabled(highest_level=logging.CRITICAL):
    """ source - https://gist.github.com/simon-weber/7853144
    A context manager that will prevent any logging messages triggered during the body from being processed.
    :param highest_level: the maximum logging level in use.
      This would only need to be changed if a custom level greater than CRITICAL is defined.
    """
    previous_level = logging.root.manager.disable
    logging.disable(highest_level)
    try:
        yield
    finally:
        logging.disable(previous_level)
